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Subject[PATCH v4 2/2] i2c: npcm7xx: add i2c controller master mode only
Date

Nuvoton NPCM7XX I2C Controller
NPCM7xx includes 16 I2C controllers. This driver operates the controller.
This module also includes a slave mode, which will be submitted later on.

---
v4 -> v3:
- typo on cover letter.

v3 -> v2:
- fix dt binding: compatible name: omit "bus"

v2 -> v1:
- run check patch in strict mode.
- use linux crc.
- define regs in constant offset without base.
- remove debug prints.
- no declarations for local functions.

v1: initial version

Signed-off-by: Tali Perry <tali.perry1@gmail.com>
Reviewed-by: Rob Herring <robh@kernel.org>
---
drivers/i2c/busses/Kconfig | 11 +
drivers/i2c/busses/Makefile | 1 +
drivers/i2c/busses/i2c-npcm7xx.c | 2017 ++++++++++++++++++++++++++++++++++++++
3 files changed, 2029 insertions(+)
create mode 100644 drivers/i2c/busses/i2c-npcm7xx.c

diff --git a/drivers/i2c/busses/Kconfig b/drivers/i2c/busses/Kconfig
index 4f8df2ec87b1..61862fed71fd 100644
--- a/drivers/i2c/busses/Kconfig
+++ b/drivers/i2c/busses/Kconfig
@@ -742,6 +742,17 @@ config I2C_NOMADIK
I2C interface from ST-Ericsson's Nomadik and Ux500 architectures,
as well as the STA2X11 PCIe I/O HUB.

+config I2C_NPCM7XX
+ tristate "Nuvoton I2C Controller"
+ depends on ARCH_NPCM7XX
+ select CRC8
+ help
+ If you say yes to this option, support will be included for the
+ Nuvoton I2C controller.
+
+ This driver can also be built as a module. If so, the module
+ will be called i2c-npcm7xx.
+
config I2C_OCORES
tristate "OpenCores I2C Controller"
help
diff --git a/drivers/i2c/busses/Makefile b/drivers/i2c/busses/Makefile
index 5a869144a0c5..80d4ec8908e1 100644
--- a/drivers/i2c/busses/Makefile
+++ b/drivers/i2c/busses/Makefile
@@ -74,6 +74,7 @@ obj-$(CONFIG_I2C_MT65XX) += i2c-mt65xx.o
obj-$(CONFIG_I2C_MV64XXX) += i2c-mv64xxx.o
obj-$(CONFIG_I2C_MXS) += i2c-mxs.o
obj-$(CONFIG_I2C_NOMADIK) += i2c-nomadik.o
+obj-$(CONFIG_I2C_NPCM7XX) += i2c-npcm7xx.o
obj-$(CONFIG_I2C_OCORES) += i2c-ocores.o
obj-$(CONFIG_I2C_OMAP) += i2c-omap.o
obj-$(CONFIG_I2C_PASEMI) += i2c-pasemi.o
diff --git a/drivers/i2c/busses/i2c-npcm7xx.c b/drivers/i2c/busses/i2c-npcm7xx.c
new file mode 100644
index 000000000000..4dc766016031
--- /dev/null
+++ b/drivers/i2c/busses/i2c-npcm7xx.c
@@ -0,0 +1,2017 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Nuvoton NPCM7xx SMB Controller driver
+ *
+ * Copyright (C) 2018 Nuvoton Technologies tali.perry@nuvoton.com
+ */
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/clk/nuvoton.h>
+#include <linux/crc8.h>
+#include <linux/errno.h>
+#include <linux/i2c.h>
+#include <linux/interrupt.h>
+#include <linux/irq.h>
+#include <linux/kernel.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+#define I2C_VERSION "0.0.3"
+
+enum smb_mode {
+ SMB_SLAVE = 1,
+ SMB_MASTER
+};
+
+/*
+ * External SMB Interface driver xfer indication values, which indicate status
+ * of the bus.
+ */
+enum smb_state_ind {
+ SMB_NO_STATUS_IND = 0,
+ SMB_SLAVE_RCV_IND = 1,
+ SMB_SLAVE_XMIT_IND = 2,
+ SMB_SLAVE_XMIT_MISSING_DATA_IND = 3,
+ SMB_SLAVE_RESTART_IND = 4,
+ SMB_SLAVE_DONE_IND = 5,
+ SMB_MASTER_DONE_IND = 6,
+ SMB_NO_DATA_IND = 7,
+ SMB_NACK_IND = 8,
+ SMB_BUS_ERR_IND = 9,
+ SMB_WAKE_UP_IND = 10,
+ SMB_MASTER_PEC_ERR_IND = 11,
+ SMB_BLOCK_BYTES_ERR_IND = 12,
+ SMB_SLAVE_PEC_ERR_IND = 13,
+ SMB_SLAVE_RCV_MISSING_DATA_IND = 14,
+};
+
+// SMBus Operation type values
+enum smb_oper {
+ SMB_NO_OPER = 0,
+ SMB_WRITE_OPER = 1,
+ SMB_READ_OPER = 2
+};
+
+// SMBus Bank (FIFO mode)
+enum smb_bank {
+ SMB_BANK_0 = 0,
+ SMB_BANK_1 = 1
+};
+
+// Internal SMB states values (for the SMB module state machine).
+enum smb_state {
+ SMB_DISABLE = 0,
+ SMB_IDLE,
+ SMB_MASTER_START,
+ SMB_SLAVE_MATCH,
+ SMB_OPER_STARTED,
+ SMB_REPEATED_START,
+ SMB_STOP_PENDING
+};
+
+// Module supports setting multiple own slave addresses:
+enum smb_addr {
+ SMB_SLAVE_ADDR1 = 0,
+ SMB_SLAVE_ADDR2,
+ SMB_SLAVE_ADDR3,
+ SMB_SLAVE_ADDR4,
+ SMB_SLAVE_ADDR5,
+ SMB_SLAVE_ADDR6,
+ SMB_SLAVE_ADDR7,
+ SMB_SLAVE_ADDR8,
+ SMB_SLAVE_ADDR9,
+ SMB_SLAVE_ADDR10,
+ SMB_GC_ADDR,
+ SMB_ARP_ADDR
+};
+
+// global regs
+static struct regmap *gcr_regmap;
+static struct regmap *clk_regmap;
+
+#define NPCM_I2CSEGCTL 0xE4
+#define NPCM_SECCNT 0x68
+#define NPCM_CNTR25M 0x6C
+#define I2CSEGCTL_VAL 0x0333F000
+
+// Common regs
+#define NPCM_SMBSDA 0x000
+#define NPCM_SMBST 0x002
+#define NPCM_SMBCST 0x004
+#define NPCM_SMBCTL1 0x006
+#define NPCM_SMBADDR1 0x008
+#define NPCM_SMBCTL2 0x00A
+#define NPCM_SMBADDR2 0x00C
+#define NPCM_SMBCTL3 0x00E
+#define NPCM_SMBCST2 0x018
+#define NPCM_SMBCST3 0x019
+#define SMB_VER 0x01F
+
+// BANK 0 regs
+#define NPCM_SMBADDR3 0x010
+#define NPCM_SMBADDR7 0x011
+#define NPCM_SMBADDR4 0x012
+#define NPCM_SMBADDR8 0x013
+#define NPCM_SMBADDR5 0x014
+#define NPCM_SMBADDR9 0x015
+#define NPCM_SMBADDR6 0x016
+#define NPCM_SMBADDR10 0x017
+
+// SMBADDR array: because the addr regs are sprincled all over the address space
+const int NPCM_SMBADDR[10] = {NPCM_SMBADDR1, NPCM_SMBADDR2, NPCM_SMBADDR3,
+ NPCM_SMBADDR4, NPCM_SMBADDR5, NPCM_SMBADDR6,
+ NPCM_SMBADDR7, NPCM_SMBADDR8, NPCM_SMBADDR9,
+ NPCM_SMBADDR10};
+
+#define NPCM_SMBCTL4 0x01A
+#define NPCM_SMBCTL5 0x01B
+#define NPCM_SMBSCLLT 0x01C // SCL Low Time
+#define NPCM_SMBFIF_CTL 0x01D // FIFO Control
+#define NPCM_SMBSCLHT 0x01E // SCL High Time
+
+// BANK 1 regs
+#define NPCM_SMBFIF_CTS 0x010 // FIFO Control
+#define NPCM_SMBTXF_CTL 0x012 // Tx-FIFO Control
+#define NPCM_SMBT_OUT 0x014 // Bus T.O.
