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Subject[PATCH 3/9] drm/bridge: extract some Analogix I2C DP common code
Date
Some code can be shared within different DP bridges by Analogix.

Extract them to a new module.

Signed-off-by: Icenowy Zheng <icenowy@aosc.io>
---
drivers/gpu/drm/bridge/analogix/Kconfig | 4 +
drivers/gpu/drm/bridge/analogix/Makefile | 2 +
.../drm/bridge/analogix/analogix-anx78xx.c | 146 +--------------
.../drm/bridge/analogix/analogix-i2c-dptx.c | 169 ++++++++++++++++++
.../drm/bridge/analogix/analogix-i2c-dptx.h | 2 +
5 files changed, 178 insertions(+), 145 deletions(-)
create mode 100644 drivers/gpu/drm/bridge/analogix/analogix-i2c-dptx.c

diff --git a/drivers/gpu/drm/bridge/analogix/Kconfig b/drivers/gpu/drm/bridge/analogix/Kconfig
index 27b37aa2ea77..eb893b465dd8 100644
--- a/drivers/gpu/drm/bridge/analogix/Kconfig
+++ b/drivers/gpu/drm/bridge/analogix/Kconfig
@@ -2,8 +2,12 @@ config DRM_ANALOGIX_DP
tristate
depends on DRM

+config DRM_ANALOGIX_DP_I2C
+ tristate
+
config DRM_ANALOGIX_ANX78XX
tristate "Analogix ANX78XX bridge"
+ select DRM_ANALOGIX_DP_I2C
select DRM_KMS_HELPER
select REGMAP_I2C
---help---
diff --git a/drivers/gpu/drm/bridge/analogix/Makefile b/drivers/gpu/drm/bridge/analogix/Makefile
index eb41be845055..c37e2ded8ce3 100644
--- a/drivers/gpu/drm/bridge/analogix/Makefile
+++ b/drivers/gpu/drm/bridge/analogix/Makefile
@@ -1,3 +1,5 @@
analogix_dp-objs := analogix_dp_core.o analogix_dp_reg.o
+analogix_dp_i2c-objs := analogix-i2c-dptx.o
obj-$(CONFIG_DRM_ANALOGIX_DP) += analogix_dp.o
+obj-$(CONFIG_DRM_ANALOGIX_DP_I2C) += analogix_dp_i2c.o
obj-$(CONFIG_DRM_ANALOGIX_ANX78XX) += analogix-anx78xx.o
diff --git a/drivers/gpu/drm/bridge/analogix/analogix-anx78xx.c b/drivers/gpu/drm/bridge/analogix/analogix-anx78xx.c
index f8433c93f463..bf8291d0ddd0 100644
--- a/drivers/gpu/drm/bridge/analogix/analogix-anx78xx.c
+++ b/drivers/gpu/drm/bridge/analogix/analogix-anx78xx.c
@@ -45,8 +45,6 @@
#define I2C_IDX_RX_P1 4

#define XTAL_CLK 270 /* 27M */
-#define AUX_CH_BUFFER_SIZE 16
-#define AUX_WAIT_TIMEOUT_MS 15

static const u8 anx78xx_i2c_addresses[] = {
[I2C_IDX_TX_P0] = TX_P0,
@@ -109,153 +107,11 @@ static int anx78xx_clear_bits(struct regmap *map, u8 reg, u8 mask)
return regmap_update_bits(map, reg, mask, 0);
}

