[PATCH 2/3] iio: adc: aspeed: Modify driver for ast2600

From: Billy Tsai
Date: Tue Oct 13 2020 - 06:35:16 EST

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This patch is used to handle the difference between ast2600
and previous versions.

Signed-off-by: Billy Tsai <billy_tsai@xxxxxxxxxxxxxx>
---
drivers/iio/adc/aspeed_adc.c | 129 ++++++++++++++++++++++++++---------
1 file changed, 95 insertions(+), 34 deletions(-)

diff --git a/drivers/iio/adc/aspeed_adc.c b/drivers/iio/adc/aspeed_adc.c
index ae400c4d6d40..fc4bbccf9348 100644
--- a/drivers/iio/adc/aspeed_adc.c
+++ b/drivers/iio/adc/aspeed_adc.c
@@ -1,6 +1,6 @@
// SPDX-License-Identifier: GPL-2.0-only
/*
- * Aspeed AST2400/2500 ADC
+ * Aspeed AST2400/2500/2600 ADC
*
* Copyright (C) 2017 Google, Inc.
*/
@@ -81,6 +81,7 @@ struct aspeed_adc_model_data {
unsigned int max_sampling_rate; // Hz
unsigned int vref_voltage; // mV
bool wait_init_sequence;
+ int num_channels;
};

struct aspeed_adc_data {
@@ -90,6 +91,7 @@ struct aspeed_adc_data {
struct clk_hw *clk_prescaler;
struct clk_hw *clk_scaler;
struct reset_control *rst;
+ unsigned int vref_voltage; // mV
};

#define ASPEED_CHAN(_idx, _data_reg_addr) { \
@@ -126,8 +128,6 @@ static int aspeed_adc_read_raw(struct iio_dev *indio_dev,
int *val, int *val2, long mask)
{
struct aspeed_adc_data *data = iio_priv(indio_dev);
- const struct aspeed_adc_model_data *model_data =
- of_device_get_match_data(data->dev);

switch (mask) {
case IIO_CHAN_INFO_RAW:
@@ -135,7 +135,7 @@ static int aspeed_adc_read_raw(struct iio_dev *indio_dev,
return IIO_VAL_INT;

case IIO_CHAN_INFO_SCALE:
- *val = model_data->vref_voltage;
+ *val = data->vref_voltage;
*val2 = ASPEED_RESOLUTION_BITS;
return IIO_VAL_FRACTIONAL_LOG2;

@@ -208,8 +208,13 @@ static int aspeed_adc_probe(struct platform_device *pdev)
struct aspeed_adc_data *data;
const struct aspeed_adc_model_data *model_data;
const char *clk_parent_name;
+ char prescaler_clk_name[32];
+ char scaler_clk_name[32];
int ret;
u32 adc_engine_control_reg_val;
+ u32 ref_voltage_cfg = 0;
+
+ model_data = of_device_get_match_data(&pdev->dev);

indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*data));
if (!indio_dev)
@@ -225,29 +230,75 @@ static int aspeed_adc_probe(struct platform_device *pdev)
/* Register ADC clock prescaler with source specified by device tree. */
spin_lock_init(&data->clk_lock);
clk_parent_name = of_clk_get_parent_name(pdev->dev.of_node, 0);
+ snprintf(prescaler_clk_name, sizeof(prescaler_clk_name),
+ "prescaler-%s", pdev->name);
+ snprintf(scaler_clk_name, sizeof(scaler_clk_name),
+ "scaler-%s", pdev->name);
+ if (!strcmp(model_data->model_name, "ast2400-adc") ||
+ !strcmp(model_data->model_name, "ast2500-adc")) {
+ /* Divider config */
+ data->clk_prescaler = clk_hw_register_divider(
+ &pdev->dev, prescaler_clk_name, clk_parent_name,
+ 0,
+ data->base + ASPEED_REG_CLOCK_CONTROL, 17, 15,
+ CLK_DIVIDER_ONE_BASED, &data->clk_lock);
+ if (IS_ERR(data->clk_prescaler))
+ return PTR_ERR(data->clk_prescaler);