+#define NPCM_SMBPEC 0x016 // PEC Data
+#define NPCM_SMBTXF_STS 0x01A // Tx-FIFO Status
+#define NPCM_SMBRXF_STS 0x01C // Rx-FIFO Status
+#define NPCM_SMBRXF_CTL 0x01E // Rx-FIFO Control
+
+// NPCM_SMBST reg fields
+#define NPCM_SMBST_XMIT BIT(0)
+#define NPCM_SMBST_MASTER BIT(1)
+#define NPCM_SMBST_NMATCH BIT(2)
+#define NPCM_SMBST_STASTR BIT(3)
+#define NPCM_SMBST_NEGACK BIT(4)
+#define NPCM_SMBST_BER BIT(5)
+#define NPCM_SMBST_SDAST BIT(6)
+#define NPCM_SMBST_SLVSTP BIT(7)
+
+// NPCM_SMBCST reg fields
+#define NPCM_SMBCST_BUSY BIT(0)
+#define NPCM_SMBCST_BB BIT(1)
+#define NPCM_SMBCST_MATCH BIT(2)
+#define NPCM_SMBCST_GCMATCH BIT(3)
+#define NPCM_SMBCST_TSDA BIT(4)
+#define NPCM_SMBCST_TGSCL BIT(5)
+#define NPCM_SMBCST_MATCHAF BIT(6)
+#define NPCM_SMBCST_ARPMATCH BIT(7)
+
+// NPCM_SMBCTL1 reg fields
+#define NPCM_SMBCTL1_START BIT(0)
+#define NPCM_SMBCTL1_STOP BIT(1)
+#define NPCM_SMBCTL1_INTEN BIT(2)
+#define NPCM_SMBCTL1_EOBINTE BIT(3)
+#define NPCM_SMBCTL1_ACK BIT(4)
+#define NPCM_SMBCTL1_GCMEN BIT(5)
+#define NPCM_SMBCTL1_NMINTE BIT(6)
+#define NPCM_SMBCTL1_STASTRE BIT(7)
+
+// RW1S fields (inside a RW reg):
+#define NPCM_SMBCTL1_RWS_FIELDS (NPCM_SMBCTL1_START | NPCM_SMBCTL1_STOP | \
+ NPCM_SMBCTL1_ACK)
+// NPCM_SMBADDR reg fields
+#define NPCM_SMBADDR_ADDR GENMASK(6, 0)
+#define NPCM_SMBADDR_SAEN BIT(7)
+
+// NPCM_SMBCTL2 reg fields
+#define SMBCTL2_ENABLE BIT(0)
+#define SMBCTL2_SCLFRQ6_0 GENMASK(7, 1)
+
+// NPCM_SMBCTL3 reg fields
+#define SMBCTL3_SCLFRQ8_7 GENMASK(1, 0)
+#define SMBCTL3_ARPMEN BIT(2)
+#define SMBCTL3_IDL_START BIT(3)
+#define SMBCTL3_400K_MODE BIT(4)
+#define SMBCTL3_BNK_SEL BIT(5)
+#define SMBCTL3_SDA_LVL BIT(6)
+#define SMBCTL3_SCL_LVL BIT(7)
+
+// NPCM_SMBCST2 reg fields
+#define NPCM_SMBCST2_MATCHA1F BIT(0)
+#define NPCM_SMBCST2_MATCHA2F BIT(1)
+#define NPCM_SMBCST2_MATCHA3F BIT(2)
+#define NPCM_SMBCST2_MATCHA4F BIT(3)
+#define NPCM_SMBCST2_MATCHA5F BIT(4)
+#define NPCM_SMBCST2_MATCHA6F BIT(5)
+#define NPCM_SMBCST2_MATCHA7F BIT(5)
+#define NPCM_SMBCST2_INTSTS BIT(7)
+
+// NPCM_SMBCST3 reg fields
+#define NPCM_SMBCST3_MATCHA8F BIT(0)
+#define NPCM_SMBCST3_MATCHA9F BIT(1)
+#define NPCM_SMBCST3_MATCHA10F BIT(2)
+#define NPCM_SMBCST3_EO_BUSY BIT(7)
+
+// NPCM_SMBCTL4 reg fields
+#define SMBCTL4_HLDT GENMASK(5, 0)
+#define SMBCTL4_LVL_WE BIT(7)
+
+// NPCM_SMBCTL5 reg fields
+#define SMBCTL5_DBNCT GENMASK(3, 0)
+
+// NPCM_SMBFIF_CTS reg fields
+#define NPCM_SMBFIF_CTS_RXF_TXE BIT(1)
+#define NPCM_SMBFIF_CTS_RFTE_IE BIT(3)
+#define NPCM_SMBFIF_CTS_CLR_FIFO BIT(6)
+#define NPCM_SMBFIF_CTS_SLVRSTR BIT(7)
+
+// NPCM_SMBTXF_CTL reg fields
+#ifdef SMB_CAPABILITY_32B_FIFO
+#define NPCM_SMBTXF_CTL_TX_THR GENMASK(5, 0)
+#else
+#define NPCM_SMBTXF_CTL_TX_THR GENMASK(4, 0)
+#endif
+#define NPCM_SMBTXF_CTL_THR_TXIE BIT(6)
+
+// NPCM_SMBT_OUT reg fields
+#define NPCM_SMBT_OUT_TO_CKDIV GENMASK(5, 0)
+#define NPCM_SMBT_OUT_T_OUTIE BIT(6)
+#define NPCM_SMBT_OUT_T_OUTST BIT(7)
+
+// NPCM_SMBTXF_STS reg fields
+#ifdef SMB_CAPABILITY_32B_FIFO
+#define NPCM_SMBTXF_STS_TX_BYTES GENMASK(5, 0)
+#else
+#define NPCM_SMBTXF_STS_TX_BYTES GENMASK(4, 0)
+#endif
+#define NPCM_SMBTXF_STS_TX_THST BIT(6)
+
+// NPCM_SMBRXF_STS reg fields
+#ifdef SMB_CAPABILITY_32B_FIFO
+#define NPCM_SMBRXF_STS_RX_BYTES GENMASK(5, 0)
+#else
+#define NPCM_SMBRXF_STS_RX_BYTES GENMASK(4, 0)
+#endif
+#define NPCM_SMBRXF_STS_RX_THST BIT(6)
+
+// NPCM_SMBFIF_CTL reg fields
+#define NPCM_SMBFIF_CTL_FIFO_EN BIT(4)
+
+// NPCM_SMBRXF_CTL reg fields
+// Note: on the next HW version of this module, this HW is about to switch to
+// 32 bytes FIFO. This size will be set using a config.
+// on current version 16 bytes FIFO is set using a define
+#ifdef SMB_CAPABILITY_32B_FIFO
+#define NPCM_SMBRXF_CTL_RX_THR GENMASK(5, 0)
+#define NPCM_SMBRXF_CTL_THR_RXIE BIT(6)
+#define NPCM_SMBRXF_CTL_LAST_PEC BIT(7)
+#define SMBUS_FIFO_SIZE 32
+#else
+#define NPCM_SMBRXF_CTL_RX_THR GENMASK(4, 0)
+#define NPCM_SMBRXF_CTL_LAST_PEC BIT(5)
+#define NPCM_SMBRXF_CTL_THR_RXIE BIT(6)
+#define SMBUS_FIFO_SIZE 16
+#endif
+
+// SMB_VER reg fields
+#define SMB_VER_VERSION GENMASK(6, 0)
+#define SMB_VER_FIFO_EN BIT(7)
+
+// stall/stuck timeout
+const unsigned int DEFAULT_STALL_COUNT = 25;
+
+// Data abort timeout
+const unsigned int ABORT_TIMEOUT = 1000;
+
+// SMBus spec. values in KHZ
+const unsigned int SMBUS_FREQ_MIN = 10;
+const unsigned int SMBUS_FREQ_MAX = 1000;
+const unsigned int SMBUS_FREQ_100KHZ = 100;
+const unsigned int SMBUS_FREQ_400KHZ = 400;
+const unsigned int SMBUS_FREQ_1MHZ = 1000;
+
+// SCLFRQ min/max field values
+const unsigned int SCLFRQ_MIN = 10;
+const unsigned int SCLFRQ_MAX = 511;
+
+// SCLFRQ field position
+#define SCLFRQ_0_TO_6 GENMASK(6, 0)
+#define SCLFRQ_7_TO_8 GENMASK(8, 7)
+
+// SMB Maximum Retry Trials (on Bus Arbitration Loss)
+const unsigned int SMB_RETRY_MAX_COUNT = 2;
+const unsigned int SMB_NUM_OF_ADDR = 10;
+
+// for logging:
+#define NPCM_I2C_EVENT_START BIT(0)
+#define NPCM_I2C_EVENT_STOP BIT(1)
+#define NPCM_I2C_EVENT_ABORT BIT(2)
+#define NPCM_I2C_EVENT_WRITE BIT(3)
+#define NPCM_I2C_EVENT_READ BIT(4)
+#define NPCM_I2C_EVENT_BER BIT(5)
+#define NPCM_I2C_EVENT_NACK BIT(6)
+#define NPCM_I2C_EVENT_TO BIT(7)
+#define NPCM_I2C_EVENT_EOB BIT(8)
+
+#define NPCM_I2C_EVENT_LOG(event) (bus->event_log |= event)
+
+#define SMB_RECOVERY_SUPPORT
+
+// slave mode: if end device reads more data than available, ask issuer or
+// request for more data:
+#define SMB_WRAP_AROUND_BUFFER
+
+// Status of one SMBus module
+struct npcm_i2c {
+ struct i2c_adapter adap;
+ struct device *dev;
+ unsigned char __iomem *reg;
+ spinlock_t lock; /* IRQ synchronization */
+ struct completion cmd_complete;
+ int irq;
+ int cmd_err;
+ struct i2c_msg *msgs;
+ int msgs_num;
+ int num;
+ u32 apb_clk;
+ enum smb_state state;
+ enum smb_oper operation;
+ enum smb_mode master_or_slave;
+ enum smb_state_ind stop_ind;
+ u8 dest_addr;
+ u8 *rd_buf;
+ u16 rd_size;
+ u16 rd_ind;
+ u8 *wr_buf;
+ u16 wr_size;
+ u16 wr_ind;
+ bool fifo_use;
+ u8 threshold_fifo;
+
+ // PEC bit mask per slave address.
+ // 1: use PEC for this address,
+ // 0: do not use PEC for this address
+ u16 PEC_mask;
+ bool PEC_use;
+ u8 crc_data;
+ bool read_block_use;
+ u8 retry_count;
+ u8 int_cnt;
+ u32 event_log;
+ u32 clk_period_us;
+ u32 int_time_stamp[2];
+};
+
+static inline void _npcm7xx_get_time_stamp(u32 *time_quad0, u32 *time_quad1)
+{
+ u32 seconds, seconds_last;
+ u32 ref_clock;
+
+ regmap_read(clk_regmap, NPCM_SECCNT, &seconds_last);
+
+ do {
+ regmap_read(clk_regmap, NPCM_SECCNT, &seconds);
+ regmap_read(clk_regmap, NPCM_CNTR25M, &ref_clock);
+ regmap_read(clk_regmap, NPCM_SECCNT, &seconds_last);
+ } while (seconds_last != seconds);
+
+ *time_quad0 = ref_clock;
+ *time_quad1 = seconds;
+}
+
+#define EXT_CLOCK_FREQUENCY_MHZ 25
+#define CNTR25M_ACCURECY EXT_CLOCK_FREQUENCY_MHZ // minimum accurecy
+
+// Function: _npcm7xx_delay_relative
+// Parameters:
+// us_delay - number of microseconds to delay since t0_time.
+// if zero: no delay.
+//
+// t0_time - start time , to measure time from.
+// get a time stamp, delay us_delay from it. If us_delay has already passed
+// since the time stamp , then no delay is executed. returns the time elapsed
+// since t0_time
+
+static inline u32 _npcm7xx_delay_relative(u32 us_delay, u32 t0_time0,
+ u32 t0_time1)
+{
+ u32 t1_time_0, t1_time_1;
+ u32 time_elapsed;
+ u32 minimum_delay = (us_delay * EXT_CLOCK_FREQUENCY_MHZ)
+ + CNTR25M_ACCURECY;
+
+ // this is equivalent to microSec/0.64 + minimal tic length.
