Message-Id: <1448746665-13422-2-git-send-email-robert.jarzmik@free.fr>
Date:	Sat, 28 Nov 2015 22:37:42 +0100
From:	Robert Jarzmik <robert.jarzmik@...e.fr>
To:	Linus Walleij <linus.walleij@...aro.org>,
	Alexandre Courbot <gnurou@...il.com>,
	Haojian Zhuang <haojian.zhuang@...il.com>
Cc:	linux-gpio@...r.kernel.org, linux-kernel@...r.kernel.org,
	Daniel Mack <zonque@...il.com>,
	Robert Jarzmik <robert.jarzmik@...e.fr>
Subject: [PATCH 1/4] gpio: pxa: convert to one gpiochip

The pxa gpio IP is provided by one chip, which holds multiple banks.

Another reason the driver should register only one gpiochip instead of
multiple gpiochips (ie. 1 per each bank) is that for pincontrol and
devicetree integration (think gpio-ranges), it's impossible to have the
contiguous pin range 0..127 mapped to gpios 0..127.

This patch, amongst other thinks, paves the path to loosen the bond with
the global structure variable pxa_gpio_chip.

Signed-off-by: Robert Jarzmik <robert.jarzmik@...e.fr>
---
 drivers/gpio/gpio-pxa.c | 221 ++++++++++++++++++++++++++----------------------
 1 file changed, 120 insertions(+), 101 deletions(-)

diff --git a/drivers/gpio/gpio-pxa.c b/drivers/gpio/gpio-pxa.c
index df2ce550f309..de2cfbeccaa1 100644
--- a/drivers/gpio/gpio-pxa.c
+++ b/drivers/gpio/gpio-pxa.c
@@ -69,15 +69,11 @@ static struct irq_domain *domain;
 static struct device_node *pxa_gpio_of_node;
 #endif
 
-struct pxa_gpio_chip {
-	struct gpio_chip chip;
+struct pxa_gpio_bank {
 	void __iomem	*regbase;
-	char label[10];
-
 	unsigned long	irq_mask;
 	unsigned long	irq_edge_rise;
 	unsigned long	irq_edge_fall;
-	int (*set_wake)(unsigned int gpio, unsigned int on);
 
 #ifdef CONFIG_PM
 	unsigned long	saved_gplr;
@@ -87,6 +83,16 @@ struct pxa_gpio_chip {
 #endif
 };
 
+struct pxa_gpio_chip {
+	struct device *dev;
+	struct gpio_chip chip;
+	struct pxa_gpio_bank *banks;
+
+	int irq0;
+	int irq1;
+	int (*set_wake)(unsigned int gpio, unsigned int on);
+};
+
 enum pxa_gpio_type {
 	PXA25X_GPIO = 0,
 	PXA26X_GPIO,
@@ -104,9 +110,8 @@ struct pxa_gpio_id {
 };
 
 static DEFINE_SPINLOCK(gpio_lock);
-static struct pxa_gpio_chip *pxa_gpio_chips;
+static struct pxa_gpio_chip *pxa_gpio_chip;
 static enum pxa_gpio_type gpio_type;
-static void __iomem *gpio_reg_base;
 
 static struct pxa_gpio_id pxa25x_id = {
 	.type		= PXA25X_GPIO,
@@ -148,17 +153,27 @@ static struct pxa_gpio_id pxa1928_id = {
 	.gpio_nums	= 224,
 };
 
-#define for_each_gpio_chip(i, c)			\
-	for (i = 0, c = &pxa_gpio_chips[0]; i <= pxa_last_gpio; i += 32, c++)
+#define for_each_gpio_bank(i, b, pc)					\
+	for (i = 0, b = pc->banks; i <= pxa_last_gpio; i += 32, b++)
 