- data->clk_prescaler = clk_hw_register_divider(
- &pdev->dev, "prescaler", clk_parent_name, 0,
- data->base + ASPEED_REG_CLOCK_CONTROL,
- 17, 15, 0, &data->clk_lock);
- if (IS_ERR(data->clk_prescaler))
- return PTR_ERR(data->clk_prescaler);
-
- /*
- * Register ADC clock scaler downstream from the prescaler. Allow rate
- * setting to adjust the prescaler as well.
- */
- data->clk_scaler = clk_hw_register_divider(
- &pdev->dev, "scaler", "prescaler",
- CLK_SET_RATE_PARENT,
- data->base + ASPEED_REG_CLOCK_CONTROL,
- 0, 10, 0, &data->clk_lock);
- if (IS_ERR(data->clk_scaler)) {
- ret = PTR_ERR(data->clk_scaler);
- goto scaler_error;
+ /*
+ * Register ADC clock scaler downstream from the prescaler. Allow rate
+ * setting to adjust the prescaler as well.
+ */
+ data->clk_scaler = clk_hw_register_divider(
+ &pdev->dev, scaler_clk_name, prescaler_clk_name,
+ CLK_SET_RATE_PARENT,
+ data->base + ASPEED_REG_CLOCK_CONTROL, 0, 10,
+ CLK_DIVIDER_ONE_BASED, &data->clk_lock);
+ if (IS_ERR(data->clk_scaler)) {
+ ret = PTR_ERR(data->clk_scaler);
+ goto scaler_error;
+ }
+ /* Get ref_voltage */
+ data->vref_voltage = model_data->vref_voltage;
+ } else if (!strcmp(model_data->model_name, "ast2600-adc")) {
+ /* Divider config */
+ data->clk_scaler = clk_hw_register_divider(
+ &pdev->dev, scaler_clk_name, clk_parent_name,
+ CLK_SET_RATE_UNGATE,
+ data->base + ASPEED_REG_CLOCK_CONTROL, 0, 16,
+ CLK_DIVIDER_ONE_BASED, &data->clk_lock);
+ if (IS_ERR(data->clk_scaler))
+ return PTR_ERR(data->clk_scaler);
+ /*
+ * Get ref_voltage:
+ * If reference voltage is between 1550~1650mv, we can set
+ * fields either ASPEED_REF_VOLTAGE_EXT_HIGH or ASPEED_REF_VOLTAGE_EXT_LOW.
+ * In this place, we select ASPEED_REF_VOLTAGE_EXT_HIGH as higher priority.
+ */
+ if (!of_property_read_u32(pdev->dev.of_node, "ref_voltage",
+ &data->vref_voltage)) {
+ if (data->vref_voltage == 2500)
+ ref_voltage_cfg = ASPEED_REF_VOLTAGE_2500mV;
+ else if (data->vref_voltage == 1200)
+ ref_voltage_cfg = ASPEED_REF_VOLTAGE_1200mV;
+ else if ((data->vref_voltage >= 1550) &&
+ (data->vref_voltage <= 2700))
+ ref_voltage_cfg = ASPEED_REF_VOLTAGE_EXT_HIGH;
+ else if ((data->vref_voltage >= 900) &&
+ (data->vref_voltage <= 1650))
+ ref_voltage_cfg = ASPEED_REF_VOLTAGE_EXT_LOW;
+ else {
+ dev_err(&pdev->dev, "ref_voltage property is out of range: %d\n",
+ data->vref_voltage);
+ return -EINVAL;
+ }
+ } else {
+ dev_err(&pdev->dev, "Couldn't read ref_voltage property\n");
+ return -EINVAL;
+ }
}

- data->rst = devm_reset_control_get_exclusive(&pdev->dev, NULL);
+ data->rst = devm_reset_control_get_shared(&pdev->dev, NULL);
if (IS_ERR(data->rst)) {
dev_err(&pdev->dev,
"invalid or missing reset controller device tree entry");
@@ -256,13 +307,14 @@ static int aspeed_adc_probe(struct platform_device *pdev)
}
reset_control_deassert(data->rst);

