[PATCH 03/11] gpio: davinci: Modify to platform driver

From: Philip Avinash
Date: Wed May 22 2013 - 03:10:42 EST

From: KV Sujith <sujithkv@xxxxxx>

Modify GPIO Davinci driver to be compliant to standard platform drivers.
The driver did not have platform driver structure or a probe. Instead,
had a davinci_gpio_setup() function which is called in the pure_init
sequence. The function also had dependency on davinci_soc_info structure
of the corresponding platform. For Device Tree(DT) implementation, we
need to get rid of the dependency on the davinci_soc_info structure.
Hence as a first stage of DT conversion, we implement a probe. Future
commits shall modify the probe to read platform related data from DT.

- Add platform_driver structure and driver register function for davinci
GPIO driver. The driver registration is made to happen in
postcore_initcall. This is required since machine init functions like
da850_lcd_hw_init() make use of GPIO.
- Convert the davinci_gpio_setup() to davinci_gpio_probe().
- Remove access of members in soc_info structure. Instead, relevant data
are taken from davinci_gpio_platform_data structure pointed by
pdev->dev.platform_data.
- Change clk_get() to devm_clk_get() as devm_clk_get() is a device
managed function and makes error handling simpler.
- Change pr_err to dev_err for ngpio error reporting.
- Arrange include files and variables in alphabetical order

Signed-off-by: KV Sujith <sujithkv@xxxxxx>
[avinashphilip@xxxxxx: Move global definition for "struct
davinci_gpio_controller" variable to local in probe and set it as driver
data.]
Signed-off-by: Philip Avinash <avinashphilip@xxxxxx>
---
arch/arm/mach-davinci/include/mach/gpio-davinci.h | 2 +
drivers/gpio/gpio-davinci.c | 121 +++++++++++++++------
2 files changed, 87 insertions(+), 36 deletions(-)

diff --git a/arch/arm/mach-davinci/include/mach/gpio-davinci.h b/arch/arm/mach-davinci/include/mach/gpio-davinci.h
index 1fdd1fd..b325a1d 100644
--- a/arch/arm/mach-davinci/include/mach/gpio-davinci.h
+++ b/arch/arm/mach-davinci/include/mach/gpio-davinci.h
@@ -60,6 +60,8 @@ struct davinci_gpio_controller {
void __iomem *set_data;
void __iomem *clr_data;
void __iomem *in_data;
+ int gpio_unbanked;
+ unsigned gpio_irq;
};

/* The __gpio_to_controller() and __gpio_mask() functions inline to constants
diff --git a/drivers/gpio/gpio-davinci.c b/drivers/gpio/gpio-davinci.c
index d308955..08830aa 100644
--- a/drivers/gpio/gpio-davinci.c
+++ b/drivers/gpio/gpio-davinci.c
@@ -11,10 +11,17 @@
*/

#include <linux/clk.h>
+#include <linux/device.h>
#include <linux/errno.h>
#include <linux/gpio.h>
#include <linux/io.h>
+#include <linux/interrupt.h>
+#include <linux/irqdomain.h>
#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/platform_data/gpio-davinci.h>
+#include <mach/gpio-davinci.h>

#include <asm/mach/irq.h>

@@ -35,10 +42,9 @@ struct davinci_gpio_regs {
#define chip2controller(chip) \
container_of(chip, struct davinci_gpio_controller, chip)

-static struct davinci_gpio_controller ctlrs[DIV_ROUND_UP(DAVINCI_N_GPIO, 32)];
static void __iomem *gpio_base;

-static struct davinci_gpio_regs __iomem __init *gpio2regs(unsigned gpio)
+static struct davinci_gpio_regs __iomem *gpio2regs(unsigned gpio)
{
void __iomem *ptr;

@@ -64,7 +70,7 @@ static inline struct davinci_gpio_regs __iomem *irq2regs(int irq)
irq_get_chip_data(irq);
}

-static int __init davinci_gpio_irq_setup(void);
+static int davinci_gpio_irq_setup(struct platform_device *pdev);

static inline int __davinci_direction(struct gpio_chip *chip,
unsigned offset, bool out, int value)
@@ -127,33 +133,52 @@ static void davinci_gpio_set(struct gpio_chip *chip, unsigned offset,
__raw_writel((1 << offset), value ? &regs->set_data : &regs->clr_data);
}

