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Subject[RESEND PATCH v1 11/15] phy: cadence-torrent: Implement PHY configure APIs
Date
From: Swapnil Jakhade <sjakhade@cadence.com>

Add support for PHY configuration APIs. These will mainly reconfigure
link rate, number of lanes, voltage swing and pre-emphasis values.

Signed-off-by: Swapnil Jakhade <sjakhade@cadence.com>
---
drivers/phy/cadence/phy-cadence-torrent.c | 424 ++++++++++++++++++++++++++++++
1 file changed, 424 insertions(+)

diff --git a/drivers/phy/cadence/phy-cadence-torrent.c b/drivers/phy/cadence/phy-cadence-torrent.c
index ebc3b68..006e786 100644
--- a/drivers/phy/cadence/phy-cadence-torrent.c
+++ b/drivers/phy/cadence/phy-cadence-torrent.c
@@ -37,6 +37,9 @@
#define PHY_AUX_CONFIG 0x00
#define PHY_AUX_CTRL 0x04
#define PHY_RESET 0x20
+#define PMA_TX_ELEC_IDLE_MASK 0xF0U
+#define PMA_TX_ELEC_IDLE_SHIFT 4
+#define PHY_L00_RESET_N_MASK 0x01U
#define PHY_PMA_XCVR_PLLCLK_EN 0x24
#define PHY_PMA_XCVR_PLLCLK_EN_ACK 0x28
#define PHY_PMA_XCVR_POWER_STATE_REQ 0x2c
@@ -120,6 +123,10 @@
#define CMN_PDIAG_PLL1_CP_IADJ_M0 0x00714
#define CMN_PDIAG_PLL1_FILT_PADJ_M0 0x00718

+#define TX_TXCC_CTRL 0x10100
+#define TX_TXCC_CPOST_MULT_00 0x10130
+#define TX_TXCC_MGNFS_MULT_000 0x10140
+#define DRV_DIAG_TX_DRV 0x10318
#define XCVR_DIAG_PLLDRC_CTRL 0x10394
#define XCVR_DIAG_HSCLK_SEL 0x10398
#define XCVR_DIAG_HSCLK_DIV 0x1039c
@@ -129,6 +136,8 @@
#define TX_PSC_A2 0x10408
#define TX_PSC_A3 0x1040c
#define TX_RCVDET_ST_TMR 0x1048c
+#define TX_DIAG_ACYA 0x1079c
+#define TX_DIAG_ACYA_HBDC_MASK 0x0001U
#define RX_PSC_A0 0x20000
#define RX_PSC_A1 0x20004
#define RX_PSC_A2 0x20008
@@ -140,6 +149,9 @@

#define PHY_PLL_CFG 0x30038

+#define PHY_PMA_CMN_CTRL2 0x38004
+#define PHY_PMA_PLL_RAW_CTRL 0x3800c
+
struct cdns_torrent_phy {
void __iomem *base; /* DPTX registers base */
void __iomem *sd_base; /* SD0801 registers base */
@@ -184,12 +196,18 @@ static void cdns_dp_phy_write_field(struct cdns_torrent_phy *cdns_phy,
unsigned char num_bits,
unsigned int val);

+static int cdns_torrent_dp_configure(struct phy *phy,
+ union phy_configure_opts *opts);
+static int cdns_torrent_dp_set_power_state(struct cdns_torrent_phy *cdns_phy,
+ u32 num_lanes,
+ enum phy_powerstate powerstate);
static int cdns_torrent_phy_on(struct phy *phy);
static int cdns_torrent_phy_off(struct phy *phy);

static const struct phy_ops cdns_torrent_phy_ops = {
.init = cdns_torrent_dp_init,
.exit = cdns_torrent_dp_exit,
+ .configure = cdns_torrent_dp_configure,
.power_on = cdns_torrent_phy_on,
.power_off = cdns_torrent_phy_off,
.owner = THIS_MODULE,
@@ -203,6 +221,16 @@ static void cdns_torrent_phy_write(struct cdns_torrent_phy *cdns_phy,
writel(val, cdns_phy->sd_base + offset);
}