+ do {
+ _npcm7xx_get_time_stamp(&t1_time_0, &t1_time_1);
+ time_elapsed = ((EXT_CLOCK_FREQUENCY_MHZ * 1000000) *
+ (t1_time_1 - t0_time1)) +
+ (t1_time_0 - t0_time0);
+ } while (time_elapsed < minimum_delay);
+
+ // return elapsed time
+ return (u32)(time_elapsed / EXT_CLOCK_FREQUENCY_MHZ);
+}
+
+static inline void npcm_smb_select_bank(struct npcm_i2c *bus,
+ enum smb_bank bank)
+{
+ if (bus->fifo_use)
+ iowrite8((ioread8(bus->reg + NPCM_SMBCTL3) & ~SMBCTL3_BNK_SEL) |
+ FIELD_PREP(SMBCTL3_BNK_SEL, bank),
+ bus->reg + NPCM_SMBCTL3);
+}
+
+DECLARE_CRC8_TABLE(npcm7xx_crc8);
+
+static u8 npcm_smb_calc_crc8(u8 crc_data, u8 data)
+{
+ crc_data = crc8(npcm7xx_crc8, &data, 1, crc_data);
+ return crc_data;
+}
+
+static void npcm_smb_calc_PEC(struct npcm_i2c *bus, u8 data)
+{
+ if (bus->PEC_use)
+ bus->crc_data = npcm_smb_calc_crc8(bus->crc_data, data);
+}
+
+static inline void npcm_smb_wr_byte(struct npcm_i2c *bus, u8 data)
+{
+ iowrite8(data, bus->reg + NPCM_SMBSDA);
+ npcm_smb_calc_PEC(bus, data);
+}
+
+static inline void npcm_smb_rd_byte(struct npcm_i2c *bus, u8 *data)
+{
+ *data = ioread8(bus->reg + NPCM_SMBSDA);
+ npcm_smb_calc_PEC(bus, *data);
+}
+
+static inline u8 npcm_smb_get_PEC(struct npcm_i2c *bus)
+{
+ if (bus->PEC_use)
+ return bus->crc_data;
+ else
+ return 0;
+}
+
+static inline void npcm_smb_write_PEC(struct npcm_i2c *bus)
+{
+ if (bus->PEC_use) {
+ // get PAC value and write to the bus:
+ npcm_smb_wr_byte(bus, npcm_smb_get_PEC(bus));
+ }
+}
+
+//
+// NPCM7XX SMB module allows writing to SCL and SDA pins directly
+// without the need to change muxing of pins.
+// This feature will be used for recovery sequences i.e.
+//
+static void npcm_smb_set_SCL(struct i2c_adapter *_adap, int level)
+{
+#ifdef SMB_CAPABILITY_FORCE_SCL_SDA
+ unsigned long flags;
+ struct npcm_i2c *bus = container_of(_adap, struct npcm_i2c, adap);
+
+ // Select Bank 0 to access NPCM_SMBCTL4
+ spin_lock_irqsave(&bus->lock, flags);
+ npcm_smb_select_bank(bus, SMB_BANK_0);
+
+ // Set SCL_LVL, SDA_LVL bits as Read/Write (R/W)
+ iowrite8(ioread8(bus->reg + NPCM_SMBCTL4) | SMBCTL4_LVL_WE,
+ bus->reg + NPCM_SMBCTL4);
+
+ // Set level
+ iowrite8((ioread8(bus->reg + NPCM_SMBCTL3)
+ & ~SMBCTL3_SCL_LVL) | FIELD_PREP(SMBCTL3_SCL_LVL,
+ level), bus->reg + NPCM_SMBCTL3);
+
+ // Set SCL_LVL, SDA_LVL bits as Read Only (RO)
+ iowrite8(ioread8(bus->reg + NPCM_SMBCTL4)
+ & ~SMBCTL4_LVL_WE, bus->reg + NPCM_SMBCTL4);
+
+ // Return to Bank 1
+ npcm_smb_select_bank(bus, SMB_BANK_1);
+ spin_unlock_irqrestore(&bus->lock, flags);
+#endif
+}
+
+static int npcm_smb_get_SCL(struct i2c_adapter *_adap)
+{
+ unsigned long flags;
+ unsigned int ret = 0;
+ struct npcm_i2c *bus = container_of(_adap, struct npcm_i2c, adap);
+
+ // Select Bank 0 to access NPCM_SMBCTL4
+ spin_lock_irqsave(&bus->lock, flags);
+ npcm_smb_select_bank(bus, SMB_BANK_0);
+
+ // Get SCL level
+ ret = FIELD_GET(SMBCTL3_SCL_LVL, ioread8(bus->reg + NPCM_SMBCTL3));
+
+ // Return to Bank 1
+ npcm_smb_select_bank(bus, SMB_BANK_1);
+ spin_unlock_irqrestore(&bus->lock, flags);
+ return ret;
+}
+
+static int npcm_smb_get_SDA(struct i2c_adapter *_adap)
+{
+ unsigned long flags;
+ unsigned int ret = 0;
+ struct npcm_i2c *bus = container_of(_adap, struct npcm_i2c, adap);
+
+ // Select Bank 0 to access NPCM_SMBCTL4
+ spin_lock_irqsave(&bus->lock, flags);
+ npcm_smb_select_bank(bus, SMB_BANK_0);
+
+ // Get SDA level
+ ret = FIELD_GET(SMBCTL3_SDA_LVL, ioread8(bus->reg + NPCM_SMBCTL3));
+
+ // Return to Bank 1
+ npcm_smb_select_bank(bus, SMB_BANK_1);
+ spin_unlock_irqrestore(&bus->lock, flags);
+ return ret;
+}
+
+static inline u16 npcm_smb_get_index(struct npcm_i2c *bus)
+{
+ u16 index = 0;
+
+ if (bus->operation == SMB_READ_OPER)
+ index = bus->rd_ind;
+ else if (bus->operation == SMB_WRITE_OPER)
+ index = bus->wr_ind;
+
+ return index;
+}
+
+// quick protocol:
+static inline bool npcm_smb_is_quick(struct npcm_i2c *bus)
+{
+ if (bus->wr_size == 0 && bus->rd_size == 0)
+ return true;
+ return false;
+}
+
+static void npcm_smb_disable(struct npcm_i2c *bus)
+{
+ int i;
+
+ // select bank 0 for SMB addresses
+ npcm_smb_select_bank(bus, SMB_BANK_0);
+
+ // Slave Addresses Removal
+ for (i = SMB_SLAVE_ADDR1; i < SMB_NUM_OF_ADDR; i++)
+ iowrite8(0, bus->reg + NPCM_SMBADDR[i]);
+
+ // select bank 0 for SMB addresses
+ npcm_smb_select_bank(bus, SMB_BANK_1);
+
+ // Disable module.
+ iowrite8(ioread8(bus->reg + NPCM_SMBCTL2) & ~SMBCTL2_ENABLE,
+ bus->reg + NPCM_SMBCTL2);
+
+ // Set module disable
+ bus->state = SMB_DISABLE;
+}
+
+static void npcm_smb_enable(struct npcm_i2c *bus)
+{
+ iowrite8((ioread8(bus->reg + NPCM_SMBCTL2) | SMBCTL2_ENABLE),
+ bus->reg + NPCM_SMBCTL2);
+}
+
+// enable\disable end of busy (EOB) interrupt
+static inline void npcm_smb_eob_int(struct npcm_i2c *bus, bool enable)
+{
+ if (enable) {
+ iowrite8((ioread8(bus->reg + NPCM_SMBCTL1) |
+ NPCM_SMBCTL1_EOBINTE) & ~NPCM_SMBCTL1_RWS_FIELDS,
+ bus->reg + NPCM_SMBCTL1);
+ } else {
+ iowrite8(ioread8(bus->reg + NPCM_SMBCTL1) &
+ ~NPCM_SMBCTL1_EOBINTE & ~NPCM_SMBCTL1_RWS_FIELDS,
+ bus->reg + NPCM_SMBCTL1);
+
+ // Clear EO_BUSY pending bit:
+ iowrite8(ioread8(bus->reg + NPCM_SMBCST3) |
+ NPCM_SMBCST3_EO_BUSY, bus->reg + NPCM_SMBCST3);
+ }
+}
+
+static inline bool npcm_smb_tx_fifo_full(struct npcm_i2c *bus)
+{
+ // check if TX FIFO full:
+ return (bool)FIELD_GET(NPCM_SMBTXF_STS_TX_THST,
+ ioread8(bus->reg + NPCM_SMBTXF_STS));
+}
+
+static inline bool npcm_smb_rx_fifo_full(struct npcm_i2c *bus)
+{
+ // check if RX FIFO full:
+ return (bool)FIELD_GET(NPCM_SMBRXF_STS_RX_THST,
+ ioread8(bus->reg + NPCM_SMBRXF_STS));
+}
+
+static inline void npcm_smb_clear_tx_fifo(struct npcm_i2c *bus)
+{
+ // clear TX FIFO:
+ iowrite8(ioread8(bus->reg + NPCM_SMBTXF_STS) |
+ NPCM_SMBTXF_STS_TX_THST,
+ bus->reg + NPCM_SMBTXF_STS);
+}
+
+static inline void npcm_smb_clear_rx_fifo(struct npcm_i2c *bus)
+{
+ // clear RX FIFO:
+ iowrite8(ioread8(bus->reg + NPCM_SMBRXF_STS) |
+ NPCM_SMBRXF_STS_RX_THST,
+ bus->reg + NPCM_SMBRXF_STS);
+}
+
+static void npcm_smb_int_enable(struct npcm_i2c *bus, bool enable)
+{
+ if (enable)
+ iowrite8((ioread8(bus->reg + NPCM_SMBCTL1) |
+ NPCM_SMBCTL1_INTEN) & ~NPCM_SMBCTL1_RWS_FIELDS,
+ bus->reg + NPCM_SMBCTL1);
+ else
+ iowrite8((ioread8(bus->reg + NPCM_SMBCTL1) &
+ ~NPCM_SMBCTL1_INTEN) & ~NPCM_SMBCTL1_RWS_FIELDS,
+ bus->reg + NPCM_SMBCTL1);
+}
+
+static inline void npcm_smb_master_start(struct npcm_i2c *bus)
+{
+ NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_START);
+
+ iowrite8((ioread8(bus->reg + NPCM_SMBCTL1) | NPCM_SMBCTL1_START) &
+ ~(NPCM_SMBCTL1_STOP | NPCM_SMBCTL1_ACK),
+ bus->reg + NPCM_SMBCTL1);
+}
+
+static inline void npcm_smb_master_stop(struct npcm_i2c *bus)
+{
+ NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_STOP);
+
+ // override HW issue: SMBus may fail to supply stop condition in Master
+ // Write operation.
