[alsa-devel] [PATCH 0/2] ASoC: pcm3168a: Poor man's RST gpio handling
Hi,
when the codec RST input is connected to a GPIO it needs to be pulled high in order to take the pcm3168a out from reset and to make it respond to register accesses via i2c.
I have a board where one GPIO line is connected to two pcm3168a codec so runtime handling of the RST gpio is not possible (one codec would place the other codec to reset as well).
The only possible solution is to request the gpio with GPIOD_FLAGS_BIT_NONEXCLUSIVE flag, ask it to be high initially and never touch it again.
If the optinal GPIO is not described then issue the reset as the driver did.
Regards, Peter --- Peter Ujfalusi (2): bindings: sound: pcm3168a: Document optional RST gpio ASoC: pcm3168a: Add support for optional RST gpio handling
.../devicetree/bindings/sound/ti,pcm3168a.txt | 7 ++++ sound/soc/codecs/pcm3168a.c | 38 +++++++++++++++++-- 2 files changed, 41 insertions(+), 4 deletions(-)
On boards where the RST line is not pulled up, but it is connected to a GPIO line this property must present in order to be able to enable the codec.
Signed-off-by: Peter Ujfalusi peter.ujfalusi@ti.com --- Documentation/devicetree/bindings/sound/ti,pcm3168a.txt | 7 +++++++ 1 file changed, 7 insertions(+)
diff --git a/Documentation/devicetree/bindings/sound/ti,pcm3168a.txt b/Documentation/devicetree/bindings/sound/ti,pcm3168a.txt index 5d9cb84c661d..f30aebc7603a 100644 --- a/Documentation/devicetree/bindings/sound/ti,pcm3168a.txt +++ b/Documentation/devicetree/bindings/sound/ti,pcm3168a.txt @@ -25,6 +25,12 @@ Required properties:
For required properties on SPI/I2C, consult SPI/I2C device tree documentation
+Optional properties: + + - rst-gpios : Optional RST gpio line for the codec + RST = low: device power-down + RST = high: device is enabled + Examples:
i2c0: i2c0@0 { @@ -34,6 +40,7 @@ i2c0: i2c0@0 { pcm3168a: audio-codec@44 { compatible = "ti,pcm3168a"; reg = <0x44>; + rst-gpios = <&gpio0 4 GPIO_ACTIVE_HIGH>; clocks = <&clk_core CLK_AUDIO>; clock-names = "scki"; VDD1-supply = <&supply3v3>;
On Wed, Nov 13, 2019 at 02:47:33PM +0200, Peter Ujfalusi wrote:
On boards where the RST line is not pulled up, but it is connected to a GPIO line this property must present in order to be able to enable the codec.
Please submit patches using subject lines reflecting the style for the subsystem, this makes it easier for people to identify relevant patches. Look at what existing commits in the area you're changing are doing and make sure your subject lines visually resemble what they're doing. There's no need to resubmit to fix this alone.
Mark,
On 18/11/2019 15.08, Mark Brown wrote:
On Wed, Nov 13, 2019 at 02:47:33PM +0200, Peter Ujfalusi wrote:
On boards where the RST line is not pulled up, but it is connected to a GPIO line this property must present in order to be able to enable the codec.
Please submit patches using subject lines reflecting the style for the subsystem, this makes it easier for people to identify relevant patches. Look at what existing commits in the area you're changing are doing and make sure your subject lines visually resemble what they're doing. There's no need to resubmit to fix this alone.
What would be the appropriate subject line for Documentation/devicetree/bindings/sound
Oops, I have missed the dt- prefix for the bindings for sure.
- Péter
Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki
On Mon, Nov 18, 2019 at 04:46:26PM +0200, Peter Ujfalusi wrote:
On 18/11/2019 15.08, Mark Brown wrote:
Please submit patches using subject lines reflecting the style for the subsystem, this makes it easier for people to identify relevant patches. Look at what existing commits in the area you're changing are doing and make sure your subject lines visually resemble what they're doing. There's no need to resubmit to fix this alone.
What would be the appropriate subject line for Documentation/devicetree/bindings/sound
Oops, I have missed the dt- prefix for the bindings for sure.
I prefer ASoC: but yeah, you missed dt-.