-static inline void __iomem *gpio_chip_base(struct gpio_chip *c)
+static inline struct pxa_gpio_chip *chip_to_pxachip(struct gpio_chip *c)
 {
-	return container_of(c, struct pxa_gpio_chip, chip)->regbase;
+	struct pxa_gpio_chip *pxa_chip =
+		container_of(c, struct pxa_gpio_chip, chip);
+
+	return pxa_chip;
 }
+static inline void __iomem *gpio_bank_base(struct gpio_chip *c, int gpio)
+{
+	struct pxa_gpio_bank *bank = chip_to_pxachip(c)->banks + (gpio / 32);
 
-static inline struct pxa_gpio_chip *gpio_to_pxachip(unsigned gpio)
+	return bank->regbase;
+}
+
+static inline struct pxa_gpio_bank *gpio_to_pxabank(struct gpio_chip *c,
+						    unsigned gpio)
 {
-	return &pxa_gpio_chips[gpio_to_bank(gpio)];
+	return chip_to_pxachip(c)->banks + gpio / 32;
 }
 
 static inline int gpio_is_pxa_type(int type)
@@ -187,15 +202,13 @@ static inline int __gpio_is_inverted(int gpio)
  * is attributed as "occupied" here (I know this terminology isn't
  * accurate, you are welcome to propose a better one :-)
  */
-static inline int __gpio_is_occupied(unsigned gpio)
+static inline int __gpio_is_occupied(struct pxa_gpio_chip *pchip, unsigned gpio)
 {
-	struct pxa_gpio_chip *pxachip;
 	void __iomem *base;
 	unsigned long gafr = 0, gpdr = 0;
 	int ret, af = 0, dir = 0;
 
-	pxachip = gpio_to_pxachip(gpio);
-	base = gpio_chip_base(&pxachip->chip);
+	base = gpio_bank_base(&pchip->chip, gpio);
 	gpdr = readl_relaxed(base + GPDR_OFFSET);
 
 	switch (gpio_type) {
@@ -220,7 +233,7 @@ static inline int __gpio_is_occupied(unsigned gpio)
 
 static int pxa_gpio_to_irq(struct gpio_chip *chip, unsigned offset)
 {
-	return chip->base + offset + irq_base;
+	return offset + irq_base;
 }
 
 int pxa_irq_to_gpio(int irq)
@@ -230,8 +243,8 @@ int pxa_irq_to_gpio(int irq)
 
 static int pxa_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
 {
-	void __iomem *base = gpio_chip_base(chip);
-	uint32_t value, mask = 1 << offset;
+	void __iomem *base = gpio_bank_base(chip, offset);
+	uint32_t value, mask = GPIO_bit(offset);
 	unsigned long flags;
 
 	spin_lock_irqsave(&gpio_lock, flags);
@@ -250,8 +263,8 @@ static int pxa_gpio_direction_input(struct gpio_chip *chip, unsigned offset)
 static int pxa_gpio_direction_output(struct gpio_chip *chip,
 				     unsigned offset, int value)
 {
-	void __iomem *base = gpio_chip_base(chip);
-	uint32_t tmp, mask = 1 << offset;
+	void __iomem *base = gpio_bank_base(chip, offset);
+	uint32_t tmp, mask = GPIO_bit(offset);
 	unsigned long flags;
 
 	writel_relaxed(mask, base + (value ? GPSR_OFFSET : GPCR_OFFSET));
@@ -271,14 +284,18 @@ static int pxa_gpio_direction_output(struct gpio_chip *chip,
 
 static int pxa_gpio_get(struct gpio_chip *chip, unsigned offset)
 {
-	u32 gplr = readl_relaxed(gpio_chip_base(chip) + GPLR_OFFSET);
-	return !!(gplr & (1 << offset));
+	void __iomem *base = gpio_bank_base(chip, offset);
+	u32 gplr = readl_relaxed(base + GPLR_OFFSET);
+
+	return !!(gplr & GPIO_bit(offset));
 }
 
 static void pxa_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
 {
-	writel_relaxed(1 << offset, gpio_chip_base(chip) +
-				(value ? GPSR_OFFSET : GPCR_OFFSET));
+	void __iomem *base = gpio_bank_base(chip, offset);
+
+	writel_relaxed(GPIO_bit(offset),
+		       base + (value ? GPSR_OFFSET : GPCR_OFFSET));
 }
 