+ // Need to delay at least 5 us from the last int, before issueing a stop
+ _npcm7xx_delay_relative(5, bus->int_time_stamp[0],
+ bus->int_time_stamp[1]);
+
+ iowrite8((ioread8(bus->reg + NPCM_SMBCTL1) | NPCM_SMBCTL1_STOP) &
+ ~(NPCM_SMBCTL1_START | NPCM_SMBCTL1_ACK),
+ bus->reg + NPCM_SMBCTL1);
+
+ if (bus->fifo_use) {
+ npcm_smb_select_bank(bus, SMB_BANK_1);
+
+ if (bus->operation == SMB_READ_OPER)
+ npcm_smb_clear_rx_fifo(bus);
+ else
+ npcm_smb_clear_tx_fifo(bus);
+
+ iowrite8(ioread8(bus->reg + NPCM_SMBFIF_CTS) |
+ NPCM_SMBFIF_CTS_SLVRSTR |
+ NPCM_SMBFIF_CTS_RXF_TXE,
+ bus->reg + NPCM_SMBFIF_CTS);
+
+ iowrite8(0, bus->reg + NPCM_SMBTXF_CTL);
+ }
+}
+
+static inline void npcm_smb_abort_data(struct npcm_i2c *bus)
+{
+ unsigned int timeout = ABORT_TIMEOUT;
+ u8 data;
+
+ NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_ABORT);
+ // Generate a STOP condition
+ npcm_smb_master_stop(bus);
+ npcm_smb_rd_byte(bus, &data);
+
+ // Clear NEGACK, STASTR and BER bits
+ iowrite8(NPCM_SMBST_STASTR | NPCM_SMBST_NEGACK |
+ NPCM_SMBST_BER, bus->reg + NPCM_SMBST);
+
+ // Wait till STOP condition is generated
+ while (FIELD_GET(NPCM_SMBCTL1_STOP, ioread8(bus->reg + NPCM_SMBCTL1))) {
+ timeout--;
+ if (!FIELD_GET(NPCM_SMBCTL1_STOP,
+ ioread8(bus->reg + NPCM_SMBCTL1)))
+ break;
+ if (timeout <= 1) {
+ dev_err(bus->dev, "%s, abort timeout!\n", __func__);
+ break;
+ }
+ }
+}
+
+static inline void npcm_smb_stall_after_start(struct npcm_i2c *bus, bool stall)
+{
+ if (stall)
+ iowrite8((ioread8(bus->reg + NPCM_SMBCTL1) |
+ NPCM_SMBCTL1_STASTRE) & ~NPCM_SMBCTL1_RWS_FIELDS,
+ bus->reg + NPCM_SMBCTL1);
+ else
+ iowrite8((ioread8(bus->reg + NPCM_SMBCTL1) &
+ ~NPCM_SMBCTL1_STASTRE) & ~NPCM_SMBCTL1_RWS_FIELDS,
+ bus->reg + NPCM_SMBCTL1);
+}
+
+static inline void npcm_smb_nack(struct npcm_i2c *bus)
+{
+ if (bus->rd_ind < (bus->rd_size - 1))
+ dev_info(bus->dev,
+ "\tNACK err bus%d, SA=0x%x, rd(%d\%d), op=%d st=%d\n",
+ bus->num, bus->dest_addr, bus->rd_ind, bus->rd_size,
+ bus->operation, bus->state);
+ iowrite8((ioread8(bus->reg + NPCM_SMBCTL1) | NPCM_SMBCTL1_ACK) &
+ ~(NPCM_SMBCTL1_STOP | NPCM_SMBCTL1_START),
+ bus->reg + NPCM_SMBCTL1);
+}
+
+static void npcm_smb_reset(struct npcm_i2c *bus)
+{
+ // Save NPCM_SMBCTL1 relevant bits. It is being cleared when the
+ // module is disabled
+ u8 smbctl1 = ioread8(bus->reg + NPCM_SMBCTL1) & (NPCM_SMBCTL1_GCMEN
+ | NPCM_SMBCTL1_INTEN
+ | NPCM_SMBCTL1_NMINTE);
+
+ // Disable the SMB module
+ iowrite8((ioread8(bus->reg + NPCM_SMBCTL2) & ~SMBCTL2_ENABLE),
+ bus->reg + NPCM_SMBCTL2);
+
+ // Enable the SMB module
+ npcm_smb_enable(bus);
+
+ // Restore NPCM_SMBCTL1 status
+ iowrite8(smbctl1 & ~NPCM_SMBCTL1_RWS_FIELDS, bus->reg + NPCM_SMBCTL1);
+
+ // Reset driver status
+ bus->state = SMB_IDLE;
+ //
+ // Configure FIFO disabled mode so slave will not use fifo
+ // (master will set it on if supported)
+ iowrite8(ioread8(bus->reg + NPCM_SMBFIF_CTL) &
+ ~NPCM_SMBFIF_CTL_FIFO_EN,
+ bus->reg + NPCM_SMBFIF_CTL);
+ bus->fifo_use = false;
+}
+
+static inline bool npcm_smb_is_master(struct npcm_i2c *bus)
+{
+ return (bool)FIELD_GET(NPCM_SMBST_MASTER,
+ ioread8(bus->reg + NPCM_SMBST));
+}
+
+static int npcm_smb_master_abort(struct npcm_i2c *bus)
+{
+ int ret = -(EIO);
+
+ // Only current master is allowed to issue Stop Condition
+ if (npcm_smb_is_master(bus)) {
+ npcm_smb_abort_data(bus);
+ ret = 0;
+ }
+
+ npcm_smb_reset(bus);
+
+ return ret;
+}
+
+static void npcm_smb_callback(struct npcm_i2c *bus,
+ enum smb_state_ind op_status, u16 info)
+{
+ struct i2c_msg *msgs = bus->msgs;
+ int msgs_num = bus->msgs_num;
+
+ switch (op_status) {
+ case SMB_MASTER_DONE_IND:
+ // Master transaction finished and all transmit bytes were sent
+ // info: number of bytes actually received after the Master
+ // receive operation (if Master didn't issue receive it
+ // should be 0)
+ // Notify that not all data was received on Master or Slave
+ // info:
+ // on receive: number of actual bytes received
+ // when PEC is used even if 'info' is the expected number
+ // of bytes, it means that PEC error occurred.
+ {
+ if (msgs[0].flags & I2C_M_RD)
+ msgs[0].len = info;
+ else if (msgs_num == 2 && msgs[1].flags & I2C_M_RD)
+ msgs[1].len = info;
+
+ bus->cmd_err = 0;
+ complete(&bus->cmd_complete);
+ }
+ break;
+
+ case SMB_NO_DATA_IND:
+ // Notify that not all data was received on Master or Slave
+ // info:
+ //on receive: number of actual bytes received
+ // when PEC is used even if 'info' is the expected number
+ // of bytes,it means that PEC error occurred.
+ {
+ if (msgs[0].flags & I2C_M_RD)
+ msgs[0].len = info;
+ else if (msgs_num == 2 && msgs[1].flags & I2C_M_RD)
+ msgs[1].len = info;
+
+ bus->cmd_err = -EFAULT;
+ complete(&bus->cmd_complete);
+ }
+ break;
+ case SMB_NACK_IND:
+ // MASTER transmit got a NAK before transmitting all bytes
+ // info: number of transmitted bytes
+ bus->cmd_err = -EAGAIN;
+ complete(&bus->cmd_complete);
+
+ break;
+ case SMB_BUS_ERR_IND:
+ // Bus error
+ // info: has no meaning
+ bus->cmd_err = -EIO;
+ complete(&bus->cmd_complete);
+ break;
+ case SMB_WAKE_UP_IND:
+ // SMBus wake up
+ // info: has no meaning
+ break;
+ default:
+ break;
+ }
+}
+
+static u32 npcm_smb_get_fifo_fullness(struct npcm_i2c *bus)
+{
+ if (bus->operation == SMB_WRITE_OPER)
+ return FIELD_GET(NPCM_SMBTXF_STS_TX_BYTES,
+ ioread8(bus->reg + NPCM_SMBTXF_STS));
+ else if (bus->operation == SMB_READ_OPER)
+ return FIELD_GET(NPCM_SMBRXF_STS_RX_BYTES,
+ ioread8(bus->reg + NPCM_SMBRXF_STS));
+ return 0;
+}
+
+static void npcm_smb_write_to_fifo(struct npcm_i2c *bus, u16 max_bytes_to_send)
+{
+ // Fill the FIFO, while the FIFO is not full and there are more bytes to
+ // write
+ while ((max_bytes_to_send--) && (SMBUS_FIFO_SIZE -
+ npcm_smb_get_fifo_fullness(bus))) {
+ // write the data
+ if (bus->wr_ind < bus->wr_size) {
+ if (bus->PEC_use &&
+ (bus->wr_ind + 1 == bus->wr_size) &&
+ (bus->rd_size == 0 ||
+ bus->master_or_slave == SMB_SLAVE)) {
+ // Master send PEC in write protocol, Slave send
+ // PEC in read protocol.
+ npcm_smb_write_PEC(bus);
+ bus->wr_ind++;
+ } else {
+ npcm_smb_wr_byte(bus,
+ bus->wr_buf[bus->wr_ind++]);
+ }
+ } else {
+#ifdef SMB_WRAP_AROUND_BUFFER
+ // We're out of bytes. Ask the higher level for
+ // more bytes. Let it know that driver
+ // used all its' bytes
+
+ npcm_smb_clear_tx_fifo(bus);
+
+ // Reset state for the remaining bytes transaction
+ bus->state = SMB_SLAVE_MATCH;
+
+ // Notify upper layer of transaction completion
+ npcm_smb_callback(bus, SMB_SLAVE_XMIT_MISSING_DATA_IND,
+ bus->wr_ind);
+
+ iowrite8(NPCM_SMBST_SDAST, bus->reg + NPCM_SMBST);
+#else
+ npcm_smb_wr_byte(bus, 0xFF);
+#endif
+ }
+ }
+}
+
+// configure the FIFO before using it. If nread is -1 RX FIFO will not be
+// configured. same for nwrite
+static void npcm_smb_set_fifo(struct npcm_i2c *bus, int nread, int nwrite)
+{
+ if (!bus->fifo_use)
+ return;
+ npcm_smb_select_bank(bus, SMB_BANK_1);
+ npcm_smb_clear_tx_fifo(bus);
+ npcm_smb_clear_rx_fifo(bus);
+
+ // configure RX FIFO
+ if (nread > 0) {
+ // clear LAST bit:
+ iowrite8(ioread8(bus->reg + NPCM_SMBRXF_CTL) &
+ (~NPCM_SMBRXF_CTL_LAST_PEC),
+ bus->reg + NPCM_SMBRXF_CTL);
+
+ if (nread > SMBUS_FIFO_SIZE)
+ iowrite8((ioread8(bus->reg + NPCM_SMBRXF_CTL) &
+ ~NPCM_SMBRXF_CTL_RX_THR)
+ | FIELD_PREP(NPCM_SMBRXF_CTL_RX_THR,
+ SMBUS_FIFO_SIZE), bus->reg + NPCM_SMBRXF_CTL);
+ else
+ iowrite8((ioread8(bus->reg + NPCM_SMBRXF_CTL) &
+ ~NPCM_SMBRXF_CTL_RX_THR) |
+ FIELD_PREP(NPCM_SMBRXF_CTL_RX_THR,
+ (u8)(nread)),
+ bus->reg + NPCM_SMBRXF_CTL);
+
+ if (nread <= SMBUS_FIFO_SIZE && !bus->read_block_use)
+ iowrite8(ioread8(bus->reg + NPCM_SMBRXF_CTL) |
+ NPCM_SMBRXF_CTL_LAST_PEC,
+ bus->reg + NPCM_SMBRXF_CTL);
+ }
+
+ // configure TX FIFO
+ if (nwrite > 0) {
+ if (nwrite > SMBUS_FIFO_SIZE)
+ // data to send is more then FIFO size.
