[PATCH V3 0/4] gpio: tegra: Cleanups and support fro debounce

[PATCH V3 0/4] gpio: tegra: Cleanups and support fro debounce

[Laxman Dewangan]

Add support for the debounce as Tegra210 support debounce in HW.
Also do the clenaups to remove all global variables.

Laxman Dewangan (4):
  gpio: tegra: Don't open code of_device_get_match_data()
  gpio: tegra: Make of_device_id compatible data to constant
  gpio: tegra: Get rid of all file scoped global variables
  gpio: tegra: Add support for gpio debounce

 drivers/gpio/gpio-tegra.c | 407 +++++++++++++++++++++++++++++-----------------
 1 file changed, 261 insertions(+), 146 deletions(-)

-- 
2.1.4

[PATCH V3 1/4] gpio: tegra: Don't open code of_device_get_match_data()

[Laxman Dewangan]

Use of_device_get_match_data() for getting matched data
instead of implementing this locally.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Reviewed-by: Stephen Warren <swarren@nvidia.com>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Acked-by: Thierry Reding <treding@nvidia.com>

---
Collected reviewed/ack by from Stephen, Alexandre and Thieery.
---
 drivers/gpio/gpio-tegra.c | 50 +++++++++++++++++++++++------------------------
 1 file changed, 24 insertions(+), 26 deletions(-)

diff --git a/drivers/gpio/gpio-tegra.c b/drivers/gpio/gpio-tegra.c
index 790bb11..1b0c497 100644
--- a/drivers/gpio/gpio-tegra.c
+++ b/drivers/gpio/gpio-tegra.c
@@ -75,6 +75,11 @@ struct tegra_gpio_bank {
 #endif
 };
 
+struct tegra_gpio_soc_config {
+	u32 bank_stride;
+	u32 upper_offset;
+};
+
 static struct device *dev;
 static struct irq_domain *irq_domain;
 static void __iomem *regs;
@@ -445,27 +450,6 @@ static const struct dev_pm_ops tegra_gpio_pm_ops = {
 	SET_SYSTEM_SLEEP_PM_OPS(tegra_gpio_suspend, tegra_gpio_resume)
 };
 
-struct tegra_gpio_soc_config {
-	u32 bank_stride;
-	u32 upper_offset;
-};
-
-static struct tegra_gpio_soc_config tegra20_gpio_config = {
-	.bank_stride = 0x80,
-	.upper_offset = 0x800,
-};
-
-static struct tegra_gpio_soc_config tegra30_gpio_config = {
-	.bank_stride = 0x100,
-	.upper_offset = 0x80,
-};
-
-static const struct of_device_id tegra_gpio_of_match[] = {
-	{ .compatible = "nvidia,tegra30-gpio", .data = &tegra30_gpio_config },
-	{ .compatible = "nvidia,tegra20-gpio", .data = &tegra20_gpio_config },
-	{ },
-};
-
 /* This lock class tells lockdep that GPIO irqs are in a different
  * category than their parents, so it won't report false recursion.
  */
@@ -473,8 +457,7 @@ static struct lock_class_key gpio_lock_class;
 
 static int tegra_gpio_probe(struct platform_device *pdev)
 {
-	const struct of_device_id *match;
-	struct tegra_gpio_soc_config *config;
+	const struct tegra_gpio_soc_config *config;
 	struct resource *res;
 	struct tegra_gpio_bank *bank;
 	int ret;
@@ -484,12 +467,11 @@ static int tegra_gpio_probe(struct platform_device *pdev)
 
 	dev = &pdev->dev;
 
-	match = of_match_device(tegra_gpio_of_match, &pdev->dev);
-	if (!match) {
+	config = of_device_get_match_data(&pdev->dev);
+	if (!config) {
 		dev_err(&pdev->dev, "Error: No device match found\n");
 		return -ENODEV;
 	}
-	config = (struct tegra_gpio_soc_config *)match->data;
 
 	tegra_gpio_bank_stride = config->bank_stride;
 	tegra_gpio_upper_offset = config->upper_offset;
@@ -578,6 +560,22 @@ static int tegra_gpio_probe(struct platform_device *pdev)
 	return 0;
 }
 
+static struct tegra_gpio_soc_config tegra20_gpio_config = {
+	.bank_stride = 0x80,
+	.upper_offset = 0x800,
+};
+
+static struct tegra_gpio_soc_config tegra30_gpio_config = {
+	.bank_stride = 0x100,
+	.upper_offset = 0x80,
+};
+
+static const struct of_device_id tegra_gpio_of_match[] = {
+	{ .compatible = "nvidia,tegra30-gpio", .data = &tegra30_gpio_config },
+	{ .compatible = "nvidia,tegra20-gpio", .data = &tegra20_gpio_config },
+	{ },
+};
+
 static struct platform_driver tegra_gpio_driver = {
 	.driver		= {
 		.name	= "tegra-gpio",
-- 
2.1.4

[PATCH V3 2/4] gpio: tegra: Make of_device_id compatible data to constant

[Laxman Dewangan]

The data member of the of_device_id is the constant type
and hence all static structure which is used for this
initialisation as static.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Suggested-by: Thierry Reding <treding@nvidia.com>

---
Changes from V2:
-This is new in series based on discussion on previous patches.
---
 drivers/gpio/gpio-tegra.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/gpio/gpio-tegra.c b/drivers/gpio/gpio-tegra.c
index 1b0c497..cd69422 100644
--- a/drivers/gpio/gpio-tegra.c
+++ b/drivers/gpio/gpio-tegra.c
@@ -560,12 +560,12 @@ static int tegra_gpio_probe(struct platform_device *pdev)
 	return 0;
 }
 
-static struct tegra_gpio_soc_config tegra20_gpio_config = {
+static const struct tegra_gpio_soc_config tegra20_gpio_config = {
 	.bank_stride = 0x80,
 	.upper_offset = 0x800,
 };
 
-static struct tegra_gpio_soc_config tegra30_gpio_config = {
+static const struct tegra_gpio_soc_config tegra30_gpio_config = {
 	.bank_stride = 0x100,
 	.upper_offset = 0x80,
 };
-- 
2.1.4

Re: [PATCH V3 2/4] gpio: tegra: Make of_device_id compatible data to constant

[Stephen Warren]

On 04/20/2016 07:30 AM, Laxman Dewangan wrote:
> The data member of the of_device_id is the constant type
> and hence all static structure which is used for this
> initialisation as static.

Reviewed-by: Stephen Warren <swarren@nvidia.com>

[PATCH V3 3/4] gpio: tegra: Get rid of all file scoped global variables

[Laxman Dewangan]

Move the file scoped multiple global variable from Tegra GPIO
driver to the structure and make this as gpiochip data which
can be referred from GPIO chip callbacks.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>

---
This patch is reworked on top of earlier patch
gpio: tegra: Remove the need of keeping device handle for gpio driver

There was review comment that we should get for all variable and hence
this is outcome of the discussion.
---
 drivers/gpio/gpio-tegra.c | 299 +++++++++++++++++++++++++++-------------------
 1 file changed, 179 insertions(+), 120 deletions(-)

diff --git a/drivers/gpio/gpio-tegra.c b/drivers/gpio/gpio-tegra.c
index cd69422..36e865f 100644
--- a/drivers/gpio/gpio-tegra.c
+++ b/drivers/gpio/gpio-tegra.c
@@ -35,24 +35,26 @@
 #define GPIO_PORT(x)		(((x) >> 3) & 0x3)
 #define GPIO_BIT(x)		((x) & 0x7)
 
