pinctrl: tegra: clear park bit for all pins

Parking bits might not be cleared by the bootloader properly (if for
instance it doesn't use the device configured by that pin). Clear
the park bits for all the pins during pinctrl probe.

This is present on T210 platforms but not earlier ones, so for earlier
generations, set parked_reg = -1 to disable.

The park bit is used to prevent glitching when reprogramming pinctrl
registers.

Based on work by:
Shravani Dingari <shravanid@nvidia.com>

Signed-off-by: Rhyland Klein <rklein@nvidia.com>
Acked-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/tegra/pinctrl-tegra.c

@@ -625,6 +625,22 @@ static struct pinctrl_desc tegra_pinctrl_desc = {
 	.owner = THIS_MODULE,
 };
 
+static void tegra_pinctrl_clear_parked_bits(struct tegra_pmx *pmx)
+{
+	int i = 0;
+	const struct tegra_pingroup *g;
+	u32 val;
+
+	for (i = 0; i < pmx->soc->ngroups; ++i) {
+		if (pmx->soc->groups[i].parked_reg >= 0) {
+			g = &pmx->soc->groups[i];
+			val = pmx_readl(pmx, g->parked_bank, g->parked_reg);
+			val &= ~(1 << g->parked_bit);
+			pmx_writel(pmx, val, g->parked_bank, g->parked_reg);
+		}
+	}
+}
+
 static bool gpio_node_has_range(void)
 {
 	struct device_node *np;
@@ -725,6 +741,8 @@ int tegra_pinctrl_probe(struct platform_device *pdev,
 		return PTR_ERR(pmx->pctl);
 	}
 
+	tegra_pinctrl_clear_parked_bits(pmx);
+
 	if (!gpio_node_has_range())
 		pinctrl_add_gpio_range(pmx->pctl, &tegra_pinctrl_gpio_range);
 

drivers/pinctrl/tegra/pinctrl-tegra.h

@@ -93,6 +93,9 @@ struct tegra_function {
  * @tri_reg:		Tri-state register offset.
  * @tri_bank:		Tri-state register bank.
  * @tri_bit:		Tri-state register bit.
+ * @parked_reg:		Parked register offset. -1 if unsupported.
+ * @parked_bank:	Parked register bank. 0 if unsupported.
+ * @parked_bit:		Parked register bit. 0 if unsupported.
  * @einput_bit:		Enable-input register bit.
  * @odrain_bit:		Open-drain register bit.
  * @lock_bit:		Lock register bit.
@@ -135,13 +138,16 @@ struct tegra_pingroup {
 	s16 pupd_reg;
 	s16 tri_reg;
 	s16 drv_reg;
+	s16 parked_reg;
 	u32 mux_bank:2;
 	u32 pupd_bank:2;
 	u32 tri_bank:2;
 	u32 drv_bank:2;
+	u32 parked_bank:2;
 	s32 mux_bit:6;
 	s32 pupd_bit:6;
 	s32 tri_bit:6;
+	s32 parked_bit:6;
 	s32 einput_bit:6;
 	s32 odrain_bit:6;
 	s32 lock_bit:6;

drivers/pinctrl/tegra/pinctrl-tegra114.c

@@ -1578,6 +1578,7 @@ static struct tegra_function tegra114_functions[] = {
 		.lock_bit = 7,						\
 		.ioreset_bit = PINGROUP_BIT_##ior(8),			\
 		.rcv_sel_bit = PINGROUP_BIT_##rcv_sel(9),		\
+		.parked_reg = -1,					\
 		.drv_reg = -1,						\
 	}
 
@@ -1598,6 +1599,7 @@ static struct tegra_function tegra114_functions[] = {
 		.rcv_sel_bit = -1,					\
 		.drv_reg = DRV_PINGROUP_REG(r),				\
 		.drv_bank = 0,						\
+		.parked_reg = -1,					\
 		.hsm_bit = hsm_b,					\
 		.schmitt_bit = schmitt_b,				\
 		.lpmd_bit = lpmd_b,					\

drivers/pinctrl/tegra/pinctrl-tegra124.c

@@ -1747,6 +1747,7 @@ static struct tegra_function tegra124_functions[] = {
 		.lock_bit = 7,						\
 		.ioreset_bit = PINGROUP_BIT_##ior(8),			\
 		.rcv_sel_bit = PINGROUP_BIT_##rcv_sel(9),		\
+		.parked_reg = -1,					\
 		.drv_reg = -1,						\
 	}
 
