| Message ID | 20220411152114.2165933-3-fabiobaltieri@chromium.org (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Add channel type support to pwm-cros-ec | expand |
On Mon, Apr 11, 2022 at 03:21:12PM +0000, Fabio Baltieri wrote: > Add support for EC_PWM_TYPE_DISPLAY_LIGHT and EC_PWM_TYPE_KB_LIGHT pwm > types to the PWM cros_ec_pwm driver. This allows specifying one of these > PWM channel by functionality, and let the EC firmware pick the correct > channel, thus abstracting the hardware implementation from the kernel > driver. > > To use it, define the node with the "google,cros-ec-pwm-type" > compatible. > > Signed-off-by: Fabio Baltieri <fabiobaltieri@chromium.org> Hey Tzung-Bi, ended up not adding your "Reviewed-by" tag since I changed a chunk of this patch after Rob's comment and there's few options for handling the DT compatibles, feel free to take another look. Thanks Fabio > --- > drivers/pwm/pwm-cros-ec.c | 109 ++++++++++++++++++++++++++++++-------- > 1 file changed, 86 insertions(+), 23 deletions(-) > > diff --git a/drivers/pwm/pwm-cros-ec.c b/drivers/pwm/pwm-cros-ec.c > index 5e29d9c682c3..83c33958d52b 100644 > --- a/drivers/pwm/pwm-cros-ec.c > +++ b/drivers/pwm/pwm-cros-ec.c > @@ -6,23 +6,30 @@ > */ > > #include <linux/module.h> > +#include <linux/of_device.h> > #include <linux/platform_data/cros_ec_commands.h> > #include <linux/platform_data/cros_ec_proto.h> > #include <linux/platform_device.h> > #include <linux/pwm.h> > #include <linux/slab.h> > > +#include <dt-bindings/mfd/cros_ec.h> > + > +#define OF_CROS_EC_PWM_TYPE ((void *)1) > + > /** > * struct cros_ec_pwm_device - Driver data for EC PWM > * > * @dev: Device node > * @ec: Pointer to EC device > * @chip: PWM controller chip > + * @use_pwm_type: Use PWM types instead of generic channels > */ > struct cros_ec_pwm_device { > struct device *dev; > struct cros_ec_device *ec; > struct pwm_chip chip; > + bool use_pwm_type; > }; > > /** > @@ -58,14 +65,31 @@ static void cros_ec_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm) > kfree(channel); > } > > -static int cros_ec_pwm_set_duty(struct cros_ec_device *ec, u8 index, u16 duty) > +static int cros_ec_dt_type_to_pwm_type(u8 dt_index, u8 *pwm_type) > { > + switch (dt_index) { > + case CROS_EC_PWM_DT_KB_LIGHT: > + *pwm_type = EC_PWM_TYPE_KB_LIGHT; > + return 0; > + case CROS_EC_PWM_DT_DISPLAY_LIGHT: > + *pwm_type = EC_PWM_TYPE_DISPLAY_LIGHT; > + return 0; > + default: > + return -EINVAL; > + } > +} > + > +static int cros_ec_pwm_set_duty(struct cros_ec_pwm_device *ec_pwm, u8 index, > + u16 duty) > +{ > + struct cros_ec_device *ec = ec_pwm->ec; > struct { > struct cros_ec_command msg; > struct ec_params_pwm_set_duty params; > } __packed buf; > struct ec_params_pwm_set_duty *params = &buf.params; > struct cros_ec_command *msg = &buf.msg; > + int ret; > > memset(&buf, 0, sizeof(buf)); > > @@ -75,14 +99,25 @@ static int cros_ec_pwm_set_duty(struct cros_ec_device *ec, u8 index, u16 duty) > msg->outsize = sizeof(*params); > > params->duty = duty; > - params->pwm_type = EC_PWM_TYPE_GENERIC; > - params->index = index; > + > + if (ec_pwm->use_pwm_type) { > + ret = cros_ec_dt_type_to_pwm_type(index, ¶ms->pwm_type); > + if (ret) { > + dev_err(ec->dev, "Invalid PWM type index: %d\n", index); > + return