-#define GPIO_REG(x)		(GPIO_BANK(x) * tegra_gpio_bank_stride + \
+#define GPIO_REG(tgi, x)	(GPIO_BANK(x) * tgi->soc->bank_stride + \
 					GPIO_PORT(x) * 4)
 
-#define GPIO_CNF(x)		(GPIO_REG(x) + 0x00)
-#define GPIO_OE(x)		(GPIO_REG(x) + 0x10)
-#define GPIO_OUT(x)		(GPIO_REG(x) + 0X20)
-#define GPIO_IN(x)		(GPIO_REG(x) + 0x30)
-#define GPIO_INT_STA(x)		(GPIO_REG(x) + 0x40)
-#define GPIO_INT_ENB(x)		(GPIO_REG(x) + 0x50)
-#define GPIO_INT_LVL(x)		(GPIO_REG(x) + 0x60)
-#define GPIO_INT_CLR(x)		(GPIO_REG(x) + 0x70)
-
-#define GPIO_MSK_CNF(x)		(GPIO_REG(x) + tegra_gpio_upper_offset + 0x00)
-#define GPIO_MSK_OE(x)		(GPIO_REG(x) + tegra_gpio_upper_offset + 0x10)
-#define GPIO_MSK_OUT(x)		(GPIO_REG(x) + tegra_gpio_upper_offset + 0X20)
-#define GPIO_MSK_INT_STA(x)	(GPIO_REG(x) + tegra_gpio_upper_offset + 0x40)
-#define GPIO_MSK_INT_ENB(x)	(GPIO_REG(x) + tegra_gpio_upper_offset + 0x50)
-#define GPIO_MSK_INT_LVL(x)	(GPIO_REG(x) + tegra_gpio_upper_offset + 0x60)
+#define GPIO_CNF(t, x)		(GPIO_REG(t, x) + 0x00)
+#define GPIO_OE(t, x)		(GPIO_REG(t, x) + 0x10)
+#define GPIO_OUT(t, x)		(GPIO_REG(t, x) + 0X20)
+#define GPIO_IN(t, x)		(GPIO_REG(t, x) + 0x30)
+#define GPIO_INT_STA(t, x)	(GPIO_REG(t, x) + 0x40)
+#define GPIO_INT_ENB(t, x)	(GPIO_REG(t, x) + 0x50)
+#define GPIO_INT_LVL(t, x)	(GPIO_REG(t, x) + 0x60)
+#define GPIO_INT_CLR(t, x)	(GPIO_REG(t, x) + 0x70)
+#define GPIO_DBC_CNT(t, x)	(GPIO_REG(t, x) + 0xF0)
+
+#define GPIO_MSK_CNF(t, x)	(GPIO_REG(t, x) + t->soc->upper_offset + 0x00)
+#define GPIO_MSK_OE(t, x)	(GPIO_REG(t, x) + t->soc->upper_offset + 0x10)
+#define GPIO_MSK_OUT(t, x)	(GPIO_REG(t, x) + t->soc->upper_offset + 0X20)
+#define GPIO_MSK_INT_STA(t, x)	(GPIO_REG(t, x) + t->soc->upper_offset + 0x40)
+#define GPIO_MSK_INT_ENB(t, x)	(GPIO_REG(t, x) + t->soc->upper_offset + 0x50)
+#define GPIO_MSK_INT_LVL(t, x)	(GPIO_REG(t, x) + t->soc->upper_offset + 0x60)
+#define GPIO_MSK_DBC_EN(t, x)	(GPIO_REG(t, x) + t->soc->upper_offset + 0x30)
 
 #define GPIO_INT_LVL_MASK		0x010101
 #define GPIO_INT_LVL_EDGE_RISING	0x000101
@@ -61,6 +63,8 @@
 #define GPIO_INT_LVL_LEVEL_HIGH		0x000001
 #define GPIO_INT_LVL_LEVEL_LOW		0x000000
 
+struct tegra_gpio_info;
+
 struct tegra_gpio_bank {
 	int bank;
 	int irq;
@@ -73,6 +77,7 @@ struct tegra_gpio_bank {
 	u32 int_lvl[4];
 	u32 wake_enb[4];
 #endif
+	struct tegra_gpio_info *tgi;
 };
 
 struct tegra_gpio_soc_config {
@@ -80,22 +85,25 @@ struct tegra_gpio_soc_config {
 	u32 upper_offset;
 };
 
-static struct device *dev;
-static struct irq_domain *irq_domain;
-static void __iomem *regs;
-static u32 tegra_gpio_bank_count;
-static u32 tegra_gpio_bank_stride;
-static u32 tegra_gpio_upper_offset;
-static struct tegra_gpio_bank *tegra_gpio_banks;
+struct tegra_gpio_info {
+	struct device				*dev;
+	void __iomem				*regs;
+	struct irq_domain			*irq_domain;
+	struct tegra_gpio_bank			*bank_info;
+	const struct tegra_gpio_soc_config	*soc;
+	struct gpio_chip			*gc;
+	u32					bank_count;
+};
 
-static inline void tegra_gpio_writel(u32 val, u32 reg)
+static inline void tegra_gpio_writel(struct tegra_gpio_info *tgi,
+				     u32 val, u32 reg)
 {
-	__raw_writel(val, regs + reg);
+	__raw_writel(val, tgi->regs + reg);
 }
 
-static inline u32 tegra_gpio_readl(u32 reg)
+static inline u32 tegra_gpio_readl(struct tegra_gpio_info *tgi, u32 reg)
 {
-	return __raw_readl(regs + reg);
+	return __raw_readl(tgi->regs + reg);
 }
 
 static int tegra_gpio_compose(int bank, int port, int bit)
@@ -103,24 +111,25 @@ static int tegra_gpio_compose(int bank, int port, int bit)
 	return (bank << 5) | ((port & 0x3) << 3) | (bit & 0x7);
 }
 
-static void tegra_gpio_mask_write(u32 reg, int gpio, int value)
+static void tegra_gpio_mask_write(struct tegra_gpio_info *tgi, u32 reg,
+				  int gpio, int value)
 {
 	u32 val;
 
 	val = 0x100 << GPIO_BIT(gpio);
 	if (value)
 		val |= 1 << GPIO_BIT(gpio);
-	tegra_gpio_writel(val, reg);
+	tegra_gpio_writel(tgi, val, reg);
 }
 
-static void tegra_gpio_enable(int gpio)
+static void tegra_gpio_enable(struct tegra_gpio_info *tgi, int gpio)
 {
-	tegra_gpio_mask_write(GPIO_MSK_CNF(gpio), gpio, 1);
+	tegra_gpio_mask_write(tgi, GPIO_MSK_CNF(tgi, gpio), gpio, 1);
 }
 
