hwmon: Add Synaptics AS370 PVT sensor driver

Add a new driver for Synaptics AS370 PVT sensors. Currently, only
temperature is supported.

Signed-off-by: Jisheng Zhang <Jisheng.Zhang@synaptics.com>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Link: https://lore.kernel.org/r/20190827113259.4fb64a17@xhacker.debian
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 9de34e4..c823b66 100644 (file)
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -246,6 +246,16 @@ config SENSORS_ADT7475
          This driver can also be built as a module. If so, the module
          will be called adt7475.
 
+config SENSORS_AS370
+       tristate "Synaptics AS370 SoC hardware monitoring driver"
+       help
+         If you say yes here you get support for the PVT sensors of
+         the Synaptics AS370 SoC
+
+         This driver can also be built as a module. If so, the module
+         will be called as370-hwmon.
+
+
 config SENSORS_ASC7621
        tristate "Andigilog aSC7621"
        depends on I2C

diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index 6a52a96..c86ce4d 100644 (file)
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -47,6 +47,7 @@ obj-$(CONFIG_SENSORS_ADT7475) += adt7475.o
 obj-$(CONFIG_SENSORS_APPLESMC) += applesmc.o
 obj-$(CONFIG_SENSORS_ARM_SCMI) += scmi-hwmon.o
 obj-$(CONFIG_SENSORS_ARM_SCPI) += scpi-hwmon.o
+obj-$(CONFIG_SENSORS_AS370)    += as370-hwmon.o
 obj-$(CONFIG_SENSORS_ASC7621)  += asc7621.o
 obj-$(CONFIG_SENSORS_ASPEED)   += aspeed-pwm-tacho.o
 obj-$(CONFIG_SENSORS_ATXP1)    += atxp1.o

diff --git a/drivers/hwmon/as370-hwmon.c b/drivers/hwmon/as370-hwmon.c
new file mode 100644 (file)
index 0000000..554f03b
--- /dev/null
+++ b/drivers/hwmon/as370-hwmon.c
@@ -0,0 +1,147 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Synaptics AS370 SoC Hardware Monitoring Driver
+ *
+ * Copyright (C) 2018 Synaptics Incorporated
+ * Author: Jisheng Zhang <jszhang@kernel.org>
+ */
+
+#include <linux/bitops.h>
+#include <linux/hwmon.h>
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of_device.h>
+
+#define CTRL           0x0
+#define  PD            BIT(0)
+#define  EN            BIT(1)
+#define  T_SEL         BIT(2)
+#define  V_SEL         BIT(3)
+#define  NMOS_SEL      BIT(8)
+#define  PMOS_SEL      BIT(9)
+#define STS            0x4
+#define  BN_MASK       GENMASK(11, 0)
+#define  EOC           BIT(12)
+
+struct as370_hwmon {
+       void __iomem *base;
+};
+
+static void init_pvt(struct as370_hwmon *hwmon)
+{
+       u32 val;
+       void __iomem *addr = hwmon->base + CTRL;
+
+       val = PD;
+       writel_relaxed(val, addr);
+       val |= T_SEL;
+       writel_relaxed(val, addr);
+       val |= EN;
+       writel_relaxed(val, addr);
+       val &= ~PD;
+       writel_relaxed(val, addr);
+}
+
+static int as370_hwmon_read(struct device *dev, enum hwmon_sensor_types type,
+                           u32 attr, int channel, long *temp)
+{
+       int val;
+       struct as370_hwmon *hwmon = dev_get_drvdata(dev);
+
+       switch (attr) {
+       case hwmon_temp_input:
+               val = readl_relaxed(hwmon->base + STS) & BN_MASK;
+               *temp = DIV_ROUND_CLOSEST(val * 251802, 4096) - 85525;
+               break;
+       default:
+               return -EOPNOTSUPP;
+       }
+
+       return 0;
+}
+
+static umode_t
+as370_hwmon_is_visible(const void *data, enum hwmon_sensor_types type,
+                      u32 attr, int channel)
+{
+       if (type != hwmon_temp)
+               return 0;
+
+       switch (attr) {
+       case hwmon_temp_input:
+               return 0444;
+       default:
+               return 0;
+       }
+}
+
+static const u32 as370_hwmon_temp_config[] = {
+       HWMON_T_INPUT,
+       0
+};
+
+static const struct hwmon_channel_info as370_hwmon_temp = {
+       .type = hwmon_temp,
+       .config = as370_hwmon_temp_config,
+};
+
+static const struct hwmon_channel_info *as370_hwmon_info[] = {
+       &as370_hwmon_temp,
+       NULL
+};
+
+static const struct hwmon_ops as370_hwmon_ops = {
+       .is_visible = as370_hwmon_is_visible,
+       .read = as370_hwmon_read,
+};
+
+static const struct hwmon_chip_info as370_chip_info = {
+       .ops = &as370_hwmon_ops,
+       .info = as370_hwmon_info,
+};
+
+static int as370_hwmon_probe(struct platform_device *pdev)
+{
+       struct resource *res;
+       struct device *hwmon_dev;
+       struct as370_hwmon *hwmon;
+       struct device *dev = &pdev->dev;
+
+       hwmon = devm_kzalloc(dev, sizeof(*hwmon), GFP_KERNEL);
+       if (!hwmon)
+               return -ENOMEM;
+
+       res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+       hwmon->base = devm_ioremap_resource(&pdev->dev, res);
+       if (IS_ERR(hwmon->base))
+               return PTR_ERR(hwmon->base);
+
+       init_pvt(hwmon);
+
+       hwmon_dev = devm_hwmon_device_register_with_info(dev,
+                                                        "as370",
+                                                        hwmon,
+                                                        &as370_chip_info,
+                                                        NULL);
+       return PTR_ERR_OR_ZERO(hwmon_dev);
+}
+
+static const struct of_device_id as370_hwmon_match[] = {
+       { .compatible = "syna,as370-hwmon" },
+       {},
+};
+MODULE_DEVICE_TABLE(of, as370_hwmon_match);
+
+static struct platform_driver as370_hwmon_driver = {
+       .probe = as370_hwmon_probe,
+       .driver = {
+               .name = "as370-hwmon",
+               .of_match_table = as370_hwmon_match,
+       },
+};
+module_platform_driver(as370_hwmon_driver);
+
+MODULE_AUTHOR("Jisheng Zhang<jszhang@kernel.org>");
+MODULE_DESCRIPTION("Synaptics AS370 SoC hardware monitor");
+MODULE_LICENSE("GPL v2");