[PATCH 3/3] iio: temperature: add a driver for the temperature sensor found in Amlogic Meson G12 SoCs

From: Guillaume La Roque
Date: Tue Jun 04 2019 - 10:51:18 EST


The code is based on Amlogic source code. No public datasheet for this.
Currently the G12A SoCs are supported.

Supported features:
- possibility to set an automatic reboot temperature

Signed-off-by: Guillaume La Roque <glaroque@xxxxxxxxxxxx>
---
drivers/iio/temperature/Kconfig | 11 +
drivers/iio/temperature/Makefile | 1 +
drivers/iio/temperature/meson_tsensor.c | 416 ++++++++++++++++++++++++
3 files changed, 428 insertions(+)
create mode 100644 drivers/iio/temperature/meson_tsensor.c

diff --git a/drivers/iio/temperature/Kconfig b/drivers/iio/temperature/Kconfig
index 737faa0901fe..712a0062790d 100644
--- a/drivers/iio/temperature/Kconfig
+++ b/drivers/iio/temperature/Kconfig
@@ -34,6 +34,17 @@ config HID_SENSOR_TEMP
To compile this driver as a module, choose M here: the module
will be called hid-sensor-temperature.

+config MESON_TSENSOR
+ tristate "Amlogic Meson temperature sensor Support"
+ default ARCH_MESON
+ depends on OF && ARCH_MESON
+ help
+ If you say yess here you get support for Meson Temperature sensor
+ for G12 SoC Family.
+
+ This driver can also be built as a module. If so, the module will
+ be called meson_tsensor.
+
config MLX90614
tristate "MLX90614 contact-less infrared sensor"
depends on I2C
diff --git a/drivers/iio/temperature/Makefile b/drivers/iio/temperature/Makefile
index baca4776ca0d..466d8c1c91d6 100644
--- a/drivers/iio/temperature/Makefile
+++ b/drivers/iio/temperature/Makefile
@@ -6,6 +6,7 @@
obj-$(CONFIG_HID_SENSOR_TEMP) += hid-sensor-temperature.o
obj-$(CONFIG_MAXIM_THERMOCOUPLE) += maxim_thermocouple.o
obj-$(CONFIG_MAX31856) += max31856.o
+obj-$(CONFIG_MESON_TSENSOR) += meson_tsensor.o
obj-$(CONFIG_MLX90614) += mlx90614.o
obj-$(CONFIG_MLX90632) += mlx90632.o
obj-$(CONFIG_TMP006) += tmp006.o
diff --git a/drivers/iio/temperature/meson_tsensor.c b/drivers/iio/temperature/meson_tsensor.c
new file mode 100644
index 000000000000..be0a8d073ba3
--- /dev/null
+++ b/drivers/iio/temperature/meson_tsensor.c
@@ -0,0 +1,416 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Amlogic Meson Temperature Sensor
+ *
+ * Copyright (C) 2017 Huan Biao <huan.biao@xxxxxxxxxxx>
+ * Copyright (C) 2019 Guillaume La Roque <glaroque@xxxxxxxxxxxx>
+ *
+ * Register value to celsius temperature formulas:
+ * Read_Val m * U
+ * U = ---------, Uptat = ---------
+ * 2^16 1 + n * U
+ *
+ * Temperature = A * ( Uptat + u_efuse / 2^16 )- B
+ *
+ * A B m n : calibration parameters
+ * u_efuse : fused calibration value, it's a signed 16 bits value
+ */
+
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/iio/iio.h>
+#include <linux/io.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+#define TSENSOR_CFG_REG1 0x4
+ #define TSENSOR_CFG_REG1_RSET_VBG BIT(12)
+ #define TSENSOR_CFG_REG1_RSET_ADC BIT(11)
+ #define TSENSOR_CFG_REG1_VCM_EN BIT(10)
+ #define TSENSOR_CFG_REG1_VBG_EN BIT(9)
+ #define TSENSOR_CFG_REG1_OUT_CTL BIT(6)
+ #define TSENSOR_CFG_REG1_FILTER_EN BIT(5)
+ #define TSENSOR_CFG_REG1_DEM_EN BIT(3)
+ #define TSENSOR_CFG_REG1_CH_SEL GENMASK(1, 0)
+ #define TSENSOR_CFG_REG1_ENABLE \
+ (TSENSOR_CFG_REG1_FILTER_EN | \
+ TSENSOR_CFG_REG1_VCM_EN | \
+ TSENSOR_CFG_REG1_VBG_EN | \
+ TSENSOR_CFG_REG1_DEM_EN | \
+ TSENSOR_CFG_REG1_CH_SEL)
+
