Re: [PATCH v3 19/30] iio: adc: sun4i-gpadc-iio: rework: support nvmem calibration data

Maxime Ripard
2018-08-31T13:13:54Z

[-- Attachment #1: Type: text/plain, Size: 2543 bytes --]

On Thu, Aug 30, 2018 at 05:45:07PM +0200, Philipp Rossak wrote:
> This patch reworks the driver to support nvmem calibration cells.
> The driver checks if the nvmem calibration is supported and reads out
> the nvmem.
>
> Signed-off-by: Philipp Rossak <embed3d@gmail.com>
> ---
> drivers/iio/adc/sun4i-gpadc-iio.c | 24 ++++++++++++++++++++++++
> 1 file changed, 24 insertions(+)
>
> diff --git a/drivers/iio/adc/sun4i-gpadc-iio.c b/drivers/iio/adc/sun4i-gpadc-iio.c
> index 18ab72e52d78..2fd73d143815 100644
> --- a/drivers/iio/adc/sun4i-gpadc-iio.c
> +++ b/drivers/iio/adc/sun4i-gpadc-iio.c
> @@ -27,6 +27,7 @@
> #include <linux/interrupt.h>
> #include <linux/io.h>
> #include <linux/module.h>
> +#include <linux/nvmem-consumer.h>
> #include <linux/of.h>
> #include <linux/of_device.h>
> #include <linux/platform_device.h>
> @@ -70,6 +71,7 @@ struct gpadc_data {
> bool has_mod_clk;
> u32 temp_data_base;
> int sensor_count;
> + bool supports_nvmem;
> };
>
> static irqreturn_t sun4i_gpadc_data_irq_handler(int irq, void *dev_id);
> @@ -146,6 +148,7 @@ struct sun4i_gpadc_iio {
> struct clk *bus_clk;
> struct clk *mod_clk;
> struct reset_control *reset;
> + u32 calibration_data[2];
> };
>
> static const struct iio_chan_spec sun4i_gpadc_channels[] = {
> @@ -484,6 +487,9 @@ static int sun4i_gpadc_probe_dt(struct platform_device *pdev,
> struct resource *mem;
> void __iomem *base;
> int ret;
> + struct nvmem_cell *cell;
> + ssize_t cell_size;
> + u32 *cell_data;
>
> info->data = of_device_get_match_data(&pdev->dev);
> if (!info->data)
> @@ -494,6 +500,24 @@ static int sun4i_gpadc_probe_dt(struct platform_device *pdev,
> if (IS_ERR(base))
> return PTR_ERR(base);
>
> + if (info->data->supports_nvmem) {
> +
> + cell = nvmem_cell_get(&pdev->dev, "calibration");
> + if (IS_ERR(cell)) {
> + if (PTR_ERR(cell) == -EPROBE_DEFER)
> + return PTR_ERR(cell);

You're masking real errors here, if the issue isn't that the property
isn't found.

> + } else {
> + cell_data = (u32 *)nvmem_cell_read(cell, &cell_size);
> + if (cell_size != 8)
> + dev_err(&pdev->dev,
> + "Calibration data has wrong size\n");
> + else {
> + info->calibration_data[0] = cell_data[0];
> + info->calibration_data[1] = cell_data[1];

How are those calibration data organized when there is multiple channels?

Maxime

--
Maxime Ripard, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com

[-- Attachment #2: signature.asc --]
[-- Type: application/pgp-signature, Size: 833 bytes --]