 #ifdef CONFIG_OF_GPIO
@@ -289,61 +306,49 @@ static int pxa_gpio_of_xlate(struct gpio_chip *gc,
 	if (gpiospec->args[0] > pxa_last_gpio)
 		return -EINVAL;
 
-	if (gc != &pxa_gpio_chips[gpiospec->args[0] / 32].chip)
-		return -EINVAL;
-
 	if (flags)
 		*flags = gpiospec->args[1];
 
-	return gpiospec->args[0] % 32;
+	return gpiospec->args[0];
 }
 #endif
 
-static int pxa_init_gpio_chip(int gpio_end,
-					int (*set_wake)(unsigned int, unsigned int))
+static int pxa_init_gpio_chip(struct pxa_gpio_chip *pchip, int ngpio,
+			      void __iomem *regbase)
 {
-	int i, gpio, nbanks = gpio_to_bank(gpio_end) + 1;
-	struct pxa_gpio_chip *chips;
+	int i, gpio, nbanks = DIV_ROUND_UP(ngpio, 32);
+	struct pxa_gpio_bank *bank;
 
-	chips = kzalloc(nbanks * sizeof(struct pxa_gpio_chip), GFP_KERNEL);
-	if (chips == NULL) {
-		pr_err("%s: failed to allocate GPIO chips\n", __func__);
+	pchip->banks = devm_kcalloc(pchip->dev, nbanks, sizeof(*pchip->banks),
+				    GFP_KERNEL);
+	if (!pchip->banks)
 		return -ENOMEM;
-	}
 
-	for (i = 0, gpio = 0; i < nbanks; i++, gpio += 32) {
-		struct gpio_chip *c = &chips[i].chip;
-
-		sprintf(chips[i].label, "gpio-%d", i);
-		chips[i].regbase = gpio_reg_base + BANK_OFF(i);
-		chips[i].set_wake = set_wake;
-
-		c->base  = gpio;
-		c->label = chips[i].label;
-
-		c->direction_input  = pxa_gpio_direction_input;
-		c->direction_output = pxa_gpio_direction_output;
-		c->get = pxa_gpio_get;
-		c->set = pxa_gpio_set;
-		c->to_irq = pxa_gpio_to_irq;
+	pchip->chip.label = "gpio-pxa";
+	pchip->chip.direction_input  = pxa_gpio_direction_input;
+	pchip->chip.direction_output = pxa_gpio_direction_output;
+	pchip->chip.get = pxa_gpio_get;
+	pchip->chip.set = pxa_gpio_set;
+	pchip->chip.to_irq = pxa_gpio_to_irq;
+	pchip->chip.ngpio = ngpio;
 #ifdef CONFIG_OF_GPIO
-		c->of_node = pxa_gpio_of_node;
-		c->of_xlate = pxa_gpio_of_xlate;
-		c->of_gpio_n_cells = 2;
+	pchip->chip.of_node = pxa_gpio_of_node;
+	pchip->chip.of_xlate = pxa_gpio_of_xlate;
+	pchip->chip.of_gpio_n_cells = 2;
 #endif
 
-		/* number of GPIOs on last bank may be less than 32 */
-		c->ngpio = (gpio + 31 > gpio_end) ? (gpio_end - gpio + 1) : 32;
-		gpiochip_add(c);
+	for (i = 0, gpio = 0; i < nbanks; i++, gpio += 32) {
+		bank = pchip->banks + i;
+		bank->regbase = regbase + BANK_OFF(i);
 	}
-	pxa_gpio_chips = chips;
-	return 0;
+
+	return gpiochip_add(&pchip->chip);
 }
 