+static u32 cdns_torrent_phy_read(struct cdns_torrent_phy *cdns_phy, u32 offset)
+{
+ return readl(cdns_phy->sd_base + offset);
+}
+
+#define cdns_torrent_phy_read_poll_timeout(cdns_phy, offset, val, cond, \
+ delay_us, timeout_us) \
+ readl_poll_timeout((cdns_phy)->sd_base + (offset), \
+ val, cond, delay_us, timeout_us)
+
/* DPTX mmr access functions */

static void cdns_torrent_dp_write(struct cdns_torrent_phy *cdns_phy,
@@ -221,6 +249,237 @@ static u32 cdns_torrent_dp_read(struct cdns_torrent_phy *cdns_phy, u32 offset)
readl_poll_timeout((cdns_phy)->base + (offset), \
val, cond, delay_us, timeout_us)

+/*
+ * Structure used to store values of PHY registers for voltage-related
+ * coefficients, for particular voltage swing and pre-emphasis level. Values
+ * are shared across all physical lanes.
+ */
+struct coefficients {
+ /* Value of DRV_DIAG_TX_DRV register to use */
+ u16 diag_tx_drv;
+ /* Value of TX_TXCC_MGNFS_MULT_000 register to use */
+ u16 mgnfs_mult;
+ /* Value of TX_TXCC_CPOST_MULT_00 register to use */
+ u16 cpost_mult;
+};
+
+/*
+ * Array consists of values of voltage-related registers for sd0801 PHY. A value
+ * of 0xFFFF is a placeholder for invalid combination, and will never be used.
+ */
+static const struct coefficients vltg_coeff[4][4] = {
+ /* voltage swing 0, pre-emphasis 0->3 */
+ { {.diag_tx_drv = 0x0003, .mgnfs_mult = 0x002A,
+ .cpost_mult = 0x0000},
+ {.diag_tx_drv = 0x0003, .mgnfs_mult = 0x001F,
+ .cpost_mult = 0x0014},
+ {.diag_tx_drv = 0x0003, .mgnfs_mult = 0x0012,
+ .cpost_mult = 0x0020},
+ {.diag_tx_drv = 0x0003, .mgnfs_mult = 0x0000,
+ .cpost_mult = 0x002A}
+ },
+
+ /* voltage swing 1, pre-emphasis 0->3 */
+ { {.diag_tx_drv = 0x0003, .mgnfs_mult = 0x001F,
+ .cpost_mult = 0x0000},
+ {.diag_tx_drv = 0x0003, .mgnfs_mult = 0x0013,
+ .cpost_mult = 0x0012},
+ {.diag_tx_drv = 0x0003, .mgnfs_mult = 0x0000,
+ .cpost_mult = 0x001F},
+ {.diag_tx_drv = 0xFFFF, .mgnfs_mult = 0xFFFF,
+ .cpost_mult = 0xFFFF}
+ },
+
+ /* voltage swing 2, pre-emphasis 0->3 */
+ { {.diag_tx_drv = 0x0003, .mgnfs_mult = 0x0013,
+ .cpost_mult = 0x0000},
+ {.diag_tx_drv = 0x0003, .mgnfs_mult = 0x0000,
+ .cpost_mult = 0x0013},
+ {.diag_tx_drv = 0xFFFF, .mgnfs_mult = 0xFFFF,
+ .cpost_mult = 0xFFFF},
+ {.diag_tx_drv = 0xFFFF, .mgnfs_mult = 0xFFFF,
+ .cpost_mult = 0xFFFF}
+ },
+
+ /* voltage swing 3, pre-emphasis 0->3 */
+ { {.diag_tx_drv = 0x0003, .mgnfs_mult = 0x0000,
+ .cpost_mult = 0x0000},
+ {.diag_tx_drv = 0xFFFF, .mgnfs_mult = 0xFFFF,
+ .cpost_mult = 0xFFFF},
+ {.diag_tx_drv = 0xFFFF, .mgnfs_mult = 0xFFFF,
+ .cpost_mult = 0xFFFF},
+ {.diag_tx_drv = 0xFFFF, .mgnfs_mult = 0xFFFF,
+ .cpost_mult = 0xFFFF}
+ }
+};
+
+/*
+ * Enable or disable PLL for selected lanes.
+ */
+static int cdns_torrent_dp_set_pll_en(struct cdns_torrent_phy *cdns_phy,
+ struct phy_configure_opts_dp *dp,
+ bool enable)
+{
+ u32 rd_val;
+ u32 ret;
+ /*
+ * Used to determine, which bits to check for or enable in
+ * PHY_PMA_XCVR_PLLCLK_EN register.
+ */
+ u32 pll_bits;
+ /* Used to enable or disable lanes. */
+ u32 pll_val;
+
+ /* Select values of registers and mask, depending on enabled lane
+ * count.
+ */
+ switch (dp->lanes) {
+ /* lane 0 */
+ case (1):
+ pll_bits = 0x00000001;
+ break;
+ /* lanes 0-1 */
+ case (2):
+ pll_bits = 0x00000003;
+ break;
+ /* lanes 0-3, all */
+ default:
+ pll_bits = 0x0000000F;
+ break;
+ }
+
+ if (enable)
+ pll_val = pll_bits;
+ else
