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

Philipp Rossak
2018-08-30T15:45:44Z

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);
+ } 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];
+ }
+ }
+ }
+
if (info->data->has_bus_clk)
info->regmap = devm_regmap_init_mmio_clk(&pdev->dev, "bus",
base, &sun4i_gpadc_regmap_config);
--
2.11.0