[PATCH 7/7] hwmon: Port TEMPMON sensor driver

[Andrey Smirnov <andrew.smirnov@gmail.com>]

Port TEMPMON sensor driver from U-Boot.

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
---
 drivers/hwmon/Kconfig       |   6 ++
 drivers/hwmon/Makefile      |   1 +
 drivers/hwmon/imx_thermal.c | 234 ++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 241 insertions(+)
 create mode 100644 drivers/hwmon/imx_thermal.c

diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index db51d26..92e27ea 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -22,4 +22,10 @@ config SENSORS_LM75

 		- National Semiconductor LM75, LM75A

+config SENSORS_IMX_THERMAL
+       tristate "Temperature sensor driver for Freescale i.MX SoCs"
+       help
+         Support for Temperature Monitor (TEMPMON) found on Freescale
+         i.MX SoCs.
+
 endif # HWMON
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index e73e681..4a0d316 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -5,3 +5,4 @@
 obj-$(CONFIG_HWMON)		+= class.o

 obj-$(CONFIG_SENSORS_LM75)	+= lm75.o
+obj-$(CONFIG_SENSORS_IMX_THERMAL) += imx_thermal.o
diff --git a/drivers/hwmon/imx_thermal.c b/drivers/hwmon/imx_thermal.c
new file mode 100644
index 0000000..f9c506b
--- /dev/null
+++ b/drivers/hwmon/imx_thermal.c
@@ -0,0 +1,234 @@
+/*
+ * tempmon.c - handle most I2C EEPROMs
+ *
+ * Copyright (C) 2005-2007 David Brownell
+ * Copyright (C) 2008 Wolfram Sang, Pengutronix
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <common.h>
+#include <init.h>
+#include <malloc.h>
+#include <clock.h>
+#include <driver.h>
+#include <xfuncs.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <linux/math64.h>
+#include <linux/log2.h>
+#include <linux/clk.h>
+#include <mach/clock.h>
+#include <mach/imx6-anadig.h>
+#include <io.h>
+#include <hwmon.h>
+
+#define FACTOR0			10000000
+#define MEASURE_FREQ		327
+#define OCOTP_ANA1_OFFSET	(0xE * sizeof(uint32_t))
+
+struct imx_thermal_data {
+	int c1, c2;
+	void __iomem *base;
+	struct clk *clk;
+
+	struct hwmon_sensor sensor;
+};
+
+static inline struct imx_thermal_data *
+to_imx_thermal_data(struct hwmon_sensor *sensor)
+{
+	return container_of(sensor, struct imx_thermal_data, sensor);
+}
+
+
+static int imx_thermal_read_temperature(struct hwmon_sensor *sensor,
+					s32 *reading)
+{
+	uint64_t start;
+	uint32_t tempsense0, tempsense1;
+	uint16_t n_meas;
+	struct imx_thermal_data *imx_thermal = to_imx_thermal_data(sensor);
+
+	/*
+	 * now we only use single measure, every time we read
+	 * the temperature, we will power on/down anadig thermal
+	 * module
+	 */
+	writel(BM_ANADIG_TEMPSENSE0_POWER_DOWN,
+	       imx_thermal->base + HW_ANADIG_TEMPSENSE0_CLR);
+	writel(BM_ANADIG_ANA_MISC0_REFTOP_SELBIASOFF,
+	       imx_thermal->base + HW_ANADIG_ANA_MISC0_SET);
+
+	/* setup measure freq */
+	tempsense1 = readl(imx_thermal->base + HW_ANADIG_TEMPSENSE1);
+	tempsense1 &= ~BM_ANADIG_TEMPSENSE1_MEASURE_FREQ;
+	tempsense1 |= MEASURE_FREQ;
+	writel(tempsense1, imx_thermal->base + HW_ANADIG_TEMPSENSE1);
+
+	/* start the measurement process */
+	writel(BM_ANADIG_TEMPSENSE0_MEASURE_TEMP,
+		imx_thermal->base + HW_ANADIG_TEMPSENSE0_CLR);
+	writel(BM_ANADIG_TEMPSENSE0_FINISHED,
+		imx_thermal->base + HW_ANADIG_TEMPSENSE0_CLR);
+	writel(BM_ANADIG_TEMPSENSE0_MEASURE_TEMP,
+	       imx_thermal->base + HW_ANADIG_TEMPSENSE0_SET);
+
+	/* make sure that the latest temp is valid */
+	start = get_time_ns();
+	do {
+		tempsense0 = readl(imx_thermal->base + HW_ANADIG_TEMPSENSE0);
+
+		if (is_timeout(start, 1 * SECOND)) {
+			dev_err(imx_thermal->sensor.dev,
+				"timeout waiting for TEMPMON measurement\n");
+			return -EIO;
+		}
