diff mbox

[1/2] mmc: hsmmc: Add reset gpio configuration option.

Message ID 1404420564-30245-1-git-send-email-marek@goldelico.com (mailing list archive)
State New, archived
Headers show

Commit Message

Marek Belisko July 3, 2014, 8:49 p.m. UTC
From: NeilBrown <neilb@suse.de>

If a 'gpio_reset' is specified, then hold it low while
turning the power regulator on.
This is needed for some wi2wi wireless modules, particularly
when the regulator is held active by some other client.
The wi2wi needs to be reset if power isn't actually removed, and
the gpio can be used to do this.

Signed-off-by: NeilBrown <neilb@suse.de>
---
 arch/arm/mach-omap2/hsmmc.c            |  7 ++++++-
 arch/arm/mach-omap2/hsmmc.h            |  3 +++
 drivers/mmc/host/omap_hsmmc.c          | 26 +++++++++++++++++++++++---
 include/linux/platform_data/mmc-omap.h |  1 +
 4 files changed, 33 insertions(+), 4 deletions(-)

Comments

Felipe Balbi July 3, 2014, 10:41 p.m. UTC | #1
Hi,

On Thu, Jul 03, 2014 at 10:49:23PM +0200, Marek Belisko wrote:
> From: NeilBrown <neilb@suse.de>
> 
> If a 'gpio_reset' is specified, then hold it low while
> turning the power regulator on.
> This is needed for some wi2wi wireless modules, particularly
> when the regulator is held active by some other client.
> The wi2wi needs to be reset if power isn't actually removed, and
> the gpio can be used to do this.
> 
> Signed-off-by: NeilBrown <neilb@suse.de>
> ---
>  arch/arm/mach-omap2/hsmmc.c            |  7 ++++++-
>  arch/arm/mach-omap2/hsmmc.h            |  3 +++
>  drivers/mmc/host/omap_hsmmc.c          | 26 +++++++++++++++++++++++---
>  include/linux/platform_data/mmc-omap.h |  1 +
>  4 files changed, 33 insertions(+), 4 deletions(-)
> 
> diff --git a/arch/arm/mach-omap2/hsmmc.c b/arch/arm/mach-omap2/hsmmc.c
> index 07d4c7b..046bfdd 100644
> --- a/arch/arm/mach-omap2/hsmmc.c
> +++ b/arch/arm/mach-omap2/hsmmc.c
> @@ -172,6 +172,10 @@ static inline void omap_hsmmc_mux(struct omap_mmc_platform_data *mmc_controller,
>  		(mmc_controller->slots[0].gpio_wp < OMAP_MAX_GPIO_LINES))
>  		omap_mux_init_gpio(mmc_controller->slots[0].gpio_wp,
>  					OMAP_PIN_INPUT_PULLUP);
> +	if (gpio_is_valid(mmc_controller->slots[0].gpio_reset) &&
> +		(mmc_controller->slots[0].gpio_reset < OMAP_MAX_GPIO_LINES))
> +		omap_mux_init_gpio(mmc_controller->slots[0].gpio_reset,
> +					OMAP_PIN_OUTPUT);
>  	if (cpu_is_omap34xx()) {
>  		if (controller_nr == 0) {
>  			omap_mux_init_signal("sdmmc1_clk",
> @@ -270,6 +274,7 @@ static int __init omap_hsmmc_pdata_init(struct omap2_hsmmc_info *c,
>  
>  	mmc->slots[0].switch_pin = c->gpio_cd;
>  	mmc->slots[0].gpio_wp = c->gpio_wp;
> +	mmc->slots[0].gpio_reset = c->gpio_reset;
>  
>  	mmc->slots[0].remux = c->remux;
>  	mmc->slots[0].init_card = c->init_card;
> @@ -389,7 +394,7 @@ void omap_hsmmc_late_init(struct omap2_hsmmc_info *c)
>  			continue;
>  
>  		mmc_pdata->slots[0].switch_pin = c->gpio_cd;
> -		mmc_pdata->slots[0].gpio_wp = c->gpio_wp;
> +		mmc_pdata->slots[0].gpio_reset = c->gpio_reset;
>  
>  		res = omap_device_register(pdev);
>  		if (res)
> diff --git a/arch/arm/mach-omap2/hsmmc.h b/arch/arm/mach-omap2/hsmmc.h
> index 7f2e790..16b2ac5 100644
> --- a/arch/arm/mach-omap2/hsmmc.h
> +++ b/arch/arm/mach-omap2/hsmmc.h
> @@ -24,6 +24,9 @@ struct omap2_hsmmc_info {
>  	bool	deferred;	/* mmc needs a deferred probe */
>  	int	gpio_cd;	/* or -EINVAL */
>  	int	gpio_wp;	/* or -EINVAL */
> +	int	gpio_reset;	/* or -EINVAL - reset is held low during
> +				 * power-on
> +				 */
>  	char	*name;		/* or NULL for default */
>  	struct platform_device *pdev;	/* mmc controller instance */
>  	int	ocr_mask;	/* temporary HACK */
> diff --git a/drivers/mmc/host/omap_hsmmc.c b/drivers/mmc/host/omap_hsmmc.c
> index 9656726..4a264fc 100644
> --- a/drivers/mmc/host/omap_hsmmc.c
> +++ b/drivers/mmc/host/omap_hsmmc.c
> @@ -300,6 +300,8 @@ static int omap_hsmmc_set_power(struct device *dev, int slot, int power_on,
>  	if (!host->vcc)
>  		return 0;
>  
> +	if (gpio_is_valid(mmc_slot(host).gpio_reset))
> +		gpio_set_value_cansleep(mmc_slot(host).gpio_reset, 0);
>  	if (mmc_slot(host).before_set_reg)
>  		mmc_slot(host).before_set_reg(dev, slot, power_on, vdd);
>  
> @@ -365,6 +367,8 @@ static int omap_hsmmc_set_power(struct device *dev, int slot, int power_on,
>  
>  	if (mmc_slot(host).after_set_reg)
>  		mmc_slot(host).after_set_reg(dev, slot, power_on, vdd);
> +	if (gpio_is_valid(mmc_slot(host).gpio_reset))
> +		gpio_set_value_cansleep(mmc_slot(host).gpio_reset, 1);
>  
>  error_set_power:
>  	return ret;
> @@ -481,10 +485,22 @@ static int omap_hsmmc_gpio_init(struct omap_mmc_platform_data *pdata)
>  	} else
>  		pdata->slots[0].gpio_wp = -EINVAL;
>  
> -	return 0;
> +	if (gpio_is_valid(pdata->slots[0].gpio_reset)) {
> +		ret = gpio_request(pdata->slots[0].gpio_reset, "mmc_reset");
> +		if (ret)
> +			goto err_free_wp;
> +		ret = gpio_direction_output(pdata->slots[0].gpio_reset, 1);
> +		if (ret)
> +			goto err_free_reset;
> +	} else
> +		pdata->slots[0].gpio_reset = -EINVAL;

