[2/4] pinctrl: imx: add gpio pinmux support for vf610

Commit Message

Stefan Agner Sept. 6, 2014, 4:25 p.m. UTC

Add pinmux support for GPIO for Vybrid (vf610) IOMUX controller.
This is needed since direction configuration is not part of the
GPIO module in Vybrid.

Signed-off-by: Stefan Agner <[e-mail]>
---
 drivers/pinctrl/pinctrl-imx.c   | 54 +++++++++++++++++++++++++++++++++++++++++
 drivers/pinctrl/pinctrl-imx.h   |  1 +
 drivers/pinctrl/pinctrl-vf610.c |  4 +--
 3 files changed, 57 insertions(+), 2 deletions(-)

Comments

Linus Walleij Sept. 23, 2014, 9:48 a.m. UTC | #1

On Sat, Sep 6, 2014 at 6:25 PM, Stefan Agner <[e-mail]> wrote:

> Add pinmux support for GPIO for Vybrid (vf610) IOMUX controller.
> This is needed since direction configuration is not part of the
> GPIO module in Vybrid.
>
> Signed-off-by: Stefan Agner <[e-mail]>
(...)

> -arch_initcall(vf610_pinctrl_init);
> +postcore_initcall(vf610_pinctrl_init);

Why is this necessary? You should be able to rely on deferred
probing to do its work here. I think this should be module_init()
or driver_initcall() really.

Yours,
Linus Walleij

Stefan Agner Sept. 23, 2014, 11:24 a.m. UTC | #2

Am 2014-09-23 11:48, schrieb Linus Walleij:
> On Sat, Sep 6, 2014 at 6:25 PM, Stefan Agner <[e-mail]> wrote:
> 
>> Add pinmux support for GPIO for Vybrid (vf610) IOMUX controller.
>> This is needed since direction configuration is not part of the
>> GPIO module in Vybrid.
>>
>> Signed-off-by: Stefan Agner <[e-mail]>
> (...)
> 
>> -arch_initcall(vf610_pinctrl_init);
>> +postcore_initcall(vf610_pinctrl_init);
> 
> Why is this necessary? You should be able to rely on deferred
> probing to do its work here. I think this should be module_init()
> or driver_initcall() really.

Currently deferred probe doesn't work for gpiolib drivers which try to
add gpio-ranges from device tree:
gpiochip_add calls of_gpiochip_add_pin_range (through of_gpiochip_add).
This function tries to get the pinctrl driver, which is not registred at
that time. Currently the driver does not defer probing but fails
silently...

We would need to alter the return values of those two functions
(of_gpiochip_add_pin_range/of_gpiochip_add) and honor the return value
in gpiochip_add. 

Currently, it seems that we quite often use an early initcall to get the
pinctrl loaded early:
$ grep -h -o ".*_initcall" drivers/pinctrl/*.c | sort | uniq -c
     18 arch_initcall
      3 core_initcall
      3 postcore_initcall
      1 subsys_initcall

IMHO for those core services, it also makes sense to have them
initialized early. I'd rather prefer this hard coded than having dozens
of "requests probe deferral" messages...

--
Stefan

Patch

diff --git a/drivers/pinctrl/pinctrl-imx.c b/drivers/pinctrl/pinctrl-imx.c
index 0d4558b..64d1b59 100644
--- a/drivers/pinctrl/pinctrl-imx.c
+++ b/drivers/pinctrl/pinctrl-imx.c
@@ -294,10 +294,59 @@  static int imx_pmx_get_groups(struct pinctrl_dev *pctldev, unsigned selector,
 	return 0;
 }
 
