Adds support for temperature sensor readings, registers with common
thermal framework, and uses the new common cpu_cooling interface.
Signed-off-by: Robert Lee <rob.lee@xxxxxxxxxx>
---
arch/arm/boot/dts/imx6q.dtsi | 1 +
drivers/thermal/Kconfig | 6 +
drivers/thermal/Makefile | 1 +
drivers/thermal/imx6q_thermal.c | 540 +++++++++++++++++++++++++++++++++++++++
4 files changed, 548 insertions(+), 0 deletions(-)
create mode 100644 drivers/thermal/imx6q_thermal.c
diff --git a/arch/arm/boot/dts/imx6q.dtsi b/arch/arm/boot/dts/imx6q.dtsi
index 7dda599..d62b88d 100644
--- a/arch/arm/boot/dts/imx6q.dtsi
+++ b/arch/arm/boot/dts/imx6q.dtsi
@@ -508,6 +508,7 @@
};
ocotp@021bc000 {
+ compatible = "fsl,imx6q-ocotp";
reg = <0x021bc000 0x4000>;
};
diff --git a/drivers/thermal/Kconfig b/drivers/thermal/Kconfig
index 298c1cd..dd8cede 100644
--- a/drivers/thermal/Kconfig
+++ b/drivers/thermal/Kconfig
@@ -29,3 +29,9 @@ config CPU_THERMAL
This will be useful for platforms using the generic thermal interface
and not the ACPI interface.
If you want this support, you should say Y or M here.
+
+config IMX6Q_THERMAL
+ bool "IMX6Q Thermal interface support"
+ depends on THERMAL && CPU_THERMAL
+ help
+ Adds thermal management for IMX6Q.
diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile
index 655cbc4..e2bcffe 100644
--- a/drivers/thermal/Makefile
+++ b/drivers/thermal/Makefile
@@ -4,3 +4,4 @@
obj-$(CONFIG_THERMAL) += thermal_sys.o
obj-$(CONFIG_CPU_THERMAL) += cpu_cooling.o
+obj-$(CONFIG_IMX6Q_THERMAL) += imx6q_thermal.o
diff --git a/drivers/thermal/imx6q_thermal.c b/drivers/thermal/imx6q_thermal.c
new file mode 100644
index 0000000..7d520c6
--- /dev/null
+++ b/drivers/thermal/imx6q_thermal.c
@@ -0,0 +1,540 @@
+/*
+ * Copyright 2012 Freescale Semiconductor, Inc.
+ * Copyright 2012 Linaro Ltd.
+ *
+ * The code contained herein is licensed under the GNU General Public
+ * License. You may obtain a copy of the GNU General Public License
+ * Version 2 or later at the following locations:
+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+
+/* i.MX6Q Thermal Implementation */
+
+#include <linux/kernel.h>
+#include <linux/device.h>
+#include <linux/module.h>
+#include <linux/dmi.h>
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/delay.h>
+#include <linux/types.h>
+#include <linux/thermal.h>
+#include <linux/io.h>
+#include <linux/syscalls.h>
+#include <linux/cpufreq.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/smp.h>
+#include <linux/cpu_cooling.h>
+#include <linux/platform_device.h>
+
+/* register define of anatop */
+#define HW_ANADIG_ANA_MISC0 0x00000150
+#define HW_ANADIG_ANA_MISC0_SET 0x00000154
+#define HW_ANADIG_ANA_MISC0_CLR 0x00000158
+#define HW_ANADIG_ANA_MISC0_TOG 0x0000015c
+#define BM_ANADIG_ANA_MISC0_REFTOP_SELBIASOFF 0x00000008
+
+#define HW_ANADIG_TEMPSENSE0 0x00000180
+#define HW_ANADIG_TEMPSENSE0_SET 0x00000184
+#define HW_ANADIG_TEMPSENSE0_CLR 0x00000188
+#define HW_ANADIG_TEMPSENSE0_TOG 0x0000018c
+
+#define BP_ANADIG_TEMPSENSE0_TEMP_VALUE 8
+#define BM_ANADIG_TEMPSENSE0_TEMP_VALUE 0x000FFF00
+#define BM_ANADIG_TEMPSENSE0_FINISHED 0x00000004
+#define BM_ANADIG_TEMPSENSE0_MEASURE_TEMP 0x00000002
+#define BM_ANADIG_TEMPSENSE0_POWER_DOWN 0x00000001
+
+#define HW_ANADIG_TEMPSENSE1 0x00000190
+#define HW_ANADIG_TEMPSENSE1_SET 0x00000194
+#define HW_ANADIG_TEMPSENSE1_CLR 0x00000198
+#define BP_ANADIG_TEMPSENSE1_MEASURE_FREQ 0
+#define BM_ANADIG_TEMPSENSE1_MEASURE_FREQ 0x0000FFFF
+
+#define HW_OCOTP_ANA1 0x000004E0
+
+#define IMX6Q_THERMAL_POLLING_FREQUENCY_MS 1000
+
+#define IMX6Q_THERMAL_ACT_TRP_PTS 3
+/* assumption: always one critical trip point */
+#define IMX6Q_THERMAL_TOTAL_TRP_PTS (IMX6Q_THERMAL_ACT_TRP_PTS + 1)
+
+struct th_sys_trip_point {
+ u32 temp; /* in celcius */
+ enum thermal_trip_type type;
+};
+
+struct imx6q_sensor_data {
+ int c1, c2;
+ char name[16];
+ u8 meas_delay; /* in milliseconds */
+ u32 noise_margin; /* in millicelcius */
+ int last_temp; /* in millicelcius */
+ /*
+ * When noise filtering, if consecutive measurements are each higher
+ * up to consec_high_limit times, assume changing temperature readings
+ * to be valid and not noise.