ret; > + } > + params->index = 0; > + } else { > + params->pwm_type = EC_PWM_TYPE_GENERIC; > + params->index = index; > + } > > return cros_ec_cmd_xfer_status(ec, msg); > } > > -static int cros_ec_pwm_get_duty(struct cros_ec_device *ec, u8 index) > +static int cros_ec_pwm_get_duty(struct cros_ec_pwm_device *ec_pwm, u8 index) > { > + struct cros_ec_device *ec = ec_pwm->ec; > struct { > struct cros_ec_command msg; > union { > @@ -102,8 +137,17 @@ static int cros_ec_pwm_get_duty(struct cros_ec_device *ec, u8 index) > msg->insize = sizeof(*resp); > msg->outsize = sizeof(*params); > > - params->pwm_type = EC_PWM_TYPE_GENERIC; > - params->index = index; > + if (ec_pwm->use_pwm_type) { > + ret = cros_ec_dt_type_to_pwm_type(index, ¶ms->pwm_type); > + if (ret) { > + dev_err(ec->dev, "Invalid PWM type index: %d\n", index); > + return ret; > + } > + params->index = 0; > + } else { > + params->pwm_type = EC_PWM_TYPE_GENERIC; > + params->index = index; > + } > > ret = cros_ec_cmd_xfer_status(ec, msg); > if (ret < 0) > @@ -133,7 +177,7 @@ static int cros_ec_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, > */ > duty_cycle = state->enabled ? state->duty_cycle : 0; > > - ret = cros_ec_pwm_set_duty(ec_pwm->ec, pwm->hwpwm, duty_cycle); > + ret = cros_ec_pwm_set_duty(ec_pwm, pwm->hwpwm, duty_cycle); > if (ret < 0) > return ret; > > @@ -149,7 +193,7 @@ static void cros_ec_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm, > struct cros_ec_pwm *channel = pwm_get_chip_data(pwm); > int ret; > > - ret = cros_ec_pwm_get_duty(ec_pwm->ec, pwm->hwpwm); > + ret = cros_ec_pwm_get_duty(ec_pwm, pwm->hwpwm); > if (ret < 0) { > dev_err(chip->dev, "error getting initial duty: %d\n", ret); > return; > @@ -204,13 +248,13 @@ static const struct pwm_ops cros_ec_pwm_ops = { > * of PWMs it supports directly, so we have to read the pwm duty cycle for > * subsequent channels until we get an error. > */ > -static int cros_ec_num_pwms(struct cros_ec_device *ec) > +static int cros_ec_num_pwms(struct cros_ec_pwm_device *ec_pwm) > { > int i, ret; > > /* The index field is only 8 bits */ > for (i = 0; i <= U8_MAX; i++) { > - ret = cros_ec_pwm_get_duty(ec, i); > + ret = cros_ec_pwm_get_duty(ec_pwm, i); > /* > * We look for SUCCESS, INVALID_COMMAND, or INVALID_PARAM > * responses; everything else is treated as an error. > @@ -232,10 +276,27 @@ static int cros_ec_num_pwms(struct cros_ec_device *ec) > return U8_MAX; > } > > +#ifdef CONFIG_OF > +static const struct of_device_id cros_ec_pwm_of_match[] = { > + { > + .compatible = "google,cros-ec-pwm", > + }, > + { > + .compatible = "google,cros-ec-pwm-type", > + .data = OF_CROS_EC_PWM_TYPE, > + }, > + {}, > +}; > +MODULE_DEVICE_TABLE(of, cros_ec_pwm_of_match); > +#else > +#define cros_ec_pwm_of_match NULL > +#endif > + > static int cros_ec_pwm_probe(struct platform_device *pdev) > { > struct cros_ec_device *ec = dev_get_drvdata(pdev->dev.parent); > struct device *dev = &pdev->dev; > + const struct of_device_id *id; > struct cros_ec_pwm_device *ec_pwm; > struct pwm_chip *chip; > int ret; > @@ -251,17 +312,27 @@ static int cros_ec_pwm_probe(struct platform_device *pdev) > chip = &ec_pwm->chip; > ec_pwm->ec = ec; > > + id = of_match_device(cros_ec_pwm_of_match, dev); > + if (id && id->data == OF_CROS_EC_PWM_TYPE) > + ec_pwm->use_pwm_type = true; > + > /* PWM chip */ > chip->dev = dev; > chip->ops = &cros_ec_pwm_ops; > chip->of_xlate = cros_ec_pwm_xlate; > chip->of_pwm_n_cells = 1; > - ret = cros_ec_num_pwms(ec); > - if (ret < 0) { > - dev_err(dev, "Couldn't find PWMs: %d\n", ret); > - return ret; > + > + if (ec_pwm->use_pwm_type) { > + chip->npwm = CROS_EC_PWM_DT_COUNT; > + } else { > + ret = cros_ec_num_pwms(ec_pwm); > + if (ret < 0) { > + dev_err(dev, "Couldn't find PWMs: %d\n", ret); > + return ret; > + } > + chip->npwm = ret; > } > - chip->npwm = ret; > + > dev_dbg(dev, "Probed %u PWMs\n", chip->npwm); > > ret = pwmchip_add(chip); > @@ -285,14 +356,6 @@ static int cros_ec_pwm_remove(struct platform_device *dev) > return 0; > } > > -#ifdef CONFIG_OF > -static const struct of_device_id cros_ec_pwm_of_match[] = { > - { .compatible = "google,cros-ec-pwm" }, > - {}, > -}; > -MODULE_DEVICE_TABLE(of, cros_ec_pwm_of_match); > -#endif > - > static struct platform_driver cros_ec_pwm_driver = { > .probe = cros_ec_pwm_probe, > .remove = cros_ec_pwm_remove, > -- > 2.35.1.1178.g4f1659d476-goog >
On Mon, Apr 11, 2022 at 03:21:12PM +0000, Fabio Baltieri wrote: > Add support for EC_PWM_TYPE_DISPLAY_LIGHT and EC_PWM_TYPE_KB_LIGHT pwm > types to the PWM cros_ec_pwm driver. This allows specifying one of these > PWM channel by functionality, and let the EC firmware pick the correct > channel, thus abstracting the hardware implementation from the kernel > driver. > > To use it, define the node with the "google,cros-ec-pwm-type" > compatible. Not sure whether you decide to leave the prefix as is or not[1], just another reminder: to be neat, suggest to remove "drivers: " prefix from the commit title. [1]: https://patchwork.kernel.org/project/chrome-platform/patch/20220331125818.3776912-3-fabiobaltieri@chromium.org/ > +#ifdef CONFIG_OF > +static const struct of_device_id cros_ec_pwm_of_match[] = { > + { > + .compatible = "google,cros-ec-pwm", > + }, > + { > + .compatible = "google,cros-ec-pwm-type", > + .data = OF_CROS_EC_PWM_TYPE, > + }, > + {}, > +}; > +MODULE_DEVICE_TABLE(of, cros_ec_pwm_of_match); > +#else > +#define cros_ec_pwm_of_match NULL > +#endif > + > static int cros_ec_pwm_probe(struct platform_device *pdev) > { > struct cros_ec_device *ec = dev_get_drvdata(pdev->dev.parent); > struct device *dev = &pdev->dev; > + const struct of_device_id *id; > struct cros_ec_pwm_device *ec_pwm; > struct pwm_chip *chip; > int ret; > @@ -251,17 +312,27 @@ static int cros_ec_pwm_probe(struct platform_device *pdev) > chip = &ec_pwm->chip; > ec_pwm->ec = ec; > > + id = of_match_device(cros_ec_pwm_of_match, dev); > + if (id && id->data == OF_CROS_EC_PWM_TYPE) > + ec_pwm->use_pwm_type = true; > + [...] > -#ifdef CONFIG_OF > -static const struct of_device_id cros_ec_pwm_of_match[] = { > - { .compatible = "google,cros-ec-pwm" }, > - {}, > -}; > -MODULE_DEVICE_TABLE(of, cros_ec_pwm_of_match); > -#endif > - Use dev->driver->of_match_table to access the table so that the table declaration doesn't actually need a move. Instead, the helper function of_device_get_match_data() is preferred. Alternatively, it could use of_device_is_compatible(..."google,cros-ec-pwm-type") so that it doesn't need to introduce OF_CROS_EC_PWM_TYPE and reduce some bits. I would prefer this way.
