Merge changes I2d63105d,Idcfdcdb9 into msm-next

QTI Global Distributed Switch Controller (GDSC) Regulator Driver

The GDSC driver, implemented under the regulator framework, is responsible for

safely collapsing and restoring power to peripheral and multimedia cores on

chipsets like SDM845 for power savings.

Required properties:

 - compatible:      Must be "qcom,gdsc"

 - regulator-name:  A string used as a descriptive name for regulator outputs

 - reg:             The address of the GDSCR register

Optional properties:

 - parent-supply:   phandle to the parent supply/regulator node

 - clock-names:     List of string names for core clocks

 - qcom,retain-mem:  Presence denotes a hardware requirement to leave the

		     forced core memory retention signals in the core's clock

		     branch control registers asserted.

 - qcom,retain-periph: Presence denotes a hardware requirement to leave the

		     forced periph memory retention signal in the core's clock

		     branch control registers asserted.

 - qcom,skip-logic-collapse: Presence denotes a requirement to leave power to

                             the core's logic enabled.

 - qcom,support-hw-trigger: Presence denotes a hardware feature to switch

			    on/off this regulator based on internal HW signals

			    to save more power.

 - qcom,enable-root-clk: Presence denotes that the clocks in the "clocks"

			property are required to be enabled before gdsc is

			turned on and disabled before turning off gdsc. This

			will be used in subsystems where reset is synchronous

			and root clk is active without sw being aware of its

			state. The clock-name which denotes the root clock

			should be named as "core_root_clk".

 - qcom,force-enable-root-clk: If set, denotes that the root clock should be

			force enabled before turning on the GDSC and then be

			immediately force disabled. Likewise for GDSC disable.

			This is used in cases where the core root clock needs

			to be force-enabled prior to turning on the core. The

			clock-name which denotes the root clock should be

			"core_root_clk".

 - qcom,clk-dis-wait-val: Input value for CLK_DIS_WAIT controls state transition

			 delay after halting clock in the collapsible core.

 - reg-names:		Names of the bases for the above "reg" registers.

			Ex. "base", "domain-addr", "sw-reset", "hw-ctrl-addr".

 - qcom,no-status-check-on-disable: Do not poll the status bit when GDSC

			is disabled.

 - qcom,disallow-clear: Presence denotes the periph & core memory will not be

			cleared, unless the required subsystem does not invoke

			the api which will allow clearing the bits.

 - qcom,gds-timeout:	Maximum time (in usecs) that might be taken by a GDSC

			to enable.

 - qcom,reset-aon-logic: If present, the GPU DEMET cells need to be reset while

			 enabling the GX GDSC.

 - resets: reset specifier pair consisting of phandle for the reset controller

			and reset lines used by this controller. These can be

			supplied only if we support qcom,skip-logic-collapse.

 - reset-names: reset signal name strings sorted in the same order as the resets

			property. These can be supplied only if we support

			qcom,skip-logic-collapse.

Example:

	gdsc_oxili_gx: qcom,gdsc@fd8c4024 {

		compatible = "qcom,gdsc";

		regulator-name = "gdsc_oxili_gx";

		parent-supply = <&pm8841_s4>;

		reg = <0xfd8c4024 0x4>;

		clock-names = "core_clk";

	};

clk-qcom-y += clk-regmap-mux.o

clk-qcom-y += reset.o

clk-qcom-y += clk-dummy.o

clk-qcom-y += gdsc-regulator.o

clk-qcom-$(CONFIG_QCOM_GDSC) += gdsc.o

# Keep alphabetically sorted by config

#include <linux/export.h>

#include <linux/clk-provider.h>

#include <linux/regmap.h>

#include <linux/clk/qcom.h>

#include "clk-branch.h"

#define to_clk_branch(_hw) \

	container_of(to_clk_regmap(_hw), struct clk_branch, clkr)

enum branch_mem_flags {

	CLKFLAG_RETAIN_PERIPH,

	CLKFLAG_NORETAIN_PERIPH,

	CLKFLAG_RETAIN_MEM,

	CLKFLAG_NORETAIN_MEM,

	CLKFLAG_PERIPH_OFF_SET,

	CLKFLAG_PERIPH_OFF_CLEAR,

};

#endif

/*

 * Copyright (c) 2017, The Linux Foundation. All rights reserved.

