Messages in this thread | | | Subject | Re: [PATCH 05/16] iio: adc: sun4i-gpadc-iio: rework: support clocks and reset | From | Philipp Rossak <> | Date | Sun, 28 Jan 2018 12:34:14 +0100 |
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On 28.01.2018 09:50, Jonathan Cameron wrote: > On Fri, 26 Jan 2018 16:19:30 +0100 > Philipp Rossak <embed3d@gmail.com> wrote: > >> For adding newer sensor some basic rework of the code is necessary. >> >> The SoCs after H3 has newer thermal sensor ADCs, which have two clock >> inputs (bus clock and sampling clock) and a reset. The registers are >> also re-arranged. >> >> This commit reworks the code, adds the process of the clocks and >> resets. >> >> Signed-off-by: Philipp Rossak <embed3d@gmail.com> >> Signed-off-by: Icenowy Zheng <icenowy@aosc.io> > > Both clock and reset code is safe against null parameters, so you can > drop a lot of 'is it here' checks in this. They could be argued to > act as documentation of the fact we really don't expect them in some cases > I suppose... > Ok, this sounds good for me! I will fix that in the next version of this patch series.
>> --- >> drivers/iio/adc/sun4i-gpadc-iio.c | 80 +++++++++++++++++++++++++++++++++++++++ >> 1 file changed, 80 insertions(+) >> >> diff --git a/drivers/iio/adc/sun4i-gpadc-iio.c b/drivers/iio/adc/sun4i-gpadc-iio.c >> index 363936b37c5a..1a80744bd472 100644 >> --- a/drivers/iio/adc/sun4i-gpadc-iio.c >> +++ b/drivers/iio/adc/sun4i-gpadc-iio.c >> @@ -22,6 +22,7 @@ >> * shutdown for not being used. >> */ >> >> +#include <linux/clk.h> >> #include <linux/completion.h> >> #include <linux/interrupt.h> >> #include <linux/io.h> >> @@ -31,6 +32,7 @@ >> #include <linux/platform_device.h> >> #include <linux/pm_runtime.h> >> #include <linux/regmap.h> >> +#include <linux/reset.h> >> #include <linux/thermal.h> >> #include <linux/delay.h> >> >> @@ -75,6 +77,9 @@ struct gpadc_data { >> u32 ctrl2_map; >> u32 sensor_en_map; >> u32 filter_map; >> + bool has_bus_clk; >> + bool has_bus_rst; >> + bool has_mod_clk; >> }; >> >> static const struct gpadc_data sun4i_gpadc_data = { >> @@ -134,6 +139,9 @@ struct sun4i_gpadc_iio { >> atomic_t ignore_temp_data_irq; >> const struct gpadc_data *data; >> bool no_irq; >> + struct clk *bus_clk; >> + struct clk *mod_clk; >> + struct reset_control *reset; >> /* prevents concurrent reads of temperature and ADC */ >> struct mutex mutex; >> struct thermal_zone_device *tzd; >> @@ -435,6 +443,12 @@ static int sun4i_gpadc_runtime_suspend(struct device *dev) >> { >> struct sun4i_gpadc_iio *info = iio_priv(dev_get_drvdata(dev)); >> >> + if (info->data->has_mod_clk) >> + clk_disable(info->mod_clk); > > Safe against null parameter... (see below) > >> + >> + if (info->data->has_bus_clk) >> + clk_disable(info->bus_clk); >> + >> return info->data->sample_end(info); >> } >> >> @@ -483,6 +497,12 @@ static int sun4i_gpadc_runtime_resume(struct device *dev) >> { >> struct sun4i_gpadc_iio *info = iio_priv(dev_get_drvdata(dev)); >> >> + if (info->data->has_mod_clk) >> + clk_enable(info->mod_clk); > > clk_enable is safe against null parameter so could do without the checks. > >> + >> + if (info->data->has_bus_clk) >> + clk_enable(info->bus_clk); >> + >> return info->data->sample_start(info); >> } >> >> @@ -597,10 +617,61 @@ static int sun4i_gpadc_probe_dt(struct platform_device *pdev, >> return ret; >> } >> >> + if (info->data->has_bus_rst) { >> + info->reset = devm_reset_control_get(&pdev->dev, NULL); >> + if (IS_ERR(info->reset)) { >> + ret = PTR_ERR(info->reset); >> + return ret; >> + } >> + >> + ret = reset_control_deassert(info->reset); >> + if (ret) >> + return ret; >> + } >> + >> + if (info->data->has_bus_clk) { >> + info->bus_clk = devm_clk_get(&pdev->dev, "bus"); >> + if (IS_ERR(info->bus_clk)) { >> + ret = PTR_ERR(info->bus_clk); >> + goto assert_reset; >> + } >> + >> + ret = clk_prepare_enable(info->bus_clk); >> + if (ret) >> + goto assert_reset; >> + } >> + >> + if (info->data->has_mod_clk) { >> + info->mod_clk = devm_clk_get(&pdev->dev, "mod"); >> + if (IS_ERR(info->mod_clk)) { >> + ret = PTR_ERR(info->mod_clk); >> + goto disable_bus_clk; >> + } >> + >> + /* Running at 6MHz */ >> + ret = clk_set_rate(info->mod_clk, 4000000); >> + if (ret) >> + goto disable_bus_clk; >> + >> + ret = clk_prepare_enable(info->mod_clk); >> + if (ret) >> + goto disable_bus_clk; >> + } >> + >> if (IS_ENABLED(CONFIG_THERMAL_OF)) >> info->sensor_device = &pdev->dev; >> >> return 0; >> + >> +disable_bus_clk: >> + if (info->data->has_bus_clk) >> + clk_disable_unprepare(info->bus_clk); >> + >> +assert_reset: >> + if (info->data->has_bus_rst) >> + reset_control_assert(info->reset); >> + >> + return ret; >> } >> >> static int sun4i_gpadc_probe_mfd(struct platform_device *pdev, >> @@ -766,6 +837,15 @@ static int sun4i_gpadc_remove(struct platform_device *pdev) >> if (!info->no_irq) >> iio_map_array_unregister(indio_dev); >> >> + if (info->data->has_mod_clk) >> + clk_disable_unprepare(info->mod_clk); > > clk_disable_unprepare is safe against a null parameter > so I don't think the checks are needed. > >> + >> + if (info->data->has_bus_clk) >> + clk_disable_unprepare(info->bus_clk); >> + >> + if (info->data->has_bus_rst) >> + reset_control_assert(info->reset); > > Safe against null parameter... > >> + >> return 0; >> } >> > Thanks, Philipp
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