Add support for enabling a specifically requested number of lanes
in the .configure() callback and disable all lanes in power off
and reset callbacks for proper hardware cleanup.

Signed-off-by: AngeloGioacchino Del Regno 
<[email protected]>
---
 drivers/phy/mediatek/phy-mtk-dp.c | 75 ++++++++++++++++++++++++++++---
 1 file changed, 68 insertions(+), 7 deletions(-)

diff --git a/drivers/phy/mediatek/phy-mtk-dp.c 
b/drivers/phy/mediatek/phy-mtk-dp.c
index f6b0e83d4833..2c8bc0b37486 100644
--- a/drivers/phy/mediatek/phy-mtk-dp.c
+++ b/drivers/phy/mediatek/phy-mtk-dp.c
@@ -10,6 +10,7 @@
  *                     AngeloGioacchino Del Regno 
<[email protected]>
  */
 
+#include <linux/bitfield.h>
 #include <linux/delay.h>
 #include <linux/io.h>
 #include <linux/mfd/syscon.h>
@@ -50,6 +51,9 @@
 #define DRIVING_PARAM_1_DEFAULT        0x0
 #define DRIVING_PARAM_2_DEFAULT        0x0
 
+/* DP_PHYD_TX_CTL_0 */
+#define PHYD_TX_LN_EN                  GENMASK(7, 4)
+
 #define XTP_LN_TX_LCTXC0_SW0_PRE0_DEFAULT      BIT(4)
 #define XTP_LN_TX_LCTXC0_SW0_PRE1_DEFAULT      (BIT(10) | BIT(12))
 #define XTP_LN_TX_LCTXC0_SW0_PRE2_DEFAULT      GENMASK(20, 19)
@@ -113,6 +117,7 @@ enum mtk_dp_phyd_dig_glb_regidx {
        DP_PHYD_SW_RST,
        DP_PHYD_BIT_RATE,
        DP_PHYD_AUX_RX_CTL,
+       DP_PHYD_TX_CTL_0,
        DP_PHYD_GLOBAL_MAX
 };
 
@@ -131,6 +136,7 @@ static const u8 mt8195_phy_dig_glb_regs[DP_PHYD_GLOBAL_MAX] 
= {
        [DP_PHYD_SW_RST] = 0x38,
        [DP_PHYD_BIT_RATE] = 0x3c,
        [DP_PHYD_AUX_RX_CTL] = 0x40,
+       [DP_PHYD_TX_CTL_0] = 0x44,
 };
 
 /**
@@ -200,6 +206,7 @@ static int mtk_dp_phy_configure(struct phy *phy, union 
phy_configure_opts *opts)
        struct mtk_dp_phy *dp_phy = phy_get_drvdata(phy);
        const struct mtk_dp_phy_pdata *pdata = dp_phy->pdata;
        u32 val;
+       int i;
 
        if (opts->dp.set_rate) {
                const u32 reg_bit_rate = pdata->regs_dig_glb[DP_PHYD_BIT_RATE];
@@ -226,6 +233,17 @@ static int mtk_dp_phy_configure(struct phy *phy, union 
phy_configure_opts *opts)
                regmap_write(dp_phy->regmap, pdata->off_dig_glb + reg_bit_rate, 
val);
        }
 
+       if (opts->dp.set_lanes) {
+               const u32 reg_dig_tx_ctl = 
pdata->regs_dig_glb[DP_PHYD_TX_CTL_0];
+
+               val = 0;
+               for (i = 0; i < opts->dp.lanes; i++)
+                       val |= FIELD_PREP(PHYD_TX_LN_EN, BIT(i));
+
+               regmap_update_bits(dp_phy->regmap, pdata->off_dig_glb + 
reg_dig_tx_ctl,
+                                  PHYD_TX_LN_EN, val);
+       }
+
        regmap_update_bits(dp_phy->regmap,
                           pdata->off_dig_glb + 
pdata->regs_dig_glb[DP_PHYD_PLL_CTL_1],
                           TPLL_SSC_EN, opts->dp.ssc ? TPLL_SSC_EN : 0);
@@ -263,31 +281,68 @@ static int mtk_dp_phy_power_on(struct phy *phy)
        return 0;
 }
 
