Re: [PATCH v2] iio: adc: rockchip_saradc: add voltage notifier so get referenced voltage once at probe
From: Jonathan Cameron <jic23@kernel.org>
Date: 2021-08-08 16:45:40
Also in:
linux-iio, linux-rockchip
On Fri, 6 Aug 2021 18:55:24 +0800 Simon Xue [off-list ref] wrote:
From: David Wu <redacted> Add voltage notifier, no need to query regulator voltage for every saradc read, just get regulator voltage once at probe. Signed-off-by: Simon Xue <redacted> Signed-off-by: David Wu <redacted> Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Looks like Andy's v1 reviews crossed with your v2. Given you are going to be doing a v3 because of signed-off-by ordering as per Andy's comments please tidy up the other thing he mentioned (repeated below). Otherwise looks good to me. Thanks, Jonathan
quoted hunk ↗ jump to hunk
--- drivers/iio/adc/rockchip_saradc.c | 47 ++++++++++++++++++++++++++----- 1 file changed, 40 insertions(+), 7 deletions(-)diff --git a/drivers/iio/adc/rockchip_saradc.c b/drivers/iio/adc/rockchip_saradc.c index f3eb8d2e50dc..295da1ad6edb 100644 --- a/drivers/iio/adc/rockchip_saradc.c +++ b/drivers/iio/adc/rockchip_saradc.c@@ -49,10 +49,12 @@ struct rockchip_saradc { struct clk *clk; struct completion completion; struct regulator *vref; + int uv_vref; struct reset_control *reset; const struct rockchip_saradc_data *data; u16 last_val; const struct iio_chan_spec *last_chan; + struct notifier_block nb; }; static void rockchip_saradc_power_down(struct rockchip_saradc *info)@@ -105,13 +107,7 @@ static int rockchip_saradc_read_raw(struct iio_dev *indio_dev, mutex_unlock(&indio_dev->mlock); return IIO_VAL_INT; case IIO_CHAN_INFO_SCALE: - ret = regulator_get_voltage(info->vref); - if (ret < 0) { - dev_err(&indio_dev->dev, "failed to get voltage\n"); - return ret; - } - - *val = ret / 1000; + *val = info->uv_vref / 1000; *val2 = chan->scan_type.realbits; return IIO_VAL_FRACTIONAL_LOG2; default:@@ -298,6 +294,26 @@ static irqreturn_t rockchip_saradc_trigger_handler(int irq, void *p) return IRQ_HANDLED; } +static int rockchip_saradc_volt_notify(struct notifier_block *nb, + unsigned long event, + void *data) +{ + struct rockchip_saradc *info = + container_of(nb, struct rockchip_saradc, nb); + + if (event & REGULATOR_EVENT_VOLTAGE_CHANGE) + info->uv_vref = (unsigned long)data; + + return NOTIFY_OK; +} + +static void rockchip_saradc_regulator_action(void *data) +{ + struct rockchip_saradc *info = data; + + regulator_unregister_notifier(info->vref, &info->nb); +} + static int rockchip_saradc_probe(struct platform_device *pdev) { struct rockchip_saradc *info = NULL;@@ -410,6 +426,13 @@ static int rockchip_saradc_probe(struct platform_device *pdev) return ret; } + info->uv_vref = regulator_get_voltage(info->vref); + if (info->uv_vref < 0) { + dev_err(&pdev->dev, "failed to get voltage\n"); + ret = info->uv_vref; + return ret; + }
Andy suggested a cleaner form of this (which I also prefer) is ret = regulator_get_voltage(info->vref); if (ret < 0) return ret; info->uv_vref = ret;
quoted hunk ↗ jump to hunk
+ ret = clk_prepare_enable(info->pclk); if (ret < 0) { dev_err(&pdev->dev, "failed to enable pclk\n");@@ -450,6 +473,16 @@ static int rockchip_saradc_probe(struct platform_device *pdev) if (ret) return ret; + info->nb.notifier_call = rockchip_saradc_volt_notify; + ret = regulator_register_notifier(info->vref, &info->nb); + if (ret) + return ret; + + ret = devm_add_action_or_reset(&pdev->dev, + rockchip_saradc_regulator_action, info); + if (ret) + return ret; + return devm_iio_device_register(&pdev->dev, indio_dev); }