[PATCH 2/7] gpio: davinci: move to platform device

From: KV Sujith
Date: Sun Aug 18 2013 - 01:18:58 EST


Modify DaVinci GPIO driver to become a platform device
driver.

The driver does not have platform driver structure or
a probe. Instead, it has pure_initcall function for
initialization. The platform specific information is
obtained using the DaVinci specific davinci_soc_info
structure. This is a problem for Device Tree (DT)
implementation.

As a first stage of DT conversion, we implement a probe.

Additional notes:

- The driver registration happens as postcore_initcall.
This is required since machine init functions like
da850_lcd_hw_init() make use of GPIO.
- Start using devres APIs for simpler error handling.

Signed-off-by: KV Sujith <sujithkv@xxxxxx>
[avinashphilip@xxxxxx: Move global definition of
"davinci_gpio_controller" to local]
Signed-off-by: Philip Avinash <avinashphilip@xxxxxx>
Acked-by: Linus Walleij <linus.walleij@xxxxxxxxxx>
[nsekhar@xxxxxx: drop unused structure member, rebase to new
clean-up patch and fix error messages]
Signed-off-by: Sekhar Nori <nsekhar@xxxxxx>
Signed-off-by: Lad, Prabhakar <prabhakar.csengg@xxxxxxxxx>
---
arch/arm/mach-davinci/include/mach/gpio-davinci.h | 1 +
drivers/gpio/gpio-davinci.c | 123 ++++++++++++++-------
include/linux/platform_data/gpio-davinci.h | 25 +++++
3 files changed, 111 insertions(+), 38 deletions(-)
create mode 100644 include/linux/platform_data/gpio-davinci.h

diff --git a/arch/arm/mach-davinci/include/mach/gpio-davinci.h b/arch/arm/mach-davinci/include/mach/gpio-davinci.h
index 1fdd1fd..551ba43 100644
--- a/arch/arm/mach-davinci/include/mach/gpio-davinci.h
+++ b/arch/arm/mach-davinci/include/mach/gpio-davinci.h
@@ -60,6 +60,7 @@ struct davinci_gpio_controller {
void __iomem *set_data;
void __iomem *clr_data;
void __iomem *in_data;
+ 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 af7ea0b..b537e31 100644
--- a/drivers/gpio/gpio-davinci.c
+++ b/drivers/gpio/gpio-davinci.c
@@ -10,12 +10,17 @@
* (at your option) any later version.
*/
#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/irq.h>
+#include <linux/irqdomain.h>
#include <linux/kernel.h>
-
-#include <asm/mach/irq.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/platform_data/gpio-davinci.h>

struct davinci_gpio_regs {
u32 dir;
@@ -35,10 +40,9 @@ struct davinci_gpio_regs {
#define chip2controller(chip) \
container_of(chip, struct davinci_gpio_controller, chip)

-static struct davinci_gpio_controller chips[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;

@@ -66,7 +70,7 @@ static inline struct davinci_gpio_regs __iomem *irq2regs(int irq)
return g;
}

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

/*--------------------------------------------------------------------------*/

@@ -132,33 +136,53 @@ davinci_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
__raw_writel((1 << offset), value ? &g->set_data : &g->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_regs *regs;
-
- if (soc_info->gpio_type != GPIO_TYPE_DAVINCI)
- return 0;
+ struct davinci_gpio_controller *chips;
+ struct davinci_gpio_platform_data *pdata;
+ struct davinci_gpio_regs __iomem *regs;
+ struct device *dev = &pdev->dev;
+ struct resource *res;
+
+ pdata = dev->platform_data;
+ if (!pdata) {
+ dev_err(dev, "No platform data found\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, "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))
+ chips = devm_kzalloc(dev,
+ ngpio * sizeof(struct davinci_gpio_controller),
+ GFP_KERNEL);
+ if (!chips) {
+ dev_err(dev, "Memory allocation failed\n");
return -ENOMEM;
+ }
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res) {
+ dev_err(dev, "Invalid memory resource\n");
+ return -EBUSY;
+ }
+
+ gpio_base = devm_ioremap_resource(dev, res);
+ if (IS_ERR(gpio_base))
+ return PTR_ERR(gpio_base);

for (i = 0, base = 0; base < ngpio; i++, base += 32) {
chips[i].chip.label = "DaVinci";
@@ -184,13 +208,10 @@ static int __init davinci_gpio_setup(void)
gpiochip_add(&chips[i].chip);
}