 *

 * This program is free software; you can redistribute it and/or modify

 * it under the terms of the GNU General Public License version 2 and

 * only version 2 as published by the Free Software Foundation.

 *

 * This program is distributed in the hope that it will be useful,

 * but WITHOUT ANY WARRANTY; without even the implied warranty of

 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

 * GNU General Public License for more details.

 */

#include <linux/kernel.h>

#include <linux/module.h>

#include <linux/io.h>

#include <linux/delay.h>

#include <linux/err.h>

#include <linux/of.h>

#include <linux/platform_device.h>

#include <linux/regulator/driver.h>

#include <linux/regulator/machine.h>

#include <linux/regulator/of_regulator.h>

#include <linux/slab.h>

#include <linux/clk.h>

#include <linux/regmap.h>

#include <linux/reset.h>

#include <linux/mfd/syscon.h>

#include <linux/clk/qcom.h>

/* GDSCR */

#define PWR_ON_MASK		BIT(31)

#define CLK_DIS_WAIT_MASK	(0xF << 12)

#define CLK_DIS_WAIT_SHIFT	(12)

#define SW_OVERRIDE_MASK	BIT(2)

#define HW_CONTROL_MASK		BIT(1)

#define SW_COLLAPSE_MASK	BIT(0)

/* Domain Address */

#define GMEM_CLAMP_IO_MASK	BIT(0)

#define GMEM_RESET_MASK         BIT(4)

/* SW Reset */

#define BCR_BLK_ARES_BIT	BIT(0)

/* Register Offset */

#define REG_OFFSET		0x0

/* Timeout Delay */

#define TIMEOUT_US		100

struct gdsc {

	struct regulator_dev	*rdev;

	struct regulator_desc	rdesc;

	void __iomem		*gdscr;

	struct regmap           *regmap;

	struct regmap           *domain_addr;

	struct regmap           *hw_ctrl;

	struct regmap           *sw_reset;

	struct clk		**clocks;

	struct reset_control	**reset_clocks;

	bool			toggle_mem;

	bool			toggle_periph;

	bool			toggle_logic;

	bool			resets_asserted;

	bool			root_en;

	bool			force_root_en;

	bool			no_status_check_on_disable;

	bool			is_gdsc_enabled;

	bool			allow_clear;

	bool			reset_aon;

	int			clock_count;

	int			reset_count;

	int			root_clk_idx;

	u32			gds_timeout;

};

enum gdscr_status {

	ENABLED,

	DISABLED,

};

static DEFINE_MUTEX(gdsc_seq_lock);

static inline u32 gdsc_mb(struct gdsc *gds)

{

	u32 reg;

	regmap_read(gds->regmap, REG_OFFSET, &reg);

	return reg;

}

void gdsc_allow_clear_retention(struct regulator *regulator)

{

	struct gdsc *sc = regulator_get_drvdata(regulator);

	if (sc)

		sc->allow_clear = true;

}

static int poll_gdsc_status(struct gdsc *sc, enum gdscr_status status)

{

	struct regmap *regmap;

	int count = sc->gds_timeout;

	u32 val;

	if (sc->hw_ctrl)

		regmap = sc->hw_ctrl;

	else

		regmap = sc->regmap;

	for (; count > 0; count--) {

		regmap_read(regmap, REG_OFFSET, &val);

		val &= PWR_ON_MASK;

		switch (status) {

		case ENABLED:

			if (val)

				return 0;

			break;

		case DISABLED:

			if (!val)

				return 0;

			break;

		}

		/*

		 * There is no guarantee about the delay needed for the enable

		 * bit in the GDSCR to be set or reset after the GDSC state

		 * changes. Hence, keep on checking for a reasonable number

		 * of times until the bit is set with the least possible delay

		 * between succeessive tries.

		 */

		udelay(1);

	}

	return -ETIMEDOUT;

}

static int gdsc_is_enabled(struct regulator_dev *rdev)

{

	struct gdsc *sc = rdev_get_drvdata(rdev);

	uint32_t regval;

	if (!sc->toggle_logic)

		return !sc->resets_asserted;

	regmap_read(sc->regmap, REG_OFFSET, &regval);

	if (regval & PWR_ON_MASK) {

		/*

		 * The GDSC might be turned on due to TZ/HYP vote on the

		 * votable GDS registers. Check the SW_COLLAPSE_MASK to

		 * determine if HLOS has voted for it.