-static bool anx78xx_aux_op_finished(struct anx78xx *anx78xx)
-{
- unsigned int value;
- int err;
-
- err = regmap_read(anx78xx->map[I2C_IDX_TX_P0], SP_DP_AUX_CH_CTRL2_REG,
- &value);
- if (err < 0)
- return false;
-
- return (value & SP_AUX_EN) == 0;
-}
-
-static int anx78xx_aux_wait(struct anx78xx *anx78xx)
-{
- unsigned long timeout;
- unsigned int status;
- int err;
-
- timeout = jiffies + msecs_to_jiffies(AUX_WAIT_TIMEOUT_MS) + 1;
-
- while (!anx78xx_aux_op_finished(anx78xx)) {
- if (time_after(jiffies, timeout)) {
- if (!anx78xx_aux_op_finished(anx78xx)) {
- DRM_ERROR("Timed out waiting AUX to finish\n");
- return -ETIMEDOUT;
- }
-
- break;
- }
-
- usleep_range(1000, 2000);
- }
-
- /* Read the AUX channel access status */
- err = regmap_read(anx78xx->map[I2C_IDX_TX_P0], SP_AUX_CH_STATUS_REG,
- &status);
- if (err < 0) {
- DRM_ERROR("Failed to read from AUX channel: %d\n", err);
- return err;
- }
-
- if (status & SP_AUX_STATUS) {
- DRM_ERROR("Failed to wait for AUX channel (status: %02x)\n",
- status);
- return -ETIMEDOUT;
- }
-
- return 0;
-}
-
-static int anx78xx_aux_address(struct anx78xx *anx78xx, unsigned int addr)
-{
- int err;
-
- err = regmap_write(anx78xx->map[I2C_IDX_TX_P0], SP_AUX_ADDR_7_0_REG,
- addr & 0xff);
- if (err)
- return err;
-
- err = regmap_write(anx78xx->map[I2C_IDX_TX_P0], SP_AUX_ADDR_15_8_REG,
- (addr & 0xff00) >> 8);
- if (err)
- return err;
-
- /*
- * DP AUX CH Address Register #2, only update bits[3:0]
- * [7:4] RESERVED
- * [3:0] AUX_ADDR[19:16], Register control AUX CH address.
- */
- err = regmap_update_bits(anx78xx->map[I2C_IDX_TX_P0],
- SP_AUX_ADDR_19_16_REG,
- SP_AUX_ADDR_19_16_MASK,
- (addr & 0xf0000) >> 16);
-
- if (err)
- return err;
-
- return 0;
-}
-
static ssize_t anx78xx_aux_transfer(struct drm_dp_aux *aux,
struct drm_dp_aux_msg *msg)
{
struct anx78xx *anx78xx = container_of(aux, struct anx78xx, aux);
- u8 ctrl1 = msg->request;
- u8 ctrl2 = SP_AUX_EN;
- u8 *buffer = msg->buffer;
- int err;
-
- /* The DP AUX transmit and receive buffer has 16 bytes. */
- if (WARN_ON(msg->size > AUX_CH_BUFFER_SIZE))
- return -E2BIG;
-
- /* Zero-sized messages specify address-only transactions. */
- if (msg->size < 1)
- ctrl2 |= SP_ADDR_ONLY;
- else /* For non-zero-sized set the length field. */
- ctrl1 |= (msg->size - 1) << SP_AUX_LENGTH_SHIFT;
-
- if ((msg->request & DP_AUX_I2C_READ) == 0) {
- /* When WRITE | MOT write values to data buffer */
- err = regmap_bulk_write(anx78xx->map[I2C_IDX_TX_P0],
- SP_DP_BUF_DATA0_REG, buffer,
- msg->size);
- if (err)
- return err;
- }
-
- /* Write address and request */
- err = anx78xx_aux_address(anx78xx, msg->address);
- if (err)
- return err;
-
- err = regmap_write(anx78xx->map[I2C_IDX_TX_P0], SP_DP_AUX_CH_CTRL1_REG,
- ctrl1);
- if (err)
- return err;
-
- /* Start transaction */
- err = regmap_update_bits(anx78xx->map[I2C_IDX_TX_P0],
- SP_DP_AUX_CH_CTRL2_REG, SP_ADDR_ONLY |
- SP_AUX_EN, ctrl2);
- if (err)
- return err;
-
- err = anx78xx_aux_wait(anx78xx);
- if (err)
- return err;
-
- msg->reply = DP_AUX_I2C_REPLY_ACK;
-
- if ((msg->size > 0) && (msg->request & DP_AUX_I2C_READ)) {
- /* Read values from data buffer */
- err = regmap_bulk_read(anx78xx->map[I2C_IDX_TX_P0],
- SP_DP_BUF_DATA0_REG, buffer,
- msg->size);
- if (err)
- return err;
- }
-
- err = anx78xx_clear_bits(anx78xx->map[I2C_IDX_TX_P0],
- SP_DP_AUX_CH_CTRL2_REG, SP_ADDR_ONLY);
- if (err)
- return err;
-
- return msg->size;
+ return anx_aux_transfer(anx78xx->map[I2C_IDX_TX_P0], msg);
}