looks like this should be implemented as a reset-gpio.c driver. This
piece of code would, then

	reset_assert(slot->reset);
	do_the_magic_dance();
	reset_deassert(slot->reset);
Russell King - ARM Linux July 3, 2014, 11:01 p.m. UTC | #2
On Thu, Jul 03, 2014 at 10:49:23PM +0200, Marek Belisko wrote:
> From: NeilBrown <neilb@suse.de>
> 
> If a 'gpio_reset' is specified, then hold it low while
> turning the power regulator on.
> This is needed for some wi2wi wireless modules, particularly
> when the regulator is held active by some other client.
> The wi2wi needs to be reset if power isn't actually removed, and
> the gpio can be used to do this.
> 
> Signed-off-by: NeilBrown <neilb@suse.de>

Obvious statement knowing what's been going on elsewhere...

A while back, Olof produced a couple of patches to add /generic/ support
to deal with power and reset controls for SDIO WIFI cards.  Patches
were posted to linux-arm-kernel and other places around January time
this year.

No real conclusion came out of it, and it kind of died.  The point here
is that this is not an OMAP problem.  We have this very same problem
on different platforms and different SoCs.

Why should we have N different solutions to the same problem.  Why can't
we have one solution to fix this issue, rather than having every host
driver implement some different solution to what's a common problem.

If everyone is going to run away from generic problems and continue
inventing their own private solutions to generic problems, the kernel
is just going to become severely bloated and unmaintainable...