+ */
+ u32 consec_high_limit;
+};
+
+struct imx6q_thermal_data {
+ struct th_sys_trip_point trp_pts[IMX6Q_THERMAL_TOTAL_TRP_PTS];
+ struct freq_pctg_table freq_tab[IMX6Q_THERMAL_ACT_TRP_PTS];
+};
+
+struct imx6q_thermal_zone {
+ struct thermal_zone_device *therm_dev;
+ struct thermal_cooling_device *cool_dev;
+ struct imx6q_sensor_data *sensor_data;
+ struct imx6q_thermal_data *thermal_data;
+ struct thermal_zone_device_ops dev_ops;
+};
+
+static struct imx6q_sensor_data g_sensor_data __initdata = {
+ .name = "imx6q-temp_sens",
+ .meas_delay = 1, /* in milliseconds */
+ .noise_margin = 3000,
+ .consec_high_limit = 3,
+};
+
+/*
+ * This data defines the various trip points that will trigger action
+ * when crossed.
+ */
+static struct imx6q_thermal_data g_thermal_data __initdata = {
+ .trp_pts[0] = {
+ .temp = 85000,
+ .type = THERMAL_TRIP_STATE_ACTIVE,
+ },
+ .freq_tab[0] = {
+ .freq_clip_pctg[0] = 5,
+ },
+ .trp_pts[1] = {
+ .temp = 90000,
+ .type = THERMAL_TRIP_STATE_ACTIVE,
+ },
+ .freq_tab[1] = {
+ .freq_clip_pctg[0] = 45,
+ },
+ .trp_pts[2] = {
+ .temp = 95000,
+ .type = THERMAL_TRIP_STATE_ACTIVE,
+ },
+ .freq_tab[2] = {
+ .freq_clip_pctg[0] = 99,
+ },
+ .trp_pts[3] = {
+ .temp = 100000,
+ .type = THERMAL_TRIP_CRITICAL,
+ },
+};
+
+static int th_sys_get_temp(struct thermal_zone_device *thermal,
+ unsigned long *temp);
+
+static struct imx6q_thermal_zone *th_zone;
+static void __iomem *anatop_base, *ocotp_base;
+
+static inline int imx6q_get_temp(int *temp, struct imx6q_sensor_data *sd)
+{
+ unsigned int n_meas;
+ unsigned int reg;
+
+ do {
+ /*
+ * For now we only using single measure. Every time we measure
+ * the temperature, we will power on/down the anadig module
+ */
+ writel_relaxed(BM_ANADIG_TEMPSENSE0_POWER_DOWN,
+ anatop_base + HW_ANADIG_TEMPSENSE0_CLR);
+
+ writel_relaxed(BM_ANADIG_TEMPSENSE0_MEASURE_TEMP,
+ anatop_base + HW_ANADIG_TEMPSENSE0_SET);
+
+ /*
+ * According to imx6q temp sensor designers,
+ * it may require up to ~17us to complete
+ * a measurement. But this timing isn't checked on every part
+ * and specified in the datasheet, so we check the
+ * 'finished' status bit to be sure of completion.
