[PATCH v3 2/2] Add hardware monitoring driver for Moortec MR75203 PVT controller

[Rahul Tanwar]

PVT controller (MR75203) is used to configure & control
Moortec embedded analog IP which contains temprature
sensor(TS), voltage monitor(VM) & process detector(PD)
modules. Add hardware monitoring driver to support
MR75203 PVT controller.

Signed-off-by: Rahul Tanwar <rahul.tanwar@xxxxxxxxxxxxxxx>
---
 drivers/hwmon/Kconfig   |  10 +
 drivers/hwmon/Makefile  |   1 +
 drivers/hwmon/mr75203.c | 605 ++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 616 insertions(+)
 create mode 100644 drivers/hwmon/mr75203.c

diff --git a/drivers/hwmon/Kconfig b/drivers/hwmon/Kconfig
index 8dc28b26916e..2defb46677b4 100644
--- a/drivers/hwmon/Kconfig
+++ b/drivers/hwmon/Kconfig
@@ -1112,6 +1112,16 @@ config SENSORS_MENF21BMC_HWMON
 	  This driver can also be built as a module. If so the module
 	  will be called menf21bmc_hwmon.
 
+config SENSORS_MR75203
+	tristate "Moortec Semiconductor MR75203 PVT Controller"
+	select REGMAP_MMIO
+	help
+	  If you say yes here you get support for Moortec MR75203
+	  PVT controller.
+
+	  This driver can also be built as a module. If so, the module
+	  will be called mr75203.
+
 config SENSORS_ADCXX
 	tristate "National Semiconductor ADCxxxSxxx"
 	depends on SPI_MASTER
diff --git a/drivers/hwmon/Makefile b/drivers/hwmon/Makefile
index a8f4b35b136b..bb4bd92a5149 100644
--- a/drivers/hwmon/Makefile
+++ b/drivers/hwmon/Makefile
@@ -142,6 +142,7 @@ obj-$(CONFIG_SENSORS_MCP3021)	+= mcp3021.o
 obj-$(CONFIG_SENSORS_TC654)	+= tc654.o
 obj-$(CONFIG_SENSORS_MLXREG_FAN) += mlxreg-fan.o
 obj-$(CONFIG_SENSORS_MENF21BMC_HWMON) += menf21bmc_hwmon.o
+obj-$(CONFIG_SENSORS_MR75203)	+= mr75203.o
 obj-$(CONFIG_SENSORS_NCT6683)	+= nct6683.o
 obj-$(CONFIG_SENSORS_NCT6775)	+= nct6775.o
 obj-$(CONFIG_SENSORS_NCT7802)	+= nct7802.o
diff --git a/drivers/hwmon/mr75203.c b/drivers/hwmon/mr75203.c
new file mode 100644
index 000000000000..30a70a3ae82b
--- /dev/null
+++ b/drivers/hwmon/mr75203.c
@@ -0,0 +1,605 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020 MaxLinear, Inc.
+ *
+ * This driver is a hardware monitoring driver for PVT controller
+ * (MR75203) which is used to configure & control Moortec embedded
+ * analog IP to enable multiple embedded temprature sensor(TS),
+ * voltage monitor(VM) & process detector(PD) modules.