		 */

		if (!(regval & SW_COLLAPSE_MASK))

			return true;

	}

	return false;

}

static int gdsc_enable(struct regulator_dev *rdev)

{

	struct gdsc *sc = rdev_get_drvdata(rdev);

	uint32_t regval, hw_ctrl_regval = 0x0;

	int i, ret = 0;

	mutex_lock(&gdsc_seq_lock);

	if (sc->root_en || sc->force_root_en)

		clk_prepare_enable(sc->clocks[sc->root_clk_idx]);

	regmap_read(sc->regmap, REG_OFFSET, &regval);

	if (regval & HW_CONTROL_MASK) {

		dev_warn(&rdev->dev, "Invalid enable while %s is under HW control\n",

				sc->rdesc.name);

		mutex_unlock(&gdsc_seq_lock);

		return -EBUSY;

	}

	if (sc->toggle_logic) {

		if (sc->sw_reset) {

			regmap_read(sc->sw_reset, REG_OFFSET, &regval);

			regval |= BCR_BLK_ARES_BIT;

			regmap_write(sc->sw_reset, REG_OFFSET, regval);

			/*

			 * BLK_ARES should be kept asserted for 1us before

			 * being de-asserted.

			 */

			gdsc_mb(sc);

			udelay(1);

			regval &= ~BCR_BLK_ARES_BIT;

			regmap_write(sc->sw_reset, REG_OFFSET, regval);

			/* Make sure de-assert goes through before continuing */

			gdsc_mb(sc);

		}

		if (sc->domain_addr) {

			if (sc->reset_aon) {

				regmap_read(sc->domain_addr, REG_OFFSET,

								&regval);

				regval |= GMEM_RESET_MASK;

				regmap_write(sc->domain_addr, REG_OFFSET,

								regval);

				/*

				 * Keep reset asserted for at-least 1us before

				 * continuing.

				 */

				gdsc_mb(sc);

				udelay(1);

				regval &= ~GMEM_RESET_MASK;

				regmap_write(sc->domain_addr, REG_OFFSET,

							regval);

				/*

				 * Make sure GMEM_RESET is de-asserted before

				 * continuing.

				 */

				gdsc_mb(sc);

			}

			regmap_read(sc->domain_addr, REG_OFFSET, &regval);

			regval &= ~GMEM_CLAMP_IO_MASK;

			regmap_write(sc->domain_addr, REG_OFFSET, regval);

			/*

			 * Make sure CLAMP_IO is de-asserted before continuing.

			 */

			gdsc_mb(sc);

		}

		regmap_read(sc->regmap, REG_OFFSET, &regval);

		regval &= ~SW_COLLAPSE_MASK;

		regmap_write(sc->regmap, REG_OFFSET, regval);

		/* Wait for 8 XO cycles before polling the status bit. */

		gdsc_mb(sc);

		udelay(1);

		ret = poll_gdsc_status(sc, ENABLED);

		if (ret) {

			regmap_read(sc->regmap, REG_OFFSET, &regval);

			if (sc->hw_ctrl) {

				regmap_read(sc->hw_ctrl, REG_OFFSET,

						&hw_ctrl_regval);

				dev_warn(&rdev->dev, "%s state (after %d us timeout): 0x%x, GDS_HW_CTRL: 0x%x. Re-polling.\n",

					sc->rdesc.name, sc->gds_timeout,

					regval, hw_ctrl_regval);

				ret = poll_gdsc_status(sc, ENABLED);

				if (ret) {

					regmap_read(sc->regmap, REG_OFFSET,

								&regval);

					regmap_read(sc->hw_ctrl, REG_OFFSET,

							&hw_ctrl_regval);

					dev_err(&rdev->dev, "%s final state (after additional %d us timeout): 0x%x, GDS_HW_CTRL: 0x%x\n",

						sc->rdesc.name, sc->gds_timeout,

						regval, hw_ctrl_regval);

					mutex_unlock(&gdsc_seq_lock);

					return ret;