+ pll_val = 0x00000000;
+
+ cdns_torrent_dp_write(cdns_phy, PHY_PMA_XCVR_PLLCLK_EN, pll_val);
+
+ /* Wait for acknowledgment from PHY. */
+ ret = cdns_torrent_dp_read_poll_timeout(cdns_phy,
+ PHY_PMA_XCVR_PLLCLK_EN_ACK,
+ rd_val,
+ (rd_val & pll_bits) == pll_val,
+ 0, POLL_TIMEOUT_US);
+ ndelay(100);
+ return ret;
+}
+
+/*
+ * Perform register operations related to setting link rate, once powerstate is
+ * set and PLL disable request was processed.
+ */
+static int cdns_torrent_dp_configure_rate(struct cdns_torrent_phy *cdns_phy,
+ struct phy_configure_opts_dp *dp)
+{
+ u32 ret;
+ u32 read_val;
+
+ /* Disable the cmn_pll0_en before re-programming the new data rate. */
+ cdns_torrent_phy_write(cdns_phy, PHY_PMA_PLL_RAW_CTRL, 0);
+
+ /*
+ * Wait for PLL ready de-assertion.
+ * For PLL0 - PHY_PMA_CMN_CTRL2[2] == 1
+ */
+ ret = cdns_torrent_phy_read_poll_timeout(cdns_phy, PHY_PMA_CMN_CTRL2,
+ read_val,
+ ((read_val >> 2) & 0x01) != 0,
+ 0, POLL_TIMEOUT_US);
+ if (ret)
+ return ret;
+ ndelay(200);
+
+ /* DP Rate Change - VCO Output settings. */
+ if (cdns_phy->ref_clk_rate == REF_CLK_19_2MHz) {
+ /* PMA common configuration 19.2MHz */
+ cdns_torrent_dp_pma_cmn_vco_cfg_19_2mhz(cdns_phy, dp->link_rate,
+ dp->ssc);
+ cdns_torrent_dp_pma_cmn_cfg_19_2mhz(cdns_phy);
+ } else if (cdns_phy->ref_clk_rate == REF_CLK_25MHz) {
+ /* PMA common configuration 25MHz */
+ cdns_torrent_dp_pma_cmn_vco_cfg_25mhz(cdns_phy, dp->link_rate,
+ dp->ssc);
+ cdns_torrent_dp_pma_cmn_cfg_25mhz(cdns_phy);
+ }
+ cdns_torrent_dp_pma_cmn_rate(cdns_phy, dp->link_rate, dp->lanes);
+
+ /* Enable the cmn_pll0_en. */
+ cdns_torrent_phy_write(cdns_phy, PHY_PMA_PLL_RAW_CTRL, 0x3);
+
+ /*
+ * Wait for PLL ready assertion.
+ * For PLL0 - PHY_PMA_CMN_CTRL2[0] == 1
+ */
+ ret = cdns_torrent_phy_read_poll_timeout(cdns_phy, PHY_PMA_CMN_CTRL2,
+ read_val,
+ (read_val & 0x01) != 0,
+ 0, POLL_TIMEOUT_US);
+ return ret;
+}
+
+/*
+ * Verify, that parameters to configure PHY with are correct.
+ */
+static int cdns_torrent_dp_verify_config(struct cdns_torrent_phy *cdns_phy,
+ struct phy_configure_opts_dp *dp)
+{
+ u8 i;
+
+ /* If changing link rate was required, verify it's supported. */
+ if (dp->set_rate) {
+ switch (dp->link_rate) {
+ case 1620:
+ case 2160:
+ case 2430:
+ case 2700:
+ case 3240:
+ case 4320:
+ case 5400:
+ case 8100:
+ /* valid bit rate */
+ break;
+ default:
+ return -EINVAL;
+ }
+ }
+
+ /* Verify lane count. */
+ switch (dp->lanes) {
+ case 1:
+ case 2:
+ case 4:
+ /* valid lane count. */
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ /* Check against actual number of PHY's lanes. */
+ if (dp->lanes > cdns_phy->num_lanes)
+ return -EINVAL;
+
+ /*
+ * If changing voltages is required, check swing and pre-emphasis
+ * levels, per-lane.
+ */
+ if (dp->set_voltages) {
+ /* Lane count verified previously. */
+ for (i = 0; i < dp->lanes; i++) {
+ if (dp->voltage[i] > 3 || dp->pre[i] > 3)
+ return -EINVAL;
+
+ /* Sum of voltage swing and pre-emphasis levels cannot
+ * exceed 3.
+ */
+ if (dp->voltage[i] + dp->pre[i] > 3)
+ return -EINVAL;
+ }
+ }
+
+ return 0;
+}
+
/* Set power state A0 and PLL clock enable to 0 on enabled lanes. */
static void cdns_torrent_dp_set_a0_pll(struct cdns_torrent_phy *cdns_phy,
u32 num_lanes)
@@ -257,6 +516,171 @@ static void cdns_torrent_dp_set_a0_pll(struct cdns_torrent_phy *cdns_phy,
cdns_torrent_dp_write(cdns_phy, PHY_PMA_XCVR_PLLCLK_EN, pll_clk_en);
}