-static void tegra_gpio_disable(int gpio)
+static void tegra_gpio_disable(struct tegra_gpio_info *tgi, int gpio)
 {
-	tegra_gpio_mask_write(GPIO_MSK_CNF(gpio), gpio, 0);
+	tegra_gpio_mask_write(tgi, GPIO_MSK_CNF(tgi, gpio), gpio, 0);
 }
 
 static int tegra_gpio_request(struct gpio_chip *chip, unsigned offset)
@@ -130,44 +139,56 @@ static int tegra_gpio_request(struct gpio_chip *chip, unsigned offset)
 
 static void tegra_gpio_free(struct gpio_chip *chip, unsigned offset)
 {
+	struct tegra_gpio_info *tgi = gpiochip_get_data(chip);
+
 	pinctrl_free_gpio(offset);
-	tegra_gpio_disable(offset);
+	tegra_gpio_disable(tgi, offset);
 }
 
 static void tegra_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
 {
-	tegra_gpio_mask_write(GPIO_MSK_OUT(offset), offset, value);
+	struct tegra_gpio_info *tgi = gpiochip_get_data(chip);
+
+	tegra_gpio_mask_write(tgi, GPIO_MSK_OUT(tgi, offset), offset, value);
 }
 
 static int tegra_gpio_get(struct gpio_chip *chip, unsigned offset)
 {
+	struct tegra_gpio_info *tgi = gpiochip_get_data(chip);
+	int bval = BIT(GPIO_BIT(offset));
+
 	/* If gpio is in output mode then read from the out value */
-	if ((tegra_gpio_readl(GPIO_OE(offset)) >> GPIO_BIT(offset)) & 1)
-		return (tegra_gpio_readl(GPIO_OUT(offset)) >>
-				GPIO_BIT(offset)) & 0x1;
+	if (tegra_gpio_readl(tgi, GPIO_OE(tgi, offset)) & bval)
+		return !!(tegra_gpio_readl(tgi, GPIO_OUT(tgi, offset)) & bval);
 
-	return (tegra_gpio_readl(GPIO_IN(offset)) >> GPIO_BIT(offset)) & 0x1;
+	return !!(tegra_gpio_readl(tgi, GPIO_IN(tgi, offset)) & bval);
 }
 
 static int tegra_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
 {
-	tegra_gpio_mask_write(GPIO_MSK_OE(offset), offset, 0);
-	tegra_gpio_enable(offset);
+	struct tegra_gpio_info *tgi = gpiochip_get_data(chip);
+
+	tegra_gpio_mask_write(tgi, GPIO_MSK_OE(tgi, offset), offset, 0);
+	tegra_gpio_enable(tgi, offset);
 	return 0;
 }
 
 static int tegra_gpio_direction_output(struct gpio_chip *chip, unsigned offset,
 					int value)
 {
+	struct tegra_gpio_info *tgi = gpiochip_get_data(chip);
+
 	tegra_gpio_set(chip, offset, value);
-	tegra_gpio_mask_write(GPIO_MSK_OE(offset), offset, 1);
-	tegra_gpio_enable(offset);
+	tegra_gpio_mask_write(tgi, GPIO_MSK_OE(tgi, offset), offset, 1);
+	tegra_gpio_enable(tgi, offset);
 	return 0;
 }
 
 static int tegra_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
 {
-	return irq_find_mapping(irq_domain, offset);
+	struct tegra_gpio_info *tgi = gpiochip_get_data(chip);
+
+	return irq_find_mapping(tgi->irq_domain, offset);
 }
 
 static struct gpio_chip tegra_gpio_chip = {
@@ -184,29 +205,36 @@ static struct gpio_chip tegra_gpio_chip = {
 
 static void tegra_gpio_irq_ack(struct irq_data *d)
 {
+	struct tegra_gpio_bank *bank = irq_data_get_irq_chip_data(d);
+	struct tegra_gpio_info *tgi = bank->tgi;
 	int gpio = d->hwirq;
 
-	tegra_gpio_writel(1 << GPIO_BIT(gpio), GPIO_INT_CLR(gpio));
+	tegra_gpio_writel(tgi, 1 << GPIO_BIT(gpio), GPIO_INT_CLR(tgi, gpio));
 }
 
 static void tegra_gpio_irq_mask(struct irq_data *d)
 {
+	struct tegra_gpio_bank *bank = irq_data_get_irq_chip_data(d);
+	struct tegra_gpio_info *tgi = bank->tgi;
 	int gpio = d->hwirq;
 
-	tegra_gpio_mask_write(GPIO_MSK_INT_ENB(gpio), gpio, 0);
+	tegra_gpio_mask_write(tgi, GPIO_MSK_INT_ENB(tgi, gpio), gpio, 0);
 }
 
 static void tegra_gpio_irq_unmask(struct irq_data *d)
 {
+	struct tegra_gpio_bank *bank = irq_data_get_irq_chip_data(d);
+	struct tegra_gpio_info *tgi = bank->tgi;
 	int gpio = d->hwirq;
 
-	tegra_gpio_mask_write(GPIO_MSK_INT_ENB(gpio), gpio, 1);
+	tegra_gpio_mask_write(tgi, GPIO_MSK_INT_ENB(tgi, gpio), gpio, 1);
 }
 
 static int tegra_gpio_irq_set_type(struct irq_data *d, unsigned int type)
 {
 	int gpio = d->hwirq;
 	struct tegra_gpio_bank *bank = irq_data_get_irq_chip_data(d);
+	struct tegra_gpio_info *tgi = bank->tgi;
 	int port = GPIO_PORT(gpio);
 	int lvl_type;
 	int val;
@@ -238,23 +266,24 @@ static int tegra_gpio_irq_set_type(struct irq_data *d, unsigned int type)
 		return -EINVAL;
 	}
 
-	ret = gpiochip_lock_as_irq(&tegra_gpio_chip, gpio);
+	ret = gpiochip_lock_as_irq(tgi->gc, gpio);
 	if (ret) {
-		dev_err(dev, "unable to lock Tegra GPIO %d as IRQ\n", gpio);
+		dev_err(tgi->dev,
+			"unable to lock Tegra GPIO %d as IRQ\n", gpio);
 		return ret;
 	}
 
 	spin_lock_irqsave(&bank->lvl_lock[port], flags);
 
-	val = tegra_gpio_readl(GPIO_INT_LVL(gpio));
+	val = tegra_gpio_readl(tgi, GPIO_INT_LVL(tgi, gpio));
 	val &= ~(GPIO_INT_LVL_MASK << GPIO_BIT(gpio));
 	val |= lvl_type << GPIO_BIT(gpio);
-	tegra_gpio_writel(val, GPIO_INT_LVL(gpio));
+	tegra_gpio_writel(tgi, val, GPIO_INT_LVL(tgi, gpio));
 
 	spin_unlock_irqrestore(&bank->lvl_lock[port], flags);
 
-	tegra_gpio_mask_write(GPIO_MSK_OE(gpio), gpio, 0);
-	tegra_gpio_enable(gpio);
+	tegra_gpio_mask_write(tgi, GPIO_MSK_OE(tgi, gpio), gpio, 0);
+	tegra_gpio_enable(tgi, gpio);
 
 	if (type & (IRQ_TYPE_LEVEL_LOW | IRQ_TYPE_LEVEL_HIGH))
 		irq_set_handler_locked(d, handle_level_irq);
@@ -266,9 +295,11 @@ static int tegra_gpio_irq_set_type(struct irq_data *d, unsigned int type)
 
 static void tegra_gpio_irq_shutdown(struct irq_data *d)
 {
+	struct tegra_gpio_bank *bank = irq_data_get_irq_chip_data(d);
+	struct tegra_gpio_info *tgi = bank->tgi;
 	int gpio = d->hwirq;
 