-static int __init davinci_gpio_setup(void)
+static int davinci_gpio_probe(struct platform_device *pdev)
{
int i, base;
unsigned ngpio;
- struct davinci_soc_info *soc_info = &davinci_soc_info;
+ struct davinci_gpio_controller *ctlrs;
+ struct davinci_gpio_platform_data *pdata;
struct davinci_gpio_regs *regs;
+ struct device *dev = &pdev->dev;
+ struct resource *res;

- if (soc_info->gpio_type != GPIO_TYPE_DAVINCI)
- return 0;
+ pdata = dev->platform_data;
+ if (!pdata) {
+ dev_err(dev, "GPIO: No Platform Data Supplied\n");
+ return -EINVAL;
+ }

/*
* The gpio banks conceptually expose a segmented bitmap,
* and "ngpio" is one more than the largest zero-based
* bit index that's valid.
*/
- ngpio = soc_info->gpio_num;
+ ngpio = pdata->ngpio;
if (ngpio == 0) {
- pr_err("GPIO setup: how many GPIOs?\n");
+ dev_err(dev, "GPIO Probe: how many GPIOs?\n");
return -EINVAL;
}

if (WARN_ON(DAVINCI_N_GPIO < ngpio))
ngpio = DAVINCI_N_GPIO;

- gpio_base = ioremap(soc_info->gpio_base, SZ_4K);
- if (WARN_ON(!gpio_base))
+ ctlrs = devm_kzalloc(dev,
+ ngpio * sizeof(struct davinci_gpio_controller), GFP_KERNEL);
+ if (!ctlrs) {
+ dev_err(dev, "Memory alloc failed\n");
return -ENOMEM;
+ }
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (unlikely(!res)) {
+ dev_err(dev, "Invalid mem resource\n");
+ return -ENODEV;
+ }
+
+ gpio_base = devm_ioremap_resource(dev, res);
+ if (!gpio_base)
+ return -EADDRNOTAVAIL;

for (i = 0, base = 0; base < ngpio; i++, base += 32) {
ctlrs[i].chip.label = "DaVinci";
@@ -179,13 +204,10 @@ static int __init davinci_gpio_setup(void)
gpiochip_add(&ctlrs[i].chip);
}

- soc_info->gpio_ctlrs = ctlrs;
- soc_info->gpio_ctlrs_num = DIV_ROUND_UP(ngpio, 32);
-
- davinci_gpio_irq_setup();
+ platform_set_drvdata(pdev, ctlrs);
+ davinci_gpio_irq_setup(pdev);
return 0;
}
-pure_initcall(davinci_gpio_setup);

/*
* We expect irqs will normally be set up as input pins, but they can also be
@@ -297,14 +319,14 @@ static int gpio_to_irq_banked(struct gpio_chip *chip, unsigned offset)

static int gpio_to_irq_unbanked(struct gpio_chip *chip, unsigned offset)
{
- struct davinci_soc_info *soc_info = &davinci_soc_info;
+ struct davinci_gpio_controller *ctlr = chip2controller(chip);

/*
* NOTE: we assume for now that only irqs in the first gpio_chip
* can provide direct-mapped IRQs to AINTC (up to 32 GPIOs).
*/
- if (offset < soc_info->gpio_unbanked)
- return soc_info->gpio_irq + offset;
+ if (offset < ctlr->irq_base)
+ return ctlr->gpio_irq + offset;
else
return -ENODEV;
}
@@ -313,12 +335,11 @@ static int gpio_irq_type_unbanked(struct irq_data *data, unsigned trigger)
{
struct davinci_gpio_controller *ctlr;
struct davinci_gpio_regs __iomem *regs;
- struct davinci_soc_info *soc_info = &davinci_soc_info;
u32 mask;

ctlr = (struct davinci_gpio_controller *)data->handler_data;
regs = (struct davinci_gpio_regs __iomem *)ctlr->regs;
- mask = __gpio_mask(data->irq - soc_info->gpio_irq);
+ mask = __gpio_mask(data->irq - ctlr->gpio_irq);

if (trigger & ~(IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING))
return -EINVAL;
@@ -339,23 +360,33 @@ static int gpio_irq_type_unbanked(struct irq_data *data, unsigned trigger)
* (dm6446) can be set appropriately for GPIOV33 pins.
*/