+/* Configure lane count as required. */
+static int cdns_torrent_dp_set_lanes(struct cdns_torrent_phy *cdns_phy,
+ struct phy_configure_opts_dp *dp)
+{
+ u32 value;
+ u32 ret;
+ u8 lane_mask = (1 << dp->lanes) - 1;
+
+ value = cdns_torrent_dp_read(cdns_phy, PHY_RESET);
+ /* clear pma_tx_elec_idle_ln_* bits. */
+ value &= ~PMA_TX_ELEC_IDLE_MASK;
+ /* Assert pma_tx_elec_idle_ln_* for disabled lanes. */
+ value |= ((~lane_mask) << PMA_TX_ELEC_IDLE_SHIFT) &
+ PMA_TX_ELEC_IDLE_MASK;
+ cdns_torrent_dp_write(cdns_phy, PHY_RESET, value);
+
+ /* reset the link by asserting phy_l00_reset_n low */
+ cdns_torrent_dp_write(cdns_phy, PHY_RESET,
+ value & (~PHY_L00_RESET_N_MASK));
+
+ /*
+ * Assert lane reset on unused lanes and lane 0 so they remain in reset
+ * and powered down when re-enabling the link
+ */
+ value = (value & 0x0000FFF0) | (0x0000000E & lane_mask);
+ cdns_torrent_dp_write(cdns_phy, PHY_RESET, value);
+
+ cdns_torrent_dp_set_a0_pll(cdns_phy, dp->lanes);
+
+ /* release phy_l0*_reset_n based on used laneCount */
+ value = (value & 0x0000FFF0) | (0x0000000F & lane_mask);
+ cdns_torrent_dp_write(cdns_phy, PHY_RESET, value);
+
+ /* Wait, until PHY gets ready after releasing PHY reset signal. */
+ ret = cdns_torrent_dp_wait_pma_cmn_ready(cdns_phy);
+ if (ret)
+ return ret;
+
+ ndelay(100);
+
+ /* release pma_xcvr_pllclk_en_ln_*, only for the master lane */
+ cdns_torrent_dp_write(cdns_phy, PHY_PMA_XCVR_PLLCLK_EN, 0x0001);
+
+ ret = cdns_torrent_dp_run(cdns_phy);
+
+ return ret;
+}
+
+/* Configure link rate as required. */
+static int cdns_torrent_dp_set_rate(struct cdns_torrent_phy *cdns_phy,
+ struct phy_configure_opts_dp *dp)
+{
+ u32 ret;
+
+ ret = cdns_torrent_dp_set_power_state(cdns_phy, dp->lanes,
+ POWERSTATE_A3);
+ if (ret)
+ return ret;
+ ret = cdns_torrent_dp_set_pll_en(cdns_phy, dp, false);
+ if (ret)
+ return ret;
+ ndelay(200);
+
+ ret = cdns_torrent_dp_configure_rate(cdns_phy, dp);
+ if (ret)
+ return ret;
+ ndelay(200);
+
+ ret = cdns_torrent_dp_set_pll_en(cdns_phy, dp, true);
+ if (ret)
+ return ret;
+ ret = cdns_torrent_dp_set_power_state(cdns_phy, dp->lanes,
+ POWERSTATE_A2);
+ if (ret)
+ return ret;
+ ret = cdns_torrent_dp_set_power_state(cdns_phy, dp->lanes,
+ POWERSTATE_A0);
+ if (ret)
+ return ret;
+ ndelay(900);
+
+ return ret;
+}
+