Please, sort out generic problems with generic solutions.
Belisko Marek July 26, 2014, 7:48 p.m. UTC | #3
Hi Russel,

On Fri, Jul 4, 2014 at 1:01 AM, Russell King - ARM Linux
<linux@arm.linux.org.uk> wrote:
> On Thu, Jul 03, 2014 at 10:49:23PM +0200, Marek Belisko wrote:
>> From: NeilBrown <neilb@suse.de>
>>
>> If a 'gpio_reset' is specified, then hold it low while
>> turning the power regulator on.
>> This is needed for some wi2wi wireless modules, particularly
>> when the regulator is held active by some other client.
>> The wi2wi needs to be reset if power isn't actually removed, and
>> the gpio can be used to do this.
>>
>> Signed-off-by: NeilBrown <neilb@suse.de>
>
> Obvious statement knowing what's been going on elsewhere...
>
> A while back, Olof produced a couple of patches to add /generic/ support
> to deal with power and reset controls for SDIO WIFI cards.  Patches
> were posted to linux-arm-kernel and other places around January time
> this year.
>
> No real conclusion came out of it, and it kind of died.  The point here
> is that this is not an OMAP problem.  We have this very same problem
> on different platforms and different SoCs.
Thanks for pointing me to Olof's patches. I pick first + update secod
for omap_hcmmc.
I use only card-reset-gios property and it works fine. As you stated
it's kind of died discussion?
Sorry for noise and not using more googling on linux-arm ML.
>
> Why should we have N different solutions to the same problem.  Why can't
> we have one solution to fix this issue, rather than having every host
> driver implement some different solution to what's a common problem.
>
> If everyone is going to run away from generic problems and continue
> inventing their own private solutions to generic problems, the kernel
> is just going to become severely bloated and unmaintainable...
>
> Please, sort out generic problems with generic solutions.
>
> --
> FTTC broadband for 0.8mile line: now at 9.7Mbps down 460kbps up... slowly
> improving, and getting towards what was expected from it.

BR,

marek
diff mbox

Patch

diff --git a/arch/arm/mach-omap2/hsmmc.c b/arch/arm/mach-omap2/hsmmc.c
index 07d4c7b..046bfdd 100644
--- a/arch/arm/mach-omap2/hsmmc.c
+++ b/arch/arm/mach-omap2/hsmmc.c
@@ -172,6 +172,10 @@  static inline void omap_hsmmc_mux(struct omap_mmc_platform_data *mmc_controller,
 		(mmc_controller->slots[0].gpio_wp < OMAP_MAX_GPIO_LINES))
 		omap_mux_init_gpio(mmc_controller->slots[0].gpio_wp,
 					OMAP_PIN_INPUT_PULLUP);
+	if (gpio_is_valid(mmc_controller->slots[0].gpio_reset) &&
+		(mmc_controller->slots[0].gpio_reset < OMAP_MAX_GPIO_LINES))
+		omap_mux_init_gpio(mmc_controller->slots[0].gpio_reset,
+					OMAP_PIN_OUTPUT);
 	if (cpu_is_omap34xx()) {
 		if (controller_nr == 0) {
 			omap_mux_init_signal("sdmmc1_clk",
@@ -270,6 +274,7 @@  static int __init omap_hsmmc_pdata_init(struct omap2_hsmmc_info *c,
 
 	mmc->slots[0].switch_pin = c->gpio_cd;
 	mmc->slots[0].gpio_wp = c->gpio_wp;
+	mmc->slots[0].gpio_reset = c->gpio_reset;
 
 	mmc->slots[0].remux = c->remux;
 	mmc->slots[0].init_card = c->init_card;
@@ -389,7 +394,7 @@  void omap_hsmmc_late_init(struct omap2_hsmmc_info *c)
 			continue;
 
 		mmc_pdata->slots[0].switch_pin = c->gpio_cd;
-		mmc_pdata->slots[0].gpio_wp = c->gpio_wp;
+		mmc_pdata->slots[0].gpio_reset = c->gpio_reset;
 
 		res = omap_device_register(pdev);
 		if (res)
diff --git a/arch/arm/mach-omap2/hsmmc.h b/arch/arm/mach-omap2/hsmmc.h
index 7f2e790..16b2ac5 100644
--- a/arch/arm/mach-omap2/hsmmc.h
+++ b/arch/arm/mach-omap2/hsmmc.h
@@ -24,6 +24,9 @@  struct omap2_hsmmc_info {
 	bool	deferred;	/* mmc needs a deferred probe */
 	int	gpio_cd;	/* or -EINVAL */
 	int	gpio_wp;	/* or -EINVAL */
+	int	gpio_reset;	/* or -EINVAL - reset is held low during
+				 * power-on
+				 */
 	char	*name;		/* or NULL for default */
 	struct platform_device *pdev;	/* mmc controller instance */
 	int	ocr_mask;	/* temporary HACK */
diff --git a/drivers/mmc/host/omap_hsmmc.c b/drivers/mmc/host/omap_hsmmc.c
index 9656726..4a264fc 100644
--- a/drivers/mmc/host/omap_hsmmc.c
+++ b/drivers/mmc/host/omap_hsmmc.c
@@ -300,6 +300,8 @@  static int omap_hsmmc_set_power(struct device *dev, int slot, int power_on,
 	if (!host->vcc)
 		return 0;
 