+ // Configure the FIFO int to be mid of FIFO.
+ iowrite8(NPCM_SMBTXF_CTL_THR_TXIE |
+ (SMBUS_FIFO_SIZE / 2),
+ bus->reg + NPCM_SMBTXF_CTL);
+ else if (nwrite > (SMBUS_FIFO_SIZE / 2) &&
+ bus->wr_ind != 0)
+ // wr_ind != 0 means that this is not the first
+ // write. since int is in the mid of FIFO, only
+ // half of the fifo is empty.
+ // Continue to configure the FIFO int to be mid
+ // of FIFO.
+ iowrite8(NPCM_SMBTXF_CTL_THR_TXIE |
+ (SMBUS_FIFO_SIZE / 2),
+ bus->reg + NPCM_SMBTXF_CTL);
+ else
+ // This is the either first write (wr_ind = 0)
+ // and data to send is less or equal to FIFO
+ // size.
+ // Or this is the last write and data to send
+ // is less or equal half FIFO size.
+ // In both cases disable the FIFO threshold int.
+ // The next int will happen after the FIFO will
+ // get empty.
+ iowrite8(0, bus->reg + NPCM_SMBTXF_CTL);
+ npcm_smb_clear_tx_fifo(bus);
+ }
+}
+
+static void npcm_smb_read_from_fifo(struct npcm_i2c *bus, u8 bytes_in_fifo)
+{
+ while (bytes_in_fifo--) {
+ // Keep read data
+ u8 data = ioread8(bus->reg + NPCM_SMBSDA);
+
+ npcm_smb_calc_PEC(bus, data);
+ if (bus->rd_ind < bus->rd_size) {
+ bus->rd_buf[bus->rd_ind++] = data;
+ if (bus->rd_ind == 1 && bus->read_block_use)
+ // First byte indicates length in block protocol
+ bus->rd_size = data;
+ }
+ }
+}
+
+static void npcm_smb_master_fifo_read(struct npcm_i2c *bus)
+{
+ u16 rcount;
+ u8 fifo_bytes;
+ enum smb_state_ind ind = SMB_MASTER_DONE_IND;
+
+ rcount = bus->rd_size - bus->rd_ind;
+
+ // In order not to change the RX_TRH during transaction (we found that
+ // this might be problematic if it takes too much time to read the FIFO)
+ // we read the data in the following way. If the number of bytes to
+ // read == FIFO Size + C (where C < FIFO Size)then first read C bytes
+ // and in the next int we read rest of the data.
+ if (rcount < (2 * SMBUS_FIFO_SIZE) && rcount > SMBUS_FIFO_SIZE)
+ fifo_bytes = (u8)(rcount - SMBUS_FIFO_SIZE);
+ else
+ fifo_bytes = npcm_smb_get_fifo_fullness(bus);
+
+ if (rcount - fifo_bytes == 0) {
+ // last byte is about to be read - end of transaction.
+ // Stop should be set before reading last byte.
+ npcm_smb_eob_int(bus, true);
+ npcm_smb_master_stop(bus);
+ npcm_smb_read_from_fifo(bus, fifo_bytes);
+
+ if (npcm_smb_get_PEC(bus) != 0)
+ ind = SMB_MASTER_PEC_ERR_IND;
+ bus->state = SMB_STOP_PENDING;
+ bus->stop_ind = ind;
+
+ } else {
+ npcm_smb_read_from_fifo(bus, fifo_bytes);
+ rcount = bus->rd_size - bus->rd_ind;
+ npcm_smb_set_fifo(bus, rcount, -1);
+ }
+}
+
+static void npcm_smb_int_master_handler_write(struct npcm_i2c *bus)
+{
+ u16 wcount;
+
+ NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_WRITE);
+ if (bus->fifo_use)
+ npcm_smb_clear_tx_fifo(bus);
+
+ // Master write operation - last byte handling
+ if (bus->wr_ind == bus->wr_size) {
+ if (bus->fifo_use && npcm_smb_get_fifo_fullness(bus) > 0)
+ // No more bytes to send (to add to the FIFO), however the FIFO is not
+ // empty yet. It is still in the middle of tx. Currently there's nothing
+ // to do except for waiting to the end of the tx.
+ // We will get an int when the FIFO will get empty.
+ return;
+
+ if (bus->rd_size == 0) {
+ // all bytes have been written, in a pure wr operation
+ npcm_smb_eob_int(bus, true);
+
+ // Issue a STOP condition on the bus
+ npcm_smb_master_stop(bus);
+ // Clear SDA Status bit (by writing dummy byte)
+ npcm_smb_wr_byte(bus, 0xFF);
+
+ bus->state = SMB_STOP_PENDING;
+ bus->stop_ind = SMB_MASTER_DONE_IND;
+ } else {
+ // last write-byte written on previous int - need to
+ // restart & send slave address
+ if (bus->PEC_use && !bus->read_block_use &&
+ !npcm_smb_is_quick(bus))
+ // PEC is used but the protocol is not block read
+ // then we add extra bytes for PEC support
+ bus->rd_size += 1;
+
+ if (bus->fifo_use) {
+ if (bus->rd_size == 1 || bus->read_block_use) {
+ // SMBus Block read transaction.
+ iowrite8(0, bus->reg + NPCM_SMBTXF_CTL);
+ iowrite8(1, bus->reg + NPCM_SMBRXF_CTL);
+ }
+ }
+
+ npcm_smb_set_fifo(bus, bus->rd_size, -1);
+
+ // Generate (Repeated) Start upon next write to SDA
+ npcm_smb_master_start(bus);
+
+ if (bus->rd_size == 1)
+
+ // Receiving one byte only - stall after successful completion of send
+ // address byte. If we NACK here, and slave doesn't ACK the address, we
+ // might unintentionally NACK the next multi-byte read
+
+ npcm_smb_stall_after_start(bus, true);
+
+ // send the slave address in read direction
+ npcm_smb_wr_byte(bus, bus->dest_addr | 0x1);
+
+ // Next int will occur on read
+ bus->operation = SMB_READ_OPER;
+ }
+ } else {
+ if (bus->PEC_use && !npcm_smb_is_quick(bus))
+ // extra bytes for PEC support
+ bus->wr_size += 1;
+
+ // write next byte not last byte and not slave address
+ if (!bus->fifo_use || bus->wr_size == 1) {
+ if (bus->PEC_use && bus->rd_size == 0 &&
+ (bus->wr_ind + 1 == bus->wr_size)) {
+ // Master write protocol to send PEC byte.
+ npcm_smb_write_PEC(bus);
+ bus->wr_ind++;
+ } else {
+ npcm_smb_wr_byte(bus,
+ bus->wr_buf[bus->wr_ind++]);
+ }
+ } else { // FIFO is used
+ wcount = bus->wr_size - bus->wr_ind;
+ npcm_smb_set_fifo(bus, -1, wcount);
+ npcm_smb_write_to_fifo(bus, wcount);
+ }
+ }
+}
+
+static void npcm_smb_int_master_handler_read(struct npcm_i2c *bus)
+{
+ u16 block_zero_bytes;
+ u32 fifo_bytes;
+
+ // Master read operation (pure read or following a write operation).
+ NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_READ);
+
+ // Initialize number of bytes to include only the first byte (presents
+ // a case where number of bytes to read is zero); add PEC if applicable
+ block_zero_bytes = 1;
+ if (bus->PEC_use)
+ block_zero_bytes++;
+
+ fifo_bytes = FIELD_GET(NPCM_SMBRXF_CTL_RX_THR,
+ ioread8(bus->reg + NPCM_SMBRXF_CTL));
+
+ // Perform master read, distinguishing between last byte and the rest of
+ // the bytes. The last byte should be read when the clock is stopped
+ if ((bus->rd_ind < (bus->rd_size - 1)) || bus->fifo_use) {
+ u8 data;
+
+ // byte to be read is not the last one
+ // Check if byte-before-last is about to be read
+ if ((bus->rd_ind == (bus->rd_size - 2)) &&
+ !bus->fifo_use){
+ // Set nack before reading byte-before-last, so that
+ // nack will be generated after receive of last byte
+ npcm_smb_nack(bus);
+
+ if (!FIELD_GET(NPCM_SMBST_SDAST,
+ ioread8(bus->reg + NPCM_SMBST))) {
+ // No data available - reset state for new xfer
+ bus->state = SMB_IDLE;
+
+ // Notify upper layer of rx completion
+ npcm_smb_callback(bus, SMB_NO_DATA_IND,
+ bus->rd_ind);
+ }
+ } else if (bus->rd_ind == 0) { //first byte handling:
+ // in block protocol first byte is the size
+ if (bus->read_block_use) {
+ npcm_smb_rd_byte(bus, &data);
+
+ // First byte indicates length in block protocol
+ bus->rd_buf[bus->rd_ind++] = data;
+ bus->rd_size = data + 1;
+
+ if (bus->PEC_use) {
+ bus->rd_size += 1;
+ data += 1;
+ }
+
+ if (bus->fifo_use) {
+ iowrite8(NPCM_SMBFIF_CTS_RXF_TXE |
+ ioread8(bus->reg +
+ NPCM_SMBFIF_CTS),
+ bus->reg + NPCM_SMBFIF_CTS);
+
+ // first byte in block protocol
+ // is zero -> not supported. read at
+ // least one byte
+ if (data == 0)
+ data = 1;
+ }
+ npcm_smb_set_fifo(bus, bus->rd_size, -1);
+ } else {
+ if (!bus->fifo_use) {
+ npcm_smb_rd_byte(bus, &data);
+ bus->rd_buf[bus->rd_ind++] = data;
+ } else {
+ npcm_smb_clear_tx_fifo(bus);
+ npcm_smb_master_fifo_read(bus);
+ }
+ }
+
+ } else {
+ if (bus->fifo_use) {
+ if (bus->rd_size == block_zero_bytes &&
+ bus->read_block_use) {
+ npcm_smb_eob_int(bus, true);
+ npcm_smb_master_stop(bus);
+ npcm_smb_read_from_fifo(bus,
+ fifo_bytes);
+ bus->state = SMB_STOP_PENDING;
+ bus->stop_ind = SMB_BLOCK_BYTES_ERR_IND;
+
+ } else {
+ npcm_smb_master_fifo_read(bus);
+ }
+ } else {
+ npcm_smb_rd_byte(bus, &data);
+ bus->rd_buf[bus->rd_ind++] = data;
+ }
+ }
+ } else {
+ // last byte is about to be read - end of transaction.
+ // Stop should be set before reading last byte.
