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-rw-r--r--drivers/hwmon/as370-hwmon.c135
1 files changed, 135 insertions, 0 deletions
diff --git a/drivers/hwmon/as370-hwmon.c b/drivers/hwmon/as370-hwmon.c
new file mode 100644
index 000000000..63b5b2d6e
--- /dev/null
+++ b/drivers/hwmon/as370-hwmon.c
@@ -0,0 +1,135 @@
+// 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 struct hwmon_channel_info *as370_hwmon_info[] = {
+ HWMON_CHANNEL_INFO(temp, HWMON_T_INPUT),
+ 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 device *hwmon_dev;
+ struct as370_hwmon *hwmon;
+ struct device *dev = &pdev->dev;
+
+ hwmon = devm_kzalloc(dev, sizeof(*hwmon), GFP_KERNEL);
+ if (!hwmon)
+ return -ENOMEM;
+
+ hwmon->base = devm_platform_ioremap_resource(pdev, 0);
+ 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");