 /* Update only those GRERx and GFERx edge detection register bits if those
  * bits are set in c->irq_mask
  */
-static inline void update_edge_detect(struct pxa_gpio_chip *c)
+static inline void update_edge_detect(struct pxa_gpio_bank *c)
 {
 	uint32_t grer, gfer;
 
@@ -357,12 +362,11 @@ static inline void update_edge_detect(struct pxa_gpio_chip *c)
 
 static int pxa_gpio_irq_type(struct irq_data *d, unsigned int type)
 {
-	struct pxa_gpio_chip *c;
+	struct pxa_gpio_chip *pchip = pxa_gpio_chip;
 	int gpio = pxa_irq_to_gpio(d->irq);
+	struct pxa_gpio_bank *c = gpio_to_pxabank(&pchip->chip, gpio);
 	unsigned long gpdr, mask = GPIO_bit(gpio);
 
-	c = gpio_to_pxachip(gpio);
-
 	if (type == IRQ_TYPE_PROBE) {
 		/* Don't mess with enabled GPIOs using preconfigured edges or
 		 * GPIOs set to alternate function or to output during probe
@@ -370,7 +374,7 @@ static int pxa_gpio_irq_type(struct irq_data *d, unsigned int type)
 		if ((c->irq_edge_rise | c->irq_edge_fall) & GPIO_bit(gpio))
 			return 0;
 
-		if (__gpio_is_occupied(gpio))
+		if (__gpio_is_occupied(pchip, gpio))
 			return 0;
 
 		type = IRQ_TYPE_EDGE_RISING | IRQ_TYPE_EDGE_FALLING;
@@ -403,18 +407,17 @@ static int pxa_gpio_irq_type(struct irq_data *d, unsigned int type)
 
 static void pxa_gpio_demux_handler(struct irq_desc *desc)
 {
-	struct pxa_gpio_chip *c;
-	int loop, gpio, gpio_base, n;
+	int loop, gpio, n, handled = 0;
 	unsigned long gedr;
 	struct irq_chip *chip = irq_desc_get_chip(desc);
+	struct pxa_gpio_chip *pchip = pxa_gpio_chip;
+	struct pxa_gpio_bank *c;
 
 	chained_irq_enter(chip, desc);
 
 	do {
 		loop = 0;
-		for_each_gpio_chip(gpio, c) {
-			gpio_base = c->chip.base;
-
+		for_each_gpio_bank(gpio, c, pchip) {
 			gedr = readl_relaxed(c->regbase + GEDR_OFFSET);
 			gedr = gedr & c->irq_mask;
 			writel_relaxed(gedr, c->regbase + GEDR_OFFSET);
@@ -422,7 +425,7 @@ static void pxa_gpio_demux_handler(struct irq_desc *desc)
 			for_each_set_bit(n, &gedr, BITS_PER_LONG) {
 				loop = 1;
 
-				generic_handle_irq(gpio_to_irq(gpio_base + n));
+				generic_handle_irq(gpio_to_irq(gpio + n));
 			}
 		}
 	} while (loop);
@@ -432,41 +435,45 @@ static void pxa_gpio_demux_handler(struct irq_desc *desc)
 
 static void pxa_ack_muxed_gpio(struct irq_data *d)
 {
+	struct pxa_gpio_chip *pchip = pxa_gpio_chip;
 	int gpio = pxa_irq_to_gpio(d->irq);
-	struct pxa_gpio_chip *c = gpio_to_pxachip(gpio);
+	void __iomem *base = gpio_bank_base(&pchip->chip, gpio);
 
-	writel_relaxed(GPIO_bit(gpio), c->regbase + GEDR_OFFSET);
+	writel_relaxed(GPIO_bit(gpio), base + GEDR_OFFSET);
 }
 
 static void pxa_mask_muxed_gpio(struct irq_data *d)
 {
+	struct pxa_gpio_chip *pchip = pxa_gpio_chip;
 	int gpio = pxa_irq_to_gpio(d->irq);
-	struct pxa_gpio_chip *c = gpio_to_pxachip(gpio);
+	struct pxa_gpio_bank *b = gpio_to_pxabank(&pchip->chip, gpio);
+	void __iomem *base = gpio_bank_base(&pchip->chip, gpio);
 	uint32_t grer, gfer;
 
