Re: [PATCH v7 1/2] thermal: Add thermal driver for Sunplus SP7021

From: Daniel Lezcano
Date: Thu Apr 14 2022 - 03:12:31 EST

On 11/04/2022 10:52, Li-hao Kuo wrote:
Add thermal driver for Sunplus SP7021.

Already asked previously : please give a more detailed description of the sensor

I've commented again this patch. There are some comments which are not taken into account from my previous review on v4


Signed-off-by: Li-hao Kuo <lhjeff911@xxxxxxxxx>
---
Changes in v7:
- Modify yaml file.

MAINTAINERS | 6 ++
drivers/thermal/Kconfig | 10 +++
drivers/thermal/Makefile | 1 +
drivers/thermal/sunplus_thermal.c | 139 ++++++++++++++++++++++++++++++++++++++
4 files changed, 156 insertions(+)
create mode 100644 drivers/thermal/sunplus_thermal.c

diff --git a/MAINTAINERS b/MAINTAINERS
index 61d9f11..307570c 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -18885,6 +18885,12 @@ 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@xxxxxxxxx>
+L: linux-pm@xxxxxxxxxxxxxxx
+S: Maintained
+F: drivers/thermal/sunplus_thermal.c
+
SUNPLUS UART DRIVER
M: Hammer Hsieh <hammerh0314@xxxxxxxxx>
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@xxxxxxxxx>
+ */
+
+#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>

Already commented, check the headers above.

+#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;

field not used outside of the function checking the return code of sensor register

+ struct platform_device *pdev;

field not used

+ enum thermal_device_mode mode;

field not used

+ 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);

See my previous comments in v4, this is wrong. Move the nvmem_cell_put() after FIELD_PREP() ... below where otp_v is no longer used.

+ if (otp_l < 3)
+ return -EINVAL;

Please replace '3' by a macro

Why this check is needed by the way ? Sounds like only 0 and 1 indexes are used here.

+ 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
+ */

nit: space after '*'

Please elaborate the comment, it is still unclear

+
+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)

Adding a function to wrap another function is pointless in this case. It is simpler to directly call devm_thermal_zone_of_sensor_register() from the probe function

+{
+ 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;

Add some space to let the code easier to read

+ 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,

and .remove ?

+ .driver = {
+ .name = "sp7021-thermal",
+ .of_match_table = of_sp7021_thermal_ids,
+ },
+};
+module_platform_driver(sp7021_thermal_driver);
+
+MODULE_AUTHOR("Li-hao Kuo <lhjeff911@xxxxxxxxx>");
+MODULE_DESCRIPTION("Thermal driver for SP7021 SoC");
+MODULE_LICENSE("GPL");


--
<http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs

Follow Linaro: <http://www.facebook.com/pages/Linaro> Facebook |
<http://twitter.com/#!/linaroorg> Twitter |
<http://www.linaro.org/linaro-blog/> Blog