Re: [RESEND v4 10/15] iio: adc: aspeed: Support ast2600 adc.

Jonathan Cameron
2021-08-29T15:30:28Z

On Tue, 24 Aug 2021 17:12:38 +0800
Billy Tsai <billy_tsai@aspeedtech.com> wrote:

> Make driver to support ast2600 adc device.
> - Use shared reset controller
> - Complete the vref configure function
> - Add the model data for ast2600 adc
>
> Signed-off-by: Billy Tsai <billy_tsai@aspeedtech.com>
Hi Billy,

A few minor things inline,

Jonathan

> ---
> drivers/iio/adc/aspeed_adc.c | 106 +++++++++++++++++++++++++++++++++--
> 1 file changed, 100 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/iio/adc/aspeed_adc.c b/drivers/iio/adc/aspeed_adc.c
> index 1c87e12a0cab..ea3e9a52fcc9 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.
> * Copyright (C) 2021 Aspeed Technology Inc.
> @@ -14,6 +14,7 @@
> #include <linux/module.h>
> #include <linux/of_platform.h>
> #include <linux/platform_device.h>
> +#include <linux/regulator/consumer.h>
> #include <linux/reset.h>
> #include <linux/spinlock.h>
> #include <linux/types.h>
> @@ -73,6 +74,7 @@ struct aspeed_adc_model_data {
> struct aspeed_adc_data {
> struct device *dev;
> const struct aspeed_adc_model_data *model_data;
> + struct regulator *regulator;
> void __iomem *base;
> spinlock_t clk_lock;
> struct clk_hw *clk_prescaler;
> @@ -208,14 +210,80 @@ static void aspeed_adc_clk_disable_unprepare(void *data)
> clk_disable_unprepare(clk);
> }
>
> +static void aspeed_adc_reg_disable(void *data)
> +{
> + struct regulator *reg = data;
> +
> + regulator_disable(reg);
> +}
> +
> static int aspeed_adc_vref_config(struct iio_dev *indio_dev)
> {
> struct aspeed_adc_data *data = iio_priv(indio_dev);
> + int ret;
> + u32 adc_engine_control_reg_val =
> + readl(data->base + ASPEED_REG_ENGINE_CONTROL);

Given you aren't going to use this if vref_fixed is set, move the read
until after that.

>
> if (data->model_data->vref_fixed) {
> data->vref = data->model_data->vref_fixed;
> return 0;
> }
> +
> + data->regulator = devm_regulator_get_optional(data->dev, "vref");
> + if (!IS_ERR(data->regulator)) {
> + ret = regulator_enable(data->regulator);
> + if (ret)
> + return ret;
> + ret = devm_add_action_or_reset(
> + data->dev, aspeed_adc_reg_disable, data->regulator);
> + if (ret)
> + return ret;
> + data->vref = regulator_get_voltage(data->regulator);
> + /* Conversion from uV to mV */
> + data->vref /= 1000;
> + if ((data->vref >= 1550) && (data->vref <= 2700))
> + writel(adc_engine_control_reg_val |
> + FIELD_PREP(
> + ASPEED_ADC_REF_VOLTAGE,
> + ASPEED_ADC_REF_VOLTAGE_EXT_HIGH),
> + data->base + ASPEED_REG_ENGINE_CONTROL);
> + else if ((data->vref >= 900) && (data->vref <= 1650))
> + writel(adc_engine_control_reg_val |
> + FIELD_PREP(
> + ASPEED_ADC_REF_VOLTAGE,
> + ASPEED_ADC_REF_VOLTAGE_EXT_LOW),
> + data->base + ASPEED_REG_ENGINE_CONTROL);
> + else {
> + dev_err(data->dev, "Regulator voltage %d not support",
> + data->vref);
> + return -EOPNOTSUPP;
> + }
> + } else {
> + if (PTR_ERR(data->regulator) != -ENODEV)
> + return PTR_ERR(data->regulator);
> + ret = of_property_read_u32(data->dev->of_node,
> + "aspeed,int_vref_mv", &data->vref);
> + if (ret < 0) {
> + dev_warn(data->dev,
> + "Using default vref: internal 2500 mv");

