diff mbox

[v5,3/3] thermal: zx2967: add thermal driver for ZTE's zx2967 family

Message ID 1484714522-26651-3-git-send-email-baoyou.xie@linaro.org (mailing list archive)
State Superseded, archived
Delegated to: Eduardo Valentin
Headers show

Commit Message

Baoyou Xie Jan. 18, 2017, 4:42 a.m. UTC
This patch adds thermal driver for ZTE's zx2967 family.

Signed-off-by: Baoyou Xie <baoyou.xie@linaro.org>
---
 drivers/thermal/Kconfig          |   8 ++
 drivers/thermal/Makefile         |   1 +
 drivers/thermal/zx2967_thermal.c | 256 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 265 insertions(+)
 create mode 100644 drivers/thermal/zx2967_thermal.c

Comments

Eduardo Valentin Feb. 2, 2017, 5:04 a.m. UTC | #1
Hey Bao,

On Wed, Jan 18, 2017 at 12:42:02PM +0800, Baoyou Xie wrote:
> This patch adds thermal driver for ZTE's zx2967 family.
> 
> Signed-off-by: Baoyou Xie <baoyou.xie@linaro.org>

<cut>

> +
> +	/*
> +	 * Calculate temperature
> +	 *   922	initial value of calibration cure
> +	 *   1.951	slope of calibration cure
> +	 */
> +	*temp = DIV_ROUND_CLOSEST((val - 922) * 1000, 1951);

You can describe the offset and slope using DT and avoid this to be hard
coded in your driver. Besides, if you read offset and slope from DT,
your driver will be ready for any upcoming sensor addition that you may
want to support in future, given that would required slope and offset
change, per sensor, per chip version.

Can you please check if you can move these to DT?

BR,
> -- 
> 2.7.4
> 
--
To unsubscribe from this list: send the line "unsubscribe linux-pm" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
diff mbox

Patch

diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
index 18f2de6..f64bd50 100644
--- a/drivers/thermal/Kconfig
+++ b/drivers/thermal/Kconfig
@@ -444,4 +444,12 @@  config BCM2835_THERMAL
 	help
 	  Support for thermal sensors on Broadcom bcm2835 SoCs.
 