The patch
ASoC: pcm3168a: Document optional RST gpio
has been applied to the asoc tree at
https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git for-5.5
All being well this means that it will be integrated into the linux-next tree (usually sometime in the next 24 hours) and sent to Linus during the next merge window (or sooner if it is a bug fix), however if problems are discovered then the patch may be dropped or reverted.
You may get further e-mails resulting from automated or manual testing and review of the tree, please engage with people reporting problems and send followup patches addressing any issues that are reported if needed.
If any updates are required or you are submitting further changes they should be sent as incremental updates against current git, existing patches will not be replaced.
Please add any relevant lists and maintainers to the CCs when replying to this mail.
Thanks, Mark
From cdacc761dae1cbd6475ac79f0e732f2b1ca021e0 Mon Sep 17 00:00:00 2001
From: Peter Ujfalusi peter.ujfalusi@ti.com Date: Wed, 13 Nov 2019 14:47:33 +0200 Subject: [PATCH] ASoC: pcm3168a: Document optional RST gpio
On boards where the RST line is not pulled up, but it is connected to a GPIO line this property must present in order to be able to enable the codec.
Signed-off-by: Peter Ujfalusi peter.ujfalusi@ti.com Link: https://lore.kernel.org/r/20191113124734.27984-2-peter.ujfalusi@ti.com Signed-off-by: Mark Brown broonie@kernel.org --- Documentation/devicetree/bindings/sound/ti,pcm3168a.txt | 7 +++++++ 1 file changed, 7 insertions(+)
diff --git a/Documentation/devicetree/bindings/sound/ti,pcm3168a.txt b/Documentation/devicetree/bindings/sound/ti,pcm3168a.txt index 5d9cb84c661d..f30aebc7603a 100644 --- a/Documentation/devicetree/bindings/sound/ti,pcm3168a.txt +++ b/Documentation/devicetree/bindings/sound/ti,pcm3168a.txt @@ -25,6 +25,12 @@ Required properties:
For required properties on SPI/I2C, consult SPI/I2C device tree documentation
+Optional properties: + + - rst-gpios : Optional RST gpio line for the codec + RST = low: device power-down + RST = high: device is enabled + Examples:
i2c0: i2c0@0 { @@ -34,6 +40,7 @@ i2c0: i2c0@0 { pcm3168a: audio-codec@44 { compatible = "ti,pcm3168a"; reg = <0x44>; + rst-gpios = <&gpio0 4 GPIO_ACTIVE_HIGH>; clocks = <&clk_core CLK_AUDIO>; clock-names = "scki"; VDD1-supply = <&supply3v3>;
On Wed, Nov 13, 2019 at 02:47:33PM +0200, Peter Ujfalusi wrote:
On boards where the RST line is not pulled up, but it is connected to a GPIO line this property must present in order to be able to enable the codec.
Signed-off-by: Peter Ujfalusi peter.ujfalusi@ti.com
Documentation/devicetree/bindings/sound/ti,pcm3168a.txt | 7 +++++++ 1 file changed, 7 insertions(+)
diff --git a/Documentation/devicetree/bindings/sound/ti,pcm3168a.txt b/Documentation/devicetree/bindings/sound/ti,pcm3168a.txt index 5d9cb84c661d..f30aebc7603a 100644 --- a/Documentation/devicetree/bindings/sound/ti,pcm3168a.txt +++ b/Documentation/devicetree/bindings/sound/ti,pcm3168a.txt @@ -25,6 +25,12 @@ Required properties:
For required properties on SPI/I2C, consult SPI/I2C device tree documentation
+Optional properties:
- rst-gpios : Optional RST gpio line for the codec
RST = low: device power-down
RST = high: device is enabled
'reset-gpios' is the standard naming for reset lines.
Examples:
i2c0: i2c0@0 { @@ -34,6 +40,7 @@ i2c0: i2c0@0 { pcm3168a: audio-codec@44 { compatible = "ti,pcm3168a"; reg = <0x44>;
clocks = <&clk_core CLK_AUDIO>; clock-names = "scki"; VDD1-supply = <&supply3v3>;rst-gpios = <&gpio0 4 GPIO_ACTIVE_HIGH>;
-- Peter
Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki. Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki
In case the RST line is connected to a GPIO line it needs to be pulled high when the driver probes to be able to use the codec.
Add support also for cases when more than one codec is is controlled by the same GPIO line by requesting the gpio with GPIOD_FLAGS_BIT_NONEXCLUSIVE.