+/* Configure voltage swing and pre-emphasis for all enabled lanes. */
+static void cdns_torrent_dp_set_voltages(struct cdns_torrent_phy *cdns_phy,
+ struct phy_configure_opts_dp *dp)
+{
+ u8 lane;
+ u16 val;
+ unsigned int lane_bits;
+
+ for (lane = 0; lane < dp->lanes; lane++) {
+ lane_bits = (lane & LANE_MASK) << 11;
+
+ val = cdns_torrent_phy_read(cdns_phy,
+ (TX_DIAG_ACYA | lane_bits));
+ /*
+ * Write 1 to register bit TX_DIAG_ACYA[0] to freeze the
+ * current state of the analog TX driver.
+ */
+ val |= TX_DIAG_ACYA_HBDC_MASK;
+ cdns_torrent_phy_write(cdns_phy,
+ (TX_DIAG_ACYA | lane_bits), val);
+
+ cdns_torrent_phy_write(cdns_phy,
+ (TX_TXCC_CTRL | lane_bits), 0x08A4);
+ val = vltg_coeff[dp->voltage[lane]][dp->pre[lane]].diag_tx_drv;
+ cdns_torrent_phy_write(cdns_phy,
+ (DRV_DIAG_TX_DRV | lane_bits), val);
+ val = vltg_coeff[dp->voltage[lane]][dp->pre[lane]].mgnfs_mult;
+ cdns_torrent_phy_write(cdns_phy,
+ (TX_TXCC_MGNFS_MULT_000 | lane_bits),
+ val);
+ val = vltg_coeff[dp->voltage[lane]][dp->pre[lane]].cpost_mult;
+ cdns_torrent_phy_write(cdns_phy,
+ (TX_TXCC_CPOST_MULT_00 | lane_bits),
+ val);
+
+ val = cdns_torrent_phy_read(cdns_phy,
+ (TX_DIAG_ACYA | lane_bits));
+ /*
+ * Write 0 to register bit TX_DIAG_ACYA[0] to allow the state of
+ * analog TX driver to reflect the new programmed one.
+ */
+ val &= ~TX_DIAG_ACYA_HBDC_MASK;
+ cdns_torrent_phy_write(cdns_phy,
+ (TX_DIAG_ACYA | lane_bits), val);
+ }
+};
+
+static int cdns_torrent_dp_configure(struct phy *phy,
+ union phy_configure_opts *opts)
+{
+ struct cdns_torrent_phy *cdns_phy = phy_get_drvdata(phy);
+ int ret;
+
+ ret = cdns_torrent_dp_verify_config(cdns_phy, &opts->dp);
+ if (ret) {
+ dev_err(&phy->dev, "invalid params for phy configure\n");
+ return ret;
+ }
+
+ if (opts->dp.set_lanes) {
+ ret = cdns_torrent_dp_set_lanes(cdns_phy, &opts->dp);
+ if (ret) {
+ dev_err(&phy->dev, "cdns_torrent_dp_set_lanes failed\n");
+ return ret;
+ }
+ }
+
+ if (opts->dp.set_rate) {
+ ret = cdns_torrent_dp_set_rate(cdns_phy, &opts->dp);
+ if (ret) {
+ dev_err(&phy->dev, "cdns_torrent_dp_set_rate failed\n");
+ return ret;
+ }
+ }
+
+ if (opts->dp.set_voltages)
+ cdns_torrent_dp_set_voltages(cdns_phy, &opts->dp);
+
+ return ret;
+}
+
static int cdns_torrent_dp_init(struct phy *phy)
{
unsigned char lane_bits;
--
2.7.4
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