+ */
+ msleep(sd->meas_delay);
+
+ reg = readl_relaxed(anatop_base + HW_ANADIG_TEMPSENSE0);
+
+ writel_relaxed(BM_ANADIG_TEMPSENSE0_MEASURE_TEMP,
+ anatop_base + HW_ANADIG_TEMPSENSE0_CLR);
+
+ writel_relaxed(BM_ANADIG_TEMPSENSE0_POWER_DOWN,
+ anatop_base + HW_ANADIG_TEMPSENSE0_SET);
+
+ } while (!(reg & BM_ANADIG_TEMPSENSE0_FINISHED) &&
+ (reg & BM_ANADIG_TEMPSENSE0_TEMP_VALUE));
+
+ n_meas = (reg & BM_ANADIG_TEMPSENSE0_TEMP_VALUE)
+ >> BP_ANADIG_TEMPSENSE0_TEMP_VALUE;
+
+ /* See imx6q_thermal_process_fuse_data for forumla derivation. */
+ *temp = sd->c2 + (sd->c1 * n_meas);
+
+ pr_debug("Temperature: %d\n", *temp / 1000);
+
+ return 0;
+}
+
+static int th_sys_get_temp(struct thermal_zone_device *thermal,
+ unsigned long *temp)
+{
+ int i, total = 0, tmp = 0;
+ const u8 loop = 5;
+ u32 consec_high = 0;
+
+ struct imx6q_sensor_data *sd;
+
+ sd = ((struct imx6q_thermal_zone *)thermal->devdata)->sensor_data;
+
+ /*
+ * Measure and handle noise
+ *
+ * While the imx6q temperature sensor is designed to minimize being
+ * affected by system noise, it's safest to run sanity checks and
+ * perform any necessary filitering.
+ */
+ for (i = 0; (sd->noise_margin) && (i < loop); i++) {
+ imx6q_get_temp(&tmp, sd);
+
+ if ((abs(tmp - sd->last_temp) <= sd->noise_margin) ||
+ (consec_high >= sd->consec_high_limit)) {
+ sd->last_temp = tmp;
+ i = 0;
+ break;
+ }
+ if (tmp > sd->last_temp)
+ consec_high++;
+
+ /*
+ * ignore first measurement as the previous measurement was
+ * a long time ago.
+ */
+ if (i)
+ total += tmp;
+
+ sd->last_temp = tmp;
+ }
+
+ if (sd->noise_margin && i)
+ tmp = total / (loop - 1);
+
+ /*
+ * The thermal framework code stores temperature in unsigned long. Also,
+ * it has references to "millicelcius" which limits the lowest
+ * temperature possible (compared to Kelvin).
+ */
+ if (tmp > 0)
+ *temp = tmp;
+ else
+ *temp = 0;
+
+ return 0;
+}
+
+static int th_sys_get_mode(struct thermal_zone_device *thermal,
+ enum thermal_device_mode *mode)
+{
+ *mode = THERMAL_DEVICE_ENABLED;
+ return 0;
+}
+
+static int th_sys_get_trip_type(struct thermal_zone_device *thermal, int trip,
+ enum thermal_trip_type *type)
+{
+ struct imx6q_thermal_data *p;
+
+ if (trip >= thermal->trips)
+ return -EINVAL;
+
+ p = ((struct imx6q_thermal_zone *)thermal->devdata)->thermal_data;
+
+ *type = p->trp_pts[trip].type;
+
+ return 0;
+}
+
+static int th_sys_get_trip_temp(struct thermal_zone_device *thermal, int trip,
+ unsigned long *temp)
+{
+ struct imx6q_thermal_data *p;
+
+ if (trip >= thermal->trips)
+ return -EINVAL;
+
+ p = ((struct imx6q_thermal_zone *)thermal->devdata)->thermal_data;
+
+ *temp = p->trp_pts[trip].temp;
+
+ return 0;
+}
+
+static int th_sys_get_crit_temp(struct thermal_zone_device *thermal,
+ unsigned long *temp)
+{
+ int i;
+ struct imx6q_thermal_data *p;
+
+ p = ((struct imx6q_thermal_zone *)thermal->devdata)->thermal_data;
+
+ for (i = thermal->trips ; i > 0 ; i--) {
+ if (p->trp_pts[i-1].type == THERMAL_TRIP_CRITICAL) {
+ *temp = p->trp_pts[i-1].temp;
+ return 0;
+ }
+ }
+
+ return -EINVAL;
+}
+
+static int th_sys_bind(struct thermal_zone_device *thermal,
