Re: [PATCH 02/11] GPIO: DA9052 GPIO module v3

From: Grant Likely
Date: Wed Jul 06 2011 - 12:37:09 EST


On Wed, Jul 06, 2011 at 04:02:13PM +0530, ashishj3 wrote:
> DA9052 PMIC has 16 bit GPIO bus for peripheral control.
>
> This patch add support for the GPIO pins on the DA9052.
>
> Signed-off-by: David Dajun Chen <dchen@xxxxxxxxxxx>
> Signed-off-by: Ashish Jangam <ashish.jangam@xxxxxxxxxxxxxxx>
> CC: Arnd Bergmann <arnd@xxxxxxxx>
> CC: Mark Brown <broonie@xxxxxxxxxxxxxxxxxxxxxxxxxxx>

Acked-by: Grant Likely <grant.likely@xxxxxxxxxxxx>

It looks like this needs to be merged via the MFD tree since it
depends on the core da9052 driver patch.

Also, comments below:

> ---
> Changes since v3:
> - Remove da9052 gpio header file
>
> Changes since v2:
> - change of file name
> - correct reference to irq_base in function to_irq()
> - remove pdata dependency
> ---
> drivers/gpio/Kconfig | 6 +
> drivers/gpio/Makefile | 1 +
> drivers/gpio/gpio-da9052.c | 279 ++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 286 insertions(+), 0 deletions(-)
> create mode 100755 drivers/gpio/gpio-da9052.c
> diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
> index d3b2953..df510d4 100644
> --- a/drivers/gpio/Kconfig
> +++ b/drivers/gpio/Kconfig
> @@ -65,6 +65,12 @@ config GPIO_SYSFS
>
> # put expanders in the right section, in alphabetical order
>
> +config GPIO_DA9052
> + tristate "Dialog DA9052 GPIO"
> + depends on PMIC_DA9052
> + help
> + Say yes here to enable the GPIO driver for the DA9052 chip.
> +
> config GPIO_MAX730X
> tristate
>
> diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
> index becef59..cbee503 100644
> --- a/drivers/gpio/Makefile
> +++ b/drivers/gpio/Makefile
> @@ -11,6 +11,7 @@ obj-$(CONFIG_GPIOLIB) += gpiolib.o
> obj-$(CONFIG_GPIO_ADP5520) += adp5520-gpio.o
> obj-$(CONFIG_GPIO_ADP5588) += adp5588-gpio.o
> obj-$(CONFIG_GPIO_BASIC_MMIO) += basic_mmio_gpio.o
> +obj-$(CONFIG_GPIO_DA9052) += gpio-da9052.o
> obj-$(CONFIG_GPIO_LANGWELL) += langwell_gpio.o
> obj-$(CONFIG_GPIO_MAX730X) += max730x.o
> obj-$(CONFIG_GPIO_MAX7300) += max7300.o
> diff --git a/drivers/gpio/gpio-da9052.c b/drivers/gpio/gpio-da9052.c
> new file mode 100755
> index 0000000..5623369
> --- /dev/null
> +++ b/drivers/gpio/gpio-da9052.c
> @@ -0,0 +1,279 @@
> +/*
> + * GPIO Driver for Dialog DA9052 PMICs.
> + *
> + * Copyright(c) 2011 Dialog Semiconductor Ltd.
> + *
> + * Author: David Dajun Chen <dchen@xxxxxxxxxxx>
> + *
> + * 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; either version 2 of the License, or (at your
> + * option) any later version.
> + *
> + */
> +#include <linux/module.h>
> +#include <linux/fs.h>
> +#include <linux/uaccess.h>
> +#include <linux/platform_device.h>
> +#include <linux/gpio.h>
> +#include <linux/syscalls.h>
> +#include <linux/seq_file.h>
> +
> +#include <linux/mfd/da9052/da9052.h>
> +#include <linux/mfd/da9052/reg.h>
> +#include <linux/mfd/da9052/pdata.h>
> +#include <linux/mfd/da9052/gpio.h>
> +
> +#define DA9052_INPUT 1
> +#define DA9052_OUTPUT_OPENDRAIN 2
> +#define DA9052_OUTPUT_PUSHPULL 3
> +
> +#define DA9052_SUPPLY_VDD_IO1 0
> +
> +#define DA9052_DEBOUNCING_OFF 0
> +#define DA9052_DEBOUNCING_ON 1
> +
> +#define DA9052_OUTPUT_LOWLEVEL 0
> +
> +#define DA9052_ACTIVE_LOW 0
> +#define DA9052_ACTIVE_HIGH 1
> +
> +#define DA9052_GPIO_MAX_PORTS_PER_REGISTER 8
> +#define DA9052_GPIO_SHIFT_COUNT(no) (no%8)
> +#define DA9052_GPIO_MASK_UPPER_NIBBLE 0xF0
> +#define DA9052_GPIO_MASK_LOWER_NIBBLE 0x0F
> +#define DA9052_GPIO_NIBBLE_SHIFT 4
> +
> +struct da9052_gpio {
> + struct da9052 *da9052;
> + struct gpio_chip gp;
> +};
> +
> +static inline struct da9052_gpio *to_da9052_gpio(struct gpio_chip *chip)
> +{
> + return container_of(chip, struct da9052_gpio, gp);
> +}
> +
