pinctrl: samsung: Fix NULL pointer exception on external interrupts on S3C24xx

After commit 8b1bd11c ("pinctrl: samsung: Add the support the
multiple IORESOURCE_MEM for one pin-bank"), the S3C24xx (and probably
S3C64xx as well) fails:

	Unable to handle kernel NULL pointer dereference at virtual address 000000a8
	...
	(s3c24xx_demux_eint4_7) from [<c004469c>] (__handle_domain_irq+0x6c/0xcc)
	(__handle_domain_irq) from [<c0009444>] (s3c24xx_handle_irq+0x6c/0x12c)
	(s3c24xx_handle_irq) from [<c000e5fc>] (__irq_svc+0x5c/0x78)

Mentioned commit moved the pointer to controller's base IO memory address
from each controller's driver data (samsung_pinctrl_drv_data) to per-bank
structure (samsung_pin_bank).  The external interrupt demux
handlers (s3c24xx_demux_eint()) tried to get this base address from opaque
pointer stored under irq_chip data:

	struct irq_data *irqd = irq_desc_get_irq_data(desc);
	struct samsung_pin_bank *bank = irq_data_get_irq_chip_data(irqd);
	...
	pend = readl(bank->eint_base + EINTPEND_REG);

which is wrong because this is hardware irq and it bank was never set
for this irq_chip.

For S3C24xx and S3C64xx, this partially reverts mentioned commit by
bringing back the virt_base stored under each controller's driver data
(samsung_pinctrl_drv_data).  This virt_base address will be now
duplicated:
 - samsung_pinctrl_drv_data->virt_base: used on S3C24xx and S3C64xx,
 - samsung_pin_bank->pctl_base: used on Exynos.

Fixes: 8b1bd11c ("pinctrl: samsung: Add the support the multiple IORESOURCE_MEM for one pin-bank")
Cc: <stable@vger.kernel.org>
Cc: Sergio Prado <sergio.prado@e-labworks.com>
Reported-by: Sergio Prado <sergio.prado@e-labworks.com>
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Tested-by: Lihua Yao <ylhuajnu@163.com>

drivers/pinctrl/samsung/pinctrl-s3c24xx.c

@@ -151,7 +151,7 @@ static void s3c24xx_eint_set_function(struct samsung_pinctrl_drv_data *d,
 	u32 val;
 
 	/* Make sure that pin is configured as interrupt */
-	reg = bank->pctl_base + bank->pctl_offset;
+	reg = d->virt_base + bank->pctl_offset;
 	shift = pin * bank_type->fld_width[PINCFG_TYPE_FUNC];
 	mask = (1 << bank_type->fld_width[PINCFG_TYPE_FUNC]) - 1;
 
@@ -184,7 +184,7 @@ static int s3c24xx_eint_type(struct irq_data *data, unsigned int type)
 	s3c24xx_eint_set_handler(data, type);
 
 	/* Set up interrupt trigger */
-	reg = bank->eint_base + EINT_REG(index);
+	reg = d->virt_base + EINT_REG(index);
 	shift = EINT_OFFS(index);
 
 	val = readl(reg);
@@ -259,29 +259,32 @@ static void s3c2410_demux_eint0_3(struct irq_desc *desc)
 static void s3c2412_eint0_3_ack(struct irq_data *data)
 {
 	struct samsung_pin_bank *bank = irq_data_get_irq_chip_data(data);
+	struct samsung_pinctrl_drv_data *d = bank->drvdata;
 
 	unsigned long bitval = 1UL << data->hwirq;
-	writel(bitval, bank->eint_base + EINTPEND_REG);
+	writel(bitval, d->virt_base + EINTPEND_REG);
 }
 
 static void s3c2412_eint0_3_mask(struct irq_data *data)
 {
 	struct samsung_pin_bank *bank = irq_data_get_irq_chip_data(data);
+	struct samsung_pinctrl_drv_data *d = bank->drvdata;
 	unsigned long mask;
 