-	gpiochip_unlock_as_irq(&tegra_gpio_chip, gpio);
+	gpiochip_unlock_as_irq(tgi->gc, gpio);
 }
 
 static void tegra_gpio_irq_handler(struct irq_desc *desc)
@@ -276,19 +307,25 @@ static void tegra_gpio_irq_handler(struct irq_desc *desc)
 	int port;
 	int pin;
 	int unmasked = 0;
+	int gpio;
+	u32 lvl;
+	unsigned long sta;
 	struct irq_chip *chip = irq_desc_get_chip(desc);
 	struct tegra_gpio_bank *bank = irq_desc_get_handler_data(desc);
+	struct tegra_gpio_info *tgi = bank->tgi;
+
 
 	chained_irq_enter(chip, desc);
 
 	for (port = 0; port < 4; port++) {
-		int gpio = tegra_gpio_compose(bank->bank, port, 0);
-		unsigned long sta = tegra_gpio_readl(GPIO_INT_STA(gpio)) &
-			tegra_gpio_readl(GPIO_INT_ENB(gpio));
-		u32 lvl = tegra_gpio_readl(GPIO_INT_LVL(gpio));
+		gpio = tegra_gpio_compose(bank->bank, port, 0);
+		sta = tegra_gpio_readl(tgi, GPIO_INT_STA(tgi, gpio)) &
+			tegra_gpio_readl(tgi, GPIO_INT_ENB(tgi, gpio));
+		lvl = tegra_gpio_readl(tgi, GPIO_INT_LVL(tgi, gpio));
 
 		for_each_set_bit(pin, &sta, 8) {
-			tegra_gpio_writel(1 << pin, GPIO_INT_CLR(gpio));
+			tegra_gpio_writel(tgi, 1 << pin,
+					  GPIO_INT_CLR(tgi, gpio));
 
 			/* if gpio is edge triggered, clear condition
 			 * before executing the handler so that we don't
@@ -311,22 +348,29 @@ static void tegra_gpio_irq_handler(struct irq_desc *desc)
 #ifdef CONFIG_PM_SLEEP
 static int tegra_gpio_resume(struct device *dev)
 {
+	struct platform_device *pdev = to_platform_device(dev);
+	struct tegra_gpio_info *tgi = platform_get_drvdata(pdev);
 	unsigned long flags;
 	int b;
 	int p;
 
 	local_irq_save(flags);
 
-	for (b = 0; b < tegra_gpio_bank_count; b++) {
-		struct tegra_gpio_bank *bank = &tegra_gpio_banks[b];
+	for (b = 0; b < tgi->bank_count; b++) {
+		struct tegra_gpio_bank *bank = &tgi->bank_info[b];
 
 		for (p = 0; p < ARRAY_SIZE(bank->oe); p++) {
 			unsigned int gpio = (b<<5) | (p<<3);
-			tegra_gpio_writel(bank->cnf[p], GPIO_CNF(gpio));
-			tegra_gpio_writel(bank->out[p], GPIO_OUT(gpio));
-			tegra_gpio_writel(bank->oe[p], GPIO_OE(gpio));
-			tegra_gpio_writel(bank->int_lvl[p], GPIO_INT_LVL(gpio));
-			tegra_gpio_writel(bank->int_enb[p], GPIO_INT_ENB(gpio));
+			tegra_gpio_writel(tgi, bank->cnf[p],
+					  GPIO_CNF(tgi, gpio));
+			tegra_gpio_writel(tgi, bank->out[p],
+					  GPIO_OUT(tgi, gpio));
+			tegra_gpio_writel(tgi, bank->oe[p],
+					  GPIO_OE(tgi, gpio));
+			tegra_gpio_writel(tgi, bank->int_lvl[p],
+					  GPIO_INT_LVL(tgi, gpio));
+			tegra_gpio_writel(tgi, bank->int_enb[p],
+					  GPIO_INT_ENB(tgi, gpio));
 		}
 	}
 
@@ -336,25 +380,32 @@ static int tegra_gpio_resume(struct device *dev)
 
 static int tegra_gpio_suspend(struct device *dev)
 {
+	struct platform_device *pdev = to_platform_device(dev);
+	struct tegra_gpio_info *tgi = platform_get_drvdata(pdev);
 	unsigned long flags;
 	int b;
 	int p;
 
 	local_irq_save(flags);
-	for (b = 0; b < tegra_gpio_bank_count; b++) {
-		struct tegra_gpio_bank *bank = &tegra_gpio_banks[b];
+	for (b = 0; b < tgi->bank_count; b++) {
+		struct tegra_gpio_bank *bank = &tgi->bank_info[b];
 
 		for (p = 0; p < ARRAY_SIZE(bank->oe); p++) {
 			unsigned int gpio = (b<<5) | (p<<3);
-			bank->cnf[p] = tegra_gpio_readl(GPIO_CNF(gpio));
-			bank->out[p] = tegra_gpio_readl(GPIO_OUT(gpio));
-			bank->oe[p] = tegra_gpio_readl(GPIO_OE(gpio));
-			bank->int_enb[p] = tegra_gpio_readl(GPIO_INT_ENB(gpio));
-			bank->int_lvl[p] = tegra_gpio_readl(GPIO_INT_LVL(gpio));
+			bank->cnf[p] = tegra_gpio_readl(tgi,
+							GPIO_CNF(tgi, gpio));
+			bank->out[p] = tegra_gpio_readl(tgi,
+							GPIO_OUT(tgi, gpio));
+			bank->oe[p] = tegra_gpio_readl(tgi,
+						       GPIO_OE(tgi, gpio));
+			bank->int_enb[p] = tegra_gpio_readl(tgi,
+						GPIO_INT_ENB(tgi, gpio));
+			bank->int_lvl[p] = tegra_gpio_readl(tgi,
+						GPIO_INT_LVL(tgi, gpio));
 
 			/* Enable gpio irq for wake up source */
-			tegra_gpio_writel(bank->wake_enb[p],
-					  GPIO_INT_ENB(gpio));
+			tegra_gpio_writel(tgi, bank->wake_enb[p],
+					  GPIO_INT_ENB(tgi, gpio));
 		}
 	}
 	local_irq_restore(flags);
@@ -387,22 +438,23 @@ static int tegra_gpio_irq_set_wake(struct irq_data *d, unsigned int enable)
 
 static int dbg_gpio_show(struct seq_file *s, void *unused)
 {
+	struct tegra_gpio_info *tgi = s->private;
 	int i;
 	int j;
 
-	for (i = 0; i < tegra_gpio_bank_count; i++) {
+	for (i = 0; i < tgi->bank_count; i++) {
 		for (j = 0; j < 4; j++) {
 			int gpio = tegra_gpio_compose(i, j, 0);
 			seq_printf(s,
 				"%d:%d %02x %02x %02x %02x %02x %02x %06x\n",
 				i, j,
-				tegra_gpio_readl(GPIO_CNF(gpio)),
-				tegra_gpio_readl(GPIO_OE(gpio)),
-				tegra_gpio_readl(GPIO_OUT(gpio)),
-				tegra_gpio_readl(GPIO_IN(gpio)),
-				tegra_gpio_readl(GPIO_INT_STA(gpio)),
-				tegra_gpio_readl(GPIO_INT_ENB(gpio)),
-				tegra_gpio_readl(GPIO_INT_LVL(gpio)));
+				tegra_gpio_readl(tgi, GPIO_CNF(tgi, gpio)),
+				tegra_gpio_readl(tgi, GPIO_OE(tgi, gpio)),
+				tegra_gpio_readl(tgi, GPIO_OUT(tgi, gpio)),
+				tegra_gpio_readl(tgi, GPIO_IN(tgi, gpio)),
+				tegra_gpio_readl(tgi, GPIO_INT_STA(tgi, gpio)),
+				tegra_gpio_readl(tgi, GPIO_INT_ENB(tgi, gpio)),
+				tegra_gpio_readl(tgi, GPIO_INT_LVL(tgi, gpio)));
 		}
 	}
 	return 0;
@@ -410,7 +462,7 @@ static int dbg_gpio_show(struct seq_file *s, void *unused)
 
 static int dbg_gpio_open(struct inode *inode, struct file *file)
 {
-	return single_open(file, dbg_gpio_show, &inode->i_private);
+	return single_open(file, dbg_gpio_show, inode->i_private);
 }
 
 static const struct file_operations debug_fops = {
@@ -420,15 +472,15 @@ static const struct file_operations debug_fops = {
 	.release	= single_release,
 };
 
