2014-07-03 20:49:40

by Marek Belisko

[permalink] [raw]
Subject: [PATCH 1/2] mmc: hsmmc: Add reset gpio configuration option.

From: NeilBrown <[email protected]>

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 <[email protected]>
---
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;

+ 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,
--
1.9.1


2014-07-03 20:49:44

by Marek Belisko

[permalink] [raw]
Subject: [PATCH 2/2] Documentation: devicetree: mmc: Document reset-gpio property

Signed-off-by: Marek Belisko <[email protected]>
---
Documentation/devicetree/bindings/mmc/mmc.txt | 2 ++
1 file changed, 2 insertions(+)

diff --git a/Documentation/devicetree/bindings/mmc/mmc.txt b/Documentation/devicetree/bindings/mmc/mmc.txt
index 431716e..b094bd2 100644
--- a/Documentation/devicetree/bindings/mmc/mmc.txt
+++ b/Documentation/devicetree/bindings/mmc/mmc.txt
@@ -21,6 +21,7 @@ Optional properties:
below for the case, when a GPIO is used for the CD line
- wp-inverted: when present, polarity on the WP line is inverted. See the note
below for the case, when a GPIO is used for the WP line
+- reset-gpios: Specify GPIOs which will be hold down when turning power regulator
- max-frequency: maximum operating clock frequency
- no-1-8-v: when present, denotes that 1.8v card voltage is not supported on
this system, even if the controller claims it is.
@@ -72,6 +73,7 @@ sdhci@ab000000 {
cd-gpios = <&gpio 69 0>;
cd-inverted;
wp-gpios = <&gpio 70 0>;
+ reset-gpios = <&gpio 71 0>;
max-frequency = <50000000>;
keep-power-in-suspend;
enable-sdio-wakeup;
--
1.9.1

2014-07-03 22:42:59

by Felipe Balbi

[permalink] [raw]
Subject: Re: [PATCH 1/2] mmc: hsmmc: Add reset gpio configuration option.

Hi,

On Thu, Jul 03, 2014 at 10:49:23PM +0200, Marek Belisko wrote:
> From: NeilBrown <[email protected]>
>
> 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 <[email protected]>
> ---
> 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);

--
balbi


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2014-07-03 23:01:31

by Russell King - ARM Linux

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

On Thu, Jul 03, 2014 at 10:49:23PM +0200, Marek Belisko wrote:
> From: NeilBrown <[email protected]>
>
> 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 <[email protected]>

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.

--
FTTC broadband for 0.8mile line: now at 9.7Mbps down 460kbps up... slowly
improving, and getting towards what was expected from it.

2014-07-26 19:48:43

by Belisko Marek

[permalink] [raw]
Subject: Re: [PATCH 1/2] mmc: hsmmc: Add reset gpio configuration option.

Hi Russel,

On Fri, Jul 4, 2014 at 1:01 AM, Russell King - ARM Linux
<[email protected]> wrote:
> On Thu, Jul 03, 2014 at 10:49:23PM +0200, Marek Belisko wrote:
>> From: NeilBrown <[email protected]>
>>
>> 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 <[email protected]>
>
> 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

--
as simple and primitive as possible
-------------------------------------------------
Marek Belisko - OPEN-NANDRA
Freelance Developer

Ruska Nova Ves 219 | Presov, 08005 Slovak Republic
Tel: +421 915 052 184
skype: marekwhite
twitter: #opennandra
web: http://open-nandra.com