| Message ID | 20190201204443.20955-1-linus.walleij@linaro.org |
|---|---|
| State | Accepted |
| Commit | 2a0b0a57fa86b951ca17cffdb4c118908dcfba65 |
| Headers | show |
| Series | None | expand |
pt., 1 lut 2019 o 21:44 Linus Walleij <linus.walleij@linaro.org> napisał(a): > > This adds a driver for Gateworks PLD GPIO, that exist in > two instances on the Gateworks Cambria GW2358-4 router > platform at least. > > Cc: Imre Kaloz <kaloz@openwrt.org> > Cc: Tim Harvey <tharvey@gateworks.com> > Signed-off-by: Linus Walleij <linus.walleij@linaro.org> > --- > ChangeLog v2->v3: > - Fix more unsigned -> unsigned int warnings, I was too trigger > happy with v2 :/ > ChangeLog v1->v2: > - Use BIT() macro for bitshifted masks. > - Use an u8 to keep track of the output value. > - Use C99 comment style in the header. > --- > drivers/gpio/Kconfig | 7 ++ > drivers/gpio/Makefile | 1 + > drivers/gpio/gpio-gw-pld.c | 136 +++++++++++++++++++++++++++++++++++++ > 3 files changed, 144 insertions(+) > create mode 100644 drivers/gpio/gpio-gw-pld.c > > diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig > index b5a2845347ec..699a8118c433 100644 > --- a/drivers/gpio/Kconfig > +++ b/drivers/gpio/Kconfig > @@ -830,6 +830,13 @@ config GPIO_ADNP > enough to represent all pins, but the driver will assume a > register layout for 64 pins (8 registers). > > +config GPIO_GW_PLD > + tristate "Gateworks PLD GPIO Expander" > + depends on OF_GPIO > + help > + Say yes here to provide access to the Gateworks I2C PLD GPIO > + Expander. This is used at least on the Cambria GW2358-4. > + > config GPIO_MAX7300 > tristate "Maxim MAX7300 GPIO expander" > select GPIO_MAX730X > diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile > index 37628f8dbf70..0568bbe6fe68 100644 > --- a/drivers/gpio/Makefile > +++ b/drivers/gpio/Makefile > @@ -55,6 +55,7 @@ obj-$(CONFIG_GPIO_FTGPIO010) += gpio-ftgpio010.o > obj-$(CONFIG_GPIO_GE_FPGA) += gpio-ge.o > obj-$(CONFIG_GPIO_GPIO_MM) += gpio-gpio-mm.o > obj-$(CONFIG_GPIO_GRGPIO) += gpio-grgpio.o > +obj-$(CONFIG_GPIO_GW_PLD) += gpio-gw-pld.o > obj-$(CONFIG_GPIO_HLWD) += gpio-hlwd.o > obj-$(CONFIG_HTC_EGPIO) += gpio-htc-egpio.o > obj-$(CONFIG_GPIO_ICH) += gpio-ich.o > diff --git a/drivers/gpio/gpio-gw-pld.c b/drivers/gpio/gpio-gw-pld.c > new file mode 100644 > index 000000000000..b3d9baec5464 > --- /dev/null > +++ b/drivers/gpio/gpio-gw-pld.c > @@ -0,0 +1,136 @@ > +// SPDX-License-Identifier: GPL-2.0+ > +// > +// Gateworks I2C PLD GPIO expander > +// > +// Copyright (C) 2019 Linus Walleij <linus.walleij@linaro.org> > +// > +// Based on code and know-how from the OpenWrt driver: > +// Copyright (C) 2009 Gateworks Corporation > +// Authors: Chris Lang, Imre Kaloz > + > +#include <linux/bits.h> > +#include <linux/kernel.h> > +#include <linux/slab.h> > +#include <linux/gpio/driver.h> > +#include <linux/i2c.h> > +#include <linux/module.h> > + > +/** > + * struct gw_pld - State container for Gateworks PLD > + * @chip: GPIO chip instance > + * @client: I2C client > + * @out: shadow register for the output bute > + */ > +struct gw_pld { > + struct gpio_chip chip; > + struct i2c_client *client; > + u8 out; > +}; > + > +/* > + * The Gateworks I2C PLD chip only expose one read and one write register. > + * Writing a "one" bit (to match the reset state) lets that pin be used as an > + * input. It is an open-drain model. > + */ > +static int gw_pld_input8(struct gpio_chip *gc, unsigned int offset) > +{ > + struct gw_pld *gw = gpiochip_get_data(gc); > + > + gw->out |= BIT(offset); > + return i2c_smbus_write_byte(gw->client, gw->out); > +} > + > +static int gw_pld_get8(struct gpio_chip *gc, unsigned int offset) > +{ > + struct gw_pld *gw = gpiochip_get_data(gc); > + s32 val; > + > + val = i2c_smbus_read_byte(gw->client); > + > + return (val < 0) ? 0 : !!