-static void tegra_gpio_debuginit(void)
+static void tegra_gpio_debuginit(struct tegra_gpio_info *tgi)
 {
 	(void) debugfs_create_file("tegra_gpio", S_IRUGO,
-					NULL, NULL, &debug_fops);
+					NULL, tgi, &debug_fops);
 }
 
 #else
 
-static inline void tegra_gpio_debuginit(void)
+static inline void tegra_gpio_debuginit(struct tegra_gpio_info *tgi)
 {
 }
 
@@ -458,6 +510,7 @@ static struct lock_class_key gpio_lock_class;
 static int tegra_gpio_probe(struct platform_device *pdev)
 {
 	const struct tegra_gpio_soc_config *config;
+	struct tegra_gpio_info *tgi;
 	struct resource *res;
 	struct tegra_gpio_bank *bank;
 	int ret;
@@ -465,79 +518,85 @@ static int tegra_gpio_probe(struct platform_device *pdev)
 	int i;
 	int j;
 
-	dev = &pdev->dev;
-
 	config = of_device_get_match_data(&pdev->dev);
 	if (!config) {
 		dev_err(&pdev->dev, "Error: No device match found\n");
 		return -ENODEV;
 	}
 
-	tegra_gpio_bank_stride = config->bank_stride;
-	tegra_gpio_upper_offset = config->upper_offset;
+	tgi = devm_kzalloc(&pdev->dev, sizeof(*tgi), GFP_KERNEL);
+	if (!tgi)
+		return -ENODEV;
+
+	tgi->soc = config;
+	tgi->dev = &pdev->dev;
 
 	for (;;) {
-		res = platform_get_resource(pdev, IORESOURCE_IRQ, tegra_gpio_bank_count);
+		res = platform_get_resource(pdev, IORESOURCE_IRQ,
+					    tgi->bank_count);
 		if (!res)
 			break;
-		tegra_gpio_bank_count++;
+		tgi->bank_count++;
 	}
-	if (!tegra_gpio_bank_count) {
+	if (!tgi->bank_count) {
 		dev_err(&pdev->dev, "Missing IRQ resource\n");
 		return -ENODEV;
 	}
 
-	tegra_gpio_chip.ngpio = tegra_gpio_bank_count * 32;
+	tgi->gc = &tegra_gpio_chip;
+	tgi->gc->ngpio = tgi->bank_count * 32;
+	tgi->gc->parent = &pdev->dev;
+	tgi->gc->of_node = pdev->dev.of_node;
 
-	tegra_gpio_banks = devm_kzalloc(&pdev->dev,
-			tegra_gpio_bank_count * sizeof(*tegra_gpio_banks),
-			GFP_KERNEL);
-	if (!tegra_gpio_banks)
+	platform_set_drvdata(pdev, tgi);
+
+	tgi->bank_info = devm_kzalloc(&pdev->dev, tgi->bank_count *
+				      sizeof(*tgi->bank_info), GFP_KERNEL);
+	if (!tgi->bank_info)
 		return -ENODEV;
 
-	irq_domain = irq_domain_add_linear(pdev->dev.of_node,
-					   tegra_gpio_chip.ngpio,
-					   &irq_domain_simple_ops, NULL);
-	if (!irq_domain)
+	tgi->irq_domain = irq_domain_add_linear(pdev->dev.of_node,
+						tgi->gc->ngpio,
+						&irq_domain_simple_ops, NULL);
+	if (!tgi->irq_domain)
 		return -ENODEV;
 
-	for (i = 0; i < tegra_gpio_bank_count; i++) {
+	for (i = 0; i < tgi->bank_count; i++) {
 		res = platform_get_resource(pdev, IORESOURCE_IRQ, i);
 		if (!res) {
 			dev_err(&pdev->dev, "Missing IRQ resource\n");
 			return -ENODEV;
 		}
 
-		bank = &tegra_gpio_banks[i];
+		bank = &tgi->bank_info[i];
 		bank->bank = i;
 		bank->irq = res->start;
+		bank->tgi = tgi;
 	}
 
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	regs = devm_ioremap_resource(&pdev->dev, res);
-	if (IS_ERR(regs))
-		return PTR_ERR(regs);
+	tgi->regs = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(tgi->regs))
+		return PTR_ERR(tgi->regs);
 
-	for (i = 0; i < tegra_gpio_bank_count; i++) {
+	for (i = 0; i < tgi->bank_count; i++) {
 		for (j = 0; j < 4; j++) {
 			int gpio = tegra_gpio_compose(i, j, 0);
-			tegra_gpio_writel(0x00, GPIO_INT_ENB(gpio));
+			tegra_gpio_writel(tgi, 0x00, GPIO_INT_ENB(tgi, gpio));
 		}
 	}
 
-	tegra_gpio_chip.of_node = pdev->dev.of_node;
-
-	ret = devm_gpiochip_add_data(&pdev->dev, &tegra_gpio_chip, NULL);
+	ret = devm_gpiochip_add_data(&pdev->dev, tgi->gc, tgi);
 	if (ret < 0) {
-		irq_domain_remove(irq_domain);
+		irq_domain_remove(tgi->irq_domain);
 		return ret;
 	}
 
-	for (gpio = 0; gpio < tegra_gpio_chip.ngpio; gpio++) {
-		int irq = irq_create_mapping(irq_domain, gpio);
+	for (gpio = 0; gpio < tgi->gc->ngpio; gpio++) {
+		int irq = irq_create_mapping(tgi->irq_domain, gpio);
 		/* No validity check; all Tegra GPIOs are valid IRQs */
 
-		bank = &tegra_gpio_banks[GPIO_BANK(gpio)];
+		bank = &tgi->bank_info[GPIO_BANK(gpio)];
 
 		irq_set_lockdep_class(irq, &gpio_lock_class);
 		irq_set_chip_data(irq, bank);
@@ -545,8 +604,8 @@ static int tegra_gpio_probe(struct platform_device *pdev)
 					 handle_simple_irq);
 	}
 
-	for (i = 0; i < tegra_gpio_bank_count; i++) {
-		bank = &tegra_gpio_banks[i];
+	for (i = 0; i < tgi->bank_count; i++) {
+		bank = &tgi->bank_info[i];
 
 		irq_set_chained_handler_and_data(bank->irq,
 						 tegra_gpio_irq_handler, bank);
@@ -555,7 +614,7 @@ static int tegra_gpio_probe(struct platform_device *pdev)
 			spin_lock_init(&bank->lvl_lock[j]);
 	}
 
-	tegra_gpio_debuginit();
+	tegra_gpio_debuginit(tgi);
 
 	return 0;
 }
-- 
2.1.4

Re: [PATCH V3 3/4] gpio: tegra: Get rid of all file scoped global variables

[Stephen Warren]

On 04/20/2016 07:30 AM, Laxman Dewangan wrote:
> Move the file scoped multiple global variable from Tegra GPIO
> driver to the structure and make this as gpiochip data which
> can be referred from GPIO chip callbacks.