static int anx78xx_set_hpd(struct anx78xx *anx78xx)
diff --git a/drivers/gpu/drm/bridge/analogix/analogix-i2c-dptx.c b/drivers/gpu/drm/bridge/analogix/analogix-i2c-dptx.c
new file mode 100644
index 000000000000..9cb30962032e
--- /dev/null
+++ b/drivers/gpu/drm/bridge/analogix/analogix-i2c-dptx.c
@@ -0,0 +1,169 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright(c) 2017 Icenowy Zheng <icenowy@aosc.io>
+ *
+ * Based on analogix-anx78xx.c, which is:
+ * Copyright(c) 2016, Analogix Semiconductor. All rights reserved.
+ */
+
+#include <linux/module.h>
+#include <linux/regmap.h>
+
+#include <drm/drm.h>
+#include <drm/drmP.h>
+#include <drm/drm_dp_helper.h>
+
+#include "analogix-i2c-dptx.h"
+
+#define AUX_WAIT_TIMEOUT_MS 15
+#define AUX_CH_BUFFER_SIZE 16
+
+static int anx_clear_bits(struct regmap *map, u8 reg, u8 mask)
+{
+ return regmap_update_bits(map, reg, mask, 0);
+}
+
+static bool anx_aux_op_finished(struct regmap *map_dptx)
+{
+ unsigned int value;
+ int err;
+
+ err = regmap_read(map_dptx, SP_DP_AUX_CH_CTRL2_REG, &value);
+ if (err < 0)
+ return false;
+
+ return (value & SP_AUX_EN) == 0;
+}
+
+static int anx_aux_wait(struct regmap *map_dptx)
+{
+ unsigned long timeout;
+ unsigned int status;
+ int err;
+
+ timeout = jiffies + msecs_to_jiffies(AUX_WAIT_TIMEOUT_MS) + 1;
+
+ while (!anx_aux_op_finished(map_dptx)) {
+ if (time_after(jiffies, timeout)) {
+ if (!anx_aux_op_finished(map_dptx)) {
+ DRM_ERROR("Timed out waiting AUX to finish\n");
+ return -ETIMEDOUT;
+ }
+
+ break;
+ }
+
+ usleep_range(1000, 2000);
+ }
+
+ /* Read the AUX channel access status */
+ err = regmap_read(map_dptx, SP_AUX_CH_STATUS_REG, &status);
+ if (err < 0) {
+ DRM_ERROR("Failed to read from AUX channel: %d\n", err);
+ return err;
+ }
+
+ if (status & SP_AUX_STATUS) {
+ DRM_ERROR("Failed to wait for AUX channel (status: %02x)\n",
+ status);
+ return -ETIMEDOUT;
+ }
+
+ return 0;
+}
+
+static int anx_aux_address(struct regmap *map_dptx, unsigned int addr)
+{
+ int err;
+
+ err = regmap_write(map_dptx, SP_AUX_ADDR_7_0_REG, addr & 0xff);
+ if (err)
+ return err;
+
+ err = regmap_write(map_dptx, SP_AUX_ADDR_15_8_REG,
+ (addr & 0xff00) >> 8);
+ if (err)
+ return err;
+
+ /*
+ * DP AUX CH Address Register #2, only update bits[3:0]
+ * [7:4] RESERVED
+ * [3:0] AUX_ADDR[19:16], Register control AUX CH address.
+ */