-static int __init davinci_gpio_irq_setup(void)
+static int davinci_gpio_irq_setup(struct platform_device *pdev)
{
- u32 binten = 0;
- unsigned gpio, irq, bank, ngpio, bank_irq;
- struct clk *clk;
+ u32 binten = 0;
+ unsigned gpio, irq, bank, ngpio, bank_irq;
+ struct clk *clk;
+ struct davinci_gpio_controller *ctlrs = platform_get_drvdata(pdev);
+ struct davinci_gpio_platform_data *pdata;
struct davinci_gpio_regs __iomem *regs;
- struct davinci_soc_info *soc_info = &davinci_soc_info;
+ struct device *dev = &pdev->dev;
+ struct resource *res;
+
+ pdata = dev->platform_data;
+ ngpio = pdata->ngpio;
+ res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
+ if (unlikely(!res)) {
+ dev_err(dev, "Invalid IRQ resource\n");
+ return -ENODEV;
+ }

- ngpio = soc_info->gpio_num;
+ bank_irq = res->start;

- bank_irq = soc_info->gpio_irq;
- if (bank_irq == 0) {
- printk(KERN_ERR "Don't know first GPIO bank IRQ.\n");
- return -EINVAL;
+ if (unlikely(!bank_irq)) {
+ dev_err(dev, "Invalid IRQ resource\n");
+ return -ENODEV;
}

- clk = clk_get(NULL, "gpio");
+ clk = devm_clk_get(dev, "gpio");
if (IS_ERR(clk)) {
printk(KERN_ERR "Error %ld getting gpio clock?\n",
PTR_ERR(clk));
@@ -371,8 +402,8 @@ static int __init davinci_gpio_irq_setup(void)
*/
for (gpio = 0, bank = 0; gpio < ngpio; bank++, gpio += 32) {
ctlrs[bank].chip.to_irq = gpio_to_irq_banked;
- ctlrs[bank].irq_base = soc_info->gpio_unbanked ?
- -EINVAL : (soc_info->intc_irq_num + gpio);
+ ctlrs[bank].irq_base = pdata->gpio_unbanked ?
+ -EINVAL : (pdata->intc_irq_num + gpio);
}

/*
@@ -380,7 +411,7 @@ static int __init davinci_gpio_irq_setup(void)
* controller only handling trigger modes. We currently assume no
* IRQ mux conflicts; gpio_irq_type_unbanked() is only for GPIOs.
*/
- if (soc_info->gpio_unbanked) {
+ if (pdata->gpio_unbanked) {
static struct irq_chip_type gpio_unbanked;

/* pass "bank 0" GPIO IRQs to AINTC */
@@ -400,7 +431,7 @@ static int __init davinci_gpio_irq_setup(void)
__raw_writel(~0, &regs->set_rising);

/* set the direct IRQs up to use that irqchip */
- for (gpio = 0; gpio < soc_info->gpio_unbanked; gpio++, irq++) {
+ for (gpio = 0; gpio < pdata->gpio_unbanked; gpio++, irq++) {
irq_set_chip(irq, &gpio_unbanked.chip);
irq_set_handler_data(irq, &ctlrs[gpio / 32]);
irq_set_status_flags(irq, IRQ_TYPE_EDGE_BOTH);
@@ -455,3 +486,21 @@ done:

return 0;
}
+
+static struct platform_driver davinci_gpio_driver = {
+ .probe = davinci_gpio_probe,
+ .driver = {
+ .name = "davinci_gpio",
+ .owner = THIS_MODULE,
+ },
+};
+
+/**
+ * gpio driver register needs to be done before machine_init functions
+ * access gpio APIs. Hence davinci_gpio_drv_reg() is a postcore_initcall.
+ */
+static int __init davinci_gpio_drv_reg(void)
+{
+ return platform_driver_register(&davinci_gpio_driver);
+}
+postcore_initcall(davinci_gpio_drv_reg);
--
1.7.9.5

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