> +static unsigned char da9052_gpio_port_odd(unsigned offset)
> +{
> + return offset % 2;
> +}
> +
> +static int da9052_gpio_get(struct gpio_chip *gc, unsigned offset)
> +{
> + struct da9052_gpio *gpio = to_da9052_gpio(gc);
> + int da9052_port_direction = 0;
> + int ret;
> +
> + ret = da9052_reg_read(gpio->da9052,
> + DA9052_GPIO_0_1_REG + (offset >> 1));
> + if (ret < 0)
> + return ret;
> +
> + if (da9052_gpio_port_odd(offset)) {
> + da9052_port_direction = ret & DA9052_GPIO_ODD_PORT_PIN;
> + da9052_port_direction >>= 4;
> + } else {
> + da9052_port_direction = ret & DA9052_GPIO_EVEN_PORT_PIN;
> + }
> +
> + switch (da9052_port_direction) {
> + case DA9052_INPUT:
> + if (offset < DA9052_GPIO_MAX_PORTS_PER_REGISTER)
> + ret = da9052_reg_read(gpio->da9052,
> + DA9052_STATUS_C_REG);
> + else
> + ret = da9052_reg_read(gpio->da9052,
> + DA9052_STATUS_D_REG);
> + if (ret < 0)
> + return ret;
> + if (ret & (1 << DA9052_GPIO_SHIFT_COUNT(offset)))
> + return 1;
> + else
> + return 0;
> + case DA9052_OUTPUT_PUSHPULL:
> + if (da9052_gpio_port_odd(offset))
> + return ret & DA9052_GPIO_ODD_PORT_MODE;
> + else
> + return ret & DA9052_GPIO_EVEN_PORT_MODE;
> + default:
> + return -EINVAL;
> + }
> +}
> +
> +static void da9052_gpio_set(struct gpio_chip *gc, unsigned offset, int value)
> +{
> + struct da9052_gpio *gpio = to_da9052_gpio(gc);
> + unsigned char register_value = 0;
> + int ret;
> +
> + if (da9052_gpio_port_odd(offset)) {
> + if (value) {
> + register_value = DA9052_GPIO_ODD_PORT_MODE;
> + ret = da9052_reg_update(gpio->da9052, (offset >> 1) +
> + DA9052_GPIO_0_1_REG,
> + DA9052_GPIO_ODD_PORT_MODE,
> + register_value);
> + if (ret != 0)
> + dev_err(gpio->da9052->dev,
> + "Failed to updated gpio odd reg,%d",
> + ret);
> + }
> + } else {
> + if (value) {
> + register_value = DA9052_GPIO_EVEN_PORT_MODE;
> + ret = da9052_reg_update(gpio->da9052, (offset >> 1) +
> + DA9052_GPIO_0_1_REG,
> + DA9052_GPIO_EVEN_PORT_MODE,
> + register_value);
> + if (ret != 0)
> + dev_err(gpio->da9052->dev,
> + "Failed to updated gpio even reg,%d",
> + ret);
> + }
> + }
> +}
> +
> +static int da9052_gpio_direction_input(struct gpio_chip *gc, unsigned offset)
> +{
> + struct da9052_gpio *gpio = to_da9052_gpio(gc);
> + unsigned char register_value;
> + int ret;
> +
> + /* Format: function - 2 bits type - 1 bit mode - 1 bit */
> + register_value = DA9052_INPUT | DA9052_ACTIVE_LOW << 2 |
> + DA9052_DEBOUNCING_ON << 3;
> +
> + if (da9052_gpio_port_odd(offset))
> + ret = da9052_reg_update(gpio->da9052, (offset >> 1) +
> + DA9052_GPIO_0_1_REG,
> + DA9052_GPIO_MASK_UPPER_NIBBLE,
> + (register_value <<
> + DA9052_GPIO_NIBBLE_SHIFT));
> + else
> + ret = da9052_reg_update(gpio->da9052, (offset >> 1) +
> + DA9052_GPIO_0_1_REG,
> + DA9052_GPIO_MASK_LOWER_NIBBLE,
> + register_value);
> +
> + return ret;
> +}
> +
> +static int da9052_gpio_direction_output(struct gpio_chip *gc,
> + unsigned offset, int value)
> +{
> + struct da9052_gpio *gpio = to_da9052_gpio(gc);
> + unsigned char register_value;
> + int ret;
> +
> + /* Format: Function - 2 bits Type - 1 bit Mode - 1 bit */
> + register_value = DA9052_OUTPUT_PUSHPULL | DA9052_SUPPLY_VDD_IO1 << 2 |
> + value << 3;
> +
> + if (da9052_gpio_port_odd(offset))
> + ret = da9052_reg_update(gpio->da9052, (offset >> 1) +
> + DA9052_GPIO_0_1_REG,
> + DA9052_GPIO_MASK_UPPER_NIBBLE,
> + (register_value <<
> + DA9052_GPIO_NIBBLE_SHIFT));
> + else
> + ret = da9052_reg_update(gpio->da9052, (offset >> 1) +
> + DA9052_GPIO_0_1_REG,
> + DA9052_GPIO_MASK_LOWER_NIBBLE,
> + register_value);
> +
> + return ret;
> +}
> +
> +static int da9052_gpio_to_irq(struct gpio_chip *gc, u32 offset)
> +{
> + struct da9052_gpio *gpio = to_da9052_gpio(gc);
> + struct da9052 *da9052 = gpio->da9052;
> +
> + return da9052->irq_base + DA9052_IRQ_GPI0 + offset;

