Messages in this thread Patch in this message | | | Date | Tue, 31 Jul 2012 08:19:06 +0200 | From | Daniel Mack <> | Subject | Re: [PATCH 1/2] onewire: w1-gpio: add ext_pullup_enable pin in platform data |
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On 31.07.2012 02:59, Ville Syrjälä wrote: > On Mon, Jul 30, 2012 at 10:12:39PM +0400, Evgeniy Polyakov wrote: >> Hi >> >> Sorry for long delay >> [resend with fixed Greg's address :)] >> >> On Wed, Jul 25, 2012 at 10:54:29PM +0200, Daniel Mack (zonque@gmail.com) wrote: >>> In the process of porting boards to devicetree implemenation, we should >>> keep information about external circuitry where they belong - the >>> individual drivers. >>> >>> This patch adds a way to specify a GPIO to drive the (optional) external >>> pull-up logic, rather than using a function pointer for that. >> >> I do not object against this patch, but I have rather limited knowledge >> about gpio driver. Patch looks good, feel free to add my >> Acked-by: Evgeniy Polyakov <zbr@ioremap.net> >> >> Greg, please pull it into your tree, if Ville does not object. > > No objections from me.
I take this as an Acked-by:?
> The only cosmetic issue I spotted was 'pdata' being assigned twice in > w1_gpio_probe().
Right. Amended patch below.
Thanks a lot, Daniel
From 37385d15bbd9dbc637f1e46d962c90be5eeb1409 Mon Sep 17 00:00:00 2001 From: Daniel Mack <zonque@gmail.com> Date: Mon, 23 Jul 2012 16:36:35 +0200 Subject: [PATCH v2] onewire: w1-gpio: add DT bindings
This patch add DT bindings to the w1-gpio driver, along with some documentation on how to use them.
Signed-off-by: Daniel Mack <zonque@gmail.com> Acked-by: Evgeniy Polyakov <zbr@ioremap.net> Acked-by: Ville Syrjala <syrjala@sci.fi> --- Documentation/devicetree/bindings/w1/w1-gpio.txt | 22 +++++++++++ drivers/w1/masters/w1-gpio.c | 48 +++++++++++++++++++++++- 2 files changed, 69 insertions(+), 1 deletion(-) create mode 100644 Documentation/devicetree/bindings/w1/w1-gpio.txt
diff --git a/Documentation/devicetree/bindings/w1/w1-gpio.txt b/Documentation/devicetree/bindings/w1/w1-gpio.txt new file mode 100644 index 0000000..6e09c35 --- /dev/null +++ b/Documentation/devicetree/bindings/w1/w1-gpio.txt @@ -0,0 +1,22 @@ +w1-gpio devicetree bindings + +Required properties: + + - compatible: "w1-gpio" + - gpios: one or two GPIO specs: + - the first one is used as data I/O pin + - the second one is optional. If specified, it is used as + enable pin for an external pin pullup. + +Optional properties: + + - linux,open-drain: if specified, the data pin is considered in + open-drain mode. + +Examples: + + onewire@0 { + compatible = "w1-gpio"; + gpios = <&gpio 126 0>, <&gpio 105 0>; + }; + diff --git a/drivers/w1/masters/w1-gpio.c b/drivers/w1/masters/w1-gpio.c index dac88ff..6012c4e 100644 --- a/drivers/w1/masters/w1-gpio.c +++ b/drivers/w1/masters/w1-gpio.c @@ -14,6 +14,8 @@ #include <linux/slab.h> #include <linux/w1-gpio.h> #include <linux/gpio.h> +#include <linux/of_platform.h> +#include <linux/of_gpio.h> #include "../w1.h" #include "../w1_int.h" @@ -42,12 +44,55 @@ static u8 w1_gpio_read_bit(void *data) return gpio_get_value(pdata->pin) ? 1 : 0; } +#ifdef CONFIG_OF +static struct of_device_id w1_gpio_dt_ids[] = { + { .compatible = "w1-gpio" }, + {} +}; +MODULE_DEVICE_TABLE(of, w1_gpio_dt_ids); + +static int w1_gpio_probe_dt(struct platform_device *pdev) +{ + struct w1_gpio_platform_data *pdata = pdev->dev.platform_data; + struct device_node *np = pdev->dev.of_node; + const struct of_device_id *of_id = + of_match_device(w1_gpio_dt_ids, &pdev->dev); + + if (!of_id) + return 0; + + pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL); + if (!pdata) + return -ENOMEM; + + if (of_get_property(np, "linux,open-drain", NULL)) + pdata->is_open_drain = 1; + + pdata->pin = of_get_gpio(np, 0); + pdata->ext_pullup_enable_pin = of_get_gpio(np, 1); + pdev->dev.platform_data = pdata; + + return 0; +} +#else +static int w1_gpio_probe_dt(struct platform_device *pdev) +{ + return 0; +} +#endif + static int __init w1_gpio_probe(struct platform_device *pdev) { struct w1_bus_master *master; - struct w1_gpio_platform_data *pdata = pdev->dev.platform_data; + struct w1_gpio_platform_data *pdata; int err; + err = w1_gpio_probe_dt(pdev); + if (err < 0) + return err; + + pdata = pdev->dev.platform_data; + if (!pdata) return -ENXIO; @@ -151,6 +196,7 @@ static struct platform_driver w1_gpio_driver = { .driver = { .name = "w1-gpio", .owner = THIS_MODULE, + .of_match_table = of_match_ptr(w1_gpio_dt_ids), }, .remove = __exit_p(w1_gpio_remove), .suspend = w1_gpio_suspend, -- 1.7.11.2
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