				}

			} else {

				dev_err(&rdev->dev, "%s enable timed out: 0x%x\n",

					sc->rdesc.name,

					regval);

				udelay(sc->gds_timeout);

				regmap_read(sc->regmap, REG_OFFSET, &regval);

				dev_err(&rdev->dev, "%s final state: 0x%x (%d us after timeout)\n",

					sc->rdesc.name, regval,

					sc->gds_timeout);

				mutex_unlock(&gdsc_seq_lock);

				return ret;

			}

		}

	} else {

		for (i = 0; i < sc->reset_count; i++)

			reset_control_deassert(sc->reset_clocks[i]);

		sc->resets_asserted = false;

	}

	for (i = 0; i < sc->clock_count; i++) {

		if (unlikely(i == sc->root_clk_idx))

			continue;

		if (sc->toggle_mem)

			clk_set_flags(sc->clocks[i], CLKFLAG_RETAIN_MEM);

		if (sc->toggle_periph)

			clk_set_flags(sc->clocks[i], CLKFLAG_RETAIN_PERIPH);

	}

	/*

	 * If clocks to this power domain were already on, they will take an

	 * additional 4 clock cycles to re-enable after the rail is enabled.

	 * Delay to account for this. A delay is also needed to ensure clocks

	 * are not enabled within 400ns of enabling power to the memories.

	 */

	udelay(1);

	/* Delay to account for staggered memory powerup. */

	udelay(1);

	if (sc->force_root_en)

		clk_disable_unprepare(sc->clocks[sc->root_clk_idx]);

	sc->is_gdsc_enabled = true;

	mutex_unlock(&gdsc_seq_lock);

	return ret;

}

static int gdsc_disable(struct regulator_dev *rdev)

{

	struct gdsc *sc = rdev_get_drvdata(rdev);

	uint32_t regval;

	int i, ret = 0;

	mutex_lock(&gdsc_seq_lock);

	if (sc->force_root_en)

		clk_prepare_enable(sc->clocks[sc->root_clk_idx]);

	for (i = sc->clock_count - 1; i >= 0; i--) {

		if (unlikely(i == sc->root_clk_idx))

			continue;

		if (sc->toggle_mem && sc->allow_clear)

			clk_set_flags(sc->clocks[i], CLKFLAG_NORETAIN_MEM);

		if (sc->toggle_periph && sc->allow_clear)

			clk_set_flags(sc->clocks[i], CLKFLAG_NORETAIN_PERIPH);

	}

	/* Delay to account for staggered memory powerdown. */

	udelay(1);

	if (sc->toggle_logic) {

		regmap_read(sc->regmap, REG_OFFSET, &regval);

		regval |= SW_COLLAPSE_MASK;

		regmap_write(sc->regmap, REG_OFFSET, regval);

		/* Wait for 8 XO cycles before polling the status bit. */

		gdsc_mb(sc);

		udelay(1);

		if (sc->no_status_check_on_disable) {

			/*

			 * Add a short delay here to ensure that gdsc_enable

			 * right after it was disabled does not put it in a

			 * weird state.

			 */

			udelay(TIMEOUT_US);

		} else {

			ret = poll_gdsc_status(sc, DISABLED);

			if (ret)

				dev_err(&rdev->dev, "%s disable timed out: 0x%x\n",

					sc->rdesc.name, regval);

		}

		if (sc->domain_addr) {

			regmap_read(sc->domain_addr, REG_OFFSET, &regval);

			regval |= GMEM_CLAMP_IO_MASK;

			regmap_write(sc->domain_addr, REG_OFFSET, regval);

		}

	} else {

		for (i = sc->reset_count - 1; i >= 0; i--)

			reset_control_assert(sc->reset_clocks[i]);

		sc->resets_asserted = true;

	}

	/*

	 * Check if gdsc_enable was called for this GDSC. If not, the root

	 * clock will not have been enabled prior to this.

