Re: [PATCH 10/22] gpio: Add WM831X GPIO driver

From: David Brownell
Date: Mon Jul 27 2009 - 16:28:00 EST

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In reply to: Mark Brown: "[PATCH 10/22] gpio: Add WM831X GPIO driver"
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On Monday 27 July 2009, Mark Brown wrote:
> Add support for the GPIO pins on the WM831x. No direct support is
> currently supplied for configuring non-gpiolib functionality such
> as pull configuration and alternate functions, soft configuration
> of these will be provided in a future patch.
>
> Currently use of these pins as interrupts is not supported due to
> the ongoing issues with generic irq not support interrupt controllers
> on interrupt driven buses. Users can directly request the interrupts
> with the wm831x-specific APIs currently provided if required.
>
> Signed-off-by: Mark Brown <broonie@xxxxxxxxxxxxxxxxxxxxxxxxxxx>
> Cc: David Brownell <dbrownell@xxxxxxxxxxxxxxxxxxxxx>

Acked-by: David Brownell <dbrownell@xxxxxxxxxxxxxxxxxxxxx>

> ---
> drivers/gpio/Kconfig | 7 +
> drivers/gpio/Makefile | 1 +
> drivers/gpio/wm831x-gpio.c | 252 +++++++++++++++++++++++++++++++++++++++
> include/linux/mfd/wm831x/gpio.h | 55 +++++++++
> 4 files changed, 315 insertions(+), 0 deletions(-)
> create mode 100644 drivers/gpio/wm831x-gpio.c
> create mode 100644 include/linux/mfd/wm831x/gpio.h
>
> diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
> index 96dda81..6b4c484 100644
> --- a/drivers/gpio/Kconfig
> +++ b/drivers/gpio/Kconfig
> @@ -155,6 +155,13 @@ config GPIO_TWL4030
> Say yes here to access the GPIO signals of various multi-function
> power management chips from Texas Instruments.
>
> +config GPIO_WM831X
> + tristate "WM831x GPIOs"
> + depends on MFD_WM831X
> + help
> + Say yes here to access the GPIO signals of WM831x power management
> + chips from Wolfson Microelectronics.
> +
> comment "PCI GPIO expanders:"
>
> config GPIO_BT8XX
> diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
> index 9244c6f..ea7c745 100644
> --- a/drivers/gpio/Makefile
> +++ b/drivers/gpio/Makefile
> @@ -14,3 +14,4 @@ obj-$(CONFIG_GPIO_TWL4030) += twl4030-gpio.o
> obj-$(CONFIG_GPIO_XILINX) += xilinx_gpio.o
> obj-$(CONFIG_GPIO_BT8XX) += bt8xxgpio.o
> obj-$(CONFIG_GPIO_VR41XX) += vr41xx_giu.o
> +obj-$(CONFIG_GPIO_WM831X) += wm831x-gpio.o
> diff --git a/drivers/gpio/wm831x-gpio.c b/drivers/gpio/wm831x-gpio.c
> new file mode 100644
> index 0000000..f9c09a5
> --- /dev/null
> +++ b/drivers/gpio/wm831x-gpio.c
> @@ -0,0 +1,252 @@
> +/*
> + * wm831x-gpio.c -- gpiolib support for Wolfson WM831x PMICs
> + *
> + * Copyright 2009 Wolfson Microelectronics PLC.