+	if (gpio_is_valid(mmc_slot(host).gpio_reset))
+		gpio_set_value_cansleep(mmc_slot(host).gpio_reset, 0);
 	if (mmc_slot(host).before_set_reg)
 		mmc_slot(host).before_set_reg(dev, slot, power_on, vdd);
 
@@ -365,6 +367,8 @@  static int omap_hsmmc_set_power(struct device *dev, int slot, int power_on,
 
 	if (mmc_slot(host).after_set_reg)
 		mmc_slot(host).after_set_reg(dev, slot, power_on, vdd);
+	if (gpio_is_valid(mmc_slot(host).gpio_reset))
+		gpio_set_value_cansleep(mmc_slot(host).gpio_reset, 1);
 
 error_set_power:
 	return ret;
@@ -481,10 +485,22 @@  static int omap_hsmmc_gpio_init(struct omap_mmc_platform_data *pdata)
 	} else
 		pdata->slots[0].gpio_wp = -EINVAL;
 
-	return 0;
+	if (gpio_is_valid(pdata->slots[0].gpio_reset)) {
+		ret = gpio_request(pdata->slots[0].gpio_reset, "mmc_reset");
+		if (ret)
+			goto err_free_wp;
+		ret = gpio_direction_output(pdata->slots[0].gpio_reset, 1);
+		if (ret)
+			goto err_free_reset;
+	} else
+		pdata->slots[0].gpio_reset = -EINVAL;
 
+	return 0;
+err_free_reset:
+	gpio_free(pdata->slots[0].gpio_reset);
 err_free_wp:
-	gpio_free(pdata->slots[0].gpio_wp);
+	if (gpio_is_valid(pdata->slots[0].gpio_wp))
+		gpio_free(pdata->slots[0].gpio_wp);
 err_free_cd:
 	if (gpio_is_valid(pdata->slots[0].switch_pin))
 err_free_sp:
@@ -494,6 +510,8 @@  err_free_sp:
 
 static void omap_hsmmc_gpio_free(struct omap_mmc_platform_data *pdata)
 {
+	if (gpio_is_valid(pdata->slots[0].gpio_reset))
+		gpio_free(pdata->slots[0].gpio_reset);
 	if (gpio_is_valid(pdata->slots[0].gpio_wp))
 		gpio_free(pdata->slots[0].gpio_wp);
 	if (gpio_is_valid(pdata->slots[0].switch_pin))
@@ -1952,10 +1970,11 @@  static struct omap_mmc_platform_data *of_get_hsmmc_pdata(struct device *dev)
 	struct omap_mmc_platform_data *pdata;
 	struct device_node *np = dev->of_node;
 	u32 bus_width, max_freq;
-	int cd_gpio, wp_gpio;
+	int cd_gpio, wp_gpio, reset_gpio;
 
 	cd_gpio = of_get_named_gpio(np, "cd-gpios", 0);
 	wp_gpio = of_get_named_gpio(np, "wp-gpios", 0);
+	reset_gpio = of_get_named_gpio(np, "reset-gpios", 0);
 	if (cd_gpio == -EPROBE_DEFER || wp_gpio == -EPROBE_DEFER)
 		return ERR_PTR(-EPROBE_DEFER);
 
@@ -1970,6 +1989,7 @@  static struct omap_mmc_platform_data *of_get_hsmmc_pdata(struct device *dev)
 	pdata->nr_slots = 1;
 	pdata->slots[0].switch_pin = cd_gpio;
 	pdata->slots[0].gpio_wp = wp_gpio;
+	pdata->slots[0].gpio_reset = reset_gpio;
 
 	if (of_find_property(np, "ti,non-removable", NULL)) {
 		pdata->slots[0].nonremovable = true;
diff --git a/include/linux/platform_data/mmc-omap.h b/include/linux/platform_data/mmc-omap.h
index 51e70cf..8f3ee4a 100644
--- a/include/linux/platform_data/mmc-omap.h
+++ b/include/linux/platform_data/mmc-omap.h
@@ -116,6 +116,7 @@  struct omap_mmc_platform_data {
 
 		int switch_pin;			/* gpio (card detect) */
 		int gpio_wp;			/* gpio (write protect) */
+		int gpio_reset;			/* gpio (reset) */
 
 		int (*set_bus_mode)(struct device *dev, int slot, int bus_mode);
 		int (*set_power)(struct device *dev, int slot,