+#define TSENSOR_CFG_REG2 0x8
+ #define TSENSOR_CFG_REG2_HITEMP_EN BIT(31)
+ #define TSENSOR_CFG_REG2_REBOOT_ALL_EN BIT(30)
+ #define TSENSOR_CFG_REG2_REBOOT_TIME GENMASK(25, 16)
+ #define TSENSOR_CFG_REG2_HITEMP_REBOOT_ENABLE \
+ (TSENSOR_CFG_REG2_HITEMP_EN | \
+ TSENSOR_CFG_REG2_REBOOT_ALL_EN | \
+ TSENSOR_CFG_REG2_REBOOT_TIME)
+ #define TSENSOR_CFG_REG2_HITEMP_REBOOT_ENABLE_MASK \
+ (GENMASK(31, 30) | GENMASK(25, 4))
+ #define TSENSOR_CFG_REG2_HITEMP_REBOOT_REG_MASK \
+ GENMASK(15, 4)
+ #define TSENSOR_CFG_REG2_HITEMP_REG_VAL(_reg_val) \
+ (FIELD_PREP(TSENSOR_CFG_REG2_HITEMP_REBOOT_REG_MASK, \
+ _reg_val) | \
+ TSENSOR_CFG_REG2_HITEMP_REBOOT_ENABLE)
+
+#define TSENSOR_CFG_REG3 0xC
+#define TSENSOR_CFG_REG4 0x10
+#define TSENSOR_CFG_REG5 0x14
+#define TSENSOR_CFG_REG6 0x18
+#define TSENSOR_CFG_REG7 0x1C
+#define TSENSOR_CFG_REG8 0x20
+
+#define TSENSOR_STAT0 0x40
+
+#define TSENSOR_STAT9 0x64
+
+#define TSENSOR_READ_TEMP_MASK GENMASK(15, 0)
+#define TSENSOR_TEMP_MASK GENMASK(11, 0)
+
+#define TSENSOR_TRIM_SIGN_MASK BIT(15)
+#define TSENSOR_TRIM_TEMP_MASK GENMASK(14, 0)
+#define TSENSOR_TRIM_VERSION_MASK GENMASK(31, 24)
+
+#define TSENSOR_TRIM_VERSION(_version) \
+ FIELD_GET(TSENSOR_TRIM_VERSION_MASK, _version)
+
+#define TSENSOR_TRIM_CALIB_VALID_MASK (GENMASK(3, 2) | BIT(7))
+
+#define TSENSOR_CALIB_OFFSET 1
+#define TSENSOR_CALIB_SHIFT 4
+
+static const struct iio_chan_spec temperature_channel[] = {
+ {
+ .type = IIO_TEMP,
+ .channel = 0,
+ .address = 0,
+ .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),
+ },
+};
+
+/**
+ * struct meson_tsensor_soc_data
+ * @A, B, m, n: calibration parameters
+ * This structure is required for configuration of meson tsensor driver.
+ */
+struct meson_tsensor_soc_data {
+ int A;
+ int B;
+ int m;
+ int n;
+};
+
+/**
+ * struct meson_tsensor_data
+ * @u_efuse_off: register offset to read fused calibration value
+ * @soc: calibration parameters structure pointer
+ * @regmap_config: regmap config for the device
+ * This structure is required for configuration of meson tsensor driver.
+ */
+struct meson_tsensor_data {
+ int u_efuse_off;
+ const struct meson_tsensor_soc_data *soc;
+ const struct regmap_config *regmap_config;
+};
+
+struct meson_tsensor {
+ int id;
+ const struct meson_tsensor_data *data;
+ struct regmap *regmap;
+ struct regmap *sec_ao_map;
+ struct clk *clk;
+ u32 trim_info;
+ void __iomem *base;
+ int reboot_temp;
+};
+
+/*
+ * tsensor treats temperature as a mapped temperature code.
+ * The temperature is converted differently depending on the calibration type.
+ */
+static u32 temp_to_code(struct meson_tsensor *priv, int temp)
+{
+ const struct meson_tsensor_soc_data *param = priv->data->soc;
+ s64 divisor, factor, uefuse;
+ u32 reg_code;
+
+ uefuse = priv->trim_info & TSENSOR_TRIM_SIGN_MASK ?
+ ~(priv->trim_info & TSENSOR_TRIM_TEMP_MASK) + 1 :
+ (priv->trim_info & TSENSOR_TRIM_TEMP_MASK);
+
+ factor = BIT(16) * (temp * 10 + param->B);
+ factor = div_s64(factor, param->A);
+ factor = factor + uefuse;
+
+ factor = factor * 100;
+
+ divisor = param->n * factor;
+ divisor = div_s64(divisor, BIT(16));
+ divisor = param->m - divisor;
+
+ reg_code = div_s64(factor, divisor);
+ reg_code = ((reg_code >> TSENSOR_CALIB_SHIFT) & TSENSOR_TEMP_MASK) +
+ TSENSOR_CALIB_OFFSET;
+
+ return reg_code;
+}
+
+/*
+ * Calculate a temperature value from a temperature code.
