thermal: broadcom: Add Stingray thermal driver

Stingray SoC has six temperature sensor and those are
configured, controlled and accessed to read temperature
and update in DDR memory using m0 firmware.
All six sensors has been given 4 bytes of memory in DDR
to write temperature in millivolts.

This thermal driver read temperature values from DDR
because no direct access to sensors.
Like this all temparature sensors are monitored and
trips at critical temperature.

If driver can't handle thermal runaways because of
any unknown reason, then firmware in m0 Processor
will handle.

Reviewed-by: Ray Jui <ray.jui@broadcom.com>
Reviewed-by: Scott Branden <scott.branden@broadcom.com>
Reviewed-by: Vikram Prakash <vikram.prakash@broadcom.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Pramod Kumar <pramod.kumar@broadcom.com>
Signed-off-by: Srinath Mannam <srinath.mannam@broadcom.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>

drivers/thermal/Kconfig

@@ -343,7 +343,8 @@ source "drivers/thermal/intel/Kconfig"
 endmenu
 
 menu "Broadcom thermal drivers"
-depends on ARCH_BCM || ARCH_BRCMSTB || ARCH_BCM2835 || COMPILE_TEST
+depends on ARCH_BCM || ARCH_BRCMSTB || ARCH_BCM2835 || ARCH_BCM_IPROC || \
+		COMPILE_TEST
 source "drivers/thermal/broadcom/Kconfig"
 endmenu
 

drivers/thermal/broadcom/Kconfig

@@ -22,3 +22,12 @@ config BCM_NS_THERMAL
 	  BCM4708, BCM4709, BCM5301x, BCM95852X, etc). It contains DMU (Device
 	  Management Unit) block with a thermal sensor that allows checking CPU
 	  temperature.
+
+config BCM_SR_THERMAL
+	tristate "Stingray thermal driver"
+	depends on ARCH_BCM_IPROC || COMPILE_TEST
+	default ARCH_BCM_IPROC
+	help
+	  Support for the Stingray family of SoCs. Its different blocks like
+	  iHost, CRMU and NITRO has thermal sensor that allows checking its
+	  temperature.

drivers/thermal/broadcom/Makefile

@@ -1,3 +1,4 @@
 obj-$(CONFIG_BCM2835_THERMAL)		+= bcm2835_thermal.o
 obj-$(CONFIG_BRCMSTB_THERMAL)		+= brcmstb_thermal.o
 obj-$(CONFIG_BCM_NS_THERMAL)		+= ns-thermal.o
+obj-$(CONFIG_BCM_SR_THERMAL)		+= sr-thermal.o

drivers/thermal/broadcom/sr-thermal.c

@@ -0,0 +1,121 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2018 Broadcom
+ */
+
+#include <linux/acpi.h>
+#include <linux/module.h>
+#include <linux/of_address.h>
+#include <linux/platform_device.h>
+#include <linux/thermal.h>
+
+/*
+ * In stingray thermal IO memory,
+ * Total Number of available TMONs MASK is at offset 0
+ * temperature registers BASE is at 4 byte offset.
+ * Each TMON temperature register size is 4.
+ */
+#define SR_TMON_TEMP_BASE(id)   ((id) * 0x4)
+
+#define SR_TMON_MAX_LIST        6
+
+struct sr_tmon {
+	struct thermal_zone_device *tz;
+	unsigned int crit_temp;
+	unsigned int tmon_id;
+	struct sr_thermal *priv;
+};
+
+struct sr_thermal {
+	void __iomem *regs;
+	unsigned int max_crit_temp;
+	struct sr_tmon tmon[SR_TMON_MAX_LIST];
+};
+
+static int sr_get_temp(void *data, int *temp)
+{
+	struct sr_tmon *tmon = data;
+	struct sr_thermal *sr_thermal = tmon->priv;
+
+	*temp = readl(sr_thermal->regs + SR_TMON_TEMP_BASE(tmon->tmon_id));
+
+	return 0;
+}
+
+static const struct thermal_zone_of_device_ops sr_tz_ops = {
+	.get_temp = sr_get_temp,
+};
+
+static int sr_thermal_probe(struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct sr_thermal *sr_thermal;
+	struct sr_tmon *tmon;
+	struct resource *res;
+	u32 sr_tmon_list = 0;
+	unsigned int i;
+	int ret;
+
+	sr_thermal = devm_kzalloc(dev, sizeof(*sr_thermal), GFP_KERNEL);
+	if (!sr_thermal)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	sr_thermal->regs = (void __iomem *)devm_memremap(&pdev->dev, res->start,
+							 resource_size(res),
+							 MEMREMAP_WB);
+	if (IS_ERR(sr_thermal->regs)) {
+		dev_err(dev, "failed to get io address\n");
+		return PTR_ERR(sr_thermal->regs);
+	}
+
+	ret = device_property_read_u32(dev, "brcm,tmon-mask", &sr_tmon_list);
+	if (ret)
+		return ret;
+
+	tmon = sr_thermal->tmon;
+	for (i = 0; i < SR_TMON_MAX_LIST; i++, tmon++) {
+		if (!(sr_tmon_list & BIT(i)))
+			continue;
+
+		/* Flush temperature registers */
+		writel(0, sr_thermal->regs + SR_TMON_TEMP_BASE(i));
+		tmon->tmon_id = i;
+		tmon->priv = sr_thermal;
+		tmon->tz = devm_thermal_zone_of_sensor_register(dev, i, tmon,
+								&sr_tz_ops);
+		if (IS_ERR(tmon->tz))
+			return PTR_ERR(tmon->tz);
+
+		dev_dbg(dev, "thermal sensor %d registered\n", i);
+	}
+	platform_set_drvdata(pdev, sr_thermal);
+
+	return 0;
+}
+
+static const struct of_device_id sr_thermal_of_match[] = {
+	{ .compatible = "brcm,sr-thermal", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, sr_thermal_of_match);
+
+static const struct acpi_device_id sr_thermal_acpi_ids[] = {
+	{ .id = "BRCM0500" },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(acpi, sr_thermal_acpi_ids);
+
+static struct platform_driver sr_thermal_driver = {
+	.probe		= sr_thermal_probe,
+	.driver = {
+		.name = "sr-thermal",
+		.of_match_table = sr_thermal_of_match,
+		.acpi_match_table = ACPI_PTR(sr_thermal_acpi_ids),
+	},
+};
+module_platform_driver(sr_thermal_driver);
+
+MODULE_AUTHOR("Pramod Kumar <pramod.kumar@broadcom.com>");
+MODULE_DESCRIPTION("Stingray thermal driver");
+MODULE_LICENSE("GPL v2");