Signed-off-by: Peter Ujfalusi peter.ujfalusi@ti.com
--- asoc: pcm3168a rst --- sound/soc/codecs/pcm3168a.c | 38 +++++++++++++++++++++++++++++++++---- 1 file changed, 34 insertions(+), 4 deletions(-)
diff --git a/sound/soc/codecs/pcm3168a.c b/sound/soc/codecs/pcm3168a.c index 313500ab36df..f3475134b519 100644 --- a/sound/soc/codecs/pcm3168a.c +++ b/sound/soc/codecs/pcm3168a.c @@ -9,7 +9,9 @@
#include <linux/clk.h> #include <linux/delay.h> +#include <linux/gpio/consumer.h> #include <linux/module.h> +#include <linux/of_gpio.h> #include <linux/pm_runtime.h> #include <linux/regulator/consumer.h>
@@ -59,6 +61,7 @@ struct pcm3168a_priv { struct regulator_bulk_data supplies[PCM3168A_NUM_SUPPLIES]; struct regmap *regmap; struct clk *scki; + struct gpio_desc *gpio_rst; unsigned long sysclk;
struct pcm3168a_io_params io_params[2]; @@ -643,6 +646,7 @@ static bool pcm3168a_readable_register(struct device *dev, unsigned int reg) static bool pcm3168a_volatile_register(struct device *dev, unsigned int reg) { switch (reg) { + case PCM3168A_RST_SMODE: case PCM3168A_DAC_ZERO: case PCM3168A_ADC_OV: return true; @@ -702,6 +706,21 @@ int pcm3168a_probe(struct device *dev, struct regmap *regmap)
dev_set_drvdata(dev, pcm3168a);
+ /* + * Request the RST gpio line as non exclusive as the same reset line + * might be connected to multiple pcm3168a codec + */ + pcm3168a->gpio_rst = devm_gpiod_get_optional(dev, "rst", + GPIOD_OUT_HIGH | + GPIOD_FLAGS_BIT_NONEXCLUSIVE); + if (IS_ERR(pcm3168a->gpio_rst)) { + ret = PTR_ERR(pcm3168a->gpio_rst); + if (ret != -EPROBE_DEFER ) + dev_err(dev, "failed to acquire RST gpio: %d\n", ret); + + return ret; + } + pcm3168a->scki = devm_clk_get(dev, "scki"); if (IS_ERR(pcm3168a->scki)) { ret = PTR_ERR(pcm3168a->scki); @@ -743,10 +762,18 @@ int pcm3168a_probe(struct device *dev, struct regmap *regmap) goto err_regulator; }
- ret = pcm3168a_reset(pcm3168a); - if (ret) { - dev_err(dev, "Failed to reset device: %d\n", ret); - goto err_regulator; + if (pcm3168a->gpio_rst) { + /* + * The device is taken out from reset via GPIO line, wait for + * 3846 SCKI clock cycles for the internal reset de-assertion + */ + msleep(DIV_ROUND_UP(3846 * 1000, pcm3168a->sysclk)); + } else { + ret = pcm3168a_reset(pcm3168a); + if (ret) { + dev_err(dev, "Failed to reset device: %d\n", ret); + goto err_regulator; + } }
pm_runtime_set_active(dev); @@ -785,6 +812,9 @@ static void pcm3168a_disable(struct device *dev)
void pcm3168a_remove(struct device *dev) { + struct pcm3168a_priv *pcm3168a = dev_get_drvdata(dev); + + gpiod_set_value_cansleep(pcm3168a->gpio_rst, 0); pm_runtime_disable(dev); #ifndef CONFIG_PM pcm3168a_disable(dev);
The patch
ASoC: pcm3168a: Add support for optional RST gpio handling
has been applied to the asoc tree at
https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound.git for-5.5
All being well this means that it will be integrated into the linux-next tree (usually sometime in the next 24 hours) and sent to Linus during the next merge window (or sooner if it is a bug fix), however if problems are discovered then the patch may be dropped or reverted.
You may get further e-mails resulting from automated or manual testing and review of the tree, please engage with people reporting problems and send followup patches addressing any issues that are reported if needed.
If any updates are required or you are submitting further changes they should be sent as incremental updates against current git, existing patches will not be replaced.
Please add any relevant lists and maintainers to the CCs when replying to this mail.