+ err = regmap_update_bits(map_dptx, SP_AUX_ADDR_19_16_REG,
+ SP_AUX_ADDR_19_16_MASK,
+ (addr & 0xf0000) >> 16);
+
+ if (err)
+ return err;
+
+ return 0;
+}
+
+ssize_t anx_aux_transfer(struct regmap *map_dptx, struct drm_dp_aux_msg *msg)
+{
+ u8 ctrl1 = msg->request;
+ u8 ctrl2 = SP_AUX_EN;
+ u8 *buffer = msg->buffer;
+ int err;
+
+ /* The DP AUX transmit and receive buffer has 16 bytes. */
+ if (WARN_ON(msg->size > AUX_CH_BUFFER_SIZE))
+ return -E2BIG;
+
+ /* Zero-sized messages specify address-only transactions. */
+ if (msg->size < 1)
+ ctrl2 |= SP_ADDR_ONLY;
+ else /* For non-zero-sized set the length field. */
+ ctrl1 |= (msg->size - 1) << SP_AUX_LENGTH_SHIFT;
+
+ if ((msg->request & DP_AUX_I2C_READ) == 0) {
+ /* When WRITE | MOT write values to data buffer */
+ err = regmap_bulk_write(map_dptx,
+ SP_DP_BUF_DATA0_REG, buffer,
+ msg->size);
+ if (err)
+ return err;
+ }
+
+ /* Write address and request */
+ err = anx_aux_address(map_dptx, msg->address);
+ if (err)
+ return err;
+
+ err = regmap_write(map_dptx, SP_DP_AUX_CH_CTRL1_REG, ctrl1);
+ if (err)
+ return err;
+
+ /* Start transaction */
+ err = regmap_update_bits(map_dptx, SP_DP_AUX_CH_CTRL2_REG,
+ SP_ADDR_ONLY | SP_AUX_EN, ctrl2);
+ if (err)
+ return err;
+
+ err = anx_aux_wait(map_dptx);
+ if (err)
+ return err;
+
+ msg->reply = DP_AUX_I2C_REPLY_ACK;
+
+ if ((msg->size > 0) && (msg->request & DP_AUX_I2C_READ)) {
+ /* Read values from data buffer */
+ err = regmap_bulk_read(map_dptx,
+ SP_DP_BUF_DATA0_REG, buffer,
+ msg->size);
+ if (err)
+ return err;
+ }
+
+ err = anx_clear_bits(map_dptx, SP_DP_AUX_CH_CTRL2_REG, SP_ADDR_ONLY);
+ if (err)
+ return err;
+
+ return msg->size;
+}
+EXPORT_SYMBOL(anx_aux_transfer);
+
+MODULE_DESCRIPTION("Analogix DisplayPort Transmitter common code");
+MODULE_AUTHOR("Icenowy Zheng <icenowy@aosc.io>");
+MODULE_LICENSE("GPL v2");
diff --git a/drivers/gpu/drm/bridge/analogix/analogix-i2c-dptx.h b/drivers/gpu/drm/bridge/analogix/analogix-i2c-dptx.h
index bc0831b127bf..c2ca854613a0 100644
--- a/drivers/gpu/drm/bridge/analogix/analogix-i2c-dptx.h
+++ b/drivers/gpu/drm/bridge/analogix/analogix-i2c-dptx.h
@@ -245,4 +245,6 @@
/* DP AUX Buffer Data Registers */
#define SP_DP_BUF_DATA0_REG 0xf0

+ssize_t anx_aux_transfer(struct regmap *map_dptx, struct drm_dp_aux_msg *msg);
+
#endif
--
2.18.1
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