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

/*--------------------------------------------------------------------------*/
/*
@@ -303,14 +324,14 @@ 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 *d = 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 < d->irq_base)
+ return d->gpio_irq + offset;
else
return -ENODEV;
}
@@ -319,12 +340,11 @@ static int gpio_irq_type_unbanked(struct irq_data *data, unsigned trigger)
{
struct davinci_gpio_controller *d;
struct davinci_gpio_regs __iomem *g;
- struct davinci_soc_info *soc_info = &davinci_soc_info;
u32 mask;

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

if (trigger & ~(IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_EDGE_RISING))
return -EINVAL;
@@ -345,24 +365,33 @@ 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)
{
unsigned gpio, irq, bank;
struct clk *clk;
u32 binten = 0;
unsigned ngpio, bank_irq;
- struct davinci_soc_info *soc_info = &davinci_soc_info;
- struct davinci_gpio_regs __iomem *g;
+ struct device *dev = &pdev->dev;
+ struct resource *res;
+ struct davinci_gpio_controller *chips = platform_get_drvdata(pdev);
+ struct davinci_gpio_platform_data *pdata = dev->platform_data;
+ struct davinci_gpio_regs __iomem *g;

- ngpio = soc_info->gpio_num;
+ ngpio = pdata->ngpio;
+ res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
+ if (!res) {
+ dev_err(dev, "Invalid IRQ resource\n");
+ return -EBUSY;
+ }

- bank_irq = soc_info->gpio_irq;
- if (bank_irq == 0) {
- printk(KERN_ERR "Don't know first GPIO bank IRQ.\n");
- return -EINVAL;
+ bank_irq = res->start;
+
+ if (!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));
@@ -378,9 +407,9 @@ static int __init davinci_gpio_irq_setup(void)
*/
for (gpio = 0, bank = 0; gpio < ngpio; bank++, gpio += 32) {
chips[bank].chip.to_irq = gpio_to_irq_banked;
- chips[bank].irq_base = soc_info->gpio_unbanked
+ chips[bank].irq_base = pdata->gpio_unbanked
? -EINVAL
- : (soc_info->intc_irq_num + gpio);
+ : (pdata->intc_irq_num + gpio);
}

/*
@@ -388,7 +417,7 @@ 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 */
@@ -408,7 +437,7 @@ static int __init davinci_gpio_irq_setup(void)
__raw_writel(~0, &g->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, &chips[gpio / 32]);
irq_set_status_flags(irq, IRQ_TYPE_EDGE_BOTH);
@@ -463,3 +492,21 @@ done:

return 0;
}
+
+static struct platform_driver davinci_gpio_driver = {
+ .probe = davinci_gpio_probe,
+ .driver = {
+ .name = "davinci_gpio",
+ .owner = THIS_MODULE,
+ },
+};
+
+/**
+ * GPIO driver registration needs to be done before machine_init functions
+ * access GPIO. 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);
diff --git a/include/linux/platform_data/gpio-davinci.h b/include/linux/platform_data/gpio-davinci.h
new file mode 100644
index 0000000..2fcc125
--- /dev/null
+++ b/include/linux/platform_data/gpio-davinci.h
@@ -0,0 +1,25 @@
+/*
+ * DaVinci GPIO Platform Related Defines
+ *
+ * Copyright (C) 2013 Texas Instruments Incorporated - http://www.ti.com/
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation version 2.
+ *
+ * This program is distributed "as is" WITHOUT ANY WARRANTY of any
+ * kind, whether express or implied; without even the implied warranty
+ * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ */
+
+#ifndef __DAVINCI_GPIO_PLATFORM_H
+#define __DAVINCI_GPIO_PLATFORM_H
+
+struct davinci_gpio_platform_data {
+ u32 ngpio;
+ u32 gpio_unbanked;
+ u32 intc_irq_num;
+};
+
+#endif
--
1.7.10.1


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