| Message ID | 1377498081-16358-1-git-send-email-archit@ti.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Mon, Aug 26, 2013 at 8:21 AM, Archit Taneja <archit@ti.com> wrote: > 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@ti.com> > --- > - 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 The devicetree portions of this patch needs to be reviewed by devicetree@vger.kernel.org, so please repost including that list. Yours, Linus Walleij
On Tuesday 27 August 2013 05:20:45 Linus Walleij wrote: > On Mon, Aug 26, 2013 at 8:21 AM, Archit Taneja <archit@ti.com> wrote: > > 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@ti.com> > > --- > > - 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 And it seems that the patch conflicts with https://lkml.org/lkml/2013/8/26/248 :-/ If we end up merging this one, I'd like to at least rename the DT n-latch property to pin-initial-states as in my patch and update the documentation, as I find it more explicit. > The devicetree portions of this patch needs to be reviewed by > devicetree@vger.kernel.org, so please repost including that > list.
On Tuesday 27 August 2013 12:17 PM, Laurent Pinchart wrote: > On Tuesday 27 August 2013 05:20:45 Linus Walleij wrote: >> On Mon, Aug 26, 2013 at 8:21 AM, Archit Taneja <archit@ti.com> wrote: >>> 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@ti.com> >>> --- >>> - 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 > > And it seems that the patch conflicts with > > https://lkml.org/lkml/2013/8/26/248 > > :-/ :/ > > If we end up merging this one, I'd like to at least rename the DT n-latch > property to pin-initial-states as in my patch and update the documentation, as > I find it more explicit. I think your patch is cleaner and more descriptive. The only thing which I am not clear about in your patch is the extra work done in getting ngpio, that should be available in i2c_device_id pointer argument in probe(id points to the array pcf857x_id already available in the driver with the number of gpios for each chip variant). Archit
Hi Archit, On Tuesday 27 August 2013 12:30:18 Archit Taneja wrote: > On Tuesday 27 August 2013 12:17 PM, Laurent Pinchart wrote: > > On Tuesday 27 August 2013 05:20:45 Linus Walleij wrote: > >> On Mon, Aug 26, 2013 at 8:21 AM, Archit Taneja <archit@ti.com> wrote: > >>> 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@ti.com> > >>> --- > >>> - 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 > > > > And it seems that the patch conflicts with > > > > https://lkml.org/lkml/2013/8/26/248 > > > > :-/ > > :/ > > > If we end up merging this one, I'd like to at least rename the DT n-latch > > property to pin-initial-states as in my patch and update the > > documentation, as I find it more explicit. > > I think your patch is cleaner and more descriptive. Thank you. > The only thing which I am not clear about in your patch is the extra work > done in getting ngpio, that should be available in i2c_device_id pointer > argument in probe(id points to the array pcf857x_id already available in the > driver with the number of gpios for each chip variant). You're right. I'll fix that and repost.
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,
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@ti.com> --- - 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