+ struct thermal_cooling_device *cdev)
+{
+ int i;
+ struct thermal_cooling_device *cd;
+
+ cd = ((struct imx6q_thermal_zone *)thermal->devdata)->cool_dev;
+
+ /* if the cooling device is the one from imx6 bind it */
+ if (cdev != cd)
+ return 0;
+
+ for (i = 0; i < IMX6Q_THERMAL_ACT_TRP_PTS; i++) {
+ if (thermal_zone_bind_cooling_device(thermal, i, cdev)) {
+ pr_err("error binding cooling dev\n");
+ return -EINVAL;
+ }
+ }
+
+ return 0;
+}
+
+static int th_sys_unbind(struct thermal_zone_device *thermal,
+ struct thermal_cooling_device *cdev)
+{
+ int i;
+
+ struct thermal_cooling_device *cd;
+
+ cd = ((struct imx6q_thermal_zone *)thermal->devdata)->cool_dev;
+
+ if (cdev != cd)
+ return 0;
+
+ for (i = 0; i < IMX6Q_THERMAL_ACT_TRP_PTS; i++) {
+ if (thermal_zone_unbind_cooling_device(thermal, i, cdev)) {
+ pr_err("error unbinding cooling dev\n");
+ return -EINVAL;
+ }
+ }
+
+ return 0;
+}
+
+static struct thermal_zone_device_ops g_dev_ops __initdata = {
+ .bind = th_sys_bind,
+ .unbind = th_sys_unbind,
+ .get_temp = th_sys_get_temp,
+ .get_mode = th_sys_get_mode,
+ .get_trip_type = th_sys_get_trip_type,
+ .get_trip_temp = th_sys_get_trip_temp,
+ .get_crit_temp = th_sys_get_crit_temp,
+};
+
+static int imx6q_thermal_process_fuse_data(unsigned int fuse_data,
+ struct imx6q_sensor_data *sd)
+{
+ int t1, t2, n1, n2;
+
+ if (fuse_data == 0 || fuse_data == 0xffffffff)
+ return -EINVAL;
+
+ /*
+ * Fuse data layout:
+ * [31:20] sensor value @ 25C
+ * [19:8] sensor value of hot
+ * [7:0] hot temperature value
+ */
+ n1 = fuse_data >> 20;
+ n2 = (fuse_data & 0xfff00) >> 8;
+ t2 = fuse_data & 0xff;
+ t1 = 25; /* t1 always 25C */
+
+ pr_debug(" -- temperature sensor calibration data --\n");
+ pr_debug("HW_OCOTP_ANA1: %x\n", fuse_data);
+ pr_debug("n1: %d\nn2: %d\nt1: %d\nt2: %d\n", n1, n2, t1, t2);
+
+ /*
+ * Derived from linear interpolation,
+ * Tmeas = T2 + (Nmeas - N2) * (T1 - T2) / (N1 - N2)
+ * We want to reduce this down to the minimum computation necessary
+ * for each temperature read. Also, we want Tmeas in millicelcius
+ * and we don't want to lose precision from integer division. So...
+ * milli_Tmeas = 1000 * T2 + 1000 * (Nmeas - N2) * (T1 - T2) / (N1 - N2)
+ * Let constant c1 = 1000 * (T1 - T2) / (N1 - N2)
+ * milli_Tmeas = (1000 * T2) + c1 * (Nmeas - N2)
+ * milli_Tmeas = (1000 * T2) + (c1 * Nmeas) - (c1 * N2)
+ * Let constant c2 = (1000 * T2) - (c1 * N2)
+ * milli_Tmeas = c2 + (c1 * Nmeas)
+ */
+ sd->c1 = (1000 * (t1 - t2)) / (n1 - n2);
+ sd->c2 = (1000 * t2) - (sd->c1 * n2);
+
+ pr_debug("c1: %i\n", sd->c1);
+ pr_debug("c2: %i\n", sd->c2);
+
+ return 0;
+}
+
+static void __exit imx6q_thermal_exit(void)
+{
+ if (th_zone && th_zone->therm_dev)
+ thermal_zone_device_unregister(th_zone->therm_dev);
+
+ if (th_zone && th_zone->cool_dev)
+ cpufreq_cooling_unregister();
+
+ kfree(th_zone->sensor_data);
+ kfree(th_zone->thermal_data);
+ kfree(th_zone);
+
+ if (ocotp_base)
+ iounmap(ocotp_base);
+
+ if (anatop_base)
+ iounmap(anatop_base);
+
+ pr_info("i.MX6Q: Kernel Thermal management unregistered\n");
+}
+
+static int __init imx6q_thermal_init(void)
+{