Who allocates the irq_descs for these irqs?

> +}
> +
> +static struct gpio_chip reference_gp{

static struct gpio_chip reference_gp __devinitdata = {

> + .label = "da9052-gpio",
> + .owner = THIS_MODULE,
> + .get = da9052_gpio_get,
> + .set = da9052_gpio_set,
> + .direction_input = da9052_gpio_direction_input,
> + .direction_output = da9052_gpio_direction_output,
> + .to_irq = da9052_gpio_to_irq,
> + .can_sleep = 1;

Nitpick: I prefer the form (single space instead of tabs before the '=')
.label = "da9052-gpio",

> +};
> +
> +static int __devinit da9052_gpio_probe(struct platform_device *pdev)
> +{
> + struct da9052_gpio *gpio;
> + struct da9052_pdata *pdata;
> + int ret;
> +
> + gpio = kzalloc(sizeof(*gpio), GFP_KERNEL);
> + if (gpio == NULL)
> + return -ENOMEM;
> +
> + gpio->da9052 = dev_get_drvdata(pdev->dev.parent);
> + pdata = gpio->da9052->dev->platform_data;
> +
> + gpio->da9052 = dev_get_drvdata(pdev->dev.parent);
> + gpio->gp = reference_gp;
> + gpio->gp.ngpio = 16;
> + if (pdata && pdata->gpio_base)
> + gpio->gp.base = pdata->gpio_base;
> + else
> + gpio->gp.base = -1;

Why not put the default values of .ngpio = 16 and .base = -1 into the
reference_gp?

> +
> + ret = gpiochip_add(&gpio->gp);
> + if (ret < 0) {
> + dev_err(&pdev->dev, "Could not register gpiochip, %d\n", ret);
> + goto err_mem;
> + }
> +
> + platform_set_drvdata(pdev, gpio);
> +
> + return 0;
> +
> +err_mem:
> + kfree(gpio);
> + return ret;
> +}
> +
> +static int __devexit da9052_gpio_remove(struct platform_device *pdev)
> +{
> + struct da9052_gpio *gpio = platform_get_drvdata(pdev);
> + int ret;
> +
> + ret = gpiochip_remove(&gpio->gp);
> + if (ret == 0)
> + kfree(gpio);
> +
> + return ret;
> +}
> +
> +static struct platform_driver da9052_gpio_driver = {
> + .probe = da9052_gpio_probe,
> + .remove = __devexit_p(da9052_gpio_remove),
> + .driver = {
> + .name = "da9052-gpio",
> + .owner = THIS_MODULE,
> + },
> +};
> +
> +static int __init da9052_gpio_init(void)
> +{
> + return platform_driver_register(&da9052_gpio_driver);
> +}
> +module_init(da9052_gpio_init);
> +
> +static void __exit da9052_gpio_exit(void)
> +{
> + return platform_driver_unregister(&da9052_gpio_driver);
> +}
> +module_exit(da9052_gpio_exit);
> +
> +MODULE_AUTHOR("David Dajun Chen <dchen@xxxxxxxxxxx>");
> +MODULE_DESCRIPTION("DA9052 GPIO Device Driver");
> +MODULE_LICENSE("GPL");
> +MODULE_ALIAS("platform:da9052-gpio");
>
>
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