lkml.org 
[lkml]   [2021]   [Jan]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
    Patch in this message
    /
    Date
    From
    Subject[PATCH v2 10/17] gpio: support ROHM BD71815 GPOs
    Support GPO(s) found from ROHM BD71815 power management IC. The IC has two
    GPO pins but only one is properly documented in data-sheet. The driver
    exposes by default only the documented GPO. The second GPO is connected to
    E5 pin and is marked as GND in data-sheet. Control for this undocumented
    pin can be enabled using a special DT property.

    This driver is derived from work by Peter Yang <yanglsh@embest-tech.com>
    although not so much of original is left.

    Signed-off-by: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
    ---
    Changes since v1:
    - removed unneeded headers
    - clarified dev/parent->dev usage
    - removed forgotten #define DEBUG

    drivers/gpio/Kconfig | 10 +++
    drivers/gpio/Makefile | 1 +
    drivers/gpio/gpio-bd71815.c | 171 ++++++++++++++++++++++++++++++++++++
    3 files changed, 182 insertions(+)
    create mode 100644 drivers/gpio/gpio-bd71815.c

    diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
    index c70f46e80a3b..fd7283af858d 100644
    --- a/drivers/gpio/Kconfig
    +++ b/drivers/gpio/Kconfig
    @@ -1096,6 +1096,16 @@ config GPIO_BD70528
    This driver can also be built as a module. If so, the module
    will be called gpio-bd70528.