+ */
+#include <linux/clk.h>
+#include <linux/hwmon.h>
+#include <linux/module.h>
+#include <linux/mod_devicetable.h>
+#include <linux/mutex.h>
+#include <linux/platform_device.h>
+#include <linux/property.h>
+#include <linux/regmap.h>
+#include <linux/reset.h>
+
+/* PVT Common register */
+#define PVT_IP_CONFIG	0x04
+#define TS_NUM_MSK	GENMASK(4, 0)
+#define TS_NUM_SFT	0
+#define PD_NUM_MSK	GENMASK(12, 8)
+#define PD_NUM_SFT	8
+#define VM_NUM_MSK	GENMASK(20, 16)
+#define VM_NUM_SFT	16
+#define CH_NUM_MSK	GENMASK(31, 24)
+#define CH_NUM_SFT	24
+
+/* Macro Common Register */
+#define CLK_SYNTH		0x00
+#define CLK_SYNTH_LO_SFT	0
+#define CLK_SYNTH_HI_SFT	8
+#define CLK_SYNTH_HOLD_SFT	16
+#define CLK_SYNTH_EN		BIT(24)
+#define CLK_SYS_CYCLES_MAX	514
+#define CLK_SYS_CYCLES_MIN	2
+#define HZ_PER_MHZ		1000000L
+
+#define SDIF_DISABLE	0x04
+
+#define SDIF_STAT	0x08
+#define SDIF_BUSY	BIT(0)
+#define SDIF_LOCK	BIT(1)
+
+#define SDIF_W		0x0c
+#define SDIF_PROG	BIT(31)
+#define SDIF_WRN_W	BIT(27)
+#define SDIF_WRN_R	0x00
+#define SDIF_ADDR_SFT	24
+
+#define SDIF_HALT	0x10
+#define SDIF_CTRL	0x14
+#define SDIF_SMPL_CTRL	0x20
+
+/* TS & PD Individual Macro Register */
+#define COM_REG_SIZE	0x40
+
+#define SDIF_DONE(n)	(COM_REG_SIZE + 0x14 + 0x40 * (n))
+#define SDIF_SMPL_DONE	BIT(0)
+
+#define SDIF_DATA(n)	(COM_REG_SIZE + 0x18 + 0x40 * (n))
+#define SAMPLE_DATA_MSK	GENMASK(15, 0)
+
+#define HILO_RESET(n)	(COM_REG_SIZE + 0x2c + 0x40 * (n))
+
+/* VM Individual Macro Register */
+#define VM_COM_REG_SIZE	0x200
+#define VM_SDIF_DONE(n)	(VM_COM_REG_SIZE + 0x34 + 0x200 * (n))
+#define VM_SDIF_DATA(n)	(VM_COM_REG_SIZE + 0x40 + 0x200 * (n))
+
+/* SDA Slave Register */
+#define IP_CTRL			0x00
+#define IP_RST_REL		BIT(1)
+#define IP_RUN_CONT		BIT(3)
+#define IP_AUTO			BIT(8)
+#define IP_VM_MODE		BIT(10)
+
+#define IP_CFG			0x01
+#define CFG0_MODE_2		BIT(0)
+#define CFG0_PARALLEL_OUT	0
+#define CFG0_12_BIT		0
+#define CFG1_VOL_MEAS_MODE	0
+#define CFG1_PARALLEL_OUT	0
+#define CFG1_14_BIT		0
+
+#define IP_DATA		0x03
+
+#define IP_POLL		0x04
+#define VM_CH_INIT	BIT(20)
+#define VM_CH_REQ	BIT(21)
+
+#define IP_TMR			0x05
+#define POWER_DELAY_CYCLE_256	0x80
+#define POWER_DELAY_CYCLE_64	0x40
+
+#define PVT_POLL_DELAY_US	20
+#define PVT_POLL_TIMEOUT_US	20000
+#define PVT_H_CONST		100000
+#define PVT_CAL5_CONST		2047
+#define PVT_G_CONST		40000
+#define PVT_CONV_BITS		10
+#define PVT_N_CONST		90
+#define PVT_R_CONST		245805
+
+struct pvt_device {
+	struct regmap		*c_map;
+	struct regmap		*t_map;
+	struct regmap		*p_map;
+	struct regmap		*v_map;
+	struct clk		*clk;
+	struct reset_control	*rst;
+	u32			t_num;
+	u32			p_num;
+	u32			v_num;
+	u32			ip_freq;
+	u8			*vm_idx;
+};
+
+static umode_t pvt_is_visible(const void *data, enum hwmon_sensor_types type,
+			      u32 attr, int channel)
+{
+	switch (type) {
+	case hwmon_temp:
+		if (attr == hwmon_temp_input)
+			return 0444;
+		else
+			return 0;
+	case hwmon_in:
+		if (attr == hwmon_in_input)
+			return 0444;
+		else
+			return 0;
+	default:
+		return 0;
+	}
+}
+
+static int pvt_read_temp(struct device *dev, u32 attr, int channel, long *val)
+{
+	struct pvt_device *pvt = dev_get_drvdata(dev);
+	struct regmap *t_map = pvt->t_map;
+	u32 stat, nbs;
+	int ret;
+	u64 tmp;
+
+	if (channel >= pvt->t_num)
+		return -EINVAL;
+
+	switch (attr) {
+	case hwmon_temp_input:
+		ret = regmap_read_poll_timeout(t_map, SDIF_DONE(channel),
+					       stat, stat & SDIF_SMPL_DONE,
+					       PVT_POLL_DELAY_US,
+					       PVT_POLL_TIMEOUT_US);
+		if (ret)
+			return ret;
+
+		regmap_read(t_map, SDIF_DATA(channel), &nbs);
+		nbs &= SAMPLE_DATA_MSK;
+
+		/*
+		 * Convert the register value to
+		 * degrees centigrade temperature
+		 */
+		tmp = nbs * PVT_H_CONST;
+		do_div(tmp, PVT_CAL5_CONST);
+		*val = tmp - PVT_G_CONST - pvt->ip_freq;
+
+		return 0;
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static int pvt_read_in(struct device *dev, u32 attr, int channel, long *val)
+{
+	struct pvt_device *pvt = dev_get_drvdata(dev);
+	struct regmap *v_map = pvt->v_map;
+	u32 n, stat;
+	u8 vm_idx;
+	int ret;
+
+	if (channel >= pvt->v_num)
+		return -EINVAL;
+
+	vm_idx = pvt->vm_idx[channel];
+
+	switch (attr) {
+	case hwmon_in_input:
+		ret = regmap_read_poll_timeout(v_map, VM_SDIF_DONE(vm_idx),
+					       stat, stat & SDIF_SMPL_DONE,
+					       PVT_POLL_DELAY_US,
+					       PVT_POLL_TIMEOUT_US);
+		if (ret)
+			return ret;
+
+		regmap_read(v_map, VM_SDIF_DATA(vm_idx), &n);
+		n &= SAMPLE_DATA_MSK;
+		/* Convert the N bitstream count into voltage */
+		*val = (PVT_N_CONST * n - PVT_R_CONST) >> PVT_CONV_BITS;
+
+		return 0;
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static int pvt_read(struct device *dev, enum hwmon_sensor_types type,
+		    u32 attr, int channel, long *val)
+{
+	switch (type) {
+	case hwmon_temp:
+		return pvt_read_temp(dev, attr, channel, val);
+	case hwmon_in:
+		return pvt_read_in(dev, attr, channel, val);
+	default:
+		return -EOPNOTSUPP;
+	}
+}
+
+static const u32 pvt_chip_config[] = {
+	HWMON_C_REGISTER_TZ,
+	0
+};
+
+static const struct hwmon_channel_info pvt_chip = {
+	.type = hwmon_chip,
+	.config = pvt_chip_config,
+};
+
+static struct hwmon_channel_info pvt_temp = {
+	.type = hwmon_temp,
+};
+
+static struct hwmon_channel_info pvt_in = {
+	.type = hwmon_in,
+};
+
+static const struct hwmon_ops pvt_hwmon_ops = {
+	.is_visible = pvt_is_visible,
+	.read = pvt_read,
+};
+
+static struct hwmon_chip_info pvt_chip_info = {
+	.ops = &pvt_hwmon_ops,
+};
+
+static int pvt_init(struct pvt_device *pvt)
+{
+	u16 sys_freq, key, middle, low = 4, high = 8;
+	struct regmap *t_map = pvt->t_map;
+	struct regmap *p_map = pvt->p_map;
+	struct regmap *v_map = pvt->v_map;