Hi Tzung-Bi, On Tue, Apr 12, 2022 at 03:32:01PM +0800, Tzung-Bi Shih wrote: > On Mon, Apr 11, 2022 at 03:21:12PM +0000, Fabio Baltieri wrote: > > Add support for EC_PWM_TYPE_DISPLAY_LIGHT and EC_PWM_TYPE_KB_LIGHT pwm > > types to the PWM cros_ec_pwm driver. This allows specifying one of these > > PWM channel by functionality, and let the EC firmware pick the correct > > channel, thus abstracting the hardware implementation from the kernel > > driver. > > > > To use it, define the node with the "google,cros-ec-pwm-type" > > compatible. > > Not sure whether you decide to leave the prefix as is or not[1], just another > reminder: to be neat, suggest to remove "drivers: " prefix from the commit > title. Sorry I messed up there, fixed in on the wrong branch and then forgot to re-fix it once I moved to the wrong one -- I'll make sure to get that right now, thanks for your patience. > > [1]: https://patchwork.kernel.org/project/chrome-platform/patch/20220331125818.3776912-3-fabiobaltieri@chromium.org/ > > > +#ifdef CONFIG_OF > > +static const struct of_device_id cros_ec_pwm_of_match[] = { > > + { > > + .compatible = "google,cros-ec-pwm", > > + }, > > + { > > + .compatible = "google,cros-ec-pwm-type", > > + .data = OF_CROS_EC_PWM_TYPE, > > + }, > > + {}, > > +}; > > +MODULE_DEVICE_TABLE(of, cros_ec_pwm_of_match); > > +#else > > +#define cros_ec_pwm_of_match NULL > > +#endif > > + > > static int cros_ec_pwm_probe(struct platform_device *pdev) > > { > > struct cros_ec_device *ec = dev_get_drvdata(pdev->dev.parent); > > struct device *dev = &pdev->dev; > > + const struct of_device_id *id; > > struct cros_ec_pwm_device *ec_pwm; > > struct pwm_chip *chip; > > int ret; > > @@ -251,17 +312,27 @@ static int cros_ec_pwm_probe(struct platform_device *pdev) > > chip = &ec_pwm->chip; > > ec_pwm->ec = ec; > > > > + id = of_match_device(cros_ec_pwm_of_match, dev); > > + if (id && id->data == OF_CROS_EC_PWM_TYPE) > > + ec_pwm->use_pwm_type = true; > > + > [...] > > -#ifdef CONFIG_OF > > -static const struct of_device_id cros_ec_pwm_of_match[] = { > > - { .compatible = "google,cros-ec-pwm" }, > > - {}, > > -}; > > -MODULE_DEVICE_TABLE(of, cros_ec_pwm_of_match); > > -#endif > > - > > Use dev->driver->of_match_table to access the table so that the table > declaration doesn't actually need a move. Instead, the helper function > of_device_get_match_data() is preferred. > > Alternatively, it could use > of_device_is_compatible(..."google,cros-ec-pwm-type") so that it doesn't > need to introduce OF_CROS_EC_PWM_TYPE and reduce some bits. I would prefer > this way. That's a very good point, should simplify things a fair bit, did not realize of_device_is_compatible() was an option somehow, will rework it for that and send a v4 soon. Thanks for the pointer. Fabio
