| Message ID | 20240506150830.23709-4-johan+linaro@kernel.org |
|---|---|
| State | New |
| Headers | show |
| Series | arm64: dts: qcom: sc8280xp-x13s: enable pm8008 camera pmic | expand |
On 06/05/2024 16:08, Johan Hovold wrote: > Request and deassert any (optional) reset gpio during probe in case it > has been left asserted by the boot firmware. > > Note the reset line is not asserted to avoid reverting to the default > I2C address in case the firmware has configured an alternate address. > > Signed-off-by: Johan Hovold <johan+linaro@kernel.org> > --- > drivers/mfd/qcom-pm8008.c | 6 ++++++ > 1 file changed, 6 insertions(+) > > diff --git a/drivers/mfd/qcom-pm8008.c b/drivers/mfd/qcom-pm8008.c > index d53c987b0d49..d0f190c2ea2b 100644 > --- a/drivers/mfd/qcom-pm8008.c > +++ b/drivers/mfd/qcom-pm8008.c > @@ -4,6 +4,7 @@ > */ > > #include <linux/bitops.h> > +#include <linux/gpio/consumer.h> > #include <linux/i2c.h> > #include <linux/interrupt.h> > #include <linux/irq.h> > @@ -158,6 +159,7 @@ static struct regmap_config qcom_mfd_regmap_cfg = { > static int pm8008_probe(struct i2c_client *client) > { > struct regmap_irq_chip_data *irq_data; > + struct gpio_desc *reset; > int rc; > struct device *dev; > struct regmap *regmap; > @@ -169,6 +171,10 @@ static int pm8008_probe(struct i2c_client *client) > > i2c_set_clientdata(client, regmap); > > + reset = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW); > + if (IS_ERR(reset)) > + return PTR_ERR(reset); > + > if (of_property_read_bool(dev->of_node, "interrupt-controller")) { > rc = devm_regmap_add_irq_chip(dev, regmap, client->irq, > IRQF_SHARED, 0, &pm8008_irq_chip, &irq_data); So not resetting is fine and I understand you want to retain the address given by the firmware, I think that's the right thing to do. You can add this now Tested-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org> In addition to adding a small delay suggested by Andy - a few microseconds pick a number, I think you should verify the chip is out of reset as we would do with many other i2c devices. A common pattern with i2c devices is take the device out of reset then read back an identity register as a smoke test. Take drivers/media/i2c/ov8856.c::ov8856_identify_module() as an example. In this case, suggest reading REVID_PERPH_TYPE @ 0x104 and REVID_PERPH_SUBTYPE @ 0x105 REVID_PERPH_TYPE @ 0x104 == 0x51 (PMIC) REVID_PERPH_SUBYTE @ 0x105 == 0x2C (PM8008) You can then add my Reviewed-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org> --- bod
diff --git a/drivers/mfd/qcom-pm8008.c b/drivers/mfd/qcom-pm8008.c index d53c987b0d49..d0f190c2ea2b 100644 --- a/drivers/mfd/qcom-pm8008.c +++ b/drivers/mfd/qcom-pm8008.c @@ -4,6 +4,7 @@ */ #include <linux/bitops.h> +#include <linux/gpio/consumer.h> #include <linux/i2c.h> #include <linux/interrupt.h> #include <linux/irq.h> @@ -158,6 +159,7 @@ static struct regmap_config qcom_mfd_regmap_cfg = { static int pm8008_probe(struct i2c_client *client) { struct regmap_irq_chip_data *irq_data; + struct gpio_desc *reset; int rc; struct device *dev; struct regmap *regmap; @@ -169,6 +171,10 @@ static int pm8008_probe(struct i2c_client *client) i2c_set_clientdata(client, regmap); + reset = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_LOW); + if (IS_ERR(reset)) + return PTR_ERR(reset); + if (of_property_read_bool(dev->of_node, "interrupt-controller")) { rc = devm_regmap_add_irq_chip(dev, regmap, client->irq, IRQF_SHARED, 0, &pm8008_irq_chip, &irq_data);
Request and deassert any (optional) reset gpio during probe in case it has been left asserted by the boot firmware. Note the reset line is not asserted to avoid reverting to the default I2C address in case the firmware has configured an alternate address. Signed-off-by: Johan Hovold <johan+linaro@kernel.org> --- drivers/mfd/qcom-pm8008.c | 6 ++++++ 1 file changed, 6 insertions(+)