+ u8 data;
+ enum smb_state_ind ind = SMB_MASTER_DONE_IND;
+
+ npcm_smb_eob_int(bus, true);
+
+ npcm_smb_master_stop(bus);
+
+ npcm_smb_rd_byte(bus, &data);
+
+ if (bus->rd_size == block_zero_bytes && bus->read_block_use) {
+ ind = SMB_BLOCK_BYTES_ERR_IND;
+ } else {
+ bus->rd_buf[bus->rd_ind++] = data;
+ if (npcm_smb_get_PEC(bus) != 0)
+ ind = SMB_MASTER_PEC_ERR_IND;
+ }
+
+ bus->state = SMB_STOP_PENDING;
+ bus->stop_ind = ind;
+ }
+}
+
+static void npcm_smb_int_master_handler(struct npcm_i2c *bus)
+{
+ // A negative acknowledge has occurred
+ if (FIELD_GET(NPCM_SMBST_NEGACK, ioread8(bus->reg + NPCM_SMBST))) {
+ NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_NACK);
+ if (bus->fifo_use) {
+ // if there are still untransmitted bytes in TX FIFO
+ // reduce them from wr_ind
+
+ if (bus->operation == SMB_WRITE_OPER)
+ bus->wr_ind -= npcm_smb_get_fifo_fullness(bus);
+ // clear the FIFO
+ iowrite8(NPCM_SMBFIF_CTS_CLR_FIFO,
+ bus->reg + NPCM_SMBFIF_CTS);
+ }
+
+ // In master write operation, NACK is a problem
+ // number of bytes sent to master less than required
+ npcm_smb_master_abort(bus);
+ bus->state = SMB_IDLE;
+
+ // In Master mode, NEGACK should be cleared only after
+ // generating STOP.
+ // In such case, the bus is released from stall only after the
+ // software clears NEGACK bit.
+ // Then a Stop condition is sent.
+ iowrite8(NPCM_SMBST_NEGACK, bus->reg + NPCM_SMBST);
+ npcm_smb_callback(bus, SMB_NACK_IND, bus->wr_ind);
+ return;
+ }
+
+ // Master mode: a Bus Error has been identified
+ if (FIELD_GET(NPCM_SMBST_BER, ioread8(bus->reg + NPCM_SMBST))) {
+ // Check whether bus arbitration or Start or Stop during data
+ // xfer bus arbitration problem should not result in recovery
+ if (npcm_smb_is_master(bus)) {
+ // Only current master is allowed to issue stop
+ npcm_smb_master_abort(bus);
+ } else {
+ // Bus arbitration loss
+ if (bus->retry_count-- > 0) {
+ // Perform a retry (generate a start condition)
+ // as soon as the SMBus is free
+ iowrite8(NPCM_SMBST_BER, bus->reg + NPCM_SMBST);
+ npcm_smb_master_start(bus);
+ return;
+ }
+ }
+ iowrite8(NPCM_SMBST_BER, bus->reg + NPCM_SMBST);
+ bus->state = SMB_IDLE;
+ npcm_smb_callback(bus, SMB_BUS_ERR_IND,
+ npcm_smb_get_index(bus));
+ return;
+ }
+
+ // A Master End of Busy (meaning Stop Condition happened)
+ // End of Busy int is on and End of Busy is set
+ if ((FIELD_GET(NPCM_SMBCTL1_EOBINTE,
+ ioread8(bus->reg + NPCM_SMBCTL1)) == 1) &&
+ (FIELD_GET(NPCM_SMBCST3_EO_BUSY,
+ ioread8(bus->reg + NPCM_SMBCST3)))) {
+ NPCM_I2C_EVENT_LOG(NPCM_I2C_EVENT_EOB);
+ npcm_smb_eob_int(bus, false);
+ bus->state = SMB_IDLE;
+ if (npcm_smb_is_quick(bus))
+ npcm_smb_callback(bus, bus->stop_ind, 0);
+ else
+ npcm_smb_callback(bus, bus->stop_ind, bus->rd_ind);
+ return;
+ }
+
+ // Address sent and requested stall occurred (Master mode)
+ if (FIELD_GET(NPCM_SMBST_STASTR, ioread8(bus->reg + NPCM_SMBST))) {
+ // Check for Quick Command SMBus protocol
+ if (npcm_smb_is_quick(bus)) {
+ npcm_smb_eob_int(bus, true);
+ npcm_smb_master_stop(bus);
+
+ // Update status
+ bus->state = SMB_STOP_PENDING;
+ bus->stop_ind = SMB_MASTER_DONE_IND;
+
+ } else if (bus->rd_size == 1) {
+ // Receiving one byte only - set NACK after ensuring
+ // slave ACKed the address byte
+ npcm_smb_nack(bus);
+ }
+
+ // Reset stall-after-address-byte
+ npcm_smb_stall_after_start(bus, false);
+
+ // Clear stall only after setting STOP
+ iowrite8(NPCM_SMBST_STASTR, bus->reg + NPCM_SMBST);
+
+ return;
+ }
+
+ // SDA status is set - transmit or receive, master
+ if (FIELD_GET(NPCM_SMBST_SDAST, ioread8(bus->reg + NPCM_SMBST)) ||
+ (bus->fifo_use &&
+ (npcm_smb_tx_fifo_full(bus) || npcm_smb_rx_fifo_full(bus)))) {
+ // Status Bit is cleared by writing to or reading from SDA
+ // (depending on current direction)
+ switch (bus->state) {
+ // Handle unsuccessful bus mastership
+ case SMB_IDLE:
+ npcm_smb_master_abort(bus);
+ return;
+
+ case SMB_MASTER_START:
+ if (npcm_smb_is_master(bus)) {
+ u8 addr_byte = bus->dest_addr;
+
+ bus->crc_data = 0;
+ if (npcm_smb_is_quick(bus)) {
+ // Need to stall after successful
+ // completion of sending address byte
+ npcm_smb_stall_after_start(bus, true);
+ } else if (bus->wr_size == 0) {
+ // Set direction to Read
+ addr_byte |= (u8)0x1;
+ bus->operation = SMB_READ_OPER;
+ } else {
+ bus->operation = SMB_WRITE_OPER;
+ }
+
+ // Receiving one byte only - stall after successful completion of
+ // sending address byte. If we NACK here, and slave doesn't ACK the
+ // address, we might unintentionally NACK the next multi-byte read
+ if (bus->wr_size == 0 && bus->rd_size == 1)
+ npcm_smb_stall_after_start(bus, true);
+
+ // Write the address to the bus
+ bus->state = SMB_OPER_STARTED;
+ npcm_smb_wr_byte(bus, addr_byte);
+ } else {
+ dev_err(bus->dev,
+ "SDA, bus%d is not master, wr %d 0x%x...\n",
+ bus->num, bus->wr_size,
+ bus->wr_buf[0]);
+ }
+ break;
+
+ // SDA status is set - transmit or receive: Handle master mode
+ case SMB_OPER_STARTED:
+ if (bus->operation == SMB_WRITE_OPER)
+ npcm_smb_int_master_handler_write(bus);
+ else if (bus->operation == SMB_READ_OPER)
+ npcm_smb_int_master_handler_read(bus);
+ else
+ pr_err("I2C%d: unknown operation\n", bus->num);
+ break;
+ default:
+ dev_err(bus->dev, "i2c%d master sda err on state machine\n",
+ bus->num);
+ }
+ }
+}
+
+static int npcm_smb_recovery(struct i2c_adapter *_adap)
+{
+ u8 iter = 27; // Allow one byte to be sent by the Slave
+ u16 timeout;
+ bool done = false;
+ struct npcm_i2c *bus = container_of(_adap, struct npcm_i2c, adap);
+
+ dev_info(bus->dev, "recovery bus%d\n", bus->num);
+
+ might_sleep();
+
+ // Disable int
+ npcm_smb_int_enable(bus, false);
+
+ // Check If the SDA line is active (low)
+ if (FIELD_GET(NPCM_SMBCST_TSDA, ioread8(bus->reg + NPCM_SMBCST)) == 0) {
+ // Repeat the following sequence until SDA is released
+ do {
+ // Issue a single SCL cycle
+ iowrite8(NPCM_SMBCST_TGSCL, bus->reg + NPCM_SMBCST);
+ timeout = ABORT_TIMEOUT;
+ while (timeout != 0 &&
+ FIELD_GET(NPCM_SMBCST_TGSCL,
+ ioread8(bus->reg + NPCM_SMBCST) == 0))
+ timeout--;
+
+ // If SDA line is inactive (high), stop
+ if (FIELD_GET(NPCM_SMBCST_TSDA,
+ ioread8(bus->reg + NPCM_SMBCST)) == 1)
+ done = true;
+ } while ((!done) && (--iter != 0));
+
+ // If SDA line is released (high)
+ if (done) {
+ // Clear BB (BUS BUSY) bit
+ iowrite8(NPCM_SMBCST_BB, bus->reg + NPCM_SMBCST);
+
+ // Generate a START, to synchronize Master and Slave
+ npcm_smb_master_start(bus);
+
+ // Wait until START condition is sent, or timeout
+ timeout = ABORT_TIMEOUT;
+ while (timeout != 0 && !npcm_smb_is_master(bus))
+ timeout--;
+
+ // If START condition was sent
+ if (timeout > 0) {
+ // Send an address byte
+ npcm_smb_wr_byte(bus, bus->dest_addr);
+
+ // Generate a STOP condition
+ npcm_smb_master_stop(bus);
+ }
+ return 0;
+ }
+ }
+
+ // check if success:
+ if (npcm_smb_get_SCL(_adap) == 1 && npcm_smb_get_SDA(_adap) == 1)
+ goto npcm_smb_recovery_done;
+
+ // hold clock low for 35ms: 25 and some spair:
+ npcm_smb_set_SCL(_adap, 0);
+ usleep_range(35000, 40000);
+ npcm_smb_set_SCL(_adap, 1);
+ usleep_range(1000, 2000);
+
+ // check if success:
+ if (npcm_smb_get_SCL(_adap) == 1 && npcm_smb_get_SDA(_adap) == 1)
+ goto npcm_smb_recovery_done;
+
+ return 0;
+
+npcm_smb_recovery_done:
+
+ npcm_smb_int_enable(bus, true);
+ return -(ENOTRECOVERABLE);
+}
+
+static bool npcm_smb_init_clk(struct npcm_i2c *bus, enum smb_mode mode,
+ u32 bus_freq)
+{
+ u32 k1 = 0;
+ u32 k2 = 0;
