[PATCH 7/7] hwmon: Port TEMPMON sensor driver
Andrey Smirnov
andrew.smirnov at gmail.com
Sun Dec 6 23:52:43 PST 2015
Port TEMPMON sensor driver from U-Boot.
Signed-off-by: Andrey Smirnov <andrew.smirnov at 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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