This patch adds thermal driver for ZTE's zx2967 family.

Signed-off-by: Baoyou Xie <baoyou....@linaro.org>
---
 drivers/thermal/Kconfig          |   8 ++
 drivers/thermal/Makefile         |   1 +
 drivers/thermal/zx2967_thermal.c | 281 +++++++++++++++++++++++++++++++++++++++
 3 files changed, 290 insertions(+)
 create mode 100644 drivers/thermal/zx2967_thermal.c

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..fba55b1c
--- /dev/null
+++ b/drivers/thermal/zx2967_thermal.c
@@ -0,0 +1,281 @@
+/*
+ * ZTE's zx2967 family thermal sensor driver
+ *
+ * Copyright (C) 2017 ZTE Ltd.
+ *
+ * Author: Baoyou Xie <baoyou....@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/iopoll.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
+#define ZX2967_POWER_MODE_LOW          0
+#define ZX2967_POWER_MODE_HIGH         1
+
+/* DCF Control Register */
+#define ZX2967_THERMAL_DCF             0x4
+#define ZX2967_DCF_EN                  BIT(1)
+#define ZX2967_DCF_FREEZE              BIT(0)
+
+/* Selection Register */
+#define ZX2967_THERMAL_SEL             0x8
+
+/* Control Register */
+#define ZX2967_THERMAL_CTRL            0x10
+
+#define ZX2967_THERMAL_READY           BIT(12)
+#define ZX2967_THERMAL_TEMP_MASK       0xfff
+#define ZX2967_THERMAL_ID_MASK         0x18
+#define ZX2967_THERMAL_ID0             0x10
+#define ZX2967_THERMAL_ID1             0x8
+
+#define ZX2967_GET_TEMP_TIMEOUT_US     (100 * 1024)
+
+struct zx2967_thermal_sensor {
+       struct zx2967_thermal_priv *priv;
+       struct thermal_zone_device *tzd;
+       int id;
+};
+
+/*
+ * Now, one sensor remains in system, but in fact, we intend to support
+ * two sensors.
+ */
+#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;
+};
+
+#ifdef CONFIG_PM_SLEEP
+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 SIMPLE_DEV_PM_OPS(zx2967_thermal_pm_ops,
+                        zx2967_thermal_suspend, zx2967_thermal_resume);
+#endif
+
+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;
+       u32 val, sel_id;
+       int ret;
+
+       if (!sensor->tzd)
+               return -EAGAIN;
+
+       regs = priv->regs;
+       mutex_lock(&priv->lock);
+       writel_relaxed(ZX2967_POWER_MODE_LOW,
+                      regs + ZX2967_THERMAL_POWER_MODE);
+       writel_relaxed(ZX2967_DCF_EN, regs + ZX2967_THERMAL_DCF);
+
+       val = readl_relaxed(regs + ZX2967_THERMAL_SEL);
+       val &= ~ZX2967_THERMAL_ID_MASK;
+       sel_id = sensor->id ? ZX2967_THERMAL_ID1 : ZX2967_THERMAL_ID0;
+       val |= sel_id;
+       writel_relaxed(val, regs + ZX2967_THERMAL_SEL);
+
+       usleep_range(100, 300);
+       ret = readx_poll_timeout(readl, regs + ZX2967_THERMAL_CTRL,
+                                val, val & ZX2967_THERMAL_READY, 300,
+                                ZX2967_GET_TEMP_TIMEOUT_US);
+       if (ret) {
+               dev_err(priv->dev, "Thermal sensor %d data timeout\n",
+                       sensor->id);
+               mutex_unlock(&priv->lock);
+               return ret;
+       }
+
+       writel_relaxed(ZX2967_DCF_FREEZE | ZX2967_DCF_EN,
+                      regs + ZX2967_THERMAL_DCF);
+       val = readl_relaxed(regs + ZX2967_THERMAL_CTRL)
+                        & ZX2967_THERMAL_TEMP_MASK;
+       writel_relaxed(ZX2967_POWER_MODE_HIGH,
+                      regs + ZX2967_THERMAL_POWER_MODE);
+
+       /*
+        * Calculate temperature
+        * In dts, coefficients are multiplied by 1000.
+        */
+       *temp = DIV_ROUND_CLOSEST(((s32)val + sensor->tzd->tzp->offset) * 1000,
+                                 sensor->tzd->tzp->slope);
+
+       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);
+               dev_err(&pdev->dev, "failed to get apb clock: %d\n", ret);
+               goto disable_clk_gate;
+       }
+
+       ret = clk_prepare_enable(priv->pclk);
+       if (ret) {
+               dev_err(&pdev->dev, "failed to enable converter clock: %d\n",
+                       ret);
+               goto disable_clk_gate;
+       }
+
+       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;
+               }
+
+               if (sensor->tzd->tzp->slope == 0) {
+                       thermal_zone_of_sensor_unregister(&pdev->dev,
+                                                       sensor->tzd);
+                       dev_err(&pdev->dev,
+                               "coefficients of sensor-%d is invalid\n", i);
+                       ret = -EINVAL;
+                       goto remove_ts;
+               }
+       }
+       priv->dev = &pdev->dev;
+       platform_set_drvdata(pdev, priv);
+
+       return 0;
+
+remove_ts:
+       for (i--; i >= 0; i--)
+               thermal_zone_of_sensor_unregister(&pdev->dev,
+                                                 priv->sensors[i].tzd);
+       clk_disable_unprepare(priv->pclk);
+disable_clk_gate:
+       clk_disable_unprepare(priv->clk_gate);
+
+       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 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,
+#ifdef CONFIG_PM_SLEEP
+               .pm = &zx2967_thermal_pm_ops,
+#endif
+       },
+};
+module_platform_driver(zx2967_thermal_driver);
+
+MODULE_AUTHOR("Baoyou Xie <baoyou....@linaro.org>");
+MODULE_DESCRIPTION("ZTE zx2967 thermal driver");
+MODULE_LICENSE("GPL v2");
-- 
2.7.4

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