> + *
> + * Author: Mark Brown <broonie@xxxxxxxxxxxxxxxxxxxxxxxxxxx>
> + *
> + * 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/kernel.h>
> +#include <linux/module.h>
> +#include <linux/gpio.h>
> +#include <linux/mfd/core.h>
> +#include <linux/platform_device.h>
> +#include <linux/seq_file.h>
> +
> +#include <linux/mfd/wm831x/core.h>
> +#include <linux/mfd/wm831x/pdata.h>
> +#include <linux/mfd/wm831x/gpio.h>
> +
> +#define WM831X_GPIO_MAX 16
> +
> +struct wm831x_gpio {
> + struct wm831x *wm831x;
> + struct gpio_chip gpio_chip;
> +};
> +
> +static inline struct wm831x_gpio *to_wm831x_gpio(struct gpio_chip *chip)
> +{
> + return container_of(chip, struct wm831x_gpio, gpio_chip);
> +}
> +
> +static int wm831x_gpio_direction_in(struct gpio_chip *chip, unsigned offset)
> +{
> + struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
> + struct wm831x *wm831x = wm831x_gpio->wm831x;
> +
> + return wm831x_set_bits(wm831x, WM831X_GPIO1_CONTROL + offset,
> + WM831X_GPN_DIR | WM831X_GPN_TRI,
> + WM831X_GPN_DIR);
> +}
> +
> +static int wm831x_gpio_get(struct gpio_chip *chip, unsigned offset)
> +{
> + struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
> + struct wm831x *wm831x = wm831x_gpio->wm831x;
> + int ret;
> +
> + ret = wm831x_reg_read(wm831x, WM831X_GPIO_LEVEL);
> + if (ret < 0)
> + return ret;
> +
> + if (ret & 1 << offset)
> + return 1;
> + else
> + return 0;
> +}
> +
> +static int wm831x_gpio_direction_out(struct gpio_chip *chip,
> + unsigned offset, int value)
> +{
> + struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
> + struct wm831x *wm831x = wm831x_gpio->wm831x;
> +
> + return wm831x_set_bits(wm831x, WM831X_GPIO1_CONTROL + offset,
> + WM831X_GPN_DIR | WM831X_GPN_TRI, 0);
> +}
> +
> +static void wm831x_gpio_set(struct gpio_chip *chip, unsigned offset, int value)
> +{
> + struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
> + struct wm831x *wm831x = wm831x_gpio->wm831x;
> +
> + wm831x_set_bits(wm831x, WM831X_GPIO_LEVEL, 1 << offset,
> + value << offset);
> +}
> +
> +#ifdef CONFIG_DEBUG_FS
> +static void wm831x_gpio_dbg_show(struct seq_file *s, struct gpio_chip *chip)
> +{
> + struct wm831x_gpio *wm831x_gpio = to_wm831x_gpio(chip);
> + struct wm831x *wm831x = wm831x_gpio->wm831x;
> + int i;
> +
> + for (i = 0; i < chip->ngpio; i++) {
> + int gpio = i + chip->base;
> + int reg;
> + const char *label, *pull, *powerdomain;
> +
> + /* We report the GPIO even if it's not requested since
> + * we're also reporting things like alternate
> + * functions which apply even when the GPIO is not in
> + * use as a GPIO.
> + */
> + label = gpiochip_is_requested(chip, i);
> + if (!label)
> + label = "Unrequested";
> +
> + seq_printf(s, " gpio-%-3d (%-20.20s) ", gpio, label);
> +
> + reg = wm831x_reg_read(wm831x, WM831X_GPIO1_CONTROL + i);
> + if (reg < 0) {
> + dev_err(wm831x->dev,
> + "GPIO control %d read failed: %d\n",
> + gpio, reg);
> + seq_printf(s, "\n");
> + continue;
> + }
> +
> + switch (reg & WM831X_GPN_PULL_MASK) {
> + case WM831X_GPIO_PULL_NONE:
> + pull = "nopull";
> + break;
> + case WM831X_GPIO_PULL_DOWN:
> + pull = "pulldown";
> + break;
> + case WM831X_GPIO_PULL_UP:
> + pull = "pullup";
> + default:
> + pull = "INVALID PULL";
> + break;
> + }
> +
> + switch (i + 1) {
> + case 1 ... 3:
> + case 7 ... 9:
> + if (reg & WM831X_GPN_PWR_DOM)
