| Message ID | 20210908034016.24119-3-samuel@sholland.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Input: sun4i-lradc-keys: R329 and D1 support | expand |
On Tue, 2021-09-07 at 22:40 -0500, Samuel Holland wrote: > Until the R329, the LRADC hardware was always active. Now it requires > enabling a clock gate and deasserting a reset line. Do this if the clock > and reset are provided in the device tree, but keep them optional to > maintain support for the existing binding. > > Signed-off-by: Samuel Holland <samuel@sholland.org> Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de> regards Philipp
Hi Samuel, On Tue, Sep 07, 2021 at 10:40:15PM -0500, Samuel Holland wrote: > Until the R329, the LRADC hardware was always active. Now it requires > enabling a clock gate and deasserting a reset line. Do this if the clock > and reset are provided in the device tree, but keep them optional to > maintain support for the existing binding. > > Signed-off-by: Samuel Holland <samuel@sholland.org> > --- > drivers/input/keyboard/sun4i-lradc-keys.c | 29 +++++++++++++++++++++++ > 1 file changed, 29 insertions(+) > > diff --git a/drivers/input/keyboard/sun4i-lradc-keys.c b/drivers/input/keyboard/sun4i-lradc-keys.c > index 4a796bed48ac..50fc18052829 100644 > --- a/drivers/input/keyboard/sun4i-lradc-keys.c > +++ b/drivers/input/keyboard/sun4i-lradc-keys.c > @@ -14,6 +14,7 @@ > * there are no boards known to use channel 1. > */ > > +#include <linux/clk.h> > #include <linux/err.h> > #include <linux/init.h> > #include <linux/input.h> > @@ -23,6 +24,7 @@ > #include <linux/of_platform.h> > #include <linux/platform_device.h> > #include <linux/regulator/consumer.h> > +#include <linux/reset.h> > #include <linux/slab.h> > > #define LRADC_CTRL 0x00 > @@ -83,6 +85,8 @@ struct sun4i_lradc_data { > struct device *dev; > struct input_dev *input; > void __iomem *base; > + struct clk *clk; > + struct reset_control *reset; > struct regulator *vref_supply; > struct sun4i_lradc_keymap *chan0_map; > const struct lradc_variant *variant; > @@ -140,6 +144,14 @@ static int sun4i_lradc_open(struct input_dev *dev) > if (error) > return error; > > + error = reset_control_deassert(lradc->reset); > + if (error) > + goto err_disable_reg; > + > + error = clk_prepare_enable(lradc->clk); > + if (error) > + goto err_assert_reset; > + > lradc->vref = regulator_get_voltage(lradc->vref_supply) * > lradc->variant->divisor_numerator / > lradc->variant->divisor_denominator; > @@ -153,6 +165,13 @@ static int sun4i_lradc_open(struct input_dev *dev) > writel(CHAN0_KEYUP_IRQ | CHAN0_KEYDOWN_IRQ, lradc->base + LRADC_INTC); > > return 0; > + > +err_assert_reset: > + reset_control_assert(lradc->reset); > +err_disable_reg: > + regulator_disable(lradc->vref_supply); > + > + return error; > } > > static void sun4i_lradc_close(struct input_dev *dev) > @@ -164,6 +183,8 @@ static void sun4i_lradc_close(struct input_dev *dev) > SAMPLE_RATE(2), lradc->base + LRADC_CTRL); > writel(0, lradc->base + LRADC_INTC); > > + clk_disable_unprepare(lradc->clk); > + reset_control_assert(lradc->reset); > regulator_disable(lradc->vref_supply); > } > > @@ -243,6 +264,14 @@ static int sun4i_lradc_probe(struct platform_device *pdev) > return -EINVAL; > } > > + lradc->clk = devm_clk_get_optional(dev, NULL); > + if (IS_ERR(lradc->clk)) > + return PTR_ERR(lradc->clk); > + > + lradc->reset = devm_reset_control_get_optional_exclusive(dev, NULL); > + if (IS_ERR(lradc->reset)) > + return PTR_ERR(lradc->reset); > + This wouldn't report an error if the clocks are missing on the R329 (and D1), even though they are required. The way we usually deal with this is through a flag in the variant structure (at least to guard clk_get / reset_control_get) Maxime
diff --git a/drivers/input/keyboard/sun4i-lradc-keys.c b/drivers/input/keyboard/sun4i-lradc-keys.c index 4a796bed48ac..50fc18052829 100644 --- a/drivers/input/keyboard/sun4i-lradc-keys.c +++ b/drivers/input/keyboard/sun4i-lradc-keys.c @@ -14,6 +14,7 @@ * there are no boards known to use channel 1. */ +#include <linux/clk.h> #include <linux/err.h> #include <linux/init.h> #include <linux/input.h> @@ -23,6 +24,7 @@ #include <linux/of_platform.h> #include <linux/platform_device.h> #include <linux/regulator/consumer.h> +#include <linux/reset.h> #include <linux/slab.h> #define LRADC_CTRL 0x00 @@ -83,6 +85,8 @@ struct sun4i_lradc_data { struct device *dev; struct input_dev *input; void __iomem *base; + struct clk *clk; + struct reset_control *reset; struct regulator *vref_supply; struct sun4i_lradc_keymap *chan0_map; const struct lradc_variant *variant; @@ -140,6 +144,14 @@ static int sun4i_lradc_open(struct input_dev *dev) if (error) return error; + error = reset_control_deassert(lradc->reset); + if (error) + goto err_disable_reg; + + error = clk_prepare_enable(lradc->clk); + if (error) + goto err_assert_reset; + lradc->vref = regulator_get_voltage(lradc->vref_supply) * lradc->variant->divisor_numerator / lradc->variant->divisor_denominator; @@ -153,6 +165,13 @@ static int sun4i_lradc_open(struct input_dev *dev) writel(CHAN0_KEYUP_IRQ | CHAN0_KEYDOWN_IRQ, lradc->base + LRADC_INTC); return 0; + +err_assert_reset: + reset_control_assert(lradc->reset); +err_disable_reg: + regulator_disable(lradc->vref_supply); + + return error; } static void sun4i_lradc_close(struct input_dev *dev) @@ -164,6 +183,8 @@ static void sun4i_lradc_close(struct input_dev *dev) SAMPLE_RATE(2), lradc->base + LRADC_CTRL); writel(0, lradc->base + LRADC_INTC); + clk_disable_unprepare(lradc->clk); + reset_control_assert(lradc->reset); regulator_disable(lradc->vref_supply); } @@ -243,6 +264,14 @@ static int sun4i_lradc_probe(struct platform_device *pdev) return -EINVAL; } + lradc->clk = devm_clk_get_optional(dev, NULL); + if (IS_ERR(lradc->clk)) + return PTR_ERR(lradc->clk); + + lradc->reset = devm_reset_control_get_optional_exclusive(dev, NULL); + if (IS_ERR(lradc->reset)) + return PTR_ERR(lradc->reset); + lradc->vref_supply = devm_regulator_get(dev, "vref"); if (IS_ERR(lradc->vref_supply)) return PTR_ERR(lradc->vref_supply);
Until the R329, the LRADC hardware was always active. Now it requires enabling a clock gate and deasserting a reset line. Do this if the clock and reset are provided in the device tree, but keep them optional to maintain support for the existing binding. Signed-off-by: Samuel Holland <samuel@sholland.org> --- drivers/input/keyboard/sun4i-lradc-keys.c | 29 +++++++++++++++++++++++ 1 file changed, 29 insertions(+)