Add code to parse the GPIO expander Device Tree node and extract platform data out of it, and populate the struct 'pcf857x_platform_data' maintained by the driver. This enables devices to reference the gpio expander from Device Tree. Add DT binding info in Documentation. Signed-off-by: Archit Taneja <archit@xxxxxx> --- - v2 posted after quite a while, sorry for the delay! Changes in v2: - second gpeio-cell description corrected in Documentation - interrupt controller description removed for now, will be added in a follow up patch - n_latch description updated .../devicetree/bindings/gpio/gpio-pcf857x.txt | 41 ++++++++++++++++ drivers/gpio/gpio-pcf857x.c | 57 ++++++++++++++++++++-- 2 files changed, 94 insertions(+), 4 deletions(-) create mode 100644 Documentation/devicetree/bindings/gpio/gpio-pcf857x.txt diff --git a/Documentation/devicetree/bindings/gpio/gpio-pcf857x.txt b/Documentation/devicetree/bindings/gpio/gpio-pcf857x.txt new file mode 100644 index 0000000..504d114 --- /dev/null +++ b/Documentation/devicetree/bindings/gpio/gpio-pcf857x.txt @@ -0,0 +1,41 @@ +PCF857x I2C based GPIO controller bindings + +Required properties: +- compatible: + - "nxp,pca9670" for NXP PCA9670 8 bit I/O expander + - "nxp,pca9672" for NXP PCA9672 8 bit I/O expander with interrupt + - "nxp,pca9674" for NXP PCA9672 8 bit I/O expander with interrupt + - "nxp,pca8574" for NXP PCA8574 8 bit I/O expander with interrupt + - "nxp,pca8575" for NXP PCA8575 16 bit I/O expander with interrupt + - "nxp,pca9671" for NXP PCA9671 16 bit I/O expander + - "nxp,pca9673" for NXP PCA9673 16 bit I/O expander with interrupt + - "nxp,pca9675" for NXP PCA9675 16 bit I/O expander with interrupt + - "ti,pcf8574" for TI PCF8574 8 bit I/O expander with interrupt + - "ti,pcf8574a" for TI PCF8574A 8 bit I/O expander with interrupt + - "ti,pcf8575" for TI PCF8575 16 bit I/O expander with interrupt + - "ti,tca9554" for TI TCA9554 8 bit I/O expander with interrupt + - "maxim,max7328" for MAXIM MAX7328 8 bit I/O expander with interrupt + - "maxim,max7329" for MAXIM MAX7329 8 bit I/O expander with interrupt +- gpio-controller : Marks the device node as a GPIO controller. +- #gpio-cells : Should be two. + - first cell is the pin number. + - second cell is used to specify optional parameters (currently unused, but + needed by gpiolib). +- reg: I2C address of the chip. + +Device speific properties: +- n_latch: optional bit-inverse of initial register value; if + you leave this initialized to zero the driver will act + like the chip was just reset. If it is a non-zero + value, the driver will program the inverted value of + n_latch as the initial state of the gpios. + +Example: + +pcf8575: pcf8575 { + compatible = "ti,pcf8575"; + gpio-controller; + #gpio-cells = <2>; + reg = <0x20>; + n_latch = <0x0>; +}; diff --git a/drivers/gpio/gpio-pcf857x.c b/drivers/gpio/gpio-pcf857x.c index e8faf53..3435790 100644 --- a/drivers/gpio/gpio-pcf857x.c +++ b/drivers/gpio/gpio-pcf857x.c @@ -21,6 +21,7 @@ #include <linux/kernel.h> #include <linux/slab.h> #include <linux/gpio.h> +#include <linux/of.h> #include <linux/i2c.h> #include <linux/i2c/pcf857x.h> #include <linux/interrupt.h> @@ -255,17 +256,42 @@ fail: /*-------------------------------------------------------------------------*/ +static struct pcf857x_platform_data *of_gpio_pcf857x(struct device *dev) +{ + struct pcf857x_platform_data *pdata; + int r; + + pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL); + if (!pdata) + return NULL; + + pdata->gpio_base = -1; + + r = of_property_read_u32(dev->of_node, "n_latch", &pdata->n_latch); + if (r) { + dev_dbg(dev, "couldn't find n-latch, use default\n"); + pdata->n_latch = 0; + } + + return pdata; +} + static int pcf857x_probe(struct i2c_client *client, const struct i2c_device_id *id) { struct pcf857x_platform_data *pdata; + struct device_node *node; struct pcf857x *gpio; int status; pdata = client->dev.platform_data; - if (!pdata) { + node = client->dev.of_node; + + if (!pdata && node) + pdata = of_gpio_pcf857x(&client->dev); + + if (!pdata) dev_dbg(&client->dev, "no platform data\n"); - } /* Allocate, initialize, and register this gpio_chip. */ gpio = devm_kzalloc(&client->dev, sizeof(*gpio), GFP_KERNEL); @@ -420,10 +446,33 @@ static int pcf857x_remove(struct i2c_client *client) return status; } +static const struct of_device_id pcf857x_dt_ids[] = { + { .compatible = "nxp,pca9670", }, + { .compatible = "nxp,pca9672", }, + { .compatible = "nxp,pca9674", }, + { .compatible = "nxp,pca8574", }, + { .compatible = "nxp,pca8575", }, + { .compatible = "nxp,pca9671", }, + { .compatible = "nxp,pca9673", }, + { .compatible = "nxp,pca9675", }, + + { .compatible = "ti,pcf8574", }, + { .compatible = "ti,pcf8574a", }, + { .compatible = "ti,pcf8575", }, + { .compatible = "ti,tca9554", }, + + { .compatible = "maxim,max7328", }, + { .compatible = "maxim,max7329", }, + { } +}; + +MODULE_DEVICE_TABLE(of, pcf857x_dt_ids); + static struct i2c_driver pcf857x_driver = { .driver = { - .name = "pcf857x", - .owner = THIS_MODULE, + .name = "pcf857x", + .owner = THIS_MODULE, + .of_match_table = pcf857x_dt_ids, }, .probe = pcf857x_probe, .remove = pcf857x_remove, -- 1.8.1.2 -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html