+ * The unit of the temperature is degree Celsius.
+ */
+static int code_to_temp(struct meson_tsensor *priv, int temp_code)
+{
+ const struct meson_tsensor_soc_data *param = priv->data->soc;
+ int temp;
+ s64 factor, Uptat, uefuse;
+
+ uefuse = priv->trim_info & TSENSOR_TRIM_SIGN_MASK ?
+ ~(priv->trim_info & TSENSOR_TRIM_TEMP_MASK) + 1 :
+ (priv->trim_info & TSENSOR_TRIM_TEMP_MASK);
+
+ factor = param->n * temp_code;
+ factor = div_s64(factor, 100);
+
+ Uptat = temp_code * param->m;
+ Uptat = div_s64(Uptat, 100);
+ Uptat = Uptat * BIT(16);
+ Uptat = div_s64(Uptat, BIT(16) + factor);
+
+ temp = (Uptat + uefuse) * param->A;
+ temp = div_s64(temp, BIT(16));
+ temp = (temp - param->B) * 100;
+
+ return temp;
+}
+
+static int meson_tsensor_initialize(struct iio_dev *indio_dev)
+{
+ struct meson_tsensor *priv = iio_priv(indio_dev);
+ u32 reg_val;
+ int ret = 0;
+ int ver;
+
+ regmap_read(priv->sec_ao_map, priv->data->u_efuse_off,
+ &priv->trim_info);
+
+ ver = TSENSOR_TRIM_VERSION(priv->trim_info);
+
+ if ((ver & TSENSOR_TRIM_CALIB_VALID_MASK) == 0) {
+ ret = -EINVAL;
+ dev_err(&indio_dev->dev,
+ "tsensor thermal calibration not supported: 0x%x!\n",
+ ver);
+ goto out;
+ }
+
+ /* init the ts reboot soc function */
+ if (priv->reboot_temp) {
+ /* register need value in celsius */
+ reg_val = temp_to_code(priv, priv->reboot_temp / 1000);
+ regmap_update_bits(priv->regmap, TSENSOR_CFG_REG2,
+ TSENSOR_CFG_REG2_HITEMP_REBOOT_ENABLE_MASK,
+ TSENSOR_CFG_REG2_HITEMP_REG_VAL(reg_val));
+ }
+
+out:
+ return ret;
+}
+
+static int meson_tsensor_enable(struct iio_dev *indio_dev)
+{
+ struct meson_tsensor *priv = iio_priv(indio_dev);
+
+ clk_prepare_enable(priv->clk);
+ regmap_update_bits(priv->regmap, TSENSOR_CFG_REG1,
+ TSENSOR_CFG_REG1_ENABLE, TSENSOR_CFG_REG1_ENABLE);
+
+ return 0;
+}
+
+static int meson_tsensor_disable(struct iio_dev *indio_dev)
+{
+ struct meson_tsensor *priv = iio_priv(indio_dev);
+
+ regmap_update_bits(priv->regmap, TSENSOR_CFG_REG1,
+ TSENSOR_CFG_REG1_ENABLE, 0);
+ clk_disable(priv->clk);
+
+ return 0;
+}
+
+static int meson_tsensor_read(struct iio_dev *indio_dev,
+ struct iio_chan_spec const *chan, int *val,
+ int *val2, long mask)
+{
+ unsigned int tvalue;
+ struct meson_tsensor *priv = iio_priv(indio_dev);
+
+ switch (mask) {
+ case IIO_CHAN_INFO_PROCESSED:
+ regmap_read(priv->regmap, TSENSOR_STAT0, &tvalue);
+ *val = code_to_temp(priv,
+ tvalue & TSENSOR_READ_TEMP_MASK);
+
+ return IIO_VAL_INT;
+ default:
+ return -EINVAL;
+ }
+}
+
+static const struct iio_info meson_tsensor_iio_info = {
+ .read_raw = &meson_tsensor_read,
+};
+
+static const struct regmap_config meson_tsensor_regmap_config_g12a = {
+ .reg_bits = 8,
+ .val_bits = 32,
+ .reg_stride = 4,
+ .max_register = TSENSOR_STAT9,
+};
+
+static const struct meson_tsensor_soc_data meson_tsensor_g12a = {
+ .A = 9411,
+ .B = 3159,
+ .m = 424,
+ .n = 324,
+};
+
+static const struct meson_tsensor_data meson_tsensor_g12a_cpu_param = {
+ .u_efuse_off = 0x128,
+ .soc = &meson_tsensor_g12a,
+ .regmap_config = &meson_tsensor_regmap_config_g12a,
+};
+
+static const struct meson_tsensor_data meson_tsensor_g12a_ddr_param = {
