[PATCH v3 1/2] pinctrl: qcom: Add support for i2c specific pull feature

[Abel Vesa <abel.vesa@linaro.org>]

Add support for the new i2c_pull property introduced for SM8550 setting
a I2C specific pull mode on I2C able pins. Add the bit to the SM8550
specific driver while at it.

Co-developed-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Abel Vesa <abel.vesa@linaro.org>
---

The v2 of this specific patch is here:
https://lore.kernel.org/all/20221123152001.694546-4-abel.vesa@linaro.org/

Changes since v2:
 * This time, this patch is sent separate w.r.t. SM8550 pinctrl driver
 * The qcom,i2c-pull is dropped, bias-pull-up with value is used instead
 * Default value for i2c pull up is 2.2kOhms and since SM8550 is the
   first one to use it, we hard code it for now
 * changed the authorship as the implementation looks entirely different now

 drivers/pinctrl/qcom/pinctrl-msm.c    | 7 +++++++
 drivers/pinctrl/qcom/pinctrl-msm.h    | 1 +
 drivers/pinctrl/qcom/pinctrl-sm8550.c | 1 +
 3 files changed, 9 insertions(+)

diff --git a/drivers/pinctrl/qcom/pinctrl-msm.c b/drivers/pinctrl/qcom/pinctrl-msm.c
index 5142c363480a..510c964dd0f5 100644
--- a/drivers/pinctrl/qcom/pinctrl-msm.c
+++ b/drivers/pinctrl/qcom/pinctrl-msm.c
@@ -310,6 +310,8 @@ static int msm_config_reg(struct msm_pinctrl *pctrl,
 	case PIN_CONFIG_BIAS_PULL_UP:
 		*bit = g->pull_bit;
 		*mask = 3;
+		if (g->i2c_pull_bit)
+			*mask |= BIT(g->i2c_pull_bit) >> *bit;
 		break;
 	case PIN_CONFIG_DRIVE_OPEN_DRAIN:
 		*bit = g->od_bit;
@@ -336,6 +338,7 @@ static int msm_config_reg(struct msm_pinctrl *pctrl,
 #define MSM_KEEPER		2
 #define MSM_PULL_UP_NO_KEEPER	2
 #define MSM_PULL_UP		3
+#define MSM_I2C_STRONG_PULL_UP	2200
 
 static unsigned msm_regval_to_drive(u32 val)
 {
@@ -387,6 +390,8 @@ static int msm_config_group_get(struct pinctrl_dev *pctldev,
 	case PIN_CONFIG_BIAS_PULL_UP:
 		if (pctrl->soc->pull_no_keeper)
 			arg = arg == MSM_PULL_UP_NO_KEEPER;
+		else if (arg & BIT(g->i2c_pull_bit))
+			arg = MSM_I2C_STRONG_PULL_UP;
 		else
 			arg = arg == MSM_PULL_UP;
 		if (!arg)
@@ -467,6 +472,8 @@ static int msm_config_group_set(struct pinctrl_dev *pctldev,
 		case PIN_CONFIG_BIAS_PULL_UP:
 			if (pctrl->soc->pull_no_keeper)
 				arg = MSM_PULL_UP_NO_KEEPER;
+			else if (g->i2c_pull_bit && arg > 1)
+				arg = BIT(g->i2c_pull_bit) | MSM_PULL_UP;
 			else
 				arg = MSM_PULL_UP;
 			break;
diff --git a/drivers/pinctrl/qcom/pinctrl-msm.h b/drivers/pinctrl/qcom/pinctrl-msm.h
index 05a1209bf9ae..985eceda2517 100644
--- a/drivers/pinctrl/qcom/pinctrl-msm.h
+++ b/drivers/pinctrl/qcom/pinctrl-msm.h
@@ -80,6 +80,7 @@ struct msm_pingroup {
 
 	unsigned pull_bit:5;
 	unsigned drv_bit:5;
+	unsigned i2c_pull_bit:5;
 
 	unsigned od_bit:5;
 	unsigned egpio_enable:5;
diff --git a/drivers/pinctrl/qcom/pinctrl-sm8550.c b/drivers/pinctrl/qcom/pinctrl-sm8550.c
index 0b7db7d4054a..c9d038098f2c 100644
--- a/drivers/pinctrl/qcom/pinctrl-sm8550.c
+++ b/drivers/pinctrl/qcom/pinctrl-sm8550.c
@@ -47,6 +47,7 @@
 		.mux_bit = 2,			\
 		.pull_bit = 0,			\
 		.drv_bit = 6,			\
+		.i2c_pull_bit = 13,		\
 		.egpio_enable = 12,		\
 		.egpio_present = 11,		\
 		.oe_bit = 9,			\
-- 
2.34.1