> diff --git a/drivers/gpio/gpio-tegra.c b/drivers/gpio/gpio-tegra.c

> +#define GPIO_MSK_CNF(t, x)	(GPIO_REG(t, x) + t->soc->upper_offset + 0x00)
> +#define GPIO_MSK_OE(t, x)	(GPIO_REG(t, x) + t->soc->upper_offset + 0x10)
> +#define GPIO_MSK_OUT(t, x)	(GPIO_REG(t, x) + t->soc->upper_offset + 0X20)
> +#define GPIO_MSK_INT_STA(t, x)	(GPIO_REG(t, x) + t->soc->upper_offset + 0x40)
> +#define GPIO_MSK_INT_ENB(t, x)	(GPIO_REG(t, x) + t->soc->upper_offset + 0x50)
> +#define GPIO_MSK_INT_LVL(t, x)	(GPIO_REG(t, x) + t->soc->upper_offset + 0x60)
> +#define GPIO_MSK_DBC_EN(t, x)	(GPIO_REG(t, x) + t->soc->upper_offset + 0x30)

DBC_EN/0x30 should be sorted correctly with the rest, and likely added 
in patch 4 instead.

> @@ -276,19 +307,25 @@ static void tegra_gpio_irq_handler(struct irq_desc *desc)

> +	struct tegra_gpio_info *tgi = bank->tgi;
> +
>
>   	chained_irq_enter(chip, desc);

No need for 2 blank lines there.

> @@ -410,7 +462,7 @@ static int dbg_gpio_show(struct seq_file *s, void *unused)
>
>   static int dbg_gpio_open(struct inode *inode, struct file *file)
>   {
> -	return single_open(file, dbg_gpio_show, &inode->i_private);
> +	return single_open(file, dbg_gpio_show, inode->i_private);

Can you explain that change? I'm not sure it's correct, but don't know 
why it was made.

Once those are fixed,
Reviewed-by: Stephen Warren <swarren@nvidia.com>

Re: [PATCH V3 3/4] gpio: tegra: Get rid of all file scoped global variables

[Laxman Dewangan]

On Friday 22 April 2016 12:03 AM, Stephen Warren wrote:
> On 04/20/2016 07:30 AM, Laxman Dewangan wrote:
>> Move the file scoped multiple global variable from Tegra GPIO
>> driver to the structure and make this as gpiochip data which
>> can be referred from GPIO chip callbacks.
>
>> diff --git a/drivers/gpio/gpio-tegra.c b/drivers/gpio/gpio-tegra.c
>
>> +#define GPIO_MSK_CNF(t, x) (GPIO_REG(t, x) + t->soc->upper_offset + 
>> 0x00)
>> +#define GPIO_MSK_OE(t, x)    (GPIO_REG(t, x) + t->soc->upper_offset 
>> + 0x10)
>> +#define GPIO_MSK_OUT(t, x)    (GPIO_REG(t, x) + t->soc->upper_offset 
>> + 0X20)
>> +#define GPIO_MSK_INT_STA(t, x)    (GPIO_REG(t, x) + 
>> t->soc->upper_offset + 0x40)
>> +#define GPIO_MSK_INT_ENB(t, x)    (GPIO_REG(t, x) + 
>> t->soc->upper_offset + 0x50)
>> +#define GPIO_MSK_INT_LVL(t, x)    (GPIO_REG(t, x) + 
>> t->soc->upper_offset + 0x60)
>> +#define GPIO_MSK_DBC_EN(t, x)    (GPIO_REG(t, x) + 
>> t->soc->upper_offset + 0x30)
>
> DBC_EN/0x30 should be sorted correctly with the rest, and likely added 
> in patch 4 instead.
>
>> @@ -276,19 +307,25 @@ static void tegra_gpio_irq_handler(struct 
>> irq_desc *desc)
>
>> +    struct tegra_gpio_info *tgi = bank->tgi;
>> +
>>
>>       chained_irq_enter(chip, desc);
>
> No need for 2 blank lines there.
>
>> @@ -410,7 +462,7 @@ static int dbg_gpio_show(struct seq_file *s, void 
>> *unused)
>>
>>   static int dbg_gpio_open(struct inode *inode, struct file *file)
>>   {
>> -    return single_open(file, dbg_gpio_show, &inode->i_private);
>> +    return single_open(file, dbg_gpio_show, inode->i_private);
>
> Can you explain that change? I'm not sure it's correct, but don't know 
> why it was made.
>
we have sysfs interface to dump register as /sys/kernel/debug/tega_gpio
On this patch, I moved the tegra_gpio_info pointer as data for 
s->private so that we will not need the global variable.
inode->i_private contains the pointer of the passed data. Hence we do 
not need to pass the pointe ro pointer of data. If we dont do then we 
will get wrong data pointer for tegra_gpio_info.



> Once those are fixed,
> Reviewed-by: Stephen Warren <swarren@nvidia.com>

Thanks for RB.

Re: [PATCH V3 3/4] gpio: tegra: Get rid of all file scoped global variables

[Stephen Warren]

On 04/21/2016 12:35 PM, Laxman Dewangan wrote:
>
> On Friday 22 April 2016 12:03 AM, Stephen Warren wrote:
>> On 04/20/2016 07:30 AM, Laxman Dewangan wrote:
>>> Move the file scoped multiple global variable from Tegra GPIO
>>> driver to the structure and make this as gpiochip data which
>>> can be referred from GPIO chip callbacks.
>>
>>> diff --git a/drivers/gpio/gpio-tegra.c b/drivers/gpio/gpio-tegra.c
>>
>>> +#define GPIO_MSK_CNF(t, x) (GPIO_REG(t, x) + t->soc->upper_offset +
>>> 0x00)
>>> +#define GPIO_MSK_OE(t, x)    (GPIO_REG(t, x) + t->soc->upper_offset
>>> + 0x10)
>>> +#define GPIO_MSK_OUT(t, x)    (GPIO_REG(t, x) + t->soc->upper_offset
>>> + 0X20)
>>> +#define GPIO_MSK_INT_STA(t, x)    (GPIO_REG(t, x) +
>>> t->soc->upper_offset + 0x40)
>>> +#define GPIO_MSK_INT_ENB(t, x)    (GPIO_REG(t, x) +
>>> t->soc->upper_offset + 0x50)
>>> +#define GPIO_MSK_INT_LVL(t, x)    (GPIO_REG(t, x) +
>>> t->soc->upper_offset + 0x60)
>>> +#define GPIO_MSK_DBC_EN(t, x)    (GPIO_REG(t, x) +
>>> t->soc->upper_offset + 0x30)
>>
>> DBC_EN/0x30 should be sorted correctly with the rest, and likely added
>> in patch 4 instead.
>>
>>> @@ -276,19 +307,25 @@ static void tegra_gpio_irq_handler(struct
>>> irq_desc *desc)
>>
>>> +    struct tegra_gpio_info *tgi = bank->tgi;
>>> +
>>>
>>>       chained_irq_enter(chip, desc);
>>
>> No need for 2 blank lines there.
>>
>>> @@ -410,7 +462,7 @@ static int dbg_gpio_show(struct seq_file *s, void
>>> *unused)
>>>
>>>   static int dbg_gpio_open(struct inode *inode, struct file *file)
>>>   {
>>> -    return single_open(file, dbg_gpio_show, &inode->i_private);
>>> +    return single_open(file, dbg_gpio_show, inode->i_private);
>>
>> Can you explain that change? I'm not sure it's correct, but don't know
>> why it was made.
>
> we have sysfs interface to dump register as /sys/kernel/debug/tega_gpio
> On this patch, I moved the tegra_gpio_info pointer as data for
> s->private so that we will not need the global variable.
> inode->i_private contains the pointer of the passed data. Hence we do
> not need to pass the pointe ro pointer of data. If we dont do then we
> will get wrong data pointer for tegra_gpio_info.