+	u32 t_num = pvt->t_num;
+	u32 p_num = pvt->p_num;
+	u32 v_num = pvt->v_num;
+	u32 clk_synth, val;
+	int ret;
+
+	sys_freq = clk_get_rate(pvt->clk) / HZ_PER_MHZ;
+	while (high >= low) {
+		middle = (low + high + 1) / 2;
+		key = DIV_ROUND_CLOSEST(sys_freq, middle);
+		if (key > CLK_SYS_CYCLES_MAX) {
+			low = middle + 1;
+			continue;
+		} else if (key < CLK_SYS_CYCLES_MIN) {
+			high = middle - 1;
+			continue;
+		}
+
+		break;
+	}
+
+	/*
+	 * The system supports 'clk_sys' to 'clk_ip' frequency ratios
+	 * from 2:1 to 512:1
+	 */
+	key = clamp_val(key, CLK_SYS_CYCLES_MIN, CLK_SYS_CYCLES_MAX) - 2;
+
+	clk_synth = ((key + 1) >> 1) << CLK_SYNTH_LO_SFT |
+		    (key >> 1) << CLK_SYNTH_HI_SFT |
+		    (key >> 1) << CLK_SYNTH_HOLD_SFT | CLK_SYNTH_EN;
+
+	pvt->ip_freq = sys_freq * 100 / (key + 2);
+
+	if (t_num) {
+		regmap_write(t_map, SDIF_SMPL_CTRL, 0x0);
+		regmap_write(t_map, SDIF_HALT, 0x0);
+		regmap_write(t_map, CLK_SYNTH, clk_synth);
+		regmap_write(t_map, SDIF_DISABLE, 0x0);
+
+		ret = regmap_read_poll_timeout(t_map, SDIF_STAT,
+					       val, !(val & SDIF_BUSY),
+					       PVT_POLL_DELAY_US,
+					       PVT_POLL_TIMEOUT_US);
+		if (ret)
+			return ret;
+
+		val = CFG0_MODE_2 | CFG0_PARALLEL_OUT | CFG0_12_BIT |
+		      IP_CFG << SDIF_ADDR_SFT | SDIF_WRN_W | SDIF_PROG;
+		regmap_write(t_map, SDIF_W, val);
+
+		ret = regmap_read_poll_timeout(t_map, SDIF_STAT,
+					       val, !(val & SDIF_BUSY),
+					       PVT_POLL_DELAY_US,
+					       PVT_POLL_TIMEOUT_US);
+		if (ret)
+			return ret;
+
+		val = POWER_DELAY_CYCLE_256 | IP_TMR << SDIF_ADDR_SFT |
+			      SDIF_WRN_W | SDIF_PROG;
+		regmap_write(t_map, SDIF_W, val);
+
+		ret = regmap_read_poll_timeout(t_map, SDIF_STAT,
+					       val, !(val & SDIF_BUSY),
+					       PVT_POLL_DELAY_US,
+					       PVT_POLL_TIMEOUT_US);
+		if (ret)
+			return ret;
+
+		val = IP_RST_REL | IP_RUN_CONT | IP_AUTO |
+		      IP_CTRL << SDIF_ADDR_SFT |
+		      SDIF_WRN_W | SDIF_PROG;
+		regmap_write(t_map, SDIF_W, val);
+	}
+
+	if (p_num) {
+		regmap_write(p_map, SDIF_HALT, 0x0);
+		regmap_write(p_map, SDIF_DISABLE, BIT(p_num) - 1);
+		regmap_write(p_map, CLK_SYNTH, clk_synth);
+	}
+
+	if (v_num) {
+		regmap_write(v_map, SDIF_SMPL_CTRL, 0x0);
+		regmap_write(v_map, SDIF_HALT, 0x0);
+		regmap_write(v_map, CLK_SYNTH, clk_synth);
+		regmap_write(v_map, SDIF_DISABLE, 0x0);
+
+		ret = regmap_read_poll_timeout(v_map, SDIF_STAT,
+					       val, !(val & SDIF_BUSY),
+					       PVT_POLL_DELAY_US,
+					       PVT_POLL_TIMEOUT_US);
+		if (ret)
+			return ret;
+
+		val = CFG1_VOL_MEAS_MODE | CFG1_PARALLEL_OUT |
+		      CFG1_14_BIT | IP_CFG << SDIF_ADDR_SFT |
+		      SDIF_WRN_W | SDIF_PROG;
+		regmap_write(v_map, SDIF_W, val);
+
+		ret = regmap_read_poll_timeout(v_map, SDIF_STAT,
+					       val, !(val & SDIF_BUSY),
+					       PVT_POLL_DELAY_US,
+					       PVT_POLL_TIMEOUT_US);