+ u8 dbnct = 0;
+ u32 sclfrq = 0;
+ u8 hldt = 7;
+ bool fast_mode = false;
+ u32 src_clk_freq; // in KHz
+
+ src_clk_freq = bus->apb_clk / 1000;
+
+ if (bus_freq <= SMBUS_FREQ_100KHZ) {
+ sclfrq = src_clk_freq / (bus_freq * 4);
+
+ if (sclfrq < SCLFRQ_MIN || sclfrq > SCLFRQ_MAX)
+ return false;
+
+ if (src_clk_freq >= 40000)
+ hldt = 17;
+ else if (src_clk_freq >= 12500)
+ hldt = 15;
+ else
+ hldt = 7;
+ }
+
+ else if (bus_freq == SMBUS_FREQ_400KHZ) {
+ sclfrq = 0;
+ fast_mode = true;
+
+ if ((mode == SMB_MASTER && src_clk_freq < 7500) ||
+ (mode == SMB_SLAVE && src_clk_freq < 10000))
+ // 400KHZ cannot be supported for master core clock < 7.5 MHZ
+ // or slave core clock < 10 MHZ
+ return false;
+
+ // Master or Slave with frequency > 25 MHZ
+ if (mode == SMB_MASTER || src_clk_freq > 25000) {
+ hldt = (u8)__KERNEL_DIV_ROUND_UP(src_clk_freq * 300,
+ 1000000) + 7;
+ if (mode == SMB_MASTER) {
+ k1 = __KERNEL_DIV_ROUND_UP(src_clk_freq * 1600,
+ 1000000);
+ k2 = __KERNEL_DIV_ROUND_UP(src_clk_freq * 900,
+ 1000000);
+ k1 = round_up(k1, 2);
+ k2 = round_up(k2 + 1, 2);
+ if (k1 < SCLFRQ_MIN || k1 > SCLFRQ_MAX ||
+ k2 < SCLFRQ_MIN || k2 > SCLFRQ_MAX)
+ return false;
+ }
+ } else { // Slave with frequency 10-25 MHZ
+ hldt = 7;
+ dbnct = 2;
+ }
+ }
+
+ else if (bus_freq == SMBUS_FREQ_1MHZ) {
+ sclfrq = 0;
+ fast_mode = true;
+
+ if ((mode == SMB_MASTER && src_clk_freq < 15000) ||
+ (mode == SMB_SLAVE && src_clk_freq < 24000))
+ // 1MHZ cannot be supported for master core clock < 15 MHZ
+ // or slave core clock < 24 MHZ
+ return false;
+
+ if (mode == SMB_MASTER) {
+ k1 = round_up((__KERNEL_DIV_ROUND_UP(src_clk_freq * 620,
+ 1000000)), 2);
+ k2 = round_up((__KERNEL_DIV_ROUND_UP(src_clk_freq * 380,
+ 1000000) + 1), 2);
+ if (k1 < SCLFRQ_MIN || k1 > SCLFRQ_MAX ||
+ k2 < SCLFRQ_MIN || k2 > SCLFRQ_MAX) {
+ return false;
+ }
+ }
+
+ // Master or Slave with frequency > 40 MHZ
+ if (mode == SMB_MASTER || src_clk_freq > 40000) {
+ // Set HLDT:
+ // SDA hold time: (HLDT-7) * T(CLK) >= 120
+ // HLDT = 120/T(CLK) + 7 = 120 * FREQ(CLK) + 7
+ hldt = (u8)__KERNEL_DIV_ROUND_UP(src_clk_freq * 120,
+ 1000000) + 7;
+
+ // Slave with frequency 24-40 MHZ
+ } else {
+ hldt = 7;
+ dbnct = 2;
+ }
+ }
+
+ // Frequency larger than 1 MHZ
+ else
+ return false;
+
+ // After clock parameters calculation update the reg
+ iowrite8((ioread8(bus->reg + NPCM_SMBCTL2)
+ & ~SMBCTL2_SCLFRQ6_0) | FIELD_PREP(SMBCTL2_SCLFRQ6_0,
+ sclfrq & 0x7F), bus->reg + NPCM_SMBCTL2);
+
+ iowrite8((ioread8(bus->reg + NPCM_SMBCTL3) & ~SMBCTL3_SCLFRQ8_7) |
+ FIELD_PREP(SMBCTL3_SCLFRQ8_7, (sclfrq >> 7) & 0x3),
+ bus->reg + NPCM_SMBCTL3);
+
+ iowrite8((ioread8(bus->reg + NPCM_SMBCTL3) & ~SMBCTL3_400K_MODE) |
+ FIELD_PREP(SMBCTL3_400K_MODE, fast_mode),
+ bus->reg + NPCM_SMBCTL3);
+
+ // Select Bank 0 to access NPCM_SMBCTL4/NPCM_SMBCTL5
+ npcm_smb_select_bank(bus, SMB_BANK_0);
+
+ if (bus_freq >= SMBUS_FREQ_400KHZ) {
+ // k1 and k2 are relevant for master mode only
+ if (mode == SMB_MASTER) {
+ // Set SCL Low/High Time:
+ // k1 = 2 * SCLLT7-0 -> Low Time = k1 / 2
+ // k2 = 2 * SCLLT7-0 -> High Time = k2 / 2
+ iowrite8((u8)k1 / 2, bus->reg + NPCM_SMBSCLLT);
+ iowrite8((u8)k2 / 2, bus->reg + NPCM_SMBSCLHT);
+ } else { // DBNCT is relevant for slave mode only
+ iowrite8((ioread8(bus->reg + NPCM_SMBCTL5) &
+ ~SMBCTL5_DBNCT) |
+ FIELD_PREP(SMBCTL5_DBNCT, dbnct),
+ bus->reg + NPCM_SMBCTL5);
+ }
+ }
+
+ iowrite8((ioread8(bus->reg + NPCM_SMBCTL4) & ~SMBCTL4_HLDT)
+ | FIELD_PREP(SMBCTL4_HLDT, hldt), bus->reg + NPCM_SMBCTL4);
+
+ // Return to Bank 1, and stay there by default:
+ npcm_smb_select_bank(bus, SMB_BANK_1);
+
+ dev_dbg(bus->dev, "k1 = %d k2 = %d dbnct = %d sclfrq = %d hldt = %d src_clk_freq %d fast_mode %d\n",
+ k1, k2, dbnct, sclfrq, hldt, src_clk_freq, fast_mode);
+
+ return true;
+}
+
+static bool npcm_smb_init_module(struct npcm_i2c *bus, enum smb_mode mode,
+ u32 bus_freq)
+{
+ // Check whether module already enabled or frequency is out of bounds
+ if ((bus->state != SMB_DISABLE && bus->state != SMB_IDLE) ||
+ bus_freq < SMBUS_FREQ_MIN || bus_freq > SMBUS_FREQ_MAX)
+ return false;
+ // Configure FIFO disabled mode so slave will not use fifo
+ // (maste will set it on if supported)
+ bus->threshold_fifo = SMBUS_FIFO_SIZE;
+ iowrite8(ioread8(bus->reg + NPCM_SMBFIF_CTL) & ~NPCM_SMBFIF_CTL_FIFO_EN,
+ bus->reg + NPCM_SMBFIF_CTL);
+
+ bus->fifo_use = false;
+
+ // Configure SMB module clock frequency
+ if (!npcm_smb_init_clk(bus, mode, bus_freq)) {
+ pr_err("npcm_smb_init_clk failed\n");
+ return false;
+ }
+ npcm_smb_disable(bus);
+
+ // Enable module (before configuring CTL1)
+ npcm_smb_enable(bus);
+ bus->state = SMB_IDLE;
+
+ // Enable SMB int and New Address Match int source
+ iowrite8((ioread8(bus->reg + NPCM_SMBCTL1) | NPCM_SMBCTL1_NMINTE) &
+ ~NPCM_SMBCTL1_RWS_FIELDS,
+ bus->reg + NPCM_SMBCTL1);
+
+ npcm_smb_int_enable(bus, true);
+ return true;
+}
+
+static int __npcm_i2c_init(struct npcm_i2c *bus, struct platform_device *pdev)
+{
+ u32 clk_freq;
+ int ret;
+
+ // Initialize the internal data structures
+ bus->state = SMB_DISABLE;
+ bus->master_or_slave = SMB_SLAVE;
+
+ ret = of_property_read_u32(pdev->dev.of_node,
+ "bus-frequency", &clk_freq);
+ if (ret < 0) {
+ dev_err(&pdev->dev,
+ "Could not read bus-frequency property\n");
+ clk_freq = 100000;
+ }
+ ret = npcm_smb_init_module(bus, SMB_MASTER, clk_freq / 1000);
+ if (!ret) {
+ dev_err(&pdev->dev,
+ "npcm_smb_init_module() failed\n");
+ return -1;
+ }
+
+ crc8_populate_lsb(npcm7xx_crc8, 0x07);
+ crc8_populate_msb(npcm7xx_crc8, 0x07);
+ return 0;
+}
+
+static irqreturn_t npcm_i2c_bus_irq(int irq, void *dev_id)
+{
+ struct npcm_i2c *bus = dev_id;
+
+ bus->int_cnt++;
+ _npcm7xx_get_time_stamp(&bus->int_time_stamp[0],
+ &bus->int_time_stamp[1]);
+ if (bus->master_or_slave == SMB_MASTER) {
+ npcm_smb_int_master_handler(bus);
+ return IRQ_HANDLED;
+ }
+
+ dev_err(bus->dev, "int unknown on bus%d\n", bus->num);
+ return IRQ_NONE;
+}
+
+static bool npcm_smb_master_start_xmit(struct npcm_i2c *bus,
+ u8 slave_addr, u16 nwrite, u16 nread,
+ u8 *write_data, u8 *read_data,
+ bool use_PEC)
+{
+ //
+ // Allow only if bus is not busy
+ //
+ if (bus->state != SMB_IDLE) {
+ dev_info(bus->dev, "\tbus%d->state != SMB_IDLE\n", bus->num);
+ return false;
+ }
+
+ // Configure FIFO mode :
+ if (FIELD_GET(SMB_VER_FIFO_EN, ioread8(bus->reg + SMB_VER))) {
+ bus->fifo_use = true;
+ iowrite8(ioread8(bus->reg + NPCM_SMBFIF_CTL) |
+ NPCM_SMBFIF_CTL_FIFO_EN, bus->reg + NPCM_SMBFIF_CTL);
+ } else {
+ bus->fifo_use = false;
+ }
+
+ // Update driver state
+ bus->master_or_slave = SMB_MASTER;
+ bus->state = SMB_MASTER_START;
+ if (nwrite > 0)
+ bus->operation = SMB_WRITE_OPER;
+ else
+ bus->operation = SMB_READ_OPER;
+
+ if (npcm_smb_is_quick(bus))
+ bus->operation = SMB_WRITE_OPER; // send the address with W bit.
+
+ bus->dest_addr = (u8)(slave_addr << 1);// Translate 7bit to 8bit format
+ bus->wr_buf = write_data;
+ bus->wr_size = nwrite;
+ bus->wr_ind = 0;
+ bus->rd_buf = read_data;
+ bus->rd_size = nread;
+ bus->rd_ind = 0;
+ bus->PEC_use = use_PEC;
+ bus->retry_count = SMB_RETRY_MAX_COUNT;
+
+ // clear BER just in case it is set due to a previous transaction
+ iowrite8(NPCM_SMBST_BER, bus->reg + NPCM_SMBST);
+
+ // Initiate SMBus master transaction
+ // Generate a Start condition on the SMBus
+ if (bus->fifo_use) {
+ // select bank 1 for FIFO regs
+ npcm_smb_select_bank(bus, SMB_BANK_1);
+
+ // clear FIFO and relevant status bits.