Thanks, Mark
From 79f6c108c87b470aacf25fc25a86f48694d03ae8 Mon Sep 17 00:00:00 2001
From: Peter Ujfalusi peter.ujfalusi@ti.com Date: Wed, 13 Nov 2019 14:47:34 +0200 Subject: [PATCH] ASoC: pcm3168a: Add support for optional RST gpio handling
In case the RST line is connected to a GPIO line it needs to be pulled high when the driver probes to be able to use the codec.
Add support also for cases when more than one codec is is controlled by the same GPIO line by requesting the gpio with GPIOD_FLAGS_BIT_NONEXCLUSIVE.
Signed-off-by: Peter Ujfalusi peter.ujfalusi@ti.com
Link: https://lore.kernel.org/r/20191113124734.27984-3-peter.ujfalusi@ti.com Signed-off-by: Mark Brown broonie@kernel.org --- sound/soc/codecs/pcm3168a.c | 38 +++++++++++++++++++++++++++++++++---- 1 file changed, 34 insertions(+), 4 deletions(-)
diff --git a/sound/soc/codecs/pcm3168a.c b/sound/soc/codecs/pcm3168a.c index 313500ab36df..f3475134b519 100644 --- a/sound/soc/codecs/pcm3168a.c +++ b/sound/soc/codecs/pcm3168a.c @@ -9,7 +9,9 @@
#include <linux/clk.h> #include <linux/delay.h> +#include <linux/gpio/consumer.h> #include <linux/module.h> +#include <linux/of_gpio.h> #include <linux/pm_runtime.h> #include <linux/regulator/consumer.h>
@@ -59,6 +61,7 @@ struct pcm3168a_priv { struct regulator_bulk_data supplies[PCM3168A_NUM_SUPPLIES]; struct regmap *regmap; struct clk *scki; + struct gpio_desc *gpio_rst; unsigned long sysclk;
struct pcm3168a_io_params io_params[2]; @@ -643,6 +646,7 @@ static bool pcm3168a_readable_register(struct device *dev, unsigned int reg) static bool pcm3168a_volatile_register(struct device *dev, unsigned int reg) { switch (reg) { + case PCM3168A_RST_SMODE: case PCM3168A_DAC_ZERO: case PCM3168A_ADC_OV: return true; @@ -702,6 +706,21 @@ int pcm3168a_probe(struct device *dev, struct regmap *regmap)
dev_set_drvdata(dev, pcm3168a);
+ /* + * Request the RST gpio line as non exclusive as the same reset line + * might be connected to multiple pcm3168a codec + */ + pcm3168a->gpio_rst = devm_gpiod_get_optional(dev, "rst", + GPIOD_OUT_HIGH | + GPIOD_FLAGS_BIT_NONEXCLUSIVE); + if (IS_ERR(pcm3168a->gpio_rst)) { + ret = PTR_ERR(pcm3168a->gpio_rst); + if (ret != -EPROBE_DEFER ) + dev_err(dev, "failed to acquire RST gpio: %d\n", ret); + + return ret; + } + pcm3168a->scki = devm_clk_get(dev, "scki"); if (IS_ERR(pcm3168a->scki)) { ret = PTR_ERR(pcm3168a->scki); @@ -743,10 +762,18 @@ int pcm3168a_probe(struct device *dev, struct regmap *regmap) goto err_regulator; }
- ret = pcm3168a_reset(pcm3168a); - if (ret) { - dev_err(dev, "Failed to reset device: %d\n", ret); - goto err_regulator; + if (pcm3168a->gpio_rst) { + /* + * The device is taken out from reset via GPIO line, wait for + * 3846 SCKI clock cycles for the internal reset de-assertion + */ + msleep(DIV_ROUND_UP(3846 * 1000, pcm3168a->sysclk)); + } else { + ret = pcm3168a_reset(pcm3168a); + if (ret) { + dev_err(dev, "Failed to reset device: %d\n", ret); + goto err_regulator; + } }
pm_runtime_set_active(dev); @@ -785,6 +812,9 @@ static void pcm3168a_disable(struct device *dev)
void pcm3168a_remove(struct device *dev) { + struct pcm3168a_priv *pcm3168a = dev_get_drvdata(dev); + + gpiod_set_value_cansleep(pcm3168a->gpio_rst, 0); pm_runtime_disable(dev); #ifndef CONFIG_PM pcm3168a_disable(dev);
participants (3)
-
Mark Brown
-
Peter Ujfalusi
-
Rob Herring