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.

Signed-off-by: Daniel Mack <zon...@gmail.com>
Cc: Evgeniy Polyakov <z...@ioremap.net>
Cc: Ville Syrjala <syrj...@sci.fi>
---
 drivers/w1/masters/w1-gpio.c |   18 +++++++++++++++++-
 include/linux/w1-gpio.h      |    1 +
 2 files changed, 18 insertions(+), 1 deletion(-)

diff --git a/drivers/w1/masters/w1-gpio.c b/drivers/w1/masters/w1-gpio.c
index df600d1..dac88ff 100644
--- a/drivers/w1/masters/w1-gpio.c
+++ b/drivers/w1/masters/w1-gpio.c
@@ -59,6 +59,13 @@ static int __init w1_gpio_probe(struct platform_device *pdev)
        if (err)
                goto free_master;
 
+       if (gpio_is_valid(pdata->ext_pullup_enable_pin)) {
+               err = gpio_request_one(pdata->ext_pullup_enable_pin,
+                                      GPIOF_INIT_LOW, "w1 pullup");
+               if (err < 0)
+                       goto free_gpio;
+       }
+
        master->data = pdata;
        master->read_bit = w1_gpio_read_bit;
 
@@ -72,15 +79,21 @@ static int __init w1_gpio_probe(struct platform_device 
*pdev)
 
        err = w1_add_master_device(master);
        if (err)
-               goto free_gpio;
+               goto free_gpio_ext_pu;
 
        if (pdata->enable_external_pullup)
                pdata->enable_external_pullup(1);
 
+       if (gpio_is_valid(pdata->ext_pullup_enable_pin))
+               gpio_set_value(pdata->ext_pullup_enable_pin, 1);
+
        platform_set_drvdata(pdev, master);
 
        return 0;
 
+ free_gpio_ext_pu:
+       if (gpio_is_valid(pdata->ext_pullup_enable_pin))
+               gpio_free(pdata->ext_pullup_enable_pin);
  free_gpio:
        gpio_free(pdata->pin);
  free_master:
@@ -97,6 +110,9 @@ static int __exit w1_gpio_remove(struct platform_device 
*pdev)
        if (pdata->enable_external_pullup)
                pdata->enable_external_pullup(0);
 
+       if (gpio_is_valid(pdata->ext_pullup_enable_pin))
+               gpio_set_value(pdata->ext_pullup_enable_pin, 0);
+
        w1_remove_master_device(master);
        gpio_free(pdata->pin);
        kfree(master);
diff --git a/include/linux/w1-gpio.h b/include/linux/w1-gpio.h
index 3adeff8..065e3ae 100644
--- a/include/linux/w1-gpio.h
+++ b/include/linux/w1-gpio.h
@@ -19,6 +19,7 @@ struct w1_gpio_platform_data {
        unsigned int pin;
        unsigned int is_open_drain:1;
        void (*enable_external_pullup)(int enable);
+       unsigned int ext_pullup_enable_pin;
 };
 
 #endif /* _LINUX_W1_GPIO_H */
-- 
1.7.10.4

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