> + powerdomain = "VPMIC";
> + else
> + powerdomain = "DBVDD";
> + break;
> +
> + case 4 ... 6:
> + case 10 ... 12:
> + if (reg & WM831X_GPN_PWR_DOM)
> + powerdomain = "SYSVDD";
> + else
> + powerdomain = "DBVDD";
> + break;
> +
> + case 13 ... 16:
> + powerdomain = "TPVDD";
> + break;
> +
> + default:
> + BUG();
> + break;
> + }
> +
> + seq_printf(s, " %s %s %s %s%s\n"
> + " %s%s (0x%4x)\n",
> + reg & WM831X_GPN_DIR ? "in" : "out",
> + wm831x_gpio_get(chip, i) ? "high" : "low",
> + pull,
> + powerdomain,
> + reg & WM831X_GPN_POL ? " inverted" : "",
> + reg & WM831X_GPN_OD ? "open-drain" : "CMOS",
> + reg & WM831X_GPN_TRI ? " tristated" : "",
> + reg);
> + }
> +}
> +#else
> +#define wm831x_gpio_dbg_show NULL
> +#endif
> +
> +static struct gpio_chip template_chip = {
> + .label = "wm831x",
> + .owner = THIS_MODULE,
> + .direction_input = wm831x_gpio_direction_in,
> + .get = wm831x_gpio_get,
> + .direction_output = wm831x_gpio_direction_out,
> + .set = wm831x_gpio_set,
> + .dbg_show = wm831x_gpio_dbg_show,
> + .can_sleep = 1,
> +};
> +
> +static int __devinit wm831x_gpio_probe(struct platform_device *pdev)
> +{
> + struct wm831x *wm831x = dev_get_drvdata(pdev->dev.parent);
> + struct wm831x_pdata *pdata = wm831x->dev->platform_data;
> + struct wm831x_gpio *wm831x_gpio;
> + int ret;
> +
> + wm831x_gpio = kzalloc(sizeof(*wm831x_gpio), GFP_KERNEL);
> + if (wm831x_gpio == NULL)
> + return -ENOMEM;
> +
> + wm831x_gpio->wm831x = wm831x;
> + wm831x_gpio->gpio_chip = template_chip;
> + wm831x_gpio->gpio_chip.ngpio = WM831X_GPIO_MAX;
> + wm831x_gpio->gpio_chip.dev = &pdev->dev;
> + if (pdata && pdata->gpio_base)
> + wm831x_gpio->gpio_chip.base = pdata->gpio_base;
> + else
> + wm831x_gpio->gpio_chip.base = -1;
> +
> + ret = gpiochip_add(&wm831x_gpio->gpio_chip);
> + if (ret < 0) {
> + dev_err(&pdev->dev, "Could not register gpiochip, %d\n",
> + ret);
> + goto err;
> + }
> +
> + platform_set_drvdata(pdev, wm831x_gpio);
> +
> + return ret;
> +
> +err:
> + kfree(wm831x_gpio);
> + return ret;
> +}
> +
> +static int __devexit wm831x_gpio_remove(struct platform_device *pdev)
> +{
> + struct wm831x_gpio *wm831x_gpio = platform_get_drvdata(pdev);
> + int ret;
> +
> + ret = gpiochip_remove(&wm831x_gpio->gpio_chip);
> + if (ret == 0)
> + kfree(wm831x_gpio);
> +
> + return ret;
> +}
> +
> +static struct platform_driver wm831x_gpio_driver = {
> + .driver.name = "wm831x-gpio",
> + .driver.owner = THIS_MODULE,
> + .probe = wm831x_gpio_probe,
> + .remove = __devexit_p(wm831x_gpio_remove),
> +};
> +
> +static int __init wm831x_gpio_init(void)
> +{
> + return platform_driver_register(&wm831x_gpio_driver);
> +}
> +subsys_initcall(wm831x_gpio_init);
> +
> +static void __exit wm831x_gpio_exit(void)
> +{
> + platform_driver_unregister(&wm831x_gpio_driver);
> +}
> +module_exit(wm831x_gpio_exit);
> +
> +MODULE_AUTHOR("Mark Brown <broonie@xxxxxxxxxxxxxxxxxxxxxxxxxxx>");
> +MODULE_DESCRIPTION("GPIO interface for WM831x PMICs");
> +MODULE_LICENSE("GPL");
> +MODULE_ALIAS("platform:wm831x-gpio");
> diff --git a/include/linux/mfd/wm831x/gpio.h b/include/linux/mfd/wm831x/gpio.h
> new file mode 100644
> index 0000000..2835614
> --- /dev/null
> +++ b/include/linux/mfd/wm831x/gpio.h
> @@ -0,0 +1,55 @@
> +/*
> + * include/linux/mfd/wm831x/gpio.h -- GPIO for WM831x
> + *
> + * Copyright 2009 Wolfson Microelectronics PLC.
