DM: thermal: Add imx thermal DM driver

Add a new thermal uclass for thermal sensor and implement the imx
thermal driver basing on this uclass.

Signed-off-by: Ye.Li <B37916@freescale.com>
Acked-by: Stefano Babic <sbabic@denx.de>

3 files changed, 216 insertions, 0 deletions

diff --git a/drivers/thermal/Makefile b/drivers/thermal/Makefile
new file mode 100644
index 0000000..6d4cacd
--- /dev/null
+++ b/drivers/thermal/Makefile
@@ -0,0 +1,9 @@
+#
+# (C) Copyright 2014 Freescale Semiconductor, Inc.
+# Author: Nitin Garg <nitin.garg@freescale.com>
+#
+# SPDX-License-Identifier:	GPL-2.0+
+#
+
+obj-$(CONFIG_DM_THERMAL) += thermal-uclass.o
+obj-$(CONFIG_IMX6_THERMAL) += imx_thermal.o
diff --git a/drivers/thermal/imx_thermal.c b/drivers/thermal/imx_thermal.c
new file mode 100644
index 0000000..1161585
--- /dev/null
+++ b/drivers/thermal/imx_thermal.c
@@ -0,0 +1,177 @@
+/*
+ * (C) Copyright 2014 Freescale Semiconductor, Inc.
+ * Author: Nitin Garg <nitin.garg@freescale.com>
+ *             Ye Li <Ye.Li@freescale.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <config.h>
+#include <common.h>
+#include <div64.h>
+#include <fuse.h>
+#include <asm/io.h>
+#include <asm/arch/clock.h>
+#include <dm.h>
+#include <errno.h>
+#include <malloc.h>
+#include <thermal.h>
+#include <imx_thermal.h>
+
+#define TEMPERATURE_MIN		-40
+#define TEMPERATURE_HOT		80
+#define TEMPERATURE_MAX		125
+#define FACTOR0			10000000
+#define FACTOR1			15976
+#define FACTOR2			4297157
+#define MEASURE_FREQ		327
+
+#define TEMPSENSE0_TEMP_CNT_SHIFT	8
+#define TEMPSENSE0_TEMP_CNT_MASK	(0xfff << TEMPSENSE0_TEMP_CNT_SHIFT)
+#define TEMPSENSE0_FINISHED		(1 << 2)
+#define TEMPSENSE0_MEASURE_TEMP		(1 << 1)
+#define TEMPSENSE0_POWER_DOWN		(1 << 0)
+#define MISC0_REFTOP_SELBIASOFF		(1 << 3)
+#define TEMPSENSE1_MEASURE_FREQ		0xffff
+
+static int read_cpu_temperature(struct udevice *dev)
+{
+	int temperature;
+	unsigned int reg, n_meas;
+	const struct imx_thermal_plat *pdata = dev_get_platdata(dev);
+	struct anatop_regs *anatop = (struct anatop_regs *)pdata->regs;
+	unsigned int *priv = dev_get_priv(dev);
+	u32 fuse = *priv;
+	int t1, n1;
+	u32 c1, c2;
+	u64 temp64;
+
+	/*
+	 * Sensor data layout:
+	 *   [31:20] - sensor value @ 25C
+	 * We use universal formula now and only need sensor value @ 25C
+	 * slope = 0.4297157 - (0.0015976 * 25C fuse)
+	 */
+	n1 = fuse >> 20;
+	t1 = 25; /* t1 always 25C */
+
+	/*
+	 * Derived from linear interpolation:
+	 * slope = 0.4297157 - (0.0015976 * 25C fuse)
+	 * slope = (FACTOR2 - FACTOR1 * n1) / FACTOR0
+	 * (Nmeas - n1) / (Tmeas - t1) = slope
+	 * We want to reduce this down to the minimum computation necessary
+	 * for each temperature read.  Also, we want Tmeas in millicelsius
+	 * and we don't want to lose precision from integer division. So...
+	 * Tmeas = (Nmeas - n1) / slope + t1
+	 * milli_Tmeas = 1000 * (Nmeas - n1) / slope + 1000 * t1
+	 * milli_Tmeas = -1000 * (n1 - Nmeas) / slope + 1000 * t1
+	 * Let constant c1 = (-1000 / slope)
+	 * milli_Tmeas = (n1 - Nmeas) * c1 + 1000 * t1
+	 * Let constant c2 = n1 *c1 + 1000 * t1
+	 * milli_Tmeas = c2 - Nmeas * c1
+	 */
+	temp64 = FACTOR0;
+	temp64 *= 1000;
+	do_div(temp64, FACTOR1 * n1 - FACTOR2);
+	c1 = temp64;
+	c2 = n1 * c1 + 1000 * t1;
+
+	/*
