[PATCH 09/33] ARM: sa1111: implement a gpio_chip for SA1111 GPIOs

Russell King
2016-08-29T10:24:51Z

Add a gpio_chip instance for SA1111 GPIOs. This allows us to use
gpiolib to lookup and manipulate SA1111 GPIOs.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
---
arch/arm/common/sa1111.c | 168 ++++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 165 insertions(+), 3 deletions(-)

diff --git a/arch/arm/common/sa1111.c b/arch/arm/common/sa1111.c
index fb0a0a4dfea4..ac19dca4c258 100644
--- a/arch/arm/common/sa1111.c
+++ b/arch/arm/common/sa1111.c
@@ -15,6 +15,7 @@
* from machine specific code with proper arguments when required.
*/
#include <linux/module.h>
+#include <linux/gpio/driver.h>
#include <linux/init.h>
#include <linux/irq.h>
#include <linux/kernel.h>
@@ -107,6 +108,7 @@ struct sa1111 {
spinlock_t lock;
void __iomem *base;
struct sa1111_platform_data *pdata;
+ struct gpio_chip gc;
#ifdef CONFIG_PM
void *saved_state;
#endif
@@ -509,6 +511,163 @@ static int sa1111_setup_irq(struct sa1111 *sachip, unsigned irq_base)
return 0;
}