-	c->irq_mask &= ~GPIO_bit(gpio);
+	b->irq_mask &= ~GPIO_bit(gpio);
 
-	grer = readl_relaxed(c->regbase + GRER_OFFSET) & ~GPIO_bit(gpio);
-	gfer = readl_relaxed(c->regbase + GFER_OFFSET) & ~GPIO_bit(gpio);
-	writel_relaxed(grer, c->regbase + GRER_OFFSET);
-	writel_relaxed(gfer, c->regbase + GFER_OFFSET);
+	grer = readl_relaxed(base + GRER_OFFSET) & ~GPIO_bit(gpio);
+	gfer = readl_relaxed(base + GFER_OFFSET) & ~GPIO_bit(gpio);
+	writel_relaxed(grer, base + GRER_OFFSET);
+	writel_relaxed(gfer, base + GFER_OFFSET);
 }
 
 static int pxa_gpio_set_wake(struct irq_data *d, unsigned int on)
 {
 	int gpio = pxa_irq_to_gpio(d->irq);
-	struct pxa_gpio_chip *c = gpio_to_pxachip(gpio);
+	struct pxa_gpio_chip *pchip = pxa_gpio_chip;
 
-	if (c->set_wake)
-		return c->set_wake(gpio, on);
+	if (pchip->set_wake)
+		return pchip->set_wake(gpio, on);
 	else
 		return 0;
 }
 
 static void pxa_unmask_muxed_gpio(struct irq_data *d)
 {
+	struct pxa_gpio_chip *pchip = pxa_gpio_chip;
 	int gpio = pxa_irq_to_gpio(d->irq);
-	struct pxa_gpio_chip *c = gpio_to_pxachip(gpio);
+	struct pxa_gpio_bank *c = gpio_to_pxabank(&pchip->chip, gpio);
 
 	c->irq_mask |= GPIO_bit(gpio);
 	update_edge_detect(c);
@@ -533,9 +540,10 @@ const struct irq_domain_ops pxa_irq_domain_ops = {
 	.xlate	= irq_domain_xlate_twocell,
 };
 
-static int pxa_gpio_probe_dt(struct platform_device *pdev)
+static int pxa_gpio_probe_dt(struct platform_device *pdev,
+			     struct pxa_gpio_chip *pchip)
 {
-	int ret = 0, nr_gpios;
+	int nr_gpios;
 	struct device_node *np = pdev->dev.of_node;
 	const struct of_device_id *of_id =
 				of_match_device(pxa_gpio_dt_ids, &pdev->dev);
@@ -554,40 +562,44 @@ static int pxa_gpio_probe_dt(struct platform_device *pdev)
 	irq_base = irq_alloc_descs(-1, 0, nr_gpios, 0);
 	if (irq_base < 0) {
 		dev_err(&pdev->dev, "Failed to allocate IRQ numbers\n");
-		ret = irq_base;
-		goto err;
+		return irq_base;
 	}
 	domain = irq_domain_add_legacy(np, nr_gpios, irq_base, 0,
-				       &pxa_irq_domain_ops, NULL);
+				       &pxa_irq_domain_ops, pchip);
 	pxa_gpio_of_node = np;
 	return 0;
-err:
-	iounmap(gpio_reg_base);
-	return ret;
 }
 #else
-#define pxa_gpio_probe_dt(pdev)		(-1)
+#define pxa_gpio_probe_dt(pdev, pchip)		(-1)
 #endif
 
 static int pxa_gpio_probe(struct platform_device *pdev)
 {
-	struct pxa_gpio_chip *c;
+	struct pxa_gpio_chip *pchip;
+	struct pxa_gpio_bank *c;
 	struct resource *res;
 	struct clk *clk;
 	struct pxa_gpio_platform_data *info;
+	void __iomem *gpio_reg_base;
 	int gpio, irq, ret, use_of = 0;
 	int irq0 = 0, irq1 = 0, irq_mux, gpio_offset = 0;
 