-	mask = readl(bank->eint_base + EINTMASK_REG);
+	mask = readl(d->virt_base + EINTMASK_REG);
 	mask |= (1UL << data->hwirq);
-	writel(mask, bank->eint_base + EINTMASK_REG);
+	writel(mask, d->virt_base + EINTMASK_REG);
 }
 
 static void s3c2412_eint0_3_unmask(struct irq_data *data)
 {
 	struct samsung_pin_bank *bank = irq_data_get_irq_chip_data(data);
+	struct samsung_pinctrl_drv_data *d = bank->drvdata;
 	unsigned long mask;
 
-	mask = readl(bank->eint_base + EINTMASK_REG);
+	mask = readl(d->virt_base + EINTMASK_REG);
 	mask &= ~(1UL << data->hwirq);
-	writel(mask, bank->eint_base + EINTMASK_REG);
+	writel(mask, d->virt_base + EINTMASK_REG);
 }
 
 static struct irq_chip s3c2412_eint0_3_chip = {
@@ -316,31 +319,34 @@ static void s3c2412_demux_eint0_3(struct irq_desc *desc)
 static void s3c24xx_eint_ack(struct irq_data *data)
 {
 	struct samsung_pin_bank *bank = irq_data_get_irq_chip_data(data);
+	struct samsung_pinctrl_drv_data *d = bank->drvdata;
 	unsigned char index = bank->eint_offset + data->hwirq;
 
-	writel(1UL << index, bank->eint_base + EINTPEND_REG);
+	writel(1UL << index, d->virt_base + EINTPEND_REG);
 }
 
 static void s3c24xx_eint_mask(struct irq_data *data)
 {
 	struct samsung_pin_bank *bank = irq_data_get_irq_chip_data(data);
+	struct samsung_pinctrl_drv_data *d = bank->drvdata;
 	unsigned char index = bank->eint_offset + data->hwirq;
 	unsigned long mask;
 
-	mask = readl(bank->eint_base + EINTMASK_REG);
+	mask = readl(d->virt_base + EINTMASK_REG);
 	mask |= (1UL << index);
-	writel(mask, bank->eint_base + EINTMASK_REG);
+	writel(mask, d->virt_base + EINTMASK_REG);
 }
 
 static void s3c24xx_eint_unmask(struct irq_data *data)
 {
 	struct samsung_pin_bank *bank = irq_data_get_irq_chip_data(data);
+	struct samsung_pinctrl_drv_data *d = bank->drvdata;
 	unsigned char index = bank->eint_offset + data->hwirq;
 	unsigned long mask;
 
-	mask = readl(bank->eint_base + EINTMASK_REG);
+	mask = readl(d->virt_base + EINTMASK_REG);
 	mask &= ~(1UL << index);
-	writel(mask, bank->eint_base + EINTMASK_REG);
+	writel(mask, d->virt_base + EINTMASK_REG);
 }
 
 static struct irq_chip s3c24xx_eint_chip = {
@@ -356,14 +362,13 @@ static inline void s3c24xx_demux_eint(struct irq_desc *desc,
 {
 	struct s3c24xx_eint_data *data = irq_desc_get_handler_data(desc);
 	struct irq_chip *chip = irq_desc_get_chip(desc);
-	struct irq_data *irqd = irq_desc_get_irq_data(desc);
-	struct samsung_pin_bank *bank = irq_data_get_irq_chip_data(irqd);
+	struct samsung_pinctrl_drv_data *d = data->drvdata;
 	unsigned int pend, mask;
 
 	chained_irq_enter(chip, desc);
 
-	pend = readl(bank->eint_base + EINTPEND_REG);
-	mask = readl(bank->eint_base + EINTMASK_REG);
+	pend = readl(d->virt_base + EINTPEND_REG);
+	mask = readl(d->virt_base + EINTMASK_REG);
 
 	pend &= ~mask;
 	pend &= range;

drivers/pinctrl/samsung/pinctrl-s3c64xx.c

@@ -280,7 +280,7 @@ static void s3c64xx_irq_set_function(struct samsung_pinctrl_drv_data *d,
 	u32 val;
 