+static int mtk_dp_phy_disable_all_lanes(struct mtk_dp_phy *dp_phy)
+{
+       const struct mtk_dp_phy_pdata *pdata = dp_phy->pdata;
+       const u8 *regs = pdata->regs_dig_glb;
+       int ret;
+       u32 val;
+
+       ret = regmap_read(dp_phy->regmap, pdata->off_dig_glb + 
regs[DP_PHYD_TX_CTL_0], &val);
+       if (ret)
+               return ret;
+
+       /* Get mask of currently enabled lane */
+       val = FIELD_GET(PHYD_TX_LN_EN, val);
+       if (val == 0)
+               return 0;
+
+       /* Disable all lanes (needs to be done one by one, from last to first) 
*/
+       do {
+               u32 lane_num = fls(val) - 1;
+               val &= ~BIT(lane_num);
+
+               ret = regmap_clear_bits(dp_phy->regmap,
+                                       pdata->off_dig_glb + 
regs[DP_PHYD_TX_CTL_0],
+                                       FIELD_PREP(PHYD_TX_LN_EN, 
BIT(lane_num)));
+               if (ret)
+                       return ret;
+       } while (val);
+
+       return 0;
+}
+
 static int mtk_dp_phy_power_off(struct phy *phy)
 {
        struct mtk_dp_phy *dp_phy = phy_get_drvdata(phy);
        const struct mtk_dp_phy_pdata *pdata = dp_phy->pdata;
        const u8 *regs_dig = pdata->regs_dig_glb;
        const u8 *regs_ana = pdata->regs_ana_glb;
-       int ret_cktx, ret_aux;
+       int ret_cktx, ret_aux, ret;
 
        ret_cktx = regmap_set_bits(dp_phy->regmap,
                                   pdata->off_ana_glb + 
regs_ana[DP_PHYA_GLB_FORCE_CTRL_1],
                                   CKM_CKTX0_EN_FORCE_MODE);
+       if (ret_cktx)
+               dev_err(&phy->dev, "Could not disable CKTX0: %d\n", ret_cktx);
 
        /* Disable RX unconditionally */
        ret_aux = regmap_write(dp_phy->regmap,
                               pdata->off_dig_glb + 
regs_dig[DP_PHYD_AUX_RX_CTL], 0);
-       if (ret_aux) {
+       if (ret_aux)
                dev_err(&phy->dev, "Could not disable AUX RX: %d\n", ret_aux);
-               return ret_aux;
+
+       ret = mtk_dp_phy_disable_all_lanes(dp_phy);
+       if (ret) {
+               dev_err(dp_phy->dev, "Could not disable lanes for poweroff!\n");
+               return ret;
        }
 
-       /* Still fail if CKTX0_EN was not disabled, but at least AUX is off */
-       if (ret_cktx) {
-               dev_err(&phy->dev, "Could not disable CKTX0: %d\n", ret_cktx);
+       /* Still return a failure if any of CKTX or AUX could not disable */
+       if (ret_cktx)
                return ret_cktx;
-       }
+       if (ret_aux)
+               return ret_aux;
 
        return 0;
 }
@@ -297,6 +352,7 @@ static int mtk_dp_phy_reset(struct phy *phy)
        struct mtk_dp_phy *dp_phy = phy_get_drvdata(phy);
        const struct mtk_dp_phy_pdata *pdata = dp_phy->pdata;
        const u32 reg_rst = pdata->regs_dig_glb[DP_PHYD_SW_RST];
+       int ret;
 
        /* Clearing bits sets reset state */
        regmap_clear_bits(dp_phy->regmap, pdata->off_dig_glb + reg_rst, 
DP_GLB_SW_RST_PHYD);
@@ -307,6 +363,11 @@ static int mtk_dp_phy_reset(struct phy *phy)
        /* Setting bits means go out of reset */
        regmap_set_bits(dp_phy->regmap, pdata->off_dig_glb + reg_rst, 
DP_GLB_SW_RST_PHYD);
 
+       /* Disable all lanes and continue reset even if this fails, but notify 
*/
+       ret = mtk_dp_phy_disable_all_lanes(dp_phy);
+       if (ret)
+               dev_err(dp_phy->dev, "Could not disable lanes during reset!\n");
+
        return 0;
 }
 
-- 
2.54.0

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