+enum {
+ SA1111_GPIO_PXDDR = (SA1111_GPIO_PADDR - SA1111_GPIO_PADDR),
+ SA1111_GPIO_PXDRR = (SA1111_GPIO_PADRR - SA1111_GPIO_PADDR),
+ SA1111_GPIO_PXDWR = (SA1111_GPIO_PADWR - SA1111_GPIO_PADDR),
+ SA1111_GPIO_PXSDR = (SA1111_GPIO_PASDR - SA1111_GPIO_PADDR),
+ SA1111_GPIO_PXSSR = (SA1111_GPIO_PASSR - SA1111_GPIO_PADDR),
+};
+
+static struct sa1111 *gc_to_sa1111(struct gpio_chip *gc)
+{
+ return container_of(gc, struct sa1111, gc);
+}
+
+static void __iomem *sa1111_gpio_map_reg(struct sa1111 *sachip, unsigned offset)
+{
+ void __iomem *reg = sachip->base + SA1111_GPIO;
+
+ if (offset < 4)
+ return reg + SA1111_GPIO_PADDR;
+ if (offset < 10)
+ return reg + SA1111_GPIO_PBDDR;
+ if (offset < 18)
+ return reg + SA1111_GPIO_PCDDR;
+ return NULL;
+}
+
+static u32 sa1111_gpio_map_bit(unsigned offset)
+{
+ if (offset < 4)
+ return BIT(offset);
+ if (offset < 10)
+ return BIT(offset - 4);
+ if (offset < 18)
+ return BIT(offset - 10);
+ return 0;
+}
+
+static void sa1111_gpio_modify(void __iomem *reg, u32 mask, u32 set)
+{
+ u32 val;
+
+ val = readl_relaxed(reg);
+ val &= ~mask;
+ val |= mask & set;
+ writel_relaxed(val, reg);
+}
+
+static int sa1111_gpio_get_direction(struct gpio_chip *gc, unsigned offset)
+{
+ struct sa1111 *sachip = gc_to_sa1111(gc);
+ void __iomem *reg = sa1111_gpio_map_reg(sachip, offset);
+ u32 mask = sa1111_gpio_map_bit(offset);
+
+ return !!(readl_relaxed(reg + SA1111_GPIO_PXDDR) & mask);
+}
+
+static int sa1111_gpio_direction_input(struct gpio_chip *gc, unsigned offset)
+{
+ struct sa1111 *sachip = gc_to_sa1111(gc);
+ unsigned long flags;
+ void __iomem *reg = sa1111_gpio_map_reg(sachip, offset);
+ u32 mask = sa1111_gpio_map_bit(offset);
+
+ spin_lock_irqsave(&sachip->lock, flags);
+ sa1111_gpio_modify(reg + SA1111_GPIO_PXDDR, mask, mask);
+ sa1111_gpio_modify(reg + SA1111_GPIO_PXSDR, mask, mask);
+ spin_unlock_irqrestore(&sachip->lock, flags);
+
+ return 0;
+}
+
+static int sa1111_gpio_direction_output(struct gpio_chip *gc, unsigned offset,
+ int value)
+{
+ struct sa1111 *sachip = gc_to_sa1111(gc);
+ unsigned long flags;
+ void __iomem *reg = sa1111_gpio_map_reg(sachip, offset);
+ u32 mask = sa1111_gpio_map_bit(offset);
+
+ spin_lock_irqsave(&sachip->lock, flags);
+ sa1111_gpio_modify(reg + SA1111_GPIO_PXDWR, mask, value ? mask : 0);
+ sa1111_gpio_modify(reg + SA1111_GPIO_PXSSR, mask, value ? mask : 0);
+ sa1111_gpio_modify(reg + SA1111_GPIO_PXDDR, mask, 0);
+ sa1111_gpio_modify(reg + SA1111_GPIO_PXSDR, mask, 0);
+ spin_unlock_irqrestore(&sachip->lock, flags);
+
+ return 0;
+}
+
+static int sa1111_gpio_get(struct gpio_chip *gc, unsigned offset)
+{
+ struct sa1111 *sachip = gc_to_sa1111(gc);
+ void __iomem *reg = sa1111_gpio_map_reg(sachip, offset);
+ u32 mask = sa1111_gpio_map_bit(offset);
+
+ return !!(readl_relaxed(reg + SA1111_GPIO_PXDRR) & mask);
+}
+
+static void sa1111_gpio_set(struct gpio_chip *gc, unsigned offset, int value)
+{
+ struct sa1111 *sachip = gc_to_sa1111(gc);
+ unsigned long flags;
+ void __iomem *reg = sa1111_gpio_map_reg(sachip, offset);
+ u32 mask = sa1111_gpio_map_bit(offset);
+
+ spin_lock_irqsave(&sachip->lock, flags);
+ sa1111_gpio_modify(reg + SA1111_GPIO_PXDWR, mask, value ? mask : 0);
+ sa1111_gpio_modify(reg + SA1111_GPIO_PXSSR, mask, value ? mask : 0);
+ spin_unlock_irqrestore(&sachip->lock, flags);
+}
+
+static void sa1111_gpio_set_multiple(struct gpio_chip *gc, unsigned long *mask,
+ unsigned long *bits)
+{
+ struct sa1111 *sachip = gc_to_sa1111(gc);
+ unsigned long flags;
+ void __iomem *reg = sachip->base + SA1111_GPIO;
+ u32 msk, val;
+
+ msk = *mask;
+ val = *bits;
+
+ spin_lock_irqsave(&sachip->lock, flags);
+ sa1111_gpio_modify(reg + SA1111_GPIO_PADWR, msk & 15, val);
+ sa1111_gpio_modify(reg + SA1111_GPIO_PASSR, msk & 15, val);
+ sa1111_gpio_modify(reg + SA1111_GPIO_PBDWR, (msk >> 4) & 255, val >> 4);
+ sa1111_gpio_modify(reg + SA1111_GPIO_PBSSR, (msk >> 4) & 255, val >> 4);
+ sa1111_gpio_modify(reg + SA1111_GPIO_PCDWR, (msk >> 12) & 255, val >> 12);
+ sa1111_gpio_modify(reg + SA1111_GPIO_PCSSR, (msk >> 12) & 255, val >> 12);
+ spin_unlock_irqrestore(&sachip->lock, flags);
+}
+
+static int sa1111_gpio_to_irq(struct gpio_chip *gc, unsigned offset)
+{
+ struct sa1111 *sachip = gc_to_sa1111(gc);
+
+ return sachip->irq_base + offset;
+}
+
+static int sa1111_setup_gpios(struct sa1111 *sachip)
+{
+ sachip->gc.label = "sa1111";
+ sachip->gc.parent = sachip->dev;
+ sachip->gc.owner = THIS_MODULE;
+ sachip->gc.get_direction = sa1111_gpio_get_direction;
+ sachip->gc.direction_input = sa1111_gpio_direction_input;
+ sachip->gc.direction_output = sa1111_gpio_direction_output;
+ sachip->gc.get = sa1111_gpio_get;
+ sachip->gc.set = sa1111_gpio_set;
+ sachip->gc.set_multiple = sa1111_gpio_set_multiple;
+ sachip->gc.to_irq = sa1111_gpio_to_irq;
+ sachip->gc.base = -1;
+ sachip->gc.ngpio = 18;
+
+ return devm_gpiochip_add_data(sachip->dev, &sachip->gc, sachip);
+}
+
/*
* Bring the SA1111 out of reset. This requires a set procedure:
* 1. nRESET asserted (by hardware)
@@ -696,7 +855,7 @@ static int __sa1111_probe(struct device *me, struct resource *mem, int irq)
if (!pd)
return -EINVAL;

- sachip = kzalloc(sizeof(struct sa1111), GFP_KERNEL);
+ sachip = devm_kzalloc(me, sizeof(struct sa1111), GFP_KERNEL);
if (!sachip)
return -ENOMEM;

@@ -747,6 +906,11 @@ static int __sa1111_probe(struct device *me, struct resource *mem, int irq)
*/
sa1111_wake(sachip);

+ /* Setup the GPIOs - should really be done after the IRQ setup */
+ ret = sa1111_setup_gpios(sachip);
+ if (ret)
+ goto err_unmap;
+
/*
* The interrupt controller must be initialised before any
* other device to ensure that the interrupts are available.
@@ -806,7 +970,6 @@ static int __sa1111_probe(struct device *me, struct resource *mem, int irq)
err_clkput:
clk_put(sachip->clk);
err_free:
- kfree(sachip);
return ret;
}

@@ -843,7 +1006,6 @@ static void __sa1111_remove(struct sa1111 *sachip)

iounmap(sachip->base);
clk_put(sachip->clk);
- kfree(sachip);
}

struct sa1111_save_data {
--
2.1.0