[v6,1/2] thermal: Add thermal driver for Sunplus SP7021

diff --git a/MAINTAINERS b/MAINTAINERS
index 237046f..4096763 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -18860,6 +18860,12 @@  S:	Maintained
 F:	Documentation/devicetree/bindings/spi/spi-sunplus-sp7021.yaml
 F:	drivers/spi/spi-sunplus-sp7021.c
 
+SUNPLUS THERMAL DRIVER
+M:	Li-hao Kuo <lhjeff911@gmail.com>
+L:	linux-pm@vger.kernel.org
+S:	Maintained
+F:	drivers/thermal/sunplus_thermal.c
+
 SUNPLUS UART DRIVER
 M:	Hammer Hsieh <hammerh0314@gmail.com>
 S:	Maintained
diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
index e37691e..66316c3 100644
--- a/drivers/thermal/Kconfig
+++ b/drivers/thermal/Kconfig
@@ -502,4 +502,14 @@  config KHADAS_MCU_FAN_THERMAL
 	  If you say yes here you get support for the FAN controlled
 	  by the Microcontroller found on the Khadas VIM boards.
 
+config SUNPLUS_THERMAL
+	tristate "Sunplus thermal drivers"
+	depends on SOC_SP7021 || COMPILE_TEST
+	help
+	  This the Sunplus SP7021 thermal driver, which supports the primitive
+	  temperature sensor embedded in Sunplus SP7021 SoC.
+
+	  If you have a Sunplus SP7021 platform say Y here and enable this option
+	  to have support for thermal management
+
 endif
diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile
index f0c36a1..38a76f9 100644
--- a/drivers/thermal/Makefile
+++ b/drivers/thermal/Makefile
@@ -61,3 +61,4 @@  obj-$(CONFIG_UNIPHIER_THERMAL)	+= uniphier_thermal.o
 obj-$(CONFIG_AMLOGIC_THERMAL)     += amlogic_thermal.o
 obj-$(CONFIG_SPRD_THERMAL)	+= sprd_thermal.o
 obj-$(CONFIG_KHADAS_MCU_FAN_THERMAL)	+= khadas_mcu_fan.o
+obj-$(CONFIG_SUNPLUS_THERMAL)	+= sunplus_thermal.o
diff --git a/drivers/thermal/sunplus_thermal.c b/drivers/thermal/sunplus_thermal.c
new file mode 100644
index 0000000..9a9b348
--- /dev/null
+++ b/drivers/thermal/sunplus_thermal.c
@@ -0,0 +1,139 @@ 
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) Sunplus Inc.
+ * Author: Li-hao Kuo <lhjeff911@gmail.com>
+ */
+
+#include <linux/bitfield.h>
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/nvmem-consumer.h>
+#include <linux/platform_device.h>
+#include <linux/reset.h>
+#include <linux/thermal.h>
+
+#define DISABLE_THERMAL		(BIT(31) | BIT(15))
+#define ENABLE_THERMAL		BIT(31)
+#define SP_THERMAL_MASK		GENMASK(10, 0)
+#define SP_TCODE_HIGH_MASK	GENMASK(10, 8)
+#define SP_TCODE_LOW_MASK	GENMASK(7, 0)
+
+#define TEMP_RATE		608
+#define TEMP_BASE		3500
+#define TEMP_OTP_BASE		1518
+
+#define SP_THERMAL_CTL0_REG	0x0000
+#define SP_THERMAL_STS0_REG	0x0030
+
+/* common data structures */
+struct sp_thermal_data {
+	struct thermal_zone_device *pcb_tz;
+	struct platform_device *pdev;
+	enum thermal_device_mode mode;
+	void __iomem *regs;
+	int otp_temp0;
+	u32 id;
+};
+
+static int sp7021_get_otp_temp_coef(struct sp_thermal_data *sp_data, struct device *dev)
+{
+	struct nvmem_cell *cell;
+	ssize_t otp_l;
+	char *otp_v;
+
+	cell = nvmem_cell_get(dev, "calib");
+	if (IS_ERR(cell))
+		return PTR_ERR(cell);
+
+	otp_v = nvmem_cell_read(cell, &otp_l);
+	nvmem_cell_put(cell);
+
+	if (otp_l < 3)
+		return -EINVAL;
+	sp_data->otp_temp0 = FIELD_PREP(SP_TCODE_LOW_MASK, otp_v[0]) |
+			     FIELD_PREP(SP_TCODE_HIGH_MASK, otp_v[1]);
+	if (sp_data->otp_temp0 == 0)
+		sp_data->otp_temp0 = TEMP_OTP_BASE;
+	return 0;
+}
+
+/*
+ *When remanufacturing, the 35 degree T_CODE will be read and stored in nvcell.
+ *TEMP_RATE is the SP7021 temperature slope.
+ *T_CODE : 11 digits in total
+ */
+
+static int sp_thermal_get_sensor_temp(void *data, int *temp)
+{
+	struct sp_thermal_data *sp_data = data;
+	int t_code;
+
+	t_code = readl(sp_data->regs + SP_THERMAL_STS0_REG);
+	t_code = FIELD_GET(SP_THERMAL_MASK, t_code);
+	*temp = ((sp_data->otp_temp0 - t_code) * 10000 / TEMP_RATE) + TEMP_BASE;
+	*temp *= 10;
+	return 0;
+}
+
+static const struct thermal_zone_of_device_ops sp_of_thermal_ops = {
+	.get_temp = sp_thermal_get_sensor_temp,
+};
+
+static int sp_thermal_register_sensor(struct platform_device *pdev,
+				      struct sp_thermal_data *data, int index)
+{
+	data->id = index;
+	data->pcb_tz = devm_thermal_zone_of_sensor_register(&pdev->dev,
+							    data->id,
+							    data, &sp_of_thermal_ops);
+	if (IS_ERR_OR_NULL(data->pcb_tz))
+		return PTR_ERR(data->pcb_tz);
+	return 0;
+}
+
+static int sp7021_thermal_probe(struct platform_device *pdev)
+{
+	struct sp_thermal_data *sp_data;
+	struct resource *res;
+	int ret;
+
+	sp_data = devm_kzalloc(&pdev->dev, sizeof(*sp_data), GFP_KERNEL);
+	if (!sp_data)
+		return -ENOMEM;
+
+	sp_data->regs = devm_platform_ioremap_resource(pdev, 0);
+	if (IS_ERR(sp_data->regs)) {
+		dev_err(&pdev->dev, "resource get fail\n");
+		return PTR_ERR(sp_data->regs);
+	}
+
+	writel(ENABLE_THERMAL, sp_data->regs + SP_THERMAL_CTL0_REG);
+
+	platform_set_drvdata(pdev, sp_data);
+	ret = sp7021_get_otp_temp_coef(sp_data, &pdev->dev);
+	if (ret)
+		return ret;
+	ret = sp_thermal_register_sensor(pdev, sp_data, 0);
+	return ret;
+}
+
+static const struct of_device_id of_sp7021_thermal_ids[] = {
+	{ .compatible = "sunplus,sp7021-thermal" },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, of_sp7021_thermal_ids);
+
+static struct platform_driver sp7021_thermal_driver = {
+	.probe	= sp7021_thermal_probe,
+	.driver	= {
+		.name	= "sp7021-thermal",
+		.of_match_table = of_sp7021_thermal_ids,
+		},
+};
+module_platform_driver(sp7021_thermal_driver);
+
+MODULE_AUTHOR("Li-hao Kuo <lhjeff911@gmail.com>");
+MODULE_DESCRIPTION("Thermal driver for SP7021 SoC");
+MODULE_LICENSE("GPL");