Perhaps document that as default in the dt-binding, then you can remove this warning and
handle this as:

data->vref = 2500;
of_property_read_u32(data->dev->of_node,
"aspeed,int-vref-mvolts", &data->vref);
etc

> + data->vref = 2500;
> + }
> + if (data->vref == 2500)
> + writel(adc_engine_control_reg_val |
> + FIELD_PREP(ASPEED_ADC_REF_VOLTAGE,
> + ASPEED_ADC writel(adc_engine_control_reg_val,
data->base + ASPEED_REG_ENGINE_CONTROL);_REF_VOLTAGE_2500mV),
> + data->base + ASPEED_REG_ENGINE_CONTROL);
> + else if (data->vref == 1200)
> + writel(adc_engine_control_reg_val |
> + FIELD_PREP(ASPEED_ADC_REF_VOLTAGE,
> + ASPEED_ADC_REF_VOLTAGE_1200mV),
> + data->base + ASPEED_REG_ENGINE_CONTROL);
> + else {
> + dev_err(data->dev, "Voltage %d not support", data->vref);
> + return -EOPNOTSUPP;
> + }
> + }
> +
> return 0;
> }
>
> @@ -279,7 +347,7 @@ static int aspeed_adc_probe(struct platform_device *pdev)
> if (ret)
> return ret;
>
> - 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");
> @@ -297,10 +365,14 @@ static int aspeed_adc_probe(struct platform_device *pdev)
> return ret;
>
> if (data->model_data->wait_init_sequence) {
> + adc_engine_control_reg_val =
> + readl(data->base + ASPEED_REG_ENGINE_CONTROL);
> + adc_engine_control_reg_val |=
> + FIELD_PREP(ASPEED_ADC_OP_MODE,
> + ASPEED_ADC_OP_MODE_NORMAL) |
> + ASPEED_ADC_ENGINE_ENABLE;
> /* Enable engine in normal mode. */
> - writel(FIELD_PREP(ASPEED_ADC_OP_MODE,
> - ASPEED_ADC_OP_MODE_NORMAL) |
> - ASPEED_ADC_ENGINE_ENABLE,
> + writel(adc_engine_control_reg_val,
> data->base + ASPEED_REG_ENGINE_CONTROL);
>
> /* Wait for initial sequence complete. */
> @@ -326,6 +398,8 @@ static int aspeed_adc_probe(struct platform_device *pdev)
> return ret;
>
> adc_engine_control_reg_val =
> + readl(data->base + ASPEED_REG_ENGINE_CONTROL);
> + adc_engine_control_reg_val |=
> ASPEED_ADC_CTRL_CHANNEL |
> FIELD_PREP(ASPEED_ADC_OP_MODE, ASPEED_ADC_OP_MODE_NORMAL) |
> ASPEED_ADC_ENGINE_ENABLE;
> @@ -376,9 +450,29 @@ static const struct aspeed_adc_model_data ast2500_model_data = {
> .num_channels = 16,
> };
>
> +static const struct aspeed_adc_model_data ast2600_adc0_model_data = {
> + .model_name = "ast2600-adc0",
> + .min_sampling_rate = 10000,
> + .max_sampling_rate = 500000,
> + .wait_init_sequence = true,
> + .scaler_bit_width = 16,
> + .num_channels = 8,
> +};
> +
> +static const struct aspeed_adc_model_data ast2600_adc1_model_data = {
> + .model_name = "ast2600-adc1",
> + .min_sampling_rate = 10000,
> + .max_sampling_rate = 500000,
> + .wait_init_sequence = true,
> + .scaler_bit_width = 16,
> + .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-adc0", .data = &ast2600_adc0_model_data },
> + { .compatible = "aspeed,ast2600-adc1", .data = &ast2600_adc1_model_data },
> {},
> };
> MODULE_DEVICE_TABLE(of, aspeed_adc_matches);
> @@ -395,5 +489,5 @@ static struct platform_driver aspeed_adc_driver = {
> module_platform_driver(aspeed_adc_driver);
>
> MODULE_AUTHOR("Rick Altherr <raltherr@google.com>");
> -MODULE_DESCRIPTION("Aspeed AST2400/2500 ADC Driver");
> +MODULE_DESCRIPTION("Aspeed AST2400/2500/2600 ADC Driver");
> MODULE_LICENSE("GPL");