@@ -1767,6 +1768,7 @@ static struct tegra_function tegra124_functions[] = {
 		.rcv_sel_bit = -1,					\
 		.drv_reg = DRV_PINGROUP_REG(r),				\
 		.drv_bank = 0,						\
+		.parked_reg = -1,					\
 		.hsm_bit = hsm_b,					\
 		.schmitt_bit = schmitt_b,				\
 		.lpmd_bit = lpmd_b,					\

drivers/pinctrl/tegra/pinctrl-tegra20.c

@@ -1994,6 +1994,7 @@ static struct tegra_function tegra20_functions[] = {
 		.tri_reg = ((tri_r) - TRISTATE_REG_A),		\
 		.tri_bank = 0,					\
 		.tri_bit = tri_b,				\
+		.parked_reg = -1,				\
 		.einput_bit = -1,				\
 		.odrain_bit = -1,				\
 		.lock_bit = -1,					\
@@ -2013,6 +2014,7 @@ static struct tegra_function tegra20_functions[] = {
 		.pupd_bank = 2,					\
 		.pupd_bit = pupd_b,				\
 		.drv_reg = -1,					\
+		.parked_reg = -1,				\
 	}
 
 /* Pin groups for drive strength registers (configurable version) */
@@ -2028,6 +2030,7 @@ static struct tegra_function tegra20_functions[] = {
 		.tri_reg = -1,					\
 		.drv_reg = ((r) - PINGROUP_REG_A),		\
 		.drv_bank = 3,					\
+		.parked_reg = -1,				\
 		.hsm_bit = hsm_b,				\
 		.schmitt_bit = schmitt_b,			\
 		.lpmd_bit = lpmd_b,				\

drivers/pinctrl/tegra/pinctrl-tegra210.c

@@ -1310,6 +1310,9 @@ static struct tegra_function tegra210_functions[] = {
 		.lock_bit = 7,						\
 		.ioreset_bit = -1,					\
 		.rcv_sel_bit = PINGROUP_BIT_##e_io_hv(10),		\
+		.parked_reg = PINGROUP_REG(r),				\
+		.parked_bank = 1,					\
+		.parked_bit = 5,					\
 		.hsm_bit = PINGROUP_BIT_##hsm(9),			\
 		.schmitt_bit = 12,					\
 		.drvtype_bit = PINGROUP_BIT_##drvtype(13),		\
@@ -1342,6 +1345,7 @@ static struct tegra_function tegra210_functions[] = {
 		.rcv_sel_bit = -1,					\
 		.drv_reg = DRV_PINGROUP_REG(r),				\
 		.drv_bank = 0,						\
+		.parked_reg = -1,					\
 		.hsm_bit = -1,						\
 		.schmitt_bit = -1,					\
 		.lpmd_bit = -1,						\

drivers/pinctrl/tegra/pinctrl-tegra30.c

@@ -2139,6 +2139,7 @@ static struct tegra_function tegra30_functions[] = {
 		.lock_bit = 7,						\
 		.ioreset_bit = PINGROUP_BIT_##ior(8),			\
 		.rcv_sel_bit = -1,					\
+		.parked_reg = -1,					\
 		.drv_reg = -1,						\
 	}
 
@@ -2159,6 +2160,7 @@ static struct tegra_function tegra30_functions[] = {
 		.rcv_sel_bit = -1,					\
 		.drv_reg = DRV_PINGROUP_REG(r),				\
 		.drv_bank = 0,						\
+		.parked_reg = -1,					\
 		.hsm_bit = hsm_b,					\
 		.schmitt_bit = schmitt_b,				\
 		.lpmd_bit = lpmd_b,					\