+config ZX2967_THERMAL
+	tristate "Thermal sensors on zx2967 SoC"
+	depends on ARCH_ZX || COMPILE_TEST
+	help
+	  Enable the zx2967 thermal sensors driver, which supports
+	  the primitive temperature sensor embedded in zx2967 SoCs.
+	  This sensor generates the real time die temperature.
+
 endif
diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile
index 677c6d9..c00c05e 100644
--- a/drivers/thermal/Makefile
+++ b/drivers/thermal/Makefile
@@ -57,3 +57,4 @@  obj-$(CONFIG_HISI_THERMAL)     += hisi_thermal.o
 obj-$(CONFIG_MTK_THERMAL)	+= mtk_thermal.o
 obj-$(CONFIG_GENERIC_ADC_THERMAL)	+= thermal-generic-adc.o
 obj-$(CONFIG_BCM2835_THERMAL)	+= bcm2835_thermal.o
+obj-$(CONFIG_ZX2967_THERMAL)	+= zx2967_thermal.o
diff --git a/drivers/thermal/zx2967_thermal.c b/drivers/thermal/zx2967_thermal.c
new file mode 100644
index 0000000..1f08c33
--- /dev/null
+++ b/drivers/thermal/zx2967_thermal.c
@@ -0,0 +1,256 @@ 
+/*
+ * ZTE's zx2967 family thermal sensor driver
+ *
+ * Copyright (C) 2017 ZTE Ltd.
+ *
+ * Author: Baoyou Xie <baoyou.xie@linaro.org>
+ *
+ * License terms: GNU General Public License (GPL) version 2
+ */
+
+#include <linux/clk.h>
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/thermal.h>
+
+/* Power Mode: 0->low 1->high */
+#define ZX2967_THERMAL_POWER_MODE	0
+
+/* DCF Control Register */
+#define ZX2967_THERMAL_DCF		0x4
+
+/* Selection Register */
+#define ZX2967_THERMAL_SEL		0x8
+
+/* Control Register */
+#define ZX2967_THERMAL_CTRL		0x10
+
+#define ZX2967_THERMAL_READY		0x1000
+#define ZX2967_THERMAL_TEMP_MASK	0xfff
+#define ZX2967_THERMAL_ID_MASK		0x18
+#define ZX2967_THERMAL_ID0		0x8
+#define ZX2967_THERMAL_ID1		0x10
+
+struct zx2967_thermal_sensor {
+	struct zx2967_thermal_priv *priv;
+	struct thermal_zone_device *tzd;
+	int id;
+};
+
+#define NUM_SENSORS	1
+
+struct zx2967_thermal_priv {
+	struct zx2967_thermal_sensor	sensors[NUM_SENSORS];
+	/* Prevents reads sensor in parallel */
+	struct mutex			lock;
+	struct clk			*clk_gate;
+	struct clk			*pclk;
+	void __iomem			*regs;
+	struct device			*dev;
+};
+
+static int zx2967_thermal_suspend(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct zx2967_thermal_priv *priv = platform_get_drvdata(pdev);
+
+	if (priv && priv->pclk)
+		clk_disable_unprepare(priv->pclk);
+
+	if (priv && priv->clk_gate)
+		clk_disable_unprepare(priv->clk_gate);
+
+	return 0;
+}
+
+static int zx2967_thermal_resume(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct zx2967_thermal_priv *priv = platform_get_drvdata(pdev);
+	int error;
+
+	error = clk_prepare_enable(priv->clk_gate);
+	if (error)
+		return error;
+
+	error = clk_prepare_enable(priv->pclk);
+	if (error) {
+		clk_disable_unprepare(priv->clk_gate);
+		return error;
+	}
+
+	return 0;
+}
+
+static int zx2967_thermal_get_temp(void *data, int *temp)
+{
+	void __iomem *regs;
+	struct zx2967_thermal_sensor *sensor = data;
+	struct zx2967_thermal_priv *priv = sensor->priv;
+	unsigned long timeout = jiffies + msecs_to_jiffies(100);
+	u32 val, sel_id;
+
+	regs = priv->regs;
+	mutex_lock(&priv->lock);
+
+	writel_relaxed(0, regs + ZX2967_THERMAL_POWER_MODE);
+	writel_relaxed(2, regs + ZX2967_THERMAL_DCF);
+
+	val = readl_relaxed(regs + ZX2967_THERMAL_SEL);
+	val &= ~ZX2967_THERMAL_ID_MASK;
+	sel_id = sensor->id ? ZX2967_THERMAL_ID0 : ZX2967_THERMAL_ID1;
+	val |= sel_id;
+	writel_relaxed(val, regs + ZX2967_THERMAL_SEL);
+
+	usleep_range(100, 300);
+	val = readl_relaxed(regs + ZX2967_THERMAL_CTRL);
+	while (!(val & ZX2967_THERMAL_READY)) {
+		if (time_after(jiffies, timeout)) {
+			dev_err(priv->dev, "Thermal sensor %d data timeout\n",
+				sensor->id);