- model_data = of_device_get_match_data(&pdev->dev);
+ adc_engine_control_reg_val = readl(data->base + ASPEED_REG_ENGINE_CONTROL);
+ /* Enable engine in normal mode and set ref_voltage */
+ adc_engine_control_reg_val |= (ASPEED_OPERATION_MODE_NORMAL |
+ ASPEED_ENGINE_ENABLE | ref_voltage_cfg);
+ writel(adc_engine_control_reg_val,
+ data->base + ASPEED_REG_ENGINE_CONTROL);

if (model_data->wait_init_sequence) {
- /* Enable engine in normal mode. */
- writel(ASPEED_OPERATION_MODE_NORMAL | ASPEED_ENGINE_ENABLE,
- data->base + ASPEED_REG_ENGINE_CONTROL);
-
/* Wait for initial sequence complete. */
ret = readl_poll_timeout(data->base + ASPEED_REG_ENGINE_CONTROL,
adc_engine_control_reg_val,
@@ -279,18 +331,16 @@ static int aspeed_adc_probe(struct platform_device *pdev)
if (ret)
goto clk_enable_error;

- adc_engine_control_reg_val = GENMASK(31, 16) |
- ASPEED_OPERATION_MODE_NORMAL | ASPEED_ENGINE_ENABLE;
+ adc_engine_control_reg_val |= ASPEED_ADC_CTRL_CH_EN_ALL;
writel(adc_engine_control_reg_val,
data->base + ASPEED_REG_ENGINE_CONTROL);

- model_data = of_device_get_match_data(&pdev->dev);
indio_dev->name = model_data->model_name;
indio_dev->dev.parent = &pdev->dev;
indio_dev->info = &aspeed_adc_iio_info;
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->channels = aspeed_adc_iio_channels;
- indio_dev->num_channels = ARRAY_SIZE(aspeed_adc_iio_channels);
+ indio_dev->num_channels = model_data->num_channels;

ret = iio_device_register(indio_dev);
if (ret)
@@ -333,6 +383,7 @@ static const struct aspeed_adc_model_data ast2400_model_data = {
.vref_voltage = 2500, // mV
.min_sampling_rate = 10000,
.max_sampling_rate = 500000,
+ .num_channels = 16,
};

static const struct aspeed_adc_model_data ast2500_model_data = {
@@ -341,11 +392,21 @@ static const struct aspeed_adc_model_data ast2500_model_data = {
.min_sampling_rate = 1,
.max_sampling_rate = 1000000,
.wait_init_sequence = true,
+ .num_channels = 16,
+};
+
+static const struct aspeed_adc_model_data ast2600_model_data = {
+ .model_name = "ast2600-adc",
+ .min_sampling_rate = 1,
+ .max_sampling_rate = 1000000,
+ .wait_init_sequence = true,
+ .num_channels = 8,
};

static const struct of_device_id aspeed_adc_matches[] = {
{ .compatible = "aspeed,ast2400-adc", .data = &ast2400_model_data },
{ .compatible = "aspeed,ast2500-adc", .data = &ast2500_model_data },
+ { .compatible = "aspeed,ast2600-adc", .data = &ast2600_model_data },
{},
};
MODULE_DEVICE_TABLE(of, aspeed_adc_matches);
@@ -362,5 +423,5 @@ static struct platform_driver aspeed_adc_driver = {
module_platform_driver(aspeed_adc_driver);

MODULE_AUTHOR("Rick Altherr <raltherr@xxxxxxxxxx>");
-MODULE_DESCRIPTION("Aspeed AST2400/2500 ADC Driver");
+MODULE_DESCRIPTION("Aspeed AST2400/2500/2600 ADC Driver");
MODULE_LICENSE("GPL");
--
2.17.1

Next message: Billy Tsai: "[PATCH 1/3] iio: adc: aspeed: Orgnaize and add the define of adc"
Previous message: Peter Zijlstra: "Re: [tip: locking/core] lockdep: Fix lockdep recursion"
In reply to: Billy Tsai: "[PATCH 3/3] iio: adc: aspeed: Setting ref_voltage in probe"
Next in thread: Billy Tsai: "[PATCH 1/3] iio: adc: aspeed: Orgnaize and add the define of adc"
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