> + *
> + * Author: Mark Brown <broonie@xxxxxxxxxxxxxxxxxxxxxxxxxxx>
> + *
> + * 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.
> + *
> + */
> +
> +#ifndef __MFD_WM831X_GPIO_H__
> +#define __MFD_WM831X_GPIO_H__
> +
> +/*
> + * R16440-16455 (0x4038-0x4047) - GPIOx Control
> + */
> +#define WM831X_GPN_DIR 0x8000 /* GPN_DIR */
> +#define WM831X_GPN_DIR_MASK 0x8000 /* GPN_DIR */
> +#define WM831X_GPN_DIR_SHIFT 15 /* GPN_DIR */
> +#define WM831X_GPN_DIR_WIDTH 1 /* GPN_DIR */
> +#define WM831X_GPN_PULL_MASK 0x6000 /* GPN_PULL - [14:13] */
> +#define WM831X_GPN_PULL_SHIFT 13 /* GPN_PULL - [14:13] */
> +#define WM831X_GPN_PULL_WIDTH 2 /* GPN_PULL - [14:13] */
> +#define WM831X_GPN_INT_MODE 0x1000 /* GPN_INT_MODE */
> +#define WM831X_GPN_INT_MODE_MASK 0x1000 /* GPN_INT_MODE */
> +#define WM831X_GPN_INT_MODE_SHIFT 12 /* GPN_INT_MODE */
> +#define WM831X_GPN_INT_MODE_WIDTH 1 /* GPN_INT_MODE */
> +#define WM831X_GPN_PWR_DOM 0x0800 /* GPN_PWR_DOM */
> +#define WM831X_GPN_PWR_DOM_MASK 0x0800 /* GPN_PWR_DOM */
> +#define WM831X_GPN_PWR_DOM_SHIFT 11 /* GPN_PWR_DOM */
> +#define WM831X_GPN_PWR_DOM_WIDTH 1 /* GPN_PWR_DOM */
> +#define WM831X_GPN_POL 0x0400 /* GPN_POL */
> +#define WM831X_GPN_POL_MASK 0x0400 /* GPN_POL */
> +#define WM831X_GPN_POL_SHIFT 10 /* GPN_POL */
> +#define WM831X_GPN_POL_WIDTH 1 /* GPN_POL */
> +#define WM831X_GPN_OD 0x0200 /* GPN_OD */
> +#define WM831X_GPN_OD_MASK 0x0200 /* GPN_OD */
> +#define WM831X_GPN_OD_SHIFT 9 /* GPN_OD */
> +#define WM831X_GPN_OD_WIDTH 1 /* GPN_OD */
> +#define WM831X_GPN_TRI 0x0080 /* GPN_TRI */
> +#define WM831X_GPN_TRI_MASK 0x0080 /* GPN_TRI */
> +#define WM831X_GPN_TRI_SHIFT 7 /* GPN_TRI */
> +#define WM831X_GPN_TRI_WIDTH 1 /* GPN_TRI */
> +#define WM831X_GPN_FN_MASK 0x000F /* GPN_FN - [3:0] */
> +#define WM831X_GPN_FN_SHIFT 0 /* GPN_FN - [3:0] */
> +#define WM831X_GPN_FN_WIDTH 4 /* GPN_FN - [3:0] */
> +
> +#define WM831X_GPIO_PULL_NONE (0 << WM831X_GPN_PULL_SHIFT)
> +#define WM831X_GPIO_PULL_DOWN (1 << WM831X_GPN_PULL_SHIFT)
> +#define WM831X_GPIO_PULL_UP (2 << WM831X_GPN_PULL_SHIFT)
> +#endif
> --
> 1.6.3.3
>
>

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