+		if (ret)
+			return ret;
+
+		val = POWER_DELAY_CYCLE_64 | IP_TMR << SDIF_ADDR_SFT |
+		      SDIF_WRN_W | SDIF_PROG;
+		regmap_write(v_map, SDIF_W, val);
+
+		ret = regmap_read_poll_timeout(v_map, SDIF_STAT,
+					       val, !(val & SDIF_BUSY),
+					       PVT_POLL_DELAY_US,
+					       PVT_POLL_TIMEOUT_US);
+		if (ret)
+			return ret;
+
+		val = IP_RST_REL | IP_RUN_CONT | IP_AUTO | IP_VM_MODE |
+		      IP_CTRL << SDIF_ADDR_SFT |
+		      SDIF_WRN_W | SDIF_PROG;
+		regmap_write(v_map, SDIF_W, val);
+	}
+
+	return 0;
+}
+
+static struct regmap_config pvt_regmap_config = {
+	.reg_bits = 32,
+	.reg_stride = 4,
+	.val_bits = 32,
+};
+
+static int pvt_get_regmap(struct platform_device *pdev, char *reg_name,
+			  struct pvt_device *pvt)
+{
+	struct device *dev = &pdev->dev;
+	struct regmap **reg_map;
+	void __iomem *io_base;
+
+	if (!strcmp(reg_name, "common"))
+		reg_map = &pvt->c_map;
+	else if (!strcmp(reg_name, "ts"))
+		reg_map = &pvt->t_map;
+	else if (!strcmp(reg_name, "pd"))
+		reg_map = &pvt->p_map;
+	else if (!strcmp(reg_name, "vm"))
+		reg_map = &pvt->v_map;
+	else
+		return -EINVAL;
+
+	io_base = devm_platform_ioremap_resource_byname(pdev, reg_name);
+	if (IS_ERR(io_base))
+		return PTR_ERR(io_base);
+
+	pvt_regmap_config.name = reg_name;
+	*reg_map = devm_regmap_init_mmio(dev, io_base, &pvt_regmap_config);
+	if (IS_ERR(*reg_map)) {
+		dev_err(dev, "failed to init register map\n");
+		return PTR_ERR(*reg_map);
+	}
+
+	return 0;
+}
+
+static void pvt_clk_disable(void *data)
+{
+	struct pvt_device *pvt = data;
+
+	clk_disable_unprepare(pvt->clk);
+}
+
+static int pvt_clk_enable(struct device *dev, struct pvt_device *pvt)
+{
+	int ret;
+
+	ret = clk_prepare_enable(pvt->clk);
+	if (ret)
+		return ret;
+
+	return devm_add_action_or_reset(dev, pvt_clk_disable, pvt);
+}
+
+static void pvt_reset_control_assert(void *data)
+{
+	struct pvt_device *pvt = data;
+
+	reset_control_assert(pvt->rst);
+}
+
+static int pvt_reset_control_deassert(struct device *dev, struct pvt_device *pvt)
+{
+	int ret;
+
+	ret = reset_control_deassert(pvt->rst);
+	if (ret)
+		return ret;
+
+	return devm_add_action_or_reset(dev, pvt_reset_control_assert, pvt);
+}
+
+static int mr75203_probe(struct platform_device *pdev)
+{
+	const struct hwmon_channel_info **pvt_info;
+	u32 ts_num, vm_num, pd_num, val, index, i;
+	struct device *dev = &pdev->dev;
+	u32 *temp_config, *in_config;
+	struct device *hwmon_dev;
+	struct pvt_device *pvt;
+	int ret;
+
+	pvt = devm_kzalloc(dev, sizeof(*pvt), GFP_KERNEL);
+	if (!pvt)
+		return -ENOMEM;
+
+	ret = pvt_get_regmap(pdev, "common", pvt);
+	if (ret)
+		return ret;
+
+	pvt->clk = devm_clk_get(dev, NULL);
+	if (IS_ERR(pvt->clk))
+		return dev_err_probe(dev, PTR_ERR(pvt->clk), "failed to get clock\n");
+
+	ret = pvt_clk_enable(dev, pvt);
+	if (ret) {
+		dev_err(dev, "failed to enable clock\n");