+	pchip = devm_kzalloc(&pdev->dev, sizeof(*pchip), GFP_KERNEL);
+	if (!pchip)
+		return -ENOMEM;
+	pchip->dev = &pdev->dev;
+
 	info = dev_get_platdata(&pdev->dev);
 	if (info) {
 		irq_base = info->irq_base;
 		if (irq_base <= 0)
 			return -EINVAL;
 		pxa_last_gpio = pxa_gpio_nums(pdev);
+		pchip->set_wake = info->gpio_set_wake;
 	} else {
 		irq_base = 0;
 		use_of = 1;
-		ret = pxa_gpio_probe_dt(pdev);
+		ret = pxa_gpio_probe_dt(pdev, pchip);
 		if (ret < 0)
 			return -EINVAL;
 	}
@@ -626,10 +638,14 @@ static int pxa_gpio_probe(struct platform_device *pdev)
 	}
 
 	/* Initialize GPIO chips */
-	pxa_init_gpio_chip(pxa_last_gpio, info ? info->gpio_set_wake : NULL);
+	ret = pxa_init_gpio_chip(pchip, pxa_last_gpio + 1, gpio_reg_base);
+	if (ret) {
+		clk_put(clk);
+		return ret;
+	}
 
 	/* clear all GPIO edge detects */
-	for_each_gpio_chip(gpio, c) {
+	for_each_gpio_bank(gpio, c, pchip) {
 		writel_relaxed(0, c->regbase + GFER_OFFSET);
 		writel_relaxed(0, c->regbase + GRER_OFFSET);
 		writel_relaxed(~0, c->regbase + GEDR_OFFSET);
@@ -664,6 +680,7 @@ static int pxa_gpio_probe(struct platform_device *pdev)
 		irq_set_chained_handler(irq0, pxa_gpio_demux_handler);
 	if (irq1 > 0)
 		irq_set_chained_handler(irq1, pxa_gpio_demux_handler);
+	pxa_gpio_chip = pchip;
 
 	irq_set_chained_handler(irq_mux, pxa_gpio_demux_handler);
 	return 0;
@@ -699,10 +716,11 @@ postcore_initcall(pxa_gpio_init);
 #ifdef CONFIG_PM
 static int pxa_gpio_suspend(void)
 {
-	struct pxa_gpio_chip *c;
+	struct pxa_gpio_chip *pchip = pxa_gpio_chip;
+	struct pxa_gpio_bank *c;
 	int gpio;
 
-	for_each_gpio_chip(gpio, c) {
+	for_each_gpio_bank(gpio, c, pchip) {
 		c->saved_gplr = readl_relaxed(c->regbase + GPLR_OFFSET);
 		c->saved_gpdr = readl_relaxed(c->regbase + GPDR_OFFSET);
 		c->saved_grer = readl_relaxed(c->regbase + GRER_OFFSET);
@@ -716,10 +734,11 @@ static int pxa_gpio_suspend(void)
 
 static void pxa_gpio_resume(void)
 {
-	struct pxa_gpio_chip *c;
+	struct pxa_gpio_chip *pchip = pxa_gpio_chip;
+	struct pxa_gpio_bank *c;
 	int gpio;
 
-	for_each_gpio_chip(gpio, c) {
+	for_each_gpio_bank(gpio, c, pchip) {
 		/* restore level with set/clear */
 		writel_relaxed(c->saved_gplr, c->regbase + GPSR_OFFSET);
 		writel_relaxed(~c->saved_gplr, c->regbase + GPCR_OFFSET);
-- 
2.1.4

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