+ iowrite8(ioread8(bus->reg + NPCM_SMBFIF_CTS) |
+ NPCM_SMBFIF_CTS_SLVRSTR |
+ NPCM_SMBFIF_CTS_CLR_FIFO |
+ NPCM_SMBFIF_CTS_RXF_TXE, bus->reg + NPCM_SMBFIF_CTS);
+
+ if (bus->operation == SMB_READ_OPER) {
+ //This is a read only operation. Configure the FIFO
+ //threshold according to the needed # of bytes to read.
+ npcm_smb_set_fifo(bus, nread, -1);
+ } else if (bus->operation == SMB_WRITE_OPER) {
+ npcm_smb_set_fifo(bus, -1, nwrite);
+ }
+ }
+
+ bus->int_cnt = 0;
+ bus->event_log = 0;
+ npcm_smb_master_start(bus);
+
+ return true;
+}
+
+static int npcm_i2c_master_xfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
+ int num)
+{
+ struct npcm_i2c *bus = adap->algo_data;
+ struct i2c_msg *msg0, *msg1;
+ unsigned long time_left, flags;
+ u16 nwrite, nread;
+ u8 *write_data, *read_data;
+ u8 slave_addr;
+ int ret = 0;
+
+ spin_lock_irqsave(&bus->lock, flags);
+ bus->cmd_err = -EPERM;
+ bus->int_cnt = 0;
+ bus->stop_ind = SMB_NO_STATUS_IND;
+ bus->read_block_use = false;
+
+ iowrite8(0xFF, bus->reg + NPCM_SMBST);
+
+ if (num > 2 || num < 1) {
+ pr_err("I2C command not supported, num of msgs = %d\n", num);
+ spin_unlock_irqrestore(&bus->lock, flags);
+ return -EINVAL;
+ }
+
+ msg0 = &msgs[0];
+ slave_addr = msg0->addr;
+ if (msg0->flags & I2C_M_RD) { // read
+ if (num == 2) {
+ pr_err(" num = 2 but first msg is rd instead of wr\n");
+ spin_unlock_irqrestore(&bus->lock, flags);
+ return -EINVAL;
+ }
+ nwrite = 0;
+ write_data = NULL;
+ if (msg0->flags & I2C_M_RECV_LEN) {
+ nread = 1;
+ bus->read_block_use = true;
+
+ } else {
+ nread = msg0->len;
+ }
+ read_data = msg0->buf;
+
+ } else { // write
+ nwrite = msg0->len;
+ write_data = msg0->buf;
+ nread = 0;
+ read_data = NULL;
+ if (num == 2) {
+ msg1 = &msgs[1];
+ if (slave_addr != msg1->addr) {
+ pr_err("SA==%02x but msg1->addr == %02x\n",
+ slave_addr, msg1->addr);
+ spin_unlock_irqrestore(&bus->lock, flags);
+ return -EINVAL;
+ }
+ if ((msg1->flags & I2C_M_RD) == 0) {
+ pr_err("num = 2 but both msg are write.\n");
+ spin_unlock_irqrestore(&bus->lock, flags);
+ return -EINVAL;
+ }
+ if (msg1->flags & I2C_M_RECV_LEN) {
+ nread = 1;
+ bus->read_block_use = true;
+ } else {
+ nread = msg1->len;
+ bus->read_block_use = false;
+ }
+
+ read_data = msg1->buf;
+ }
+ }
+
+ bus->msgs = msgs;
+ bus->msgs_num = num;
+
+ if (nwrite >= 32 * 1024 || nread >= 32 * 1024) {
+ pr_err("i2c%d buffer too big\n", bus->num);
+ return -EINVAL;
+ }
+
+ reinit_completion(&bus->cmd_complete);
+
+ if (npcm_smb_master_start_xmit(bus, slave_addr, nwrite, nread,
+ write_data, read_data, 0) == false)
+ ret = -(EBUSY);
+
+ if (ret != -(EBUSY)) {
+ time_left = wait_for_completion_timeout(&bus->cmd_complete,
+ bus->adap.timeout);
+
+ if (time_left == 0 && bus->cmd_err == -EPERM) {
+ npcm_smb_master_abort(bus);
+ ret = -ETIMEDOUT;
+ } else {
+ ret = bus->cmd_err;
+ }
+ }
+
+ bus->msgs = NULL;
+ bus->msgs_num = 0;
+ spin_unlock_irqrestore(&bus->lock, flags);
+
+ // If nothing went wrong, return number of messages xferred.
+ if (ret >= 0)
+ return num;
+ else
+ return ret;
+}
+
+static u32 npcm_i2c_functionality(struct i2c_adapter *adap)
+{
+ return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL | I2C_FUNC_SMBUS_BLOCK_DATA;
+}
+
+static const struct i2c_algorithm npcm_i2c_algo = {
+ .master_xfer = npcm_i2c_master_xfer,
+ .functionality = npcm_i2c_functionality,
+};
+
+static struct i2c_bus_recovery_info npcm_i2c_recovery = {
+ .recover_bus = npcm_smb_recovery,
+ .get_scl = npcm_smb_get_SCL,
+ .set_scl = npcm_smb_set_SCL,
+ .get_sda = npcm_smb_get_SDA,
+};
+
+static int npcm_i2c_probe_bus(struct platform_device *pdev)
+{
+ struct npcm_i2c *bus;
+ struct resource *res;
+ struct clk *i2c_clk;
+ int ret;
+ int num;
+
+ bus = devm_kzalloc(&pdev->dev, sizeof(*bus), GFP_KERNEL);
+ if (!bus)
+ return -ENOMEM;
+
+#ifdef CONFIG_OF
+ num = of_alias_get_id(pdev->dev.of_node, "i2c");
+ bus->num = num;
+ i2c_clk = devm_clk_get(&pdev->dev, NULL);
+ if (IS_ERR(i2c_clk)) {
+ pr_err(" I2C probe failed: can't read clk.\n");
+ return -EPROBE_DEFER;
+ }
+ bus->apb_clk = clk_get_rate(i2c_clk);
+ dev_dbg(bus->dev, "I2C APB clock is %d\n", bus->apb_clk);
+#endif // CONFIG_OF
+
+ gcr_regmap = syscon_regmap_lookup_by_compatible("nuvoton,npcm750-gcr");
+ if (IS_ERR(gcr_regmap)) {
+ pr_err("%s: failed to find nuvoton,npcm750-gcr\n", __func__);
+ return IS_ERR(gcr_regmap);
+ }
+ regmap_write(gcr_regmap, NPCM_I2CSEGCTL, I2CSEGCTL_VAL);
+ dev_dbg(bus->dev, "I2C%d: gcr mapped\n", bus->num);
+
+ clk_regmap = syscon_regmap_lookup_by_compatible("nuvoton,npcm750-clk");
+ if (IS_ERR(clk_regmap)) {
+ pr_err("%s: failed to find nuvoton,npcm750-clk\n", __func__);
+ return IS_ERR(clk_regmap);
+ }
+ dev_dbg(bus->dev, "I2C%d: clk mapped\n", bus->num);
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ dev_dbg(bus->dev, "resource: %pR\n", res);
+ bus->reg = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR((bus)->reg))
+ return PTR_ERR((bus)->reg);
+ dev_dbg(bus->dev, "base = %p\n", bus->reg);
+
+ // Initialize the I2C adapter
+ spin_lock_init(&bus->lock);
+ init_completion(&bus->cmd_complete);
+ bus->adap.owner = THIS_MODULE;
+ bus->adap.class = I2C_CLASS_HWMON | I2C_CLASS_SPD;
+ bus->adap.retries = 0;
+ bus->adap.timeout = 500 * HZ / 1000;
+ bus->adap.algo = &npcm_i2c_algo;
+ bus->adap.algo_data = bus;
+ bus->adap.dev.parent = &pdev->dev;
+ bus->adap.dev.of_node = pdev->dev.of_node;
+ bus->adap.bus_recovery_info = &npcm_i2c_recovery;
+
+ snprintf(bus->adap.name, sizeof(bus->adap.name), "Nuvoton i2c");
+
+ bus->dev = &pdev->dev;
+
+ ret = __npcm_i2c_init(bus, pdev);
+ if (ret < 0)
+ return ret;
+
+ bus->irq = platform_get_irq(pdev, 0);
+ if (bus->irq < 0) {
+ pr_err("I2C platform_get_irq error.");
+ return -ENODEV;
+ }
+ dev_dbg(bus->dev, "irq = %d\n", bus->irq);
+
+ ret = request_irq(bus->irq, npcm_i2c_bus_irq, 0,
+ dev_name(&pdev->dev), (void *)bus);
+ if (ret) {
+ dev_err(&pdev->dev, "I2C%d: request_irq fail\n", bus->num);
+ return ret;
+ }
+
+ ret = i2c_add_adapter(&bus->adap);
+ if (ret < 0) {
+ dev_err(&pdev->dev, "I2C%d: i2c_add_adapter fail\n", bus->num);
+ return ret;
+ }
+
+ platform_set_drvdata(pdev, bus);
+ pr_info("i2c bus %d registered\n", bus->adap.nr);
+
+ return 0;
+}
+
+static int npcm_i2c_remove_bus(struct platform_device *pdev)
+{
+ unsigned long lock_flags;
+ struct npcm_i2c *bus = platform_get_drvdata(pdev);
+
+ spin_lock_irqsave(&bus->lock, lock_flags);
+ npcm_smb_disable(bus);
+ spin_unlock_irqrestore(&bus->lock, lock_flags);
+ i2c_del_adapter(&bus->adap);
+
+ return 0;
+}
+
+static const struct of_device_id npcm_i2c_bus_of_table[] = {
+ { .compatible = "nuvoton,npcm750-i2c", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, npcm_i2c_bus_of_table);
+
+static struct platform_driver npcm_i2c_bus_driver = {
+ .probe = npcm_i2c_probe_bus,
+ .remove = npcm_i2c_remove_bus,
+ .driver = {
+ .name = "nuvoton-i2c-bus",
+ .of_match_table = npcm_i2c_bus_of_table,
+ }
+};
+module_platform_driver(npcm_i2c_bus_driver);
+
+MODULE_AUTHOR("Avi Fishman <avi.fishman@gmail.com>");
+MODULE_AUTHOR("Tali Perry <tali.perry@nuvoton.com>");
+MODULE_DESCRIPTION("Nuvoton I2C Bus Driver");
+MODULE_LICENSE("GPL v2");
+MODULE_VERSION(I2C_VERSION);
--
2.14.1
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  Last update: 2018-08-19 22:34    [W:0.087 / U:1.956 seconds]
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