+	 * now we only use single measure, every time we read
+	 * the temperature, we will power on/down anadig thermal
+	 * module
+	 */
+	writel(TEMPSENSE0_POWER_DOWN, &anatop->tempsense0_clr);
+	writel(MISC0_REFTOP_SELBIASOFF, &anatop->ana_misc0_set);
+
+	/* setup measure freq */
+	reg = readl(&anatop->tempsense1);
+	reg &= ~TEMPSENSE1_MEASURE_FREQ;
+	reg |= MEASURE_FREQ;
+	writel(reg, &anatop->tempsense1);
+
+	/* start the measurement process */
+	writel(TEMPSENSE0_MEASURE_TEMP, &anatop->tempsense0_clr);
+	writel(TEMPSENSE0_FINISHED, &anatop->tempsense0_clr);
+	writel(TEMPSENSE0_MEASURE_TEMP, &anatop->tempsense0_set);
+
+	/* make sure that the latest temp is valid */
+	while ((readl(&anatop->tempsense0) &
+		TEMPSENSE0_FINISHED) == 0)
+		udelay(10000);
+
+	/* read temperature count */
+	reg = readl(&anatop->tempsense0);
+	n_meas = (reg & TEMPSENSE0_TEMP_CNT_MASK)
+		>> TEMPSENSE0_TEMP_CNT_SHIFT;
+	writel(TEMPSENSE0_FINISHED, &anatop->tempsense0_clr);
+
+	/* milli_Tmeas = c2 - Nmeas * c1 */
+	temperature = (c2 - n_meas * c1)/1000;
+
+	/* power down anatop thermal sensor */
+	writel(TEMPSENSE0_POWER_DOWN, &anatop->tempsense0_set);
+	writel(MISC0_REFTOP_SELBIASOFF, &anatop->ana_misc0_clr);
+
+	return temperature;
+}
+
+int imx_thermal_get_temp(struct udevice *dev, int *temp)
+{
+	int cpu_tmp = 0;
+
+	cpu_tmp = read_cpu_temperature(dev);
+	while (cpu_tmp > TEMPERATURE_MIN && cpu_tmp < TEMPERATURE_MAX) {
+		if (cpu_tmp >= TEMPERATURE_HOT) {
+			printf("CPU Temperature is %d C, too hot to boot, waiting...\n",
+			       cpu_tmp);
+			udelay(5000000);
+			cpu_tmp = read_cpu_temperature(dev);
+		} else {
+			break;
+		}
+	}
+
+	*temp = cpu_tmp;
+
+	return 0;
+}
+
+static const struct dm_thermal_ops imx_thermal_ops = {
+	.get_temp	= imx_thermal_get_temp,
+};
+
+static int imx_thermal_probe(struct udevice *dev)
+{
+	unsigned int fuse = ~0;
+
+	const struct imx_thermal_plat *pdata = dev_get_platdata(dev);
+	unsigned int *priv = dev_get_priv(dev);
+
+	/* Read Temperature calibration data fuse */
+	fuse_read(pdata->fuse_bank, pdata->fuse_word, &fuse);
+
+	/* Check for valid fuse */
+	if (fuse == 0 || fuse == ~0) {
+		printf("CPU:   Thermal invalid data, fuse: 0x%x\n", fuse);
+		return -EPERM;
+	} else {
+		printf("CPU:   Thermal calibration data: 0x%x\n", fuse);
+	}
+
+	*priv = fuse;
+
+	enable_thermal_clk();
+
+	return 0;
+}
+
+U_BOOT_DRIVER(imx_thermal) = {
+	.name	= "imx_thermal",
+	.id	= UCLASS_THERMAL,
+	.ops	= &imx_thermal_ops,
+	.probe	= imx_thermal_probe,
+	.priv_auto_alloc_size = sizeof(unsigned int),
+	.flags  = DM_FLAG_PRE_RELOC,
+};
diff --git a/drivers/thermal/thermal-uclass.c b/drivers/thermal/thermal-uclass.c
new file mode 100644
index 0000000..3bee1a7
--- /dev/null
+++ b/drivers/thermal/thermal-uclass.c
@@ -0,0 +1,30 @@
+/*
+ * (C) Copyright 2014 Freescale Semiconductor, Inc
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <thermal.h>
+#include <errno.h>
+#include <fdtdec.h>
+#include <malloc.h>
+#include <asm/io.h>
+#include <linux/list.h>
+
+
+int thermal_get_temp(struct udevice *dev, int *temp)
+{
+	const struct dm_thermal_ops *ops = device_get_ops(dev);
+
+	if (!ops->get_temp)
+		return -ENOSYS;
+
+	return ops->get_temp(dev, temp);
+}
+
+UCLASS_DRIVER(thermal) = {
+	.id		= UCLASS_THERMAL,
+	.name		= "thermal",
+};