	 */

	if ((sc->is_gdsc_enabled && sc->root_en) || sc->force_root_en)

		clk_disable_unprepare(sc->clocks[sc->root_clk_idx]);

	sc->is_gdsc_enabled = false;

	mutex_unlock(&gdsc_seq_lock);

	return ret;

}

static unsigned int gdsc_get_mode(struct regulator_dev *rdev)

{

	struct gdsc *sc = rdev_get_drvdata(rdev);

	uint32_t regval;

	mutex_lock(&gdsc_seq_lock);

	regmap_read(sc->regmap, REG_OFFSET, &regval);

	mutex_unlock(&gdsc_seq_lock);

	if (regval & HW_CONTROL_MASK)

		return REGULATOR_MODE_FAST;

	return REGULATOR_MODE_NORMAL;

}

static int gdsc_set_mode(struct regulator_dev *rdev, unsigned int mode)

{

	struct gdsc *sc = rdev_get_drvdata(rdev);

	uint32_t regval;

	int ret = 0;

	mutex_lock(&gdsc_seq_lock);

	regmap_read(sc->regmap, REG_OFFSET, &regval);

	switch (mode) {

	case REGULATOR_MODE_FAST:

		/* Turn on HW trigger mode */

		regval |= HW_CONTROL_MASK;

		regmap_write(sc->regmap, REG_OFFSET, regval);

		/*

		 * There may be a race with internal HW trigger signal,

		 * that will result in GDSC going through a power down and

		 * up cycle.  In case HW trigger signal is controlled by

		 * firmware that also poll same status bits as we do, FW

		 * might read an 'on' status before the GDSC can finish

		 * power cycle.  We wait 1us before returning to ensure

		 * FW can't immediately poll the status bit.

		 */

		gdsc_mb(sc);

		udelay(1);

		break;

	case REGULATOR_MODE_NORMAL:

		/* Turn off HW trigger mode */

		regval &= ~HW_CONTROL_MASK;

		regmap_write(sc->regmap, REG_OFFSET, regval);

		/*

		 * There may be a race with internal HW trigger signal,

		 * that will result in GDSC going through a power down and

		 * up cycle.  If we poll too early, status bit will

		 * indicate 'on' before the GDSC can finish the power cycle.

		 * Account for this case by waiting 1us before polling.

		 */

		gdsc_mb(sc);

		udelay(1);

		ret = poll_gdsc_status(sc, ENABLED);

		if (ret)

			dev_err(&rdev->dev, "%s set_mode timed out: 0x%x\n",

				sc->rdesc.name, regval);

		break;

	default:

		ret = -EINVAL;

		break;

	}

	mutex_unlock(&gdsc_seq_lock);

	return ret;

}

static struct regulator_ops gdsc_ops = {

	.is_enabled = gdsc_is_enabled,

	.enable = gdsc_enable,

	.disable = gdsc_disable,

	.set_mode = gdsc_set_mode,

	.get_mode = gdsc_get_mode,

};

static const struct regmap_config gdsc_regmap_config = {

	.reg_bits   = 32,

	.reg_stride = 4,

	.val_bits   = 32,

	.fast_io    = true,

};

static int gdsc_probe(struct platform_device *pdev)

{

	static atomic_t gdsc_count = ATOMIC_INIT(-1);

	struct regulator_config reg_config = {};

	struct regulator_init_data *init_data;

	struct resource *res;

	struct gdsc *sc;

	uint32_t regval, clk_dis_wait_val = 0;

	bool retain_mem, retain_periph, support_hw_trigger;

	int i, ret;

	u32 timeout;

	sc = devm_kzalloc(&pdev->dev, sizeof(struct gdsc), GFP_KERNEL);

	if (sc == NULL)

		return -ENOMEM;

	init_data = of_get_regulator_init_data(&pdev->dev, pdev->dev.of_node,

								&sc->rdesc);

	if (init_data == NULL)

		return -ENOMEM;

	if (of_get_property(pdev->dev.of_node, "parent-supply", NULL))

		init_data->supply_regulator = "parent";

	ret = of_property_read_string(pdev->dev.of_node, "regulator-name",

							&sc->rdesc.name);

	if (ret)

		return ret;

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);

	if (res == NULL) {

		dev_err(&pdev->dev, "Failed to get resources\n");

		return -EINVAL;

	}

	sc->gdscr = devm_ioremap(&pdev->dev, res->start, resource_size(res));

	if (sc->gdscr == NULL)

		return -ENOMEM;

	sc->regmap = devm_regmap_init_mmio(&pdev->dev, sc->gdscr,

							&gdsc_regmap_config);

	if (!sc->regmap) {

		dev_err(&pdev->dev, "Couldn't get regmap\n");

		return -EINVAL;