diff --git a/drivers/pwm/pwm-cros-ec.c b/drivers/pwm/pwm-cros-ec.c index 5e29d9c682c3..83c33958d52b 100644 --- a/drivers/pwm/pwm-cros-ec.c +++ b/drivers/pwm/pwm-cros-ec.c @@ -6,23 +6,30 @@ */ #include <linux/module.h> +#include <linux/of_device.h> #include <linux/platform_data/cros_ec_commands.h> #include <linux/platform_data/cros_ec_proto.h> #include <linux/platform_device.h> #include <linux/pwm.h> #include <linux/slab.h> +#include <dt-bindings/mfd/cros_ec.h> + +#define OF_CROS_EC_PWM_TYPE ((void *)1) + /** * struct cros_ec_pwm_device - Driver data for EC PWM * * @dev: Device node * @ec: Pointer to EC device * @chip: PWM controller chip + * @use_pwm_type: Use PWM types instead of generic channels */ struct cros_ec_pwm_device { struct device *dev; struct cros_ec_device *ec; struct pwm_chip chip; + bool use_pwm_type; }; /** @@ -58,14 +65,31 @@ static void cros_ec_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm) kfree(channel); } -static int cros_ec_pwm_set_duty(struct cros_ec_device *ec, u8 index, u16 duty) +static int cros_ec_dt_type_to_pwm_type(u8 dt_index, u8 *pwm_type) { + switch (dt_index) { + case CROS_EC_PWM_DT_KB_LIGHT: + *pwm_type = EC_PWM_TYPE_KB_LIGHT; + return 0; + case CROS_EC_PWM_DT_DISPLAY_LIGHT: + *pwm_type = EC_PWM_TYPE_DISPLAY_LIGHT; + return 0; + default: + return -EINVAL; + } +} + +static int cros_ec_pwm_set_duty(struct cros_ec_pwm_device *ec_pwm, u8 index, + u16 duty) +{ + struct cros_ec_device *ec = ec_pwm->ec; struct { struct cros_ec_command msg; struct ec_params_pwm_set_duty params; } __packed buf; struct ec_params_pwm_set_duty *params = &buf.params; struct cros_ec_command *msg = &buf.msg; + int ret; memset(&buf, 0, sizeof(buf)); @@ -75,14 +99,25 @@ static int cros_ec_pwm_set_duty(struct cros_ec_device *ec, u8 index, u16 duty) msg->outsize = sizeof(*params); params->duty = duty; - params->pwm_type = EC_PWM_TYPE_GENERIC; - params->index = index; + + if (ec_pwm->use_pwm_type) { + ret = cros_ec_dt_type_to_pwm_type(index, ¶ms->pwm_type); + if (ret) { + dev_err(ec->dev, "Invalid PWM type index: %d\n", index); + return ret; + } + params->index = 0; + } else { + params->pwm_type = EC_PWM_TYPE_GENERIC; + params->index = index; + } return cros_ec_cmd_xfer_status(ec, msg); } -static int cros_ec_pwm_get_duty(struct cros_ec_device *ec, u8 index) +static int cros_ec_pwm_get_duty(struct cros_ec_pwm_device *ec_pwm, u8 index) { + struct cros_ec_device *ec = ec_pwm->ec; struct { struct cros_ec_command msg; union { @@ -102,8 +137,17 @@ static int cros_ec_pwm_get_duty(struct cros_ec_device *ec, u8 index) msg->insize = sizeof(*resp); msg->outsize = sizeof(*params); - params->pwm_type = EC_PWM_TYPE_GENERIC; - params->index = index; + if (ec_pwm->use_pwm_type) { + ret = cros_ec_dt_type_to_pwm_type(index, ¶ms->pwm_type); + if (ret) { + dev_err(ec->dev, "Invalid PWM type index: %d\n", index); + return ret; + } + params->index = 0; + } else { + params->pwm_type = EC_PWM_TYPE_GENERIC; + params->index = index; + } ret = cros_ec_cmd_xfer_status(ec, msg); if (ret < 0) @@ -133,7 +177,7 @@ static int cros_ec_pwm_apply(struct pwm_chip *chip, struct pwm_device *pwm, */ duty_cycle = state->enabled ? state->duty_cycle : 0; - ret = cros_ec_pwm_set_duty(ec_pwm->ec, pwm->hwpwm, duty_cycle); + ret = cros_ec_pwm_set_duty(ec_pwm, pwm->hwpwm, duty_cycle); if (ret < 0) return ret; @@ -149,7 +193,7 @@ static void cros_ec_pwm_get_state(struct pwm_chip *chip, struct pwm_device *pwm, struct cros_ec_pwm *channel = pwm_get_chip_data(pwm); int ret; - ret = cros_ec_pwm_get_duty(ec_pwm->ec, pwm->hwpwm); + ret = cros_ec_pwm_get_duty(ec_pwm, pwm->hwpwm); if (ret < 0) { dev_err(chip->dev, "error getting initial duty: %d\n", ret); return; @@ -204,13 +248,13 @@ static const struct pwm_ops cros_ec_pwm_ops = { * of PWMs it supports directly, so we have to read the pwm duty cycle for * subsequent channels until we get an error. */ -static int cros_ec_num_pwms(struct cros_ec_device *ec) +static int cros_ec_num_pwms(struct cros_ec_pwm_device *ec_pwm) { int i, ret; /* The index field is only 8 bits */ for (i = 0; i <= U8_MAX; i++) { - ret = cros_ec_pwm_get_duty(ec, i); + ret = cros_ec_pwm_get_duty(ec_pwm, i); /* * We look for SUCCESS, INVALID_COMMAND, or INVALID_PARAM * responses; everything else is treated as an error. @@ -232,10 +276,27 @@ static int cros_ec_num_pwms(struct cros_ec_device *ec) return U8_MAX; } +#ifdef CONFIG_OF +static const struct of_device_id cros_ec_pwm_of_match[] = { + { + .compatible = "google,cros-ec-pwm", + }, + { + .compatible = "google,cros-ec-pwm-type", + .data = OF_CROS_EC_PWM_TYPE, + }, + {}, +}; +MODULE_DEVICE_TABLE(of, cros_ec_pwm_of_match); +#else +#define cros_ec_pwm_of_match NULL +#endif + static int cros_ec_pwm_probe(struct platform_device *pdev) { struct cros_ec_device *ec = dev_get_drvdata(pdev->dev.parent); struct device *dev = &pdev->dev; + const struct of_device_id *id; struct cros_ec_pwm_device *ec_pwm; struct pwm_chip *chip; int ret; @@ -251,17 +312,27 @@ static int cros_ec_pwm_probe(struct platform_device *pdev) chip = &ec_pwm->chip; ec_pwm->ec = ec; + id = of_match_device(cros_ec_pwm_of_match, dev); + if (id && id->data == OF_CROS_EC_PWM_TYPE) + ec_pwm->use_pwm_type = true; + /* PWM chip */ chip->dev = dev; chip->ops = &cros_ec_pwm_ops; chip->of_xlate = cros_ec_pwm_xlate; chip->of_pwm_n_cells = 1; - ret = cros_ec_num_pwms(ec); - if (ret < 0) { - dev_err(dev, "Couldn't find PWMs: %d\n", ret); - return ret; + + if (ec_pwm->use_pwm_type) { + chip->npwm = CROS_EC_PWM_DT_COUNT; + } else { + ret = cros_ec_num_pwms(ec_pwm); + if (ret < 0) { + dev_err(dev, "Couldn't find PWMs: %d\n", ret); + return ret; + } + chip->npwm = ret; } - chip->npwm = ret; + dev_dbg(dev, "Probed %u PWMs\n", chip->npwm); ret = pwmchip_add(chip); @@ -285,14 +356,6 @@ static int cros_ec_pwm_remove(struct platform_device *dev) return 0; } -#ifdef CONFIG_OF -static const struct of_device_id cros_ec_pwm_of_match[] = { - { .compatible = "google,cros-ec-pwm" }, - {}, -}; -MODULE_DEVICE_TABLE(of, cros_ec_pwm_of_match); -#endif - static struct platform_driver cros_ec_pwm_driver = { .probe = cros_ec_pwm_probe, .remove = cros_ec_pwm_remove,
Add support for EC_PWM_TYPE_DISPLAY_LIGHT and EC_PWM_TYPE_KB_LIGHT pwm types to the PWM cros_ec_pwm driver. This allows specifying one of these PWM channel by functionality, and let the EC firmware pick the correct channel, thus abstracting the hardware implementation from the kernel driver. To use it, define the node with the "google,cros-ec-pwm-type" compatible. Signed-off-by: Fabio Baltieri <fabiobaltieri@chromium.org> --- drivers/pwm/pwm-cros-ec.c | 109 ++++++++++++++++++++++++++++++-------- 1 file changed, 86 insertions(+), 23 deletions(-)