Oh I see. The old value wasn't ever used at all, so it wasn't set to 
anything in particular. This isn't so much a change as just using the 
data for the first time, and hence setting it correctly.

>> Once those are fixed,
>> Reviewed-by: Stephen Warren <swarren@nvidia.com>
>
> Thanks for RB.

[PATCH V3 4/4] gpio: tegra: Add support for gpio debounce

[Laxman Dewangan]

NVIDIA's Tegra210 support the HW debounce in the GPIO
controller for all its GPIO pins.

Add support for setting debounce timing by implementing the
set_debounce callback of gpiochip.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>

---
Changes from V1:
- Write debounce count before enable.
- Make sure the debounce count do not have any boot residuals.

Changes from V2:
- Only access register fo debounce when SoC support debounce.
---
 drivers/gpio/gpio-tegra.c | 58 +++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 58 insertions(+)

diff --git a/drivers/gpio/gpio-tegra.c b/drivers/gpio/gpio-tegra.c
index 36e865f..1f8ec24 100644
--- a/drivers/gpio/gpio-tegra.c
+++ b/drivers/gpio/gpio-tegra.c
@@ -76,11 +76,14 @@ struct tegra_gpio_bank {
 	u32 int_enb[4];
 	u32 int_lvl[4];
 	u32 wake_enb[4];
+	u32 dbc_enb[4];
 #endif
+	u32 dbc_cnt[4];
 	struct tegra_gpio_info *tgi;
 };
 
 struct tegra_gpio_soc_config {
+	bool debounce_supported;
 	u32 bank_stride;
 	u32 upper_offset;
 };
@@ -184,6 +187,35 @@ static int tegra_gpio_direction_output(struct gpio_chip *chip, unsigned offset,
 	return 0;
 }
 
+static int tegra_gpio_set_debounce(struct gpio_chip *chip, unsigned int offset,
+				   unsigned int debounce)
+{
+	struct tegra_gpio_info *tgi = gpiochip_get_data(chip);
+	unsigned int debounce_ms = DIV_ROUND_UP(debounce, 1000);
+	int port = GPIO_PORT(offset);
+	int bank = GPIO_BANK(offset);
+
+	if (!debounce_ms) {
+		tegra_gpio_mask_write(tgi, GPIO_MSK_DBC_EN(tgi, offset),
+				      offset, 0);
+		return 0;
+	}
+
+	debounce_ms = min(debounce_ms, 255U);
+
+	/* There is only one debounce count register per port and hence
+	 * set the maximum of current and requested debounce time.
+	 */
+	if (tgi->bank_info[bank].dbc_cnt[port] < debounce_ms) {
+		tegra_gpio_writel(tgi, debounce_ms, GPIO_DBC_CNT(tgi, offset));
+		tgi->bank_info[bank].dbc_cnt[port] = debounce_ms;
+	}
+
+	tegra_gpio_mask_write(tgi, GPIO_MSK_DBC_EN(tgi, offset), offset, 1);
+
+	return 0;
+}
+
 static int tegra_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
 {
 	struct tegra_gpio_info *tgi = gpiochip_get_data(chip);
@@ -199,6 +231,7 @@ static struct gpio_chip tegra_gpio_chip = {
 	.get			= tegra_gpio_get,
 	.direction_output	= tegra_gpio_direction_output,
 	.set			= tegra_gpio_set,
+	.set_debounce		= tegra_gpio_set_debounce,
 	.to_irq			= tegra_gpio_to_irq,
 	.base			= 0,
 };
@@ -363,6 +396,14 @@ static int tegra_gpio_resume(struct device *dev)
 			unsigned int gpio = (b<<5) | (p<<3);
 			tegra_gpio_writel(tgi, bank->cnf[p],
 					  GPIO_CNF(tgi, gpio));
+
+			if (tgi->soc->debounce_supported) {
+				tegra_gpio_writel(tgi, bank->dbc_cnt[p],
+						  GPIO_DBC_CNT(tgi, gpio));
+				tegra_gpio_writel(tgi, bank->dbc_enb[p],
+						  GPIO_MSK_DBC_EN(tgi, gpio));
+			}
+
 			tegra_gpio_writel(tgi, bank->out[p],
 					  GPIO_OUT(tgi, gpio));
 			tegra_gpio_writel(tgi, bank->oe[p],
@@ -398,6 +439,13 @@ static int tegra_gpio_suspend(struct device *dev)
 							GPIO_OUT(tgi, gpio));
 			bank->oe[p] = tegra_gpio_readl(tgi,
 						       GPIO_OE(tgi, gpio));
+			if (tgi->soc->debounce_supported) {
+				bank->dbc_enb[p] = tegra_gpio_readl(tgi,
+						GPIO_MSK_DBC_EN(tgi, gpio));
+				bank->dbc_enb[p] = (bank->dbc_enb[p] << 8) |
+							bank->dbc_enb[p];
+			}
+
 			bank->int_enb[p] = tegra_gpio_readl(tgi,
 						GPIO_INT_ENB(tgi, gpio));
 			bank->int_lvl[p] = tegra_gpio_readl(tgi,
@@ -550,6 +598,9 @@ static int tegra_gpio_probe(struct platform_device *pdev)
 
 	platform_set_drvdata(pdev, tgi);
 
+	if (!config->debounce_supported)
+		tgi->gc->set_debounce = NULL;
+
 	tgi->bank_info = devm_kzalloc(&pdev->dev, tgi->bank_count *
 				      sizeof(*tgi->bank_info), GFP_KERNEL);
 	if (!tgi->bank_info)
@@ -629,7 +680,14 @@ static const struct tegra_gpio_soc_config tegra30_gpio_config = {
 	.upper_offset = 0x80,
 };
 
+static const struct tegra_gpio_soc_config tegra210_gpio_config = {
+	.debounce_supported = true,
+	.bank_stride = 0x100,
+	.upper_offset = 0x80,
+};
+
 static const struct of_device_id tegra_gpio_of_match[] = {
+	{ .compatible = "nvidia,tegra210-gpio", .data = &tegra210_gpio_config },
 	{ .compatible = "nvidia,tegra30-gpio", .data = &tegra30_gpio_config },
 	{ .compatible = "nvidia,tegra20-gpio", .data = &tegra20_gpio_config },
 	{ },
-- 
2.1.4

Re: [PATCH V3 4/4] gpio: tegra: Add support for gpio debounce

[Stephen Warren]

On 04/20/2016 07:30 AM, Laxman Dewangan wrote:
> NVIDIA's Tegra210 support the HW debounce in the GPIO
> controller for all its GPIO pins.
>
> Add support for setting debounce timing by implementing the
> set_debounce callback of gpiochip.

> diff --git a/drivers/gpio/gpio-tegra.c b/drivers/gpio/gpio-tegra.c

> +static int tegra_gpio_set_debounce(struct gpio_chip *chip, unsigned int offset,

> +	/* There is only one debounce count register per port and hence
> +	 * set the maximum of current and requested debounce time.
> +	 */
> +	if (tgi->bank_info[bank].dbc_cnt[port] < debounce_ms) {
> +		tegra_gpio_writel(tgi, debounce_ms, GPIO_DBC_CNT(tgi, offset));
> +		tgi->bank_info[bank].dbc_cnt[port] = debounce_ms;
> +	}

Do we need any locking there? I imagine the GPIO core doesn't prevent 
different threads/drivers from manipulating different GPIOs in parallel 
on different cores.