+	} while (!(tempsense0 & BM_ANADIG_TEMPSENSE0_FINISHED));
+
+	n_meas = (tempsense0 & BM_ANADIG_TEMPSENSE0_TEMP_VALUE)
+		>> BP_ANADIG_TEMPSENSE0_TEMP_VALUE;
+	writel(BM_ANADIG_TEMPSENSE0_FINISHED,
+	       imx_thermal->base + HW_ANADIG_TEMPSENSE0_CLR);
+
+	*reading = (int)n_meas * imx_thermal->c1 + imx_thermal->c2;
+
+	/* power down anatop thermal sensor */
+	writel(BM_ANADIG_TEMPSENSE0_POWER_DOWN,
+	       imx_thermal->base + HW_ANADIG_TEMPSENSE0_SET);
+	writel(BM_ANADIG_ANA_MISC0_REFTOP_SELBIASOFF,
+	       imx_thermal->base + HW_ANADIG_ANA_MISC0_CLR);
+
+	return 0;
+}
+
+static int imx_thermal_probe(struct device_d *dev)
+{
+	uint32_t ocotp_ana1;
+	struct device_node *node;
+	struct imx_thermal_data *imx_thermal;
+	struct cdev *ocotp;
+	struct device_d *anatop;
+	int t1, n1, t2, n2;
+	int ret;
+
+	node = of_parse_phandle(dev->device_node, "fsl,tempmon-data", 0);
+	if (!node) {
+		dev_err(dev, "no calibration data source\n");
+		return -ENODEV;
+	}
+
+	ocotp = cdev_by_device_node(node);
+	if (!ocotp) {
+		dev_err(dev, "no OCOTP character device\n");
+		return -ENODEV;
+	}
+
+	ret = cdev_do_open(ocotp, O_RDONLY);
+	if (!ret) {
+		ret = cdev_read(ocotp,
+				&ocotp_ana1, sizeof(ocotp_ana1),
+				OCOTP_ANA1_OFFSET, 0);
+
+		cdev_close(ocotp);
+
+		if (ret != sizeof(ocotp_ana1)) {
+			dev_err(dev, "failed to read calibration data\n");
+			return -EINVAL;
+		}
+	} else {
+		dev_err(dev, "failed to open %s\n", ocotp->name);
+		return -EINVAL;
+	}
+
+	if (ocotp_ana1 == 0 || ocotp_ana1 == ~0) {
+		dev_err(dev, "invalid sensor calibration data\n");
+		return -EINVAL;
+	}
+
+	node = of_parse_phandle(dev->device_node, "fsl,tempmon", 0);
+	if (!node) {
+		dev_err(dev, "failed to get the value of 'fsl,tempmon'\n");
+		return -ENODEV;
+	}
+
+	anatop = of_find_device_by_node(node);
+	if (!anatop) {
+		dev_err(dev, "failed to find 'fsl,tempmon' device\n");
+		return -ENODEV;
+
+	}
+
+	imx_thermal = xzalloc(sizeof(*imx_thermal));
+
+	imx_thermal->base = dev_request_mem_region(anatop, 0);
+	if (IS_ERR(imx_thermal->base)) {
+		ret = PTR_ERR(imx_thermal->base);
+		goto fail;
+	}
+
+	n1 = ocotp_ana1 >> 20;
+	t1 = 25;
+	n2 = (ocotp_ana1 & 0x000FFF00) >> 8;
+	t2 = ocotp_ana1 & 0xFF;
+
+	imx_thermal->c1 = (-1000 * (t2 - t1)) / (n1 - n2);
+	imx_thermal->c2 = 1000 * t2 + (1000 * n2 * (t2 - t1)) / (n1 - n2);
+
+	imx_thermal->clk = clk_get(dev, NULL);
+	if (IS_ERR(imx_thermal->clk)) {
+		ret = PTR_ERR(imx_thermal->clk);
+		goto fail;
+	}
+
+	clk_enable(imx_thermal->clk);
+
+	if (!dev->device_node) {
+		dev_err(dev, "No device_node associated with the device\n");
+		ret = -EINVAL;
+		goto disable_clock;
+	}
+
+	imx_thermal->sensor.name = of_get_property(dev->device_node,
+						   "barebox,sensor-name",
+						   NULL);
+	if (!imx_thermal->sensor.name) {
+		dev_err(dev, "No sensor-name specified\n");
+		ret = -EINVAL;
+		goto disable_clock;
+	}
+
+	imx_thermal->sensor.read = imx_thermal_read_temperature;
+	imx_thermal->sensor.dev = dev;
+
+	return hwmon_sensor_register(&imx_thermal->sensor);
+
+disable_clock:
+	clk_disable(imx_thermal->clk);
+fail:
+	kfree(imx_thermal);
+	return ret;
+}
+
+static const struct of_device_id of_imx_thermal_match[] = {
+	{ .compatible = "fsl,imx6q-tempmon", },
+	{ .compatible = "fsl,imx6sx-tempmon", },
+	{ /* end */ }
+};
+
+
+static struct driver_d imx_thermal_driver = {
+	.name		= "imx_thermal",
+	.probe		= imx_thermal_probe,
+	.of_compatible	= DRV_OF_COMPAT(of_imx_thermal_match),
+};
+
+static int imx_thermal_init(void)
+{
+	platform_driver_register(&imx_thermal_driver);
+	return 0;
+}
+device_initcall(imx_thermal_init);
--
2.5.0

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