iio: adc: rockchip_saradc: add support for rk3066-tsadc variant
From: =?UTF-8?q?Heiko=20St=C3=BCbner?= <heiko@...> Date: Thu, 11 Sep 2014 00:22:35 +0200
Commit-Message
Older Rockchip SoCs, at least the rk3066, used a slightly modified saradc for temperature measurements. This so called tsadc does not contain any active parts like temperature interrupts and only supports polling the current temperature. The returned voltage can then be converted by a suitable thermal driver to and actual temperature and used for thermal handling. Signed-off-by: Heiko Stuebner <heiko@...>
Patch-Comment
changes since v2: - adapt message about the clk rate changes since v1: - use GENMASK instead of creating the mask manually as suggested by Hartmut Knaack .../bindings/iio/adc/rockchip-saradc.txt | 2 +- drivers/iio/adc/rockchip_saradc.c | 64 +++++++++++++++++----- 2 files changed, 51 insertions(+), 15 deletions(-)
Statistics
- 51 lines added
- 15 lines removed
Changes
-------- Documentation/devicetree/bindings/iio/adc/rockchip-saradc.txt ---------
index 5d3ec1d..a9a5fe1 100644
@@ -1,7 +1,7 @@
Rockchip Successive Approximation Register (SAR) A/D Converter bindings
Required properties:
+- compatible: Should be "rockchip,saradc" or "rockchip,rk3066-tsadc"
- reg: physical base address of the controller and length of memory mapped
region.
- interrupts: The interrupt number to the cpu. The interrupt specifier format
---------------------- drivers/iio/adc/rockchip_saradc.c -----------------------
index e074a0b..b546bc1 100644
@@ -18,13 +18,13 @@
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/of.h>
+#include <linux/of_device.h>
#include <linux/clk.h>
#include <linux/completion.h>
#include <linux/regulator/consumer.h>
#include <linux/iio/iio.h>
#define SARADC_DATA 0x00
#define SARADC_STAS 0x04
#define SARADC_STAS_BUSY BIT(0)
@@ -38,15 +38,22 @@
#define SARADC_DLY_PU_SOC 0x0c
#define SARADC_DLY_PU_SOC_MASK 0x3f
#define SARADC_TIMEOUT msecs_to_jiffies(100)
+struct rockchip_saradc_data {
+ int num_bits;
+ const struct iio_chan_spec *channels;
+ int num_channels;
+ unsigned long clk_rate;
+};
+
struct rockchip_saradc {
void __iomem *regs;
struct clk *pclk;
struct clk *clk;
struct completion completion;
struct regulator *vref;
+ const struct rockchip_saradc_data *data;
u16 last_val;
};
@@ -90,7 +97,7 @@ static int rockchip_saradc_read_raw(struct iio_dev *indio_dev,
}
*val = ret / 1000;
+ *val2 = info->data->num_bits;
return IIO_VAL_FRACTIONAL_LOG2;
default:
return -EINVAL;
@@ -103,7 +110,7 @@ static irqreturn_t rockchip_saradc_isr(int irq, void *dev_id)
/* Read value */
info->last_val = readl_relaxed(info->regs + SARADC_DATA);
+ info->last_val &= GENMASK(info->data->num_bits - 1, 0);
/* Clear irq & power down adc */
writel_relaxed(0, info->regs + SARADC_CTRL);
@@ -133,12 +140,44 @@ static const struct iio_chan_spec rockchip_saradc_iio_channels[] = {
ADC_CHANNEL(2, "adc2"),
};
+static const struct rockchip_saradc_data saradc_data = {
+ .num_bits = 10,
+ .channels = rockchip_saradc_iio_channels,
+ .num_channels = ARRAY_SIZE(rockchip_saradc_iio_channels),
+ .clk_rate = 1000000,
+};
+
+static const struct iio_chan_spec rockchip_rk3066_tsadc_iio_channels[] = {
+ ADC_CHANNEL(0, "adc0"),
+ ADC_CHANNEL(1, "adc1"),
+};
+
+static const struct rockchip_saradc_data rk3066_tsadc_data = {
+ .num_bits = 12,
+ .channels = rockchip_rk3066_tsadc_iio_channels,
+ .num_channels = ARRAY_SIZE(rockchip_rk3066_tsadc_iio_channels),
+ .clk_rate = 50000,
+};
+
+static const struct of_device_id rockchip_saradc_match[] = {
+ {
+ .compatible = "rockchip,saradc",
+ .data = &saradc_data,
+ }, {
+ .compatible = "rockchip,rk3066-tsadc",
+ .data = &rk3066_tsadc_data,
+ },
+ {},
+};
+MODULE_DEVICE_TABLE(of, rockchip_saradc_match);
+
static int rockchip_saradc_probe(struct platform_device *pdev)
{
struct rockchip_saradc *info = NULL;
struct device_node *np = pdev->dev.of_node;
struct iio_dev *indio_dev = NULL;
struct resource *mem;
+ const struct of_device_id *match;
int ret;
int irq;
@@ -152,6 +191,9 @@ static int rockchip_saradc_probe(struct platform_device *pdev)
}
info = iio_priv(indio_dev);
+ match = of_match_device(rockchip_saradc_match, &pdev->dev);
+ info->data = match->data;
+
mem = platform_get_resource(pdev, IORESOURCE_MEM, 0);
info->regs = devm_ioremap_resource(&pdev->dev, mem);
if (IS_ERR(info->regs))
@@ -192,10 +234,10 @@ static int rockchip_saradc_probe(struct platform_device *pdev)
}
/*
+ * Use a default value for the converter clock.
* This may become user-configurable in the future.
*/
+ ret = clk_set_rate(info->clk, info->data->clk_rate);
if (ret < 0) {
dev_err(&pdev->dev, "failed to set adc clk rate, %d\n", ret);
return ret;
@@ -227,8 +269,8 @@ static int rockchip_saradc_probe(struct platform_device *pdev)
indio_dev->info = &rockchip_saradc_iio_info;
indio_dev->modes = INDIO_DIRECT_MODE;
+ indio_dev->channels = info->data->channels;
+ indio_dev->num_channels = info->data->num_channels;
ret = iio_device_register(indio_dev);
if (ret)
@@ -296,12 +338,6 @@ static int rockchip_saradc_resume(struct device *dev)
static SIMPLE_DEV_PM_OPS(rockchip_saradc_pm_ops,
rockchip_saradc_suspend, rockchip_saradc_resume);
static struct platform_driver rockchip_saradc_driver = {
.probe = rockchip_saradc_probe,
.remove = rockchip_saradc_remove,