    +config GPIO_BD71815
    + tristate "ROHM BD71815 PMIC GPIO support"
    + depends on MFD_ROHM_BD71828
    + help
    + Support for GPO(s) on ROHM BD71815 PMIC. There are two GPOs
    + available on the ROHM PMIC.
    +
    + This driver can also be built as a module. If so, the module
    + will be called gpio-bd71815.
    +
    config GPIO_BD71828
    tristate "ROHM BD71828 GPIO support"
    depends on MFD_ROHM_BD71828
    diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
    index 35e3b6026665..86bb680522a6 100644
    --- a/drivers/gpio/Makefile
    +++ b/drivers/gpio/Makefile
    @@ -39,6 +39,7 @@ obj-$(CONFIG_GPIO_ATH79) += gpio-ath79.o
    obj-$(CONFIG_GPIO_BCM_KONA) += gpio-bcm-kona.o
    obj-$(CONFIG_GPIO_BCM_XGS_IPROC) += gpio-xgs-iproc.o
    obj-$(CONFIG_GPIO_BD70528) += gpio-bd70528.o
    +obj-$(CONFIG_GPIO_BD71815) += gpio-bd71815.o
    obj-$(CONFIG_GPIO_BD71828) += gpio-bd71828.o
    obj-$(CONFIG_GPIO_BD9571MWV) += gpio-bd9571mwv.o
    obj-$(CONFIG_GPIO_BRCMSTB) += gpio-brcmstb.o
    diff --git a/drivers/gpio/gpio-bd71815.c b/drivers/gpio/gpio-bd71815.c
    new file mode 100644
    index 000000000000..664de5f69bf1
    --- /dev/null
    +++ b/drivers/gpio/gpio-bd71815.c
    @@ -0,0 +1,171 @@
    +// SPDX-License-Identifier: GPL-2.0
    +/*
    + * Support to GPOs on ROHM BD71815
    + */
    +#include <linux/module.h>
    +#include <linux/init.h>
    +#include <linux/irq.h>
    +#include <linux/gpio/driver.h>
    +#include <linux/platform_device.h>
    +#include <linux/of.h>
    +/* For the BD71815 register definitions */
    +#include <linux/mfd/rohm-bd71815.h>
    +
    +struct bd71815_gpio {
    + struct gpio_chip chip;
    + struct device *dev;
    + struct regmap *regmap;
    + /*
    + * Sigh. The BD71815 and BD71817 were originally designed to support two
    + * GPO pins. At some point it was noticed the second GPO pin which is
    + * the E5 pin located at the center of IC is hard to use on PCB (due to
    + * the location). It was decided to not promote this second GPO and pin
    + * is marked as GND on the data-sheet. The functionality is still there
    + * though! I guess driving GPO connected to ground is a bad idea. Thus
    + * we do not support it by default. OTOH - the original driver written
    + * by colleagues at Embest did support controlling this second GPO. It
    + * is thus possible this is used in some of the products.
    + *
    + * This driver does not by default support configuring this second GPO
    + * but allows using it by providing the DT property
    + * "rohm,enable-hidden-gpo".
    + */
    + bool e5_pin_is_gpo;
    +};
    +
    +static int bd71815gpo_get(struct gpio_chip *chip, unsigned int offset)
    +{
    + struct bd71815_gpio *bd71815 = gpiochip_get_data(chip);
    + int ret = 0;
    + int val;
    +
    + ret = regmap_read(bd71815->regmap, BD71815_REG_GPO, &val);
    + if (ret)
    + return ret;
    +
    + return (val >> offset) & 1;
    +}
    +
    +static void bd71815gpo_set(struct gpio_chip *chip, unsigned int offset,
    + int value)
    +{
    + struct bd71815_gpio *bd71815 = gpiochip_get_data(chip);
    + int ret, val, mask;
    +
    + if (!bd71815->e5_pin_is_gpo && offset)
    + return;
    +
    + mask = BIT(offset);
    + val = value ? mask : 0;
    + ret = regmap_update_bits(bd71815->regmap, BD71815_REG_GPO, mask, val);
    + if (ret)
    + dev_warn(bd71815->dev, "failed to toggle GPO\n");
    +}
    +
    +static int bd71815_gpio_set_config(struct gpio_chip *chip, unsigned int offset,
    + unsigned long config)
    +{
    + struct bd71815_gpio *bdgpio = gpiochip_get_data(chip);
    +
    + if (!bdgpio->e5_pin_is_gpo && offset)
    + return -EOPNOTSUPP;
    +
    + switch (pinconf_to_config_param(config)) {
    + case PIN_CONFIG_DRIVE_OPEN_DRAIN:
    + return regmap_update_bits(bdgpio->regmap,
    + BD71815_REG_GPO,
    + BD71815_GPIO_DRIVE_MASK << offset,
    + BD71815_GPIO_OPEN_DRAIN << offset);
    + case PIN_CONFIG_DRIVE_PUSH_PULL:
    + return regmap_update_bits(bdgpio->regmap,
    + BD71815_REG_GPO,
    + BD71815_GPIO_DRIVE_MASK << offset,
    + BD71815_GPIO_CMOS << offset);
    + default:
    + break;
    + }
    + return -EOPNOTSUPP;
    +}
    +
    +/* BD71815 GPIO is actually GPO */
    +static int bd71815gpo_direction_get(struct gpio_chip *gc, unsigned int offset)
    +{
    + return GPIO_LINE_DIRECTION_OUT;
    +}
    +
    +/* Template for GPIO chip */
    +static struct gpio_chip bd71815gpo_chip = {
    + .label = "bd71815",
    + .owner = THIS_MODULE,
    + .get = bd71815gpo_get,
    + .get_direction = bd71815gpo_direction_get,
    + .set = bd71815gpo_set,
    + .set_config = bd71815_gpio_set_config,
    + .can_sleep = 1,
    +};
    +
    +static int gpo_bd71815_probe(struct platform_device *pdev)
    +{
    + int ret;
    + struct bd71815_gpio *g;
    + struct device *dev;
    + struct device *parent;
    +
    + /*
    + * Bind devm lifetime to this platform device => use dev for devm.
    + * also the prints should originate from this device.
    + */
    + dev = &pdev->dev;
    + /* The device-tree and regmap come from MFD => use parent for that */
    + parent = dev->parent;
    +
    + g = devm_kzalloc(dev, sizeof(*g), GFP_KERNEL);
    + if (!g)
    + return -ENOMEM;
    +
    + g->e5_pin_is_gpo = of_property_read_bool(parent->of_node,
    + "rohm,enable-hidden-gpo");
    + g->chip = bd71815gpo_chip;
    + g->chip.base = -1;
    +
    + if (g->e5_pin_is_gpo)
    + g->chip.ngpio = 2;
    + else
    + g->chip.ngpio = 1;
    +
    + g->chip.parent = parent;
    + g->chip.of_node = parent->of_node;
    + g->regmap = dev_get_regmap(parent, NULL);
    + g->dev = dev;
    +
    + ret = devm_gpiochip_add_data(dev, &g->chip, g);
    + if (ret < 0) {
    + dev_err(dev, "could not register gpiochip, %d\n", ret);
    + return ret;
    + }
    +
    + return ret;
    +}
    +static const struct platform_device_id bd7181x_gpo_id[] = {
    + { "bd71815-gpo" },
    + { },
    +};
    +MODULE_DEVICE_TABLE(platform, bd7181x_gpo_id);
    +
    +static struct platform_driver gpo_bd71815_driver = {
    + .driver = {
    + .name = "bd71815-gpo",
    + .owner = THIS_MODULE,
    + },
    + .probe = gpo_bd71815_probe,
    + .id_table = bd7181x_gpo_id,
    +};
    +
    +module_platform_driver(gpo_bd71815_driver);
    +
    +/* Note: this hardware lives inside an I2C-based multi-function device. */
    +MODULE_ALIAS("platform:bd71815-gpo");
    +
    +MODULE_AUTHOR("Peter Yang <yanglsh@embest-tech.com>");
    +MODULE_DESCRIPTION("GPO interface for BD71815");
    +MODULE_LICENSE("GPL");
    --
    2.25.4

    --
    Matti Vaittinen, Linux device drivers
    ROHM Semiconductors, Finland SWDC
    Kiviharjunlenkki 1E
    90220 OULU
    FINLAND

    ~~~ "I don't think so," said Rene Descartes. Just then he vanished ~~~
    Simon says - in Latin please.
    ~~~ "non cogito me" dixit Rene Descarte, deinde evanescavit ~~~
    Thanks to Simon Glass for the translation =]

    \
     
     \ /
      Last update: 2021-01-19 08:29    [W:4.368 / U:0.056 seconds]
    ©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site