This driver is generic and aims to support all Technologic Systems's boards embedding FPGA GPIOs with an I2C interface.
This driver supports TS-4900, TS-7970, TS-7990 and TS-4100 series. Signed-off-by: Lucile Quirion <[email protected]> --- drivers/gpio/Kconfig | 6 ++ drivers/gpio/Makefile | 1 + drivers/gpio/gpio-ts4900.c | 238 +++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 245 insertions(+) create mode 100644 drivers/gpio/gpio-ts4900.c diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig index 98dd47a..459fb71 100644 --- a/drivers/gpio/Kconfig +++ b/drivers/gpio/Kconfig @@ -779,6 +779,12 @@ config GPIO_TPIC2810 To compile this driver as a module, choose M here: the module will be called gpio-tpic2810. +config GPIO_TS4900 + bool "Technologic Systems FPGA I2C GPIO" + help + Say yes here to enabled the GPIO driver for Technologic's FPGA core. + Series supported include TS-4100, TS-4900, TS-7970 and TS-7990. + endmenu menu "MFD GPIO expanders" diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile index 2a035ed..4dcc21f 100644 --- a/drivers/gpio/Makefile +++ b/drivers/gpio/Makefile @@ -110,6 +110,7 @@ obj-$(CONFIG_GPIO_TPS6586X) += gpio-tps6586x.o obj-$(CONFIG_GPIO_TPS65910) += gpio-tps65910.o obj-$(CONFIG_GPIO_TPS65912) += gpio-tps65912.o obj-$(CONFIG_GPIO_TS4800) += gpio-ts4800.o +obj-$(CONFIG_GPIO_TS4900) += gpio-ts4900.o obj-$(CONFIG_GPIO_TS5500) += gpio-ts5500.o obj-$(CONFIG_GPIO_TWL4030) += gpio-twl4030.o obj-$(CONFIG_GPIO_TWL6040) += gpio-twl6040.o diff --git a/drivers/gpio/gpio-ts4900.c b/drivers/gpio/gpio-ts4900.c new file mode 100644 index 0000000..104d1e0 --- /dev/null +++ b/drivers/gpio/gpio-ts4900.c @@ -0,0 +1,238 @@ +/* + * Digital I/O driver for Technologic Systems I2C FPGA Core + * + * Copyright (C) 2015 Technologic Systems + * Copyright (C) 2016 Savoir-Faire Linux + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed "as is" WITHOUT ANY WARRANTY of any + * kind, whether expressed or implied; without even the implied warranty + * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License version 2 for more details. + */ + +#include <linux/gpio/driver.h> +#include <linux/i2c.h> +#include <linux/of_device.h> +#include <linux/module.h> + +#define DEFAULT_PIN_NUMBER 32 +/* + * Register bits used by the GPIO device + * Some boards, such as TS-7970 do not have a separate input bit + */ +#define TS4900_GPIO_OE 0x01 +#define TS4900_GPIO_OD 0x02 +#define TS4900_GPIO_ID 0x04 +#define TS7970_GPIO_ID 0x02 + +struct ts4900_gpio_priv { + struct i2c_client *client; + struct gpio_chip gpio_chip; + unsigned int input_bit; +}; + +static int ts4900_gpio_write(struct i2c_client *client, u16 addr, u8 data) +{ + struct i2c_msg msg; + u8 buf[3]; + int ret; + + buf[0] = addr >> 8; + buf[1] = addr & 0xFF; + buf[2] = data; + + msg.addr = client->addr; + msg.flags = 0; + msg.len = 3; + msg.buf = buf; + + ret = i2c_transfer(client->adapter, &msg, 1); + if (ret != 1) { + dev_err(&client->dev, "%s: write error, ret=%d\n", + __func__, ret); + return -EIO; + } + + return 0; +} + +static int ts4900_gpio_read(struct i2c_client *client, u16 addr) +{ + struct i2c_msg msgs[2]; + u8 buf[2]; + int ret; + + buf[0] = addr >> 8; + buf[1] = addr & 0xFF; + + msgs[0].addr = client->addr; + msgs[0].flags = 0; + msgs[0].len = 2; + msgs[0].buf = buf; + + msgs[1].addr = client->addr; + msgs[1].flags = I2C_M_RD; + msgs[1].len = 1; + msgs[1].buf = buf; + + ret = i2c_transfer(client->adapter, msgs, ARRAY_SIZE(msgs)); + if (ret != ARRAY_SIZE(msgs)) { + dev_err(&client->dev, "%s: read error, ret=%d\n", + __func__, ret); + return -EIO; + } + + return buf[0]; +} + +static int __ts4900_gpio_direction_output(struct i2c_client *client, int gpio, + int value) +{ + u8 reg = 0; + + if (value) + reg = TS4900_GPIO_OD | TS4900_GPIO_OE; + else + reg = TS4900_GPIO_OE; + + return ts4900_gpio_write(client, gpio, reg); +} + +static int ts4900_gpio_direction_input(struct gpio_chip *chip, + unsigned int offset) +{ + struct ts4900_gpio_priv *priv = gpiochip_get_data(chip); + + /* + * This will clear the output enable bit, the other bits are + * dontcare when this is cleared + */ + return ts4900_gpio_write(priv->client, offset, 0); +} + +static int ts4900_gpio_direction_output(struct gpio_chip *chip, + unsigned int offset, int value) +{ + struct ts4900_gpio_priv *priv = gpiochip_get_data(chip); + + return __ts4900_gpio_direction_output(priv->client, offset, value); +} + +static int ts4900_gpio_get(struct gpio_chip *chip, unsigned int offset) +{ + struct ts4900_gpio_priv *priv = gpiochip_get_data(chip); + int ret; + u8 reg; + + reg = ts4900_gpio_read(priv->client, offset); + + ret = (reg & priv->input_bit) ? 1 : 0; + + return ret; +} + +static void ts4900_gpio_set(struct gpio_chip *chip, unsigned int offset, + int value) +{ + struct ts4900_gpio_priv *priv = gpiochip_get_data(chip); + + __ts4900_gpio_direction_output(priv->client, offset, value); +} + +static struct gpio_chip template_chip = { + .label = "ts4900-gpio", + .owner = THIS_MODULE, + .direction_input = ts4900_gpio_direction_input, + .direction_output = ts4900_gpio_direction_output, + .get = ts4900_gpio_get, + .set = ts4900_gpio_set, + .base = -1, + .can_sleep = true, +}; + +static const struct of_device_id ts4900_gpio_of_match_table[] = { + { + .compatible = "technologic,ts4900-gpio", + .data = (void *)TS4900_GPIO_ID, + }, { + .compatible = "technologic,ts7970-gpio", + .data = (void *)TS7970_GPIO_ID, + }, + { /* sentinel */ }, +}; +MODULE_DEVICE_TABLE(of, ts4900_gpio_of_match_table); + +static int ts4900_gpio_probe(struct i2c_client *client, + const struct i2c_device_id *id) +{ + const struct of_device_id *match; + struct ts4900_gpio_priv *priv; + u32 ngpio; + int ret; + + if (!i2c_check_functionality(client->adapter, + I2C_FUNC_SMBUS_BYTE_DATA)) + return -EIO; + + match = of_match_device(ts4900_gpio_of_match_table, &client->dev); + if (!match) + return -EINVAL; + + if (of_property_read_u32(client->dev.of_node, "ngpios", &ngpio)) + ngpio = DEFAULT_PIN_NUMBER; + + priv = devm_kzalloc(&client->dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + i2c_set_clientdata(client, priv); + + priv->client = client; + priv->gpio_chip = template_chip; + priv->gpio_chip.label = "ts4900-gpio"; + priv->gpio_chip.ngpio = ngpio; + priv->gpio_chip.parent = &client->dev; + priv->input_bit = (uintptr_t)match->data; + + ret = gpiochip_add_data(&priv->gpio_chip, priv); + if (ret < 0) { + dev_err(&client->dev, "Unable to register gpiochip\n"); + return ret; + } + + return 0; +} + +static int ts4900_gpio_remove(struct i2c_client *client) +{ + struct ts4900_gpio_priv *priv = i2c_get_clientdata(client); + + gpiochip_remove(&priv->gpio_chip); + + return 0; +} + +static const struct i2c_device_id ts4900_gpio_id_table[] = { + { "ts4900-gpio", }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(i2c, ts4900_gpio_id_table); + +static struct i2c_driver ts4900_gpio_driver = { + .driver = { + .name = "ts4900-gpio", + .of_match_table = ts4900_gpio_of_match_table, + }, + .probe = ts4900_gpio_probe, + .remove = ts4900_gpio_remove, + .id_table = ts4900_gpio_id_table, +}; +module_i2c_driver(ts4900_gpio_driver); + +MODULE_AUTHOR("Technologic Systems"); +MODULE_DESCRIPTION("GPIO interface for Technologic Systems I2C-FPGA core"); +MODULE_LICENSE("GPL"); -- 2.5.5