+			mutex_unlock(&priv->lock);
+			return -ETIMEDOUT;
+		}
+		usleep_range(100, 300);
+		val = readl_relaxed(regs + ZX2967_THERMAL_CTRL);
+	}
+
+	writel_relaxed(3, regs + ZX2967_THERMAL_DCF);
+	val = readl_relaxed(regs + ZX2967_THERMAL_CTRL)
+			 & ZX2967_THERMAL_TEMP_MASK;
+	writel_relaxed(1, regs + ZX2967_THERMAL_POWER_MODE);
+
+	/*
+	 * Calculate temperature
+	 *   922	initial value of calibration cure
+	 *   1.951	slope of calibration cure
+	 */
+	*temp = DIV_ROUND_CLOSEST((val - 922) * 1000, 1951);
+
+	mutex_unlock(&priv->lock);
+
+	return 0;
+}
+
+static struct thermal_zone_of_device_ops zx2967_of_thermal_ops = {
+	.get_temp = zx2967_thermal_get_temp,
+};
+
+static int zx2967_thermal_probe(struct platform_device *pdev)
+{
+	struct zx2967_thermal_priv *priv;
+	struct resource *res;
+	int ret, i;
+
+	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	priv->regs = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(priv->regs))
+		return PTR_ERR(priv->regs);
+
+	priv->clk_gate = devm_clk_get(&pdev->dev, "gate");
+	if (IS_ERR(priv->clk_gate)) {
+		ret = PTR_ERR(priv->clk_gate);
+		dev_err(&pdev->dev, "failed to get clock gate: %d\n", ret);
+		return ret;
+	}
+
+	ret = clk_prepare_enable(priv->clk_gate);
+	if (ret) {
+		dev_err(&pdev->dev, "failed to enable converter clock: %d\n",
+			ret);
+		return ret;
+	}
+
+	priv->pclk = devm_clk_get(&pdev->dev, "pclk");
+	if (IS_ERR(priv->pclk)) {
+		ret = PTR_ERR(priv->pclk);
+		clk_disable_unprepare(priv->clk_gate);
+		dev_err(&pdev->dev, "failed to get apb clock: %d\n", ret);
+		return ret;
+	}
+
+	ret = clk_prepare_enable(priv->pclk);
+	if (ret) {
+		clk_disable_unprepare(priv->clk_gate);
+		dev_err(&pdev->dev, "failed to enable converter clock: %d\n",
+			ret);
+		return ret;
+	}
+
+	mutex_init(&priv->lock);
+	for (i = 0; i < NUM_SENSORS; i++) {
+		struct zx2967_thermal_sensor *sensor = &priv->sensors[i];
+
+		sensor->priv = priv;
+		sensor->id = i;
+		sensor->tzd = thermal_zone_of_sensor_register(&pdev->dev,
+					i, sensor, &zx2967_of_thermal_ops);
+		if (IS_ERR(sensor->tzd)) {
+			ret = PTR_ERR(sensor->tzd);
+			dev_err(&pdev->dev, "failed to register sensor %d: %d\n",
+				i, ret);
+			goto remove_ts;
+		}
+	}
+	priv->dev = &pdev->dev;
+	platform_set_drvdata(pdev, priv);
+
+	return 0;
+
+remove_ts:
+	clk_disable_unprepare(priv->clk_gate);
+	clk_disable_unprepare(priv->pclk);
+	for (i--; i >= 0; i--)
+		thermal_zone_of_sensor_unregister(&pdev->dev,
+						  priv->sensors[i].tzd);
+
+	return ret;
+}
+
+static int zx2967_thermal_exit(struct platform_device *pdev)
+{
+	struct zx2967_thermal_priv *priv = platform_get_drvdata(pdev);
+	int i;
+
+	for (i = 0; i < NUM_SENSORS; i++) {
+		struct zx2967_thermal_sensor *sensor = &priv->sensors[i];
+
+		thermal_zone_of_sensor_unregister(&pdev->dev, sensor->tzd);
+	}
+	clk_disable_unprepare(priv->pclk);
+	clk_disable_unprepare(priv->clk_gate);
+
+	return 0;
+}
+
+static const struct of_device_id zx2967_thermal_id_table[] = {
+	{ .compatible = "zte,zx296718-thermal" },
+	{}
+};
+MODULE_DEVICE_TABLE(of, zx2967_thermal_id_table);
+
+static SIMPLE_DEV_PM_OPS(zx2967_thermal_pm_ops,
+			 zx2967_thermal_suspend, zx2967_thermal_resume);
+
+static struct platform_driver zx2967_thermal_driver = {
+	.probe = zx2967_thermal_probe,
+	.remove = zx2967_thermal_exit,
+	.driver = {
+		.name = "zx2967_thermal",
+		.of_match_table = zx2967_thermal_id_table,
+		.pm = &zx2967_thermal_pm_ops,
+	},
+};
+module_platform_driver(zx2967_thermal_driver);
+
+MODULE_AUTHOR("Baoyou Xie <baoyou.xie@linaro.org>");
+MODULE_DESCRIPTION("ZTE zx2967 thermal driver");
+MODULE_LICENSE("GPL v2");