 	/* Make sure that pin is configured as interrupt */
-	reg = bank->pctl_base + bank->pctl_offset;
+	reg = d->virt_base + bank->pctl_offset;
 	shift = pin;
 	if (bank_type->fld_width[PINCFG_TYPE_FUNC] * shift >= 32) {
 		/* 4-bit bank type with 2 con regs */
@@ -308,8 +308,9 @@ static void s3c64xx_irq_set_function(struct samsung_pinctrl_drv_data *d,
 static inline void s3c64xx_gpio_irq_set_mask(struct irq_data *irqd, bool mask)
 {
 	struct samsung_pin_bank *bank = irq_data_get_irq_chip_data(irqd);
+	struct samsung_pinctrl_drv_data *d = bank->drvdata;
 	unsigned char index = EINT_OFFS(bank->eint_offset) + irqd->hwirq;
-	void __iomem *reg = bank->eint_base + EINTMASK_REG(bank->eint_offset);
+	void __iomem *reg = d->virt_base + EINTMASK_REG(bank->eint_offset);
 	u32 val;
 
 	val = readl(reg);
@@ -333,8 +334,9 @@ static void s3c64xx_gpio_irq_mask(struct irq_data *irqd)
 static void s3c64xx_gpio_irq_ack(struct irq_data *irqd)
 {
 	struct samsung_pin_bank *bank = irq_data_get_irq_chip_data(irqd);
+	struct samsung_pinctrl_drv_data *d = bank->drvdata;
 	unsigned char index = EINT_OFFS(bank->eint_offset) + irqd->hwirq;
-	void __iomem *reg = bank->eint_base + EINTPEND_REG(bank->eint_offset);
+	void __iomem *reg = d->virt_base + EINTPEND_REG(bank->eint_offset);
 
 	writel(1 << index, reg);
 }
@@ -357,7 +359,7 @@ static int s3c64xx_gpio_irq_set_type(struct irq_data *irqd, unsigned int type)
 	s3c64xx_irq_set_handler(irqd, type);
 
 	/* Set up interrupt trigger */
-	reg = bank->eint_base + EINTCON_REG(bank->eint_offset);
+	reg = d->virt_base + EINTCON_REG(bank->eint_offset);
 	shift = EINT_OFFS(bank->eint_offset) + irqd->hwirq;
 	shift = 4 * (shift / 4); /* 4 EINTs per trigger selector */
 
@@ -409,8 +411,7 @@ static void s3c64xx_eint_gpio_irq(struct irq_desc *desc)
 {
 	struct irq_chip *chip = irq_desc_get_chip(desc);
 	struct s3c64xx_eint_gpio_data *data = irq_desc_get_handler_data(desc);
-	struct irq_data *irqd = irq_desc_get_irq_data(desc);
-	struct samsung_pin_bank *bank = irq_data_get_irq_chip_data(irqd);
+	struct samsung_pinctrl_drv_data *drvdata = data->drvdata;
 
 	chained_irq_enter(chip, desc);
 
@@ -420,7 +421,7 @@ static void s3c64xx_eint_gpio_irq(struct irq_desc *desc)
 		unsigned int pin;
 		unsigned int virq;
 
-		svc = readl(bank->eint_base + SERVICE_REG);
+		svc = readl(drvdata->virt_base + SERVICE_REG);
 		group = SVC_GROUP(svc);
 		pin = svc & SVC_NUM_MASK;
 
@@ -515,15 +516,15 @@ static inline void s3c64xx_eint0_irq_set_mask(struct irq_data *irqd, bool mask)
 {
 	struct s3c64xx_eint0_domain_data *ddata =
 					irq_data_get_irq_chip_data(irqd);
-	struct samsung_pin_bank *bank = ddata->bank;
+	struct samsung_pinctrl_drv_data *d = ddata->bank->drvdata;
 	u32 val;
 
-	val = readl(bank->eint_base + EINT0MASK_REG);
+	val = readl(d->virt_base + EINT0MASK_REG);
 	if (mask)
 		val |= 1 << ddata->eints[irqd->hwirq];
 	else
 		val &= ~(1 << ddata->eints[irqd->hwirq]);
-	writel(val, bank->eint_base + EINT0MASK_REG);
+	writel(val, d->virt_base + EINT0MASK_REG);
 }
 
 static void s3c64xx_eint0_irq_unmask(struct irq_data *irqd)
@@ -540,10 +541,10 @@ static void s3c64xx_eint0_irq_ack(struct irq_data *irqd)
 {
 	struct s3c64xx_eint0_domain_data *ddata =
 					irq_data_get_irq_chip_data(irqd);
-	struct samsung_pin_bank *bank = ddata->bank;
+	struct samsung_pinctrl_drv_data *d = ddata->bank->drvdata;
 