+		return ret;
+	}
+
+	pvt->rst = devm_reset_control_get_exclusive(dev, NULL);
+	if (IS_ERR(pvt->rst))
+		return dev_err_probe(dev, PTR_ERR(pvt->rst),
+				     "failed to get reset control\n");
+
+	ret = pvt_reset_control_deassert(dev, pvt);
+	if (ret)
+		return dev_err_probe(dev, ret, "cannot deassert reset control\n");
+
+	regmap_read(pvt->c_map, PVT_IP_CONFIG, &val);
+	ts_num = (val & TS_NUM_MSK) >> TS_NUM_SFT;
+	pd_num = (val & PD_NUM_MSK) >> PD_NUM_SFT;
+	vm_num = (val & VM_NUM_MSK) >> VM_NUM_SFT;
+	pvt->t_num = ts_num;
+	pvt->p_num = pd_num;
+	pvt->v_num = vm_num;
+	val = 0;
+	if (ts_num)
+		val++;
+	if (vm_num)
+		val++;
+	if (!val)
+		return -ENODEV;
+
+	pvt_info = devm_kcalloc(dev, val + 2, sizeof(*pvt_info), GFP_KERNEL);
+	if (!pvt_info)
+		return -ENOMEM;
+	pvt_info[0] = &pvt_chip;
+	index = 1;
+
+	if (ts_num) {
+		ret = pvt_get_regmap(pdev, "ts", pvt);
+		if (ret)
+			return ret;
+
+		temp_config = devm_kcalloc(dev, ts_num + 1,
+					   sizeof(*temp_config), GFP_KERNEL);
+		if (!temp_config)
+			return -ENOMEM;
+
+		for (i = 0; i < ts_num; i++)
+			temp_config[i] = HWMON_T_INPUT;
+
+		temp_config[ts_num] = 0;
+		pvt_temp.config = temp_config;
+
+		pvt_info[index++] = &pvt_temp;
+	}
+
+	if (pd_num) {
+		ret = pvt_get_regmap(pdev, "pd", pvt);
+		if (ret)
+			return ret;
+	}
+
+	if (vm_num) {
+		u32 num = vm_num;
+
+		ret = pvt_get_regmap(pdev, "vm", pvt);
+		if (ret)
+			return ret;
+
+		pvt->vm_idx = devm_kcalloc(dev, vm_num, sizeof(*pvt->vm_idx),
+					   GFP_KERNEL);
+		if (!pvt->vm_idx)
+			return -ENOMEM;
+
+		for (i = 0; i < vm_num; i++)
+			pvt->vm_idx[i] = i;
+
+		ret = device_property_read_u8_array(dev, "intel,vm-map",
+						    pvt->vm_idx, vm_num);
+		if (!ret)
+			for (i = 0; i < vm_num; i++)
+				if (pvt->vm_idx[i] >= vm_num ||
+				    pvt->vm_idx[i] == 0xff) {
+					num = i;
+					break;
+				}
+
+		in_config = devm_kcalloc(dev, num + 1,
+					 sizeof(*in_config), GFP_KERNEL);
+		if (!in_config)
+			return -ENOMEM;
+
+		memset32(in_config, HWMON_I_INPUT, num);
+		in_config[num] = 0;
+		pvt_in.config = in_config;
+
+		pvt_info[index++] = &pvt_in;
+	}
+
+	ret = pvt_init(pvt);
+	if (ret) {
+		dev_err(dev, "failed to init pvt: %d\n", ret);
+		return ret;
+	}
+
+	pvt_chip_info.info = pvt_info;
+	hwmon_dev = devm_hwmon_device_register_with_info(dev, "pvt",
+							 pvt,
+							 &pvt_chip_info,
+							 NULL);
+
+	return PTR_ERR_OR_ZERO(hwmon_dev);
+}
+
+static const struct of_device_id moortec_pvt_of_match[] = {
+	{ .compatible = "moortec,mr75203" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, moortec_pvt_of_match);
+
+static struct platform_driver moortec_pvt_driver = {
+	.driver = {
+		.name = "moortec-pvt",
+		.of_match_table = moortec_pvt_of_match,
+	},
+	.probe = mr75203_probe,
+};
+module_platform_driver(moortec_pvt_driver);
+
+MODULE_LICENSE("GPL v2");
-- 
2.11.0