	}

	if (of_find_property(pdev->dev.of_node, "domain-addr", NULL)) {

		sc->domain_addr = syscon_regmap_lookup_by_phandle

					(pdev->dev.of_node, "domain-addr");

		if (IS_ERR(sc->domain_addr))

			return -ENODEV;

	}

	if (of_find_property(pdev->dev.of_node, "sw-reset", NULL)) {

		sc->sw_reset = syscon_regmap_lookup_by_phandle

						(pdev->dev.of_node, "sw-reset");

		if (IS_ERR(sc->sw_reset))

			return -ENODEV;

	}

	if (of_find_property(pdev->dev.of_node, "hw-ctrl-addr", NULL)) {

		sc->hw_ctrl = syscon_regmap_lookup_by_phandle(

					pdev->dev.of_node, "hw-ctrl-addr");

		if (IS_ERR(sc->hw_ctrl))

			return -ENODEV;

	}

	sc->gds_timeout = TIMEOUT_US;

	ret = of_property_read_u32(pdev->dev.of_node, "qcom,gds-timeout",

							&timeout);

	if (!ret)

		sc->gds_timeout = timeout;

	sc->clock_count = of_property_count_strings(pdev->dev.of_node,

					    "clock-names");

	if (sc->clock_count == -EINVAL) {

		sc->clock_count = 0;

	} else if (sc->clock_count < 0) {

		dev_err(&pdev->dev, "Failed to get clock names\n");

		return -EINVAL;

	}

	sc->clocks = devm_kzalloc(&pdev->dev,

			sizeof(struct clk *) * sc->clock_count, GFP_KERNEL);

	if (!sc->clocks)

		return -ENOMEM;

	sc->root_clk_idx = -1;

	sc->root_en = of_property_read_bool(pdev->dev.of_node,

						"qcom,enable-root-clk");

	sc->force_root_en = of_property_read_bool(pdev->dev.of_node,

						"qcom,force-enable-root-clk");

	for (i = 0; i < sc->clock_count; i++) {

		const char *clock_name;

		of_property_read_string_index(pdev->dev.of_node, "clock-names",

				i, &clock_name);

		sc->clocks[i] = devm_clk_get(&pdev->dev, clock_name);

		if (IS_ERR(sc->clocks[i])) {

			int rc = PTR_ERR(sc->clocks[i]);

			if (rc != -EPROBE_DEFER)

				dev_err(&pdev->dev, "Failed to get %s\n",

					clock_name);

			return rc;

		}

		if (!strcmp(clock_name, "core_root_clk"))

			sc->root_clk_idx = i;

	}

	if ((sc->root_en || sc->force_root_en) && (sc->root_clk_idx == -1)) {

		dev_err(&pdev->dev, "Failed to get root clock name\n");

		return -EINVAL;

	}

	sc->reset_aon = of_property_read_bool(pdev->dev.of_node,

							"qcom,reset-aon-logic");

	sc->rdesc.id = atomic_inc_return(&gdsc_count);

	sc->rdesc.ops = &gdsc_ops;

	sc->rdesc.type = REGULATOR_VOLTAGE;

	sc->rdesc.owner = THIS_MODULE;

	platform_set_drvdata(pdev, sc);

	/*

	 * Disable HW trigger: collapse/restore occur based on registers writes.

	 * Disable SW override: Use hardware state-machine for sequencing.

	 */

	regmap_read(sc->regmap, REG_OFFSET, &regval);

	regval &= ~(HW_CONTROL_MASK | SW_OVERRIDE_MASK);

	if (!of_property_read_u32(pdev->dev.of_node, "qcom,clk-dis-wait-val",

				  &clk_dis_wait_val)) {

		clk_dis_wait_val = clk_dis_wait_val << CLK_DIS_WAIT_SHIFT;

		/* Configure wait time between states. */

		regval &= ~(CLK_DIS_WAIT_MASK);

		regval |= clk_dis_wait_val;

	}

	regmap_write(sc->regmap, REG_OFFSET, regval);

	sc->no_status_check_on_disable =

			of_property_read_bool(pdev->dev.of_node,

					"qcom,no-status-check-on-disable");

	retain_mem = of_property_read_bool(pdev->dev.of_node,

					    "qcom,retain-mem");