 	writel(1 << ddata->eints[irqd->hwirq],
-					bank->eint_base + EINT0PEND_REG);
+					d->virt_base + EINT0PEND_REG);
 }
 
 static int s3c64xx_eint0_irq_set_type(struct irq_data *irqd, unsigned int type)
@@ -551,7 +552,7 @@ static int s3c64xx_eint0_irq_set_type(struct irq_data *irqd, unsigned int type)
 	struct s3c64xx_eint0_domain_data *ddata =
 					irq_data_get_irq_chip_data(irqd);
 	struct samsung_pin_bank *bank = ddata->bank;
-	struct samsung_pinctrl_drv_data *d = ddata->bank->drvdata;
+	struct samsung_pinctrl_drv_data *d = bank->drvdata;
 	void __iomem *reg;
 	int trigger;
 	u8 shift;
@@ -566,7 +567,7 @@ static int s3c64xx_eint0_irq_set_type(struct irq_data *irqd, unsigned int type)
 	s3c64xx_irq_set_handler(irqd, type);
 
 	/* Set up interrupt trigger */
-	reg = bank->eint_base + EINT0CON0_REG;
+	reg = d->virt_base + EINT0CON0_REG;
 	shift = ddata->eints[irqd->hwirq];
 	if (shift >= EINT_MAX_PER_REG) {
 		reg += 4;
@@ -598,19 +599,14 @@ static struct irq_chip s3c64xx_eint0_irq_chip = {
 static inline void s3c64xx_irq_demux_eint(struct irq_desc *desc, u32 range)
 {
 	struct irq_chip *chip = irq_desc_get_chip(desc);
-	struct irq_data *irqd = irq_desc_get_irq_data(desc);
-	struct s3c64xx_eint0_domain_data *ddata =
-					irq_data_get_irq_chip_data(irqd);
-	struct samsung_pin_bank *bank = ddata->bank;
-
 	struct s3c64xx_eint0_data *data = irq_desc_get_handler_data(desc);
-
+	struct samsung_pinctrl_drv_data *drvdata = data->drvdata;
 	unsigned int pend, mask;
 
 	chained_irq_enter(chip, desc);
 
-	pend = readl(bank->eint_base + EINT0PEND_REG);
-	mask = readl(bank->eint_base + EINT0MASK_REG);
+	pend = readl(drvdata->virt_base + EINT0PEND_REG);
+	mask = readl(drvdata->virt_base + EINT0MASK_REG);
 
 	pend = pend & range & ~mask;
 	pend &= range;

drivers/pinctrl/samsung/pinctrl-samsung.c

@@ -1013,6 +1013,12 @@ samsung_pinctrl_get_soc_data(struct samsung_pinctrl_drv_data *d,
 		bank->eint_base = virt_base[0];
 		bank->pctl_base = virt_base[bdata->pctl_res_idx];
 	}
+	/*
+	 * Legacy platforms should provide only one resource with IO memory.
+	 * Store it as virt_base because legacy driver needs to access it
+	 * through samsung_pinctrl_drv_data.
+	 */
+	d->virt_base = virt_base[0];
 
 	for_each_child_of_node(node, np) {
 		if (!of_find_property(np, "gpio-controller", NULL))

drivers/pinctrl/samsung/pinctrl-samsung.h

@@ -247,6 +247,10 @@ struct samsung_pin_ctrl {
 /**
  * struct samsung_pinctrl_drv_data: wrapper for holding driver data together.
  * @node: global list node
+ * @virt_base: register base address of the controller; this will be equal
+ *             to each bank samsung_pin_bank->pctl_base and used on legacy
+ *             platforms (like S3C24XX or S3C64XX) which has to access the base
+ *             through samsung_pinctrl_drv_data, not samsung_pin_bank).
  * @dev: device instance representing the controller.
  * @irq: interrpt number used by the controller to notify gpio interrupts.
  * @ctrl: pin controller instance managed by the driver.
@@ -262,6 +266,7 @@ struct samsung_pin_ctrl {
  */
 struct samsung_pinctrl_drv_data {
 	struct list_head		node;
+	void __iomem			*virt_base;
 	struct device			*dev;
 	int				irq;