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iio: adc: at91_adc: rework resolution selection 

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 even have the LOWRES
bit.

Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Reviewed-by: Ludovic Desroches <ludovic.desroches@microchip.com>
Link: https://lore.kernel.org/r/20201128222818.1910764-3-alexandre.belloni@bootlin.com
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
This commit is contained in:
Alexandre Belloni 2020-11-28 23:28:10 +01:00 committed by Jonathan Cameron
parent 197cefcdc8
commit 5eb39ef81a
1 changed files with 40 additions and 57 deletions
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97
drivers/iio/adc/at91_adc.c
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@ -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;
const 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)
{
@ -889,6 +839,7 @@ 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 = of_device_get_match_data(&pdev->dev);
@ -921,9 +872,13 @@ 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;
@ -1245,7 +1200,7 @@ 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;
@ -1360,6 +1315,8 @@ 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,
@ -1374,6 +1331,8 @@ 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,
@ -1388,6 +1347,8 @@ 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,
@ -1405,6 +1366,8 @@ 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,
@ -1416,11 +1379,31 @@ 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);