+ struct device_node *np_ocotp, *np_anatop;
+ unsigned int fuse_data;
+ int ret;
+
+ np_ocotp = of_find_compatible_node(NULL, NULL, "fsl,imx6q-ocotp");
+ np_anatop = of_find_compatible_node(NULL, NULL, "fsl,imx6q-anatop");
+
+ if (!(np_ocotp && np_anatop))
+ return -ENXIO; /* not a compatible platform */
+
+ ocotp_base = of_iomap(np_ocotp, 0);
+
+ if (!ocotp_base) {
+ pr_err("Could not retrieve ocotp-base\n");
+ ret = -ENXIO;
+ goto err_unregister;
+ }
+
+ anatop_base = of_iomap(np_anatop, 0);
+
+ if (!anatop_base) {
+ pr_err("Could not retrieve anantop-base\n");
+ ret = -ENXIO;
+ goto err_unregister;
+ }
+
+ fuse_data = readl_relaxed(ocotp_base + HW_OCOTP_ANA1);
+
+ th_zone = kzalloc(sizeof(struct imx6q_thermal_zone), GFP_KERNEL);
+ if (!th_zone) {
+ ret = -ENOMEM;
+ goto err_unregister;
+ }
+
+ th_zone->dev_ops = g_dev_ops;
+
+ th_zone->thermal_data =
+ kzalloc(sizeof(struct imx6q_thermal_data), GFP_KERNEL);
+
+ if (!th_zone->thermal_data) {
+ ret = -ENOMEM;
+ goto err_unregister;
+ }
+
+ memcpy(th_zone->thermal_data, &g_thermal_data,
+ sizeof(struct imx6q_thermal_data));
+
+ th_zone->sensor_data =
+ kzalloc(sizeof(struct imx6q_sensor_data), GFP_KERNEL);
+
+ if (!th_zone->sensor_data) {
+ ret = -ENOMEM;
+ goto err_unregister;
+ }
+
+ memcpy(th_zone->sensor_data, &g_sensor_data,
+ sizeof(struct imx6q_sensor_data));
+
+ ret = imx6q_thermal_process_fuse_data(fuse_data, th_zone->sensor_data);
+
+ if (ret) {
+ pr_err("Invalid temperature calibration data.\n");
+ goto err_unregister;
+ }
+
+ if (!th_zone->sensor_data->meas_delay)
+ th_zone->sensor_data->meas_delay = 1;
+
+ /* Make sure sensor is in known good state for measurements */
+ writel_relaxed(BM_ANADIG_TEMPSENSE0_POWER_DOWN,
+ anatop_base + HW_ANADIG_TEMPSENSE0_CLR);
+
+ writel_relaxed(BM_ANADIG_TEMPSENSE0_MEASURE_TEMP,
+ anatop_base + HW_ANADIG_TEMPSENSE0_CLR);
+
+ writel_relaxed(BM_ANADIG_TEMPSENSE1_MEASURE_FREQ,
+ anatop_base + HW_ANADIG_TEMPSENSE1_CLR);
+
+ writel_relaxed(BM_ANADIG_ANA_MISC0_REFTOP_SELBIASOFF,
+ anatop_base + HW_ANADIG_ANA_MISC0_SET);
+
+ writel_relaxed(BM_ANADIG_TEMPSENSE0_POWER_DOWN,
+ anatop_base + HW_ANADIG_TEMPSENSE0_SET);
+
+ th_zone->cool_dev = cpufreq_cooling_register(
+ (struct freq_pctg_table *)th_zone->thermal_data->freq_tab,
+ IMX6Q_THERMAL_ACT_TRP_PTS, cpumask_of(0));
+
+ if (IS_ERR(th_zone->cool_dev)) {
+ pr_err("Failed to register cpufreq cooling device\n");
+ ret = -EINVAL;
+ goto err_unregister;
+ }
+
+ th_zone->therm_dev = thermal_zone_device_register(
+ th_zone->sensor_data->name, IMX6Q_THERMAL_TOTAL_TRP_PTS,
+ th_zone, &th_zone->dev_ops, 0, 0, 0,
+ IMX6Q_THERMAL_POLLING_FREQUENCY_MS);
+
+ if (IS_ERR(th_zone->therm_dev)) {
+ pr_err("Failed to register thermal zone device\n");
+ ret = -EINVAL;
+ goto err_unregister;
+ }
+
+ return 0;
+
+err_unregister:
+ imx6q_thermal_exit();
+ return ret;
+}
+
+module_init(imx6q_thermal_init);
+module_exit(imx6q_thermal_exit);
+
+MODULE_AUTHOR("Freescale Semiconductor");
+MODULE_DESCRIPTION("i.MX6Q SoC thermal driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:imx6q-thermal");
--
1.7.1
--
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