[PATCH 2/9] iio: adc: at91_adc: rework resolution selection
From: Alexandre Belloni
Date: Fri Nov 13 2020 - 16:28:19 EST
Move the possible resolution values back to the driver. This removes the
atmel,adc-res and atmel,adc-res-names properties, leaving only
atmel,adc-use-res. As atmel,adc-res-names had to contain "lowres" and
"highres", those where already the only allowed values for
atmel,adc-use-res.
Also introduce a new compatible string for the sama5d3 as this is the only
one with a different resolution. Also it doesn't event have the LOWRES
bit.
Signed-off-by: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxx>
---
.../devicetree/bindings/iio/adc/at91_adc.txt | 13 +--
drivers/iio/adc/at91_adc.c | 97 ++++++++-----------
2 files changed, 44 insertions(+), 66 deletions(-)
diff --git a/Documentation/devicetree/bindings/iio/adc/at91_adc.txt b/Documentation/devicetree/bindings/iio/adc/at91_adc.txt
index f65b04fb7962..da393ac5c05f 100644
--- a/Documentation/devicetree/bindings/iio/adc/at91_adc.txt
+++ b/Documentation/devicetree/bindings/iio/adc/at91_adc.txt
@@ -2,7 +2,7 @@
Required properties:
- compatible: Should be "atmel,<chip>-adc"
- <chip> can be "at91sam9260", "at91sam9g45" or "at91sam9x5"
+ <chip> can be "at91sam9260", "at91sam9g45", "at91sam9x5" or "sama5d3"
- reg: Should contain ADC registers location and length
- interrupts: Should contain the IRQ line for the ADC
- clock-names: tuple listing input clock names.
@@ -13,17 +13,12 @@ Required properties:
- atmel,adc-startup-time: Startup Time of the ADC in microseconds as
defined in the datasheet
- atmel,adc-vref: Reference voltage in millivolts for the conversions
- - atmel,adc-res: List of resolutions in bits supported by the ADC. List size
- must be two at least.
- - atmel,adc-res-names: Contains one identifier string for each resolution
- in atmel,adc-res property. "lowres" and "highres"
- identifiers are required.
Optional properties:
- atmel,adc-use-external-triggers: Boolean to enable the external triggers
- - atmel,adc-use-res: String corresponding to an identifier from
- atmel,adc-res-names property. If not specified, the highest
- resolution will be used.
+ - atmel,adc-use-res: String selecting the resolution, can be "lowres" or
+ "highres". If not specified, the highest resolution will
+ be used.
- atmel,adc-sleep-mode: Boolean to enable sleep mode when no conversion
- atmel,adc-sample-hold-time: Sample and Hold Time in microseconds
- atmel,adc-ts-wires: Number of touchscreen wires. Should be 4 or 5. If this
diff --git a/drivers/iio/adc/at91_adc.c b/drivers/iio/adc/at91_adc.c
index 62bd35af8b13..0d67c812ef3d 100644
--- a/drivers/iio/adc/at91_adc.c
+++ b/drivers/iio/adc/at91_adc.c
@@ -204,6 +204,9 @@ struct at91_adc_caps {
u32 (*calc_startup_ticks)(u32 startup_time, u32 adc_clk_khz);
u8 num_channels;
+
+ u8 low_res_bits;
+ u8 high_res_bits;
struct at91_adc_reg_desc registers;
};
@@ -229,7 +232,6 @@ struct at91_adc_state {
bool use_external;
u32 vref_mv;
u32 res; /* resolution used for convertions */
- bool low_res; /* the resolution corresponds to the lowest one */
wait_queue_head_t wq_data_avail;
struct at91_adc_caps *caps;
@@ -754,58 +756,6 @@ static int at91_adc_read_raw(struct iio_dev *idev,
return -EINVAL;
}
-static int at91_adc_of_get_resolution(struct iio_dev *idev,
- struct platform_device *pdev)
-{
- struct at91_adc_state *st = iio_priv(idev);
- struct device_node *np = pdev->dev.of_node;
- int count, i, ret = 0;
- char *res_name, *s;
- u32 *resolutions;
-
- count = of_property_count_strings(np, "atmel,adc-res-names");
- if (count < 2) {
- dev_err(&idev->dev, "You must specified at least two resolution names for "
- "adc-res-names property in the DT\n");
- return count;
- }
-
- resolutions = kmalloc_array(count, sizeof(*resolutions), GFP_KERNEL);
- if (!resolutions)
- return -ENOMEM;
-
- if (of_property_read_u32_array(np, "atmel,adc-res", resolutions, count)) {
- dev_err(&idev->dev, "Missing adc-res property in the DT.\n");
- ret = -ENODEV;
- goto ret;
- }
-