+static int imx_pmx_gpio_request_enable(struct pinctrl_dev *pctldev,
+			struct pinctrl_gpio_range *range, unsigned offset)
+{
+	struct imx_pinctrl *ipctl = pinctrl_dev_get_drvdata(pctldev);
+	const struct imx_pinctrl_soc_info *info = ipctl->info;
+	const struct imx_pin_reg *pin_reg;
+	u32 reg;
+
+	if (!(info->flags & GPIO_CONTROL))
+		return -EINVAL;
+
+	pin_reg = &info->pin_regs[offset];
+	if (pin_reg->mux_reg == -1)
+		return -EINVAL;
+
+	reg = readl(ipctl->base + pin_reg->mux_reg);
+	reg &= ~(0x7 << 20);
+	writel(reg, ipctl->base + pin_reg->mux_reg);
+
+	return 0;
+}
+
+static int imx_pmx_gpio_set_direction(struct pinctrl_dev *pctldev,
+	   struct pinctrl_gpio_range *range, unsigned offset, bool input)
+{
+	struct imx_pinctrl *ipctl = pinctrl_dev_get_drvdata(pctldev);
+	const struct imx_pinctrl_soc_info *info = ipctl->info;
+	const struct imx_pin_reg *pin_reg;
+	u32 reg;
+
+	if (!(info->flags & GPIO_CONTROL))
+		return -EINVAL;
+
+	pin_reg = &info->pin_regs[offset];
+	if (pin_reg->mux_reg == -1)
+		return -EINVAL;
+
+	reg = readl(ipctl->base + pin_reg->mux_reg);
+	if (input)
+		reg &= ~0x2;
+	else
+		reg |= 0x2;
+	writel(reg, ipctl->base + pin_reg->mux_reg);
+
+	return 0;
+}
+
 static const struct pinmux_ops imx_pmx_ops = {
 	.get_functions_count = imx_pmx_get_funcs_count,
 	.get_function_name = imx_pmx_get_func_name,
 	.get_function_groups = imx_pmx_get_groups,
+	.gpio_request_enable = imx_pmx_gpio_request_enable,
+	.gpio_set_direction = imx_pmx_gpio_set_direction,
 	.enable = imx_pmx_enable,
 };
 
@@ -579,6 +628,11 @@  int imx_pinctrl_probe(struct platform_device *pdev,
 		dev_err(&pdev->dev, "wrong pinctrl info\n");
 		return -EINVAL;
 	}
+
+	/* GPIO control functions only intended for shared mux/conf register */
+	if (info->flags & GPIO_CONTROL)
+		BUG_ON(!(info->flags & SHARE_MUX_CONF_REG));
+
 	info->dev = &pdev->dev;
 
 	/* Create state holders etc for this driver */
diff --git a/drivers/pinctrl/pinctrl-imx.h b/drivers/pinctrl/pinctrl-imx.h
index 49e55d3..8f37ca4 100644
--- a/drivers/pinctrl/pinctrl-imx.h
+++ b/drivers/pinctrl/pinctrl-imx.h
@@ -84,6 +84,7 @@  struct imx_pinctrl_soc_info {
 };
 
 #define SHARE_MUX_CONF_REG	0x1
+#define GPIO_CONTROL		0x2
 
 #define NO_MUX		0x0
 #define NO_PAD		0x0
diff --git a/drivers/pinctrl/pinctrl-vf610.c b/drivers/pinctrl/pinctrl-vf610.c
index b788e15..d34a3ac 100644
--- a/drivers/pinctrl/pinctrl-vf610.c
+++ b/drivers/pinctrl/pinctrl-vf610.c
@@ -299,7 +299,7 @@  static const struct pinctrl_pin_desc vf610_pinctrl_pads[] = {
 static struct imx_pinctrl_soc_info vf610_pinctrl_info = {
 	.pins = vf610_pinctrl_pads,
 	.npins = ARRAY_SIZE(vf610_pinctrl_pads),
-	.flags = SHARE_MUX_CONF_REG,
+	.flags = SHARE_MUX_CONF_REG | GPIO_CONTROL,
 };
 
 static struct of_device_id vf610_pinctrl_of_match[] = {
@@ -326,7 +326,7 @@  static int __init vf610_pinctrl_init(void)
 {
 	return platform_driver_register(&vf610_pinctrl_driver);
 }
-arch_initcall(vf610_pinctrl_init);
+postcore_initcall(vf610_pinctrl_init);
 
 static void __exit vf610_pinctrl_exit(void)
 {