+ .u_efuse_off = 0xF0,
+ .soc = &meson_tsensor_g12a,
+ .regmap_config = &meson_tsensor_regmap_config_g12a,
+};
+
+static const struct of_device_id meson_tsensor_of_match[] = {
+ {
+ .compatible = "amlogic,meson-g12a-ddr-tsensor",
+ .data = &meson_tsensor_g12a_ddr_param,
+ },
+ {
+ .compatible = "amlogic,meson-g12a-cpu-tsensor",
+ .data = &meson_tsensor_g12a_cpu_param,
+ },
+ {},
+};
+MODULE_DEVICE_TABLE(of, meson_tsensor_of_match);
+
+static int meson_tsensor_probe(struct platform_device *pdev)
+{
+ struct meson_tsensor *priv;
+ struct iio_dev *indio_dev;
+ struct resource *res;
+
+ int ret;
+
+ indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*priv));
+ if (!indio_dev) {
+ dev_err(&pdev->dev, "failed allocating iio device\n");
+ return -ENOMEM;
+ }
+
+ priv = iio_priv(indio_dev);
+ priv->data = of_device_get_match_data(&pdev->dev);
+ if (!priv->data) {
+ dev_err(&pdev->dev, "failed to get match data\n");
+ return -ENODEV;
+ }
+
+ indio_dev->channels = temperature_channel;
+ indio_dev->num_channels = ARRAY_SIZE(temperature_channel);
+ indio_dev->name = dev_name(&pdev->dev);
+ indio_dev->dev.parent = &pdev->dev;
+ indio_dev->dev.of_node = pdev->dev.of_node;
+ indio_dev->modes = INDIO_DIRECT_MODE;
+ indio_dev->info = &meson_tsensor_iio_info;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ priv->base = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(priv->base))
+ return PTR_ERR(priv->base);
+
+ priv->regmap = devm_regmap_init_mmio(&pdev->dev, priv->base,
+ priv->data->regmap_config);
+ if (IS_ERR(priv->regmap))
+ return PTR_ERR(priv->regmap);
+
+ priv->clk = devm_clk_get(&pdev->dev, NULL);
+ if (IS_ERR(priv->clk)) {
+ if (PTR_ERR(priv->clk) != -EPROBE_DEFER)
+ dev_err(&pdev->dev, "failed to get clock\n");
+ return PTR_ERR(priv->clk);
+ }
+
+ if (of_property_read_u32(pdev->dev.of_node,
+ "amlogic,critical-temperature",
+ &priv->reboot_temp)) {
+ priv->reboot_temp = 0;
+ }
+
+ priv->sec_ao_map = syscon_regmap_lookup_by_phandle
+ (pdev->dev.of_node, "amlogic,ao-secure");
+ if (IS_ERR(priv->sec_ao_map)) {
+ dev_err(&pdev->dev, "syscon regmap lookup failed.\n");
+ return PTR_ERR(priv->sec_ao_map);
+ }
+
+ ret = meson_tsensor_initialize(indio_dev);
+ if (ret)
+ return ret;
+
+ ret = meson_tsensor_enable(indio_dev);
+ if (ret)
+ goto err;
+
+ platform_set_drvdata(pdev, indio_dev);
+ ret = iio_device_register(indio_dev);
+ if (ret)
+ goto err_hw;
+
+ return 0;
+
+err_hw:
+ meson_tsensor_disable(indio_dev);
+err:
+ clk_unprepare(priv->clk);
+
+ return ret;
+}
+
+static int meson_tsensor_remove(struct platform_device *pdev)
+{
+ struct iio_dev *indio_dev = platform_get_drvdata(pdev);
+
+ iio_device_unregister(indio_dev);
+
+ return meson_tsensor_disable(indio_dev);
+}
+
+static struct platform_driver meson_tsensor_driver = {
+ .probe = meson_tsensor_probe,
+ .remove = meson_tsensor_remove,
+ .driver = {
+ .name = "meson-tsensor",
+ .of_match_table = meson_tsensor_of_match,
+ },
+};
+
+module_platform_driver(meson_tsensor_driver);
+
+MODULE_AUTHOR("Guillaume La Roque <glaroque@xxxxxxxxxxxx>");
+MODULE_DESCRIPTION("Amlogic Meson Temperature Sensor Driver");
+MODULE_LICENSE("GPL v2");
--
2.17.1