(val & BIT(offset)); > +} > + > +static int gw_pld_output8(struct gpio_chip *gc, unsigned int offset, int value) > +{ > + struct gw_pld *gw = gpiochip_get_data(gc); > + > + if (value) > + gw->out |= BIT(offset); > + else > + gw->out &= ~BIT(offset); > + > + return i2c_smbus_write_byte(gw->client, gw->out); > +} > + > +static void gw_pld_set8(struct gpio_chip *gc, unsigned int offset, int value) > +{ > + gw_pld_output8(gc, offset, value); > +} > + > +static int gw_pld_probe(struct i2c_client *client, > + const struct i2c_device_id *id) > +{ > + struct device *dev = &client->dev; > + struct device_node *np = dev->of_node; > + struct gw_pld *gw; > + int ret; > + > + gw = devm_kzalloc(dev, sizeof(*gw), GFP_KERNEL); > + if (!gw) > + return -ENOMEM; > + > + gw->chip.base = -1; > + gw->chip.can_sleep = true; > + gw->chip.parent = dev; > + gw->chip.of_node = np; > + gw->chip.owner = THIS_MODULE; > + gw->chip.label = dev_name(dev); > + gw->chip.ngpio = 8; > + gw->chip.direction_input = gw_pld_input8; > + gw->chip.get = gw_pld_get8; > + gw->chip.direction_output = gw_pld_output8; > + gw->chip.set = gw_pld_set8; > + gw->client = client; > + > + /* > + * The Gateworks I2C PLD chip does not properly send the acknowledge > + * bit at all times, but we can still use the standard i2c_smbus > + * functions by simply ignoring this bit. > + */ > + client->flags |= I2C_M_IGNORE_NAK; > + gw->out = 0xFF; > + > + i2c_set_clientdata(client, gw); > + > + ret = devm_gpiochip_add_data(dev, &gw->chip, gw); > + if (ret) > + return ret; > + > + dev_info(dev, "registered Gateworks PLD GPIO device\n"); > + > + return 0; > +} > + > +static const struct i2c_device_id gw_pld_id[] = { > + { "gw-pld", }, > + { } > +}; > +MODULE_DEVICE_TABLE(i2c, gw_pld_id); > + > +static const struct of_device_id gw_pld_dt_ids[] = { > + { .compatible = "gateworks,pld-gpio", }, > +}; > +MODULE_DEVICE_TABLE(of, gw_pld_dt_ids); > + > +static struct i2c_driver gw_pld_driver = { > + .driver = { > + .name = "gw_pld", > + .of_match_table = gw_pld_dt_ids, > + }, > + .probe = gw_pld_probe, > + .id_table = gw_pld_id, > +}; > +module_i2c_driver(gw_pld_driver); > + > +MODULE_LICENSE("GPL"); > +MODULE_AUTHOR("Linus Walleij <linus.walleij@linaro.org>"); > -- > 2.20.1 > I missed the fact about this driver's i2c protocol. Now looks good. Reviewed-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig index b5a2845347ec..699a8118c433 100644 --- a/drivers/gpio/Kconfig +++ b/drivers/gpio/Kconfig @@ -830,6 +830,13 @@ config GPIO_ADNP enough to represent all pins, but the driver will assume a register layout for 64 pins (8 registers). +config GPIO_GW_PLD + tristate "Gateworks PLD GPIO Expander" + depends on OF_GPIO + help + Say yes here to provide access to the Gateworks I2C PLD GPIO + Expander. This is used at least on the Cambria GW2358-4. + config GPIO_MAX7300 tristate "Maxim MAX7300 GPIO expander" select GPIO_MAX730X diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile index 37628f8dbf70..0568bbe6fe68 100644 --- a/drivers/gpio/Makefile +++ b/drivers/gpio/Makefile @@ -55,6 +55,7 @@ obj-$(CONFIG_GPIO_FTGPIO010) += gpio-ftgpio010.o obj-$(CONFIG_GPIO_GE_FPGA) += gpio-ge.o obj-$(CONFIG_GPIO_GPIO_MM) += gpio-gpio-mm.o obj-$(CONFIG_GPIO_GRGPIO) += gpio-grgpio.o +obj-$(CONFIG_GPIO_GW_PLD) += gpio-gw-pld.o obj-$(CONFIG_GPIO_HLWD) += gpio-hlwd.o obj-$(CONFIG_HTC_EGPIO) += gpio-htc-egpio.o obj-$(CONFIG_GPIO_ICH) += gpio-ich.o diff --git a/drivers/gpio/gpio-gw-pld.c b/drivers/gpio/gpio-gw-pld.c new file mode 100644 index 000000000000..b3d9baec5464 --- /dev/null +++ b/drivers/gpio/gpio-gw-pld.c @@ -0,0 +1,136 @@ +// SPDX-License-Identifier: GPL-2.0+ +// +// Gateworks I2C PLD GPIO expander +// +// Copyright (C) 2019 Linus Walleij <linus.walleij@linaro.org> +// +// Based on code and know-how from the OpenWrt driver: +// Copyright (C) 2009 Gateworks Corporation +// Authors: Chris Lang, Imre Kaloz + +#include <linux/bits.h> +#include <linux/kernel.h> +#include <linux/slab.h> +#include <linux/gpio/driver.h> +#include <linux/i2c.h> +#include <linux/module.h> + +/** + * struct gw_pld - State container for Gateworks PLD + * @chip: GPIO chip instance + * @client: I2C client + * @out: shadow register for the output bute + */ +struct gw_pld { + struct gpio_chip chip; + struct i2c_client *client; + u8 out; +}; + +/* + * The Gateworks I2C PLD chip only expose one read and one write register. + * Writing a "one" bit (to match the reset state) lets that pin be used as an + * input. It is an open-drain model. + */ +static int gw_pld_input8(struct gpio_chip *gc, unsigned int offset) +{ + struct gw_pld *gw = gpiochip_get_data(gc); + + gw->out |= BIT(offset); + return i2c_smbus_write_byte(gw->client, gw->out); +} + +static int gw_pld_get8(struct gpio_chip *gc, unsigned int offset) +{ + struct gw_pld *gw = gpiochip_get_data(gc); + s32 val; + + val = i2c_smbus_read_byte(gw->client); + + return (val < 0) ? 0 : !!(val & BIT(offset)); +} + +static int gw_pld_output8(struct gpio_chip *gc, unsigned int offset, int value) +{ + struct gw_pld *gw = gpiochip_get_data(gc); + + if (value) + gw->out |= BIT(offset); + else + gw->out &= ~BIT(offset); + + return i2c_smbus_write_byte(gw->client, gw->out); +} + +static void gw_pld_set8(struct gpio_chip *gc, unsigned int offset, int value) +{ + gw_pld_output8(gc, offset, value); +} + +static int gw_pld_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + struct device *dev = &client->dev; + struct device_node *np = dev->of_node; + struct gw_pld *gw; + int ret; + + gw = devm_kzalloc(dev, sizeof(*gw), GFP_KERNEL); + if (!gw) + return -ENOMEM; + + gw->chip.base = -1; + gw->chip.can_sleep = true; + gw->chip.parent = dev; + gw->chip.of_node = np; + gw->chip.owner = THIS_MODULE; + gw->chip.label = dev_name(dev); + gw->chip.ngpio = 8; + gw->chip.direction_input = gw_pld_input8; + gw->chip.get = gw_pld_get8; + gw->chip.direction_output = gw_pld_output8; + gw->chip.set = gw_pld_set8; + gw->client = client; + + /* + * The Gateworks I2C PLD chip does not properly send the acknowledge + * bit at all times, but we can still use the standard i2c_smbus + * functions by simply ignoring this bit. + */ + client->flags |= I2C_M_IGNORE_NAK; + gw->out = 0xFF; + + i2c_set_clientdata(client, gw); + + ret = devm_gpiochip_add_data(dev, &gw->chip, gw); + if (ret) + return ret; + + dev_info(dev, "registered Gateworks PLD GPIO device\n"); + + return 0; +} + +static const struct i2c_device_id gw_pld_id[] = { + { "gw-pld", }, + { } +}; +MODULE_DEVICE_TABLE(i2c, gw_pld_id); + +static const struct of_device_id gw_pld_dt_ids[] = { + { .compatible = "gateworks,pld-gpio", }, +}; +MODULE_DEVICE_TABLE(of, gw_pld_dt_ids); + +static struct i2c_driver gw_pld_driver = { + .driver = { + .name = "gw_pld", + .of_match_table = gw_pld_dt_ids, + }, + .probe = gw_pld_probe, + .id_table = gw_pld_id, +}; +module_i2c_driver(gw_pld_driver); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Linus Walleij <linus.walleij@linaro.org>");
This adds a driver for Gateworks PLD GPIO, that exist in two instances on the Gateworks Cambria GW2358-4 router platform at least. Cc: Imre Kaloz <kaloz@openwrt.org> Cc: Tim Harvey <tharvey@gateworks.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org> --- ChangeLog v2->v3: - Fix more unsigned -> unsigned int warnings, I was too trigger happy with v2 :/ ChangeLog v1->v2: - Use BIT() macro for bitshifted masks. - Use an u8 to keep track of the output value. - Use C99 comment style in the header. --- drivers/gpio/Kconfig | 7 ++ drivers/gpio/Makefile | 1 + drivers/gpio/gpio-gw-pld.c | 136 +++++++++++++++++++++++++++++++++++++ 3 files changed, 144 insertions(+) create mode 100644 drivers/gpio/gpio-gw-pld.c -- 2.20.1