Re: [PATCH V3 4/4] gpio: tegra: Add support for gpio debounce

[Alexandre Courbot]

On Wed, Apr 20, 2016 at 10:30 PM, Laxman Dewangan <ldewangan@nvidia.com> wrote:
> NVIDIA's Tegra210 support the HW debounce in the GPIO
> controller for all its GPIO pins.
>
> Add support for setting debounce timing by implementing the
> set_debounce callback of gpiochip.
>
> Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
>
> ---
> Changes from V1:
> - Write debounce count before enable.
> - Make sure the debounce count do not have any boot residuals.
>
> Changes from V2:
> - Only access register fo debounce when SoC support debounce.
> ---
>  drivers/gpio/gpio-tegra.c | 58 +++++++++++++++++++++++++++++++++++++++++++++++
>  1 file changed, 58 insertions(+)
>
> diff --git a/drivers/gpio/gpio-tegra.c b/drivers/gpio/gpio-tegra.c
> index 36e865f..1f8ec24 100644
> --- a/drivers/gpio/gpio-tegra.c
> +++ b/drivers/gpio/gpio-tegra.c
> @@ -76,11 +76,14 @@ struct tegra_gpio_bank {
>         u32 int_enb[4];
>         u32 int_lvl[4];
>         u32 wake_enb[4];
> +       u32 dbc_enb[4];
>  #endif
> +       u32 dbc_cnt[4];
>         struct tegra_gpio_info *tgi;
>  };
>
>  struct tegra_gpio_soc_config {
> +       bool debounce_supported;
>         u32 bank_stride;
>         u32 upper_offset;
>  };
> @@ -184,6 +187,35 @@ static int tegra_gpio_direction_output(struct gpio_chip *chip, unsigned offset,
>         return 0;
>  }
>
> +static int tegra_gpio_set_debounce(struct gpio_chip *chip, unsigned int offset,
> +                                  unsigned int debounce)
> +{
> +       struct tegra_gpio_info *tgi = gpiochip_get_data(chip);
> +       unsigned int debounce_ms = DIV_ROUND_UP(debounce, 1000);
> +       int port = GPIO_PORT(offset);
> +       int bank = GPIO_BANK(offset);
> +
> +       if (!debounce_ms) {
> +               tegra_gpio_mask_write(tgi, GPIO_MSK_DBC_EN(tgi, offset),
> +                                     offset, 0);
> +               return 0;
> +       }
> +
> +       debounce_ms = min(debounce_ms, 255U);
> +
> +       /* There is only one debounce count register per port and hence
> +        * set the maximum of current and requested debounce time.
> +        */
> +       if (tgi->bank_info[bank].dbc_cnt[port] < debounce_ms) {
> +               tegra_gpio_writel(tgi, debounce_ms, GPIO_DBC_CNT(tgi, offset));
> +               tgi->bank_info[bank].dbc_cnt[port] = debounce_ms;
> +       }
> +
> +       tegra_gpio_mask_write(tgi, GPIO_MSK_DBC_EN(tgi, offset), offset, 1);
> +
> +       return 0;
> +}
> +
>  static int tegra_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
>  {
>         struct tegra_gpio_info *tgi = gpiochip_get_data(chip);
> @@ -199,6 +231,7 @@ static struct gpio_chip tegra_gpio_chip = {
>         .get                    = tegra_gpio_get,
>         .direction_output       = tegra_gpio_direction_output,
>         .set                    = tegra_gpio_set,
> +       .set_debounce           = tegra_gpio_set_debounce,
>         .to_irq                 = tegra_gpio_to_irq,
>         .base                   = 0,
>  };
> @@ -363,6 +396,14 @@ static int tegra_gpio_resume(struct device *dev)
>                         unsigned int gpio = (b<<5) | (p<<3);
>                         tegra_gpio_writel(tgi, bank->cnf[p],
>                                           GPIO_CNF(tgi, gpio));
> +
> +                       if (tgi->soc->debounce_supported) {
> +                               tegra_gpio_writel(tgi, bank->dbc_cnt[p],
> +                                                 GPIO_DBC_CNT(tgi, gpio));
> +                               tegra_gpio_writel(tgi, bank->dbc_enb[p],
> +                                                 GPIO_MSK_DBC_EN(tgi, gpio));
> +                       }
> +
>                         tegra_gpio_writel(tgi, bank->out[p],
>                                           GPIO_OUT(tgi, gpio));
>                         tegra_gpio_writel(tgi, bank->oe[p],
> @@ -398,6 +439,13 @@ static int tegra_gpio_suspend(struct device *dev)
>                                                         GPIO_OUT(tgi, gpio));
>                         bank->oe[p] = tegra_gpio_readl(tgi,
>                                                        GPIO_OE(tgi, gpio));
> +                       if (tgi->soc->debounce_supported) {
> +                               bank->dbc_enb[p] = tegra_gpio_readl(tgi,
> +                                               GPIO_MSK_DBC_EN(tgi, gpio));
> +                               bank->dbc_enb[p] = (bank->dbc_enb[p] << 8) |
> +                                                       bank->dbc_enb[p];
> +                       }
> +
>                         bank->int_enb[p] = tegra_gpio_readl(tgi,
>                                                 GPIO_INT_ENB(tgi, gpio));
>                         bank->int_lvl[p] = tegra_gpio_readl(tgi,
> @@ -550,6 +598,9 @@ static int tegra_gpio_probe(struct platform_device *pdev)
>
>         platform_set_drvdata(pdev, tgi);
>
> +       if (!config->debounce_supported)
> +               tgi->gc->set_debounce = NULL;

This last line is equivalent to doing

     tegra_gpio_chip.set_debounce = NULL

Which means that after that no one can reinstanciate this driver and
use debounce. Granted, this does not happen in real life, but the
purpose of the previous patch that removes all static variables is
supposedly to make this scenario possible. I think you can easily fix
this though: make tgi->gc a non-pointer member, do tgi->gc =
tegra_gpio_chip to copy the initial data, and then set
tgi->gc.set_debounce to NULL if needed.

tegra_gpio_chip can then be made constant, and maybe even __initdata?

Re: [PATCH V3 4/4] gpio: tegra: Add support for gpio debounce

[Laxman Dewangan]

On Monday 25 April 2016 10:25 AM, Alexandre Courbot wrote:
> On Wed, Apr 20, 2016 at 10:30 PM, Laxman Dewangan <ldewangan@nvidia.com> wrote:
>>                       bank->int_lvl[p] = tegra_gpio_readl(tgi,
>> @@ -550,6 +598,9 @@ static int tegra_gpio_probe(struct platform_device *pdev)
>>
>>          platform_set_drvdata(pdev, tgi);
>>
>> +       if (!config->debounce_supported)
>> +               tgi->gc->set_debounce = NULL;
> This last line is equivalent to doing
>
>       tegra_gpio_chip.set_debounce = NULL
>
> Which means that after that no one can reinstanciate this driver and
> use debounce. Granted, this does not happen in real life, but the
> purpose of the previous patch that removes all static variables is
> supposedly to make this scenario possible. I think you can easily fix
> this though: make tgi->gc a non-pointer member, do tgi->gc =
> tegra_gpio_chip to copy the initial data, and then set
> tgi->gc.set_debounce to NULL if needed.

As there is only single instance of the tegra gpio driver, I avoided the 
copy of the tegra_gpio_chip.
I am not expecting multiple instance of this driver and hence should be 
fine. When multiple instances are needed, it can be just use as:

But let me make this as you suggested.


> tegra_gpio_chip can then be made constant, and maybe even __initdata?
I have not seen the usage of __initdata now a days. I think it is 
removed from most of places.
Will use the const.