- if (of_property_read_string(np, "atmel,adc-use-res", (const char **)&res_name))
- res_name = "highres";
-
- for (i = 0; i < count; i++) {
- if (of_property_read_string_index(np, "atmel,adc-res-names", i, (const char **)&s))
- continue;
-
- if (strcmp(res_name, s))
- continue;
-
- st->res = resolutions[i];
- if (!strcmp(res_name, "lowres"))
- st->low_res = true;
- else
- st->low_res = false;
-
- dev_info(&idev->dev, "Resolution used: %u bits\n", st->res);
- goto ret;
- }
-
- dev_err(&idev->dev, "There is no resolution for %s\n", res_name);
-
-ret:
- kfree(resolutions);
- return ret;
-}
static u32 calc_startup_ticks_9260(u32 startup_time, u32 adc_clk_khz)
{
@@ -891,6 +841,7 @@ static int at91_adc_probe_dt(struct iio_dev *idev,
struct device_node *trig_node;
int i = 0, ret;
u32 prop;
+ char *s;
st->caps = (struct at91_adc_caps *)
of_match_device(at91_adc_dt_ids, &pdev->dev)->data;
@@ -924,9 +875,13 @@ static int at91_adc_probe_dt(struct iio_dev *idev,
}
st->vref_mv = prop;
- ret = at91_adc_of_get_resolution(idev, pdev);
- if (ret)
- goto error_ret;
+ st->res = st->caps->high_res_bits;
+ if (st->caps->low_res_bits &&
+ !of_property_read_string(node, "atmel,adc-use-res", (const char **)&s)
+ && !strcmp(s, "lowres"))
+ st->res = st->caps->low_res_bits;
+
+ dev_info(&idev->dev, "Resolution used: %u bits\n", st->res);
st->registers = &st->caps->registers;
st->num_channels = st->caps->num_channels;
@@ -1248,7 +1203,7 @@ static int at91_adc_probe(struct platform_device *pdev)
reg = AT91_ADC_PRESCAL_(prsc) & st->registers->mr_prescal_mask;
reg |= AT91_ADC_STARTUP_(ticks) & st->registers->mr_startup_mask;
- if (st->low_res)
+ if (st->res == st->caps->low_res_bits)
reg |= AT91_ADC_LOWRES;
if (st->sleep_mode)
reg |= AT91_ADC_SLEEP;
@@ -1363,6 +1318,8 @@ static SIMPLE_DEV_PM_OPS(at91_adc_pm_ops, at91_adc_suspend, at91_adc_resume);
static struct at91_adc_caps at91sam9260_caps = {
.calc_startup_ticks = calc_startup_ticks_9260,
.num_channels = 4,
+ .low_res_bits = 8,
+ .high_res_bits = 10,
.registers = {
.channel_base = AT91_ADC_CHR(0),
.drdy_mask = AT91_ADC_DRDY,
@@ -1377,6 +1334,8 @@ static struct at91_adc_caps at91sam9rl_caps = {
.has_ts = true,
.calc_startup_ticks = calc_startup_ticks_9260, /* same as 9260 */
.num_channels = 6,
+ .low_res_bits = 8,
+ .high_res_bits = 10,
.registers = {
.channel_base = AT91_ADC_CHR(0),
.drdy_mask = AT91_ADC_DRDY,
@@ -1391,6 +1350,8 @@ static struct at91_adc_caps at91sam9g45_caps = {
.has_ts = true,
.calc_startup_ticks = calc_startup_ticks_9260, /* same as 9260 */
.num_channels = 8,
+ .low_res_bits = 8,
+ .high_res_bits = 10,
.registers = {
.channel_base = AT91_ADC_CHR(0),
.drdy_mask = AT91_ADC_DRDY,
@@ -1408,6 +1369,8 @@ static struct at91_adc_caps at91sam9x5_caps = {
.ts_pen_detect_sensitivity = 2,
.calc_startup_ticks = calc_startup_ticks_9x5,
.num_channels = 12,
+ .low_res_bits = 8,
+ .high_res_bits = 10,
.registers = {
.channel_base = AT91_ADC_CDR0_9X5,
.drdy_mask = AT91_ADC_SR_DRDY_9X5,
@@ -1419,11 +1382,31 @@ static struct at91_adc_caps at91sam9x5_caps = {
},
};
+static struct at91_adc_caps sama5d3_caps = {
+ .has_ts = true,
+ .has_tsmr = true,
+ .ts_filter_average = 3,
+ .ts_pen_detect_sensitivity = 2,
+ .calc_startup_ticks = calc_startup_ticks_9x5,
+ .num_channels = 12,
+ .low_res_bits = 0,
+ .high_res_bits = 12,
+ .registers = {
+ .channel_base = AT91_ADC_CDR0_9X5,
+ .drdy_mask = AT91_ADC_SR_DRDY_9X5,
+ .status_register = AT91_ADC_SR_9X5,
+ .trigger_register = AT91_ADC_TRGR_9X5,
+ .mr_prescal_mask = AT91_ADC_PRESCAL_9G45,
+ .mr_startup_mask = AT91_ADC_STARTUP_9X5,
+ },
+};
+
static const struct of_device_id at91_adc_dt_ids[] = {
{ .compatible = "atmel,at91sam9260-adc", .data = &at91sam9260_caps },
{ .compatible = "atmel,at91sam9rl-adc", .data = &at91sam9rl_caps },
{ .compatible = "atmel,at91sam9g45-adc", .data = &at91sam9g45_caps },
{ .compatible = "atmel,at91sam9x5-adc", .data = &at91sam9x5_caps },
+ { .compatible = "atmel,sama5d3-adc", .data = &sama5d3_caps },
{},
};
MODULE_DEVICE_TABLE(of, at91_adc_dt_ids);
--
2.28.0