Merge "NFC: Add support for LDO voting" (78f3b94f) · Commits · e / devices / android_kernel_oneplus_sm7250

drivers/nfc/nq-nci.c

+166 −2

Original line number	Diff line number	Diff line
		// SPDX-License-Identifier: GPL-2.0-only
		/*
		* Copyright (c) 2015-2019, The Linux Foundation. All rights reserved.
		* Copyright (c) 2015-2020, The Linux Foundation. All rights reserved.
		*/

		#include <linux/kernel.h>
		@@ -22,6 +22,7 @@
		#include <linux/compat.h>
		#endif
		#include <linux/jiffies.h>
		#include <linux/regulator/consumer.h>

		struct nqx_platform_data {
		unsigned int irq_gpio;
		@@ -29,6 +30,8 @@ struct nqx_platform_data {
		unsigned int clkreq_gpio;
		unsigned int firm_gpio;
		unsigned int ese_gpio;
		int vdd_levels[2];
		int max_current;
		const char *clk_src_name;
		/* NFC_CLK pin voting state */
		bool clk_pin_voting;
		@@ -67,6 +70,8 @@ struct nqx_dev {
		/* NFC_IRQ wake-up state */
		bool irq_wake_up;
		bool cold_reset_rsp_pending;
		bool is_vreg_enabled;
		bool is_ese_session_active;
		uint8_t cold_reset_status;
		spinlock_t irq_enabled_lock;
		unsigned int count_irq;
		@@ -81,6 +86,7 @@ struct nqx_dev {
		size_t kbuflen;
		u8 *kbuf;
		struct nqx_platform_data *pdata;
		struct regulator *reg;
		};

		static int nfcc_reboot(struct notifier_block *notifier, unsigned long val,
		@@ -455,6 +461,7 @@ static int sn100_ese_pwr(struct nqx_dev *nqx_dev, unsigned long arg)
		} else {
		dev_dbg(&nqx_dev->client->dev, "en_gpio already HIGH\n");
		}
		nqx_dev->is_ese_session_active = true;
		r = 0;
		} else if (arg == ESE_POWER_OFF) {
		if (!nqx_dev->nfc_ven_enabled) {
		@@ -465,6 +472,7 @@ static int sn100_ese_pwr(struct nqx_dev *nqx_dev, unsigned long arg)
		} else {
		dev_dbg(&nqx_dev->client->dev, "keep en_gpio high as NFC is enabled\n");
		}
		nqx_dev->is_ese_session_active = false;
		r = 0;
		} else if (arg == ESE_COLD_RESET) {
		// set default value for status as failure
		@@ -618,6 +626,123 @@ static int nqx_ese_pwr(struct nqx_dev *nqx_dev, unsigned long arg)
		return r;
		}

		/**
		* nfc_ldo_vote()
		* @nqx_dev: NFC device containing regulator handle
		*
		* LDO voting based on voltage and current entries in DT
		*
		* Return: 0 on success and -ve on failure
		*/
		static int nfc_ldo_vote(struct nqx_dev *nqx_dev)
		{
		struct device *dev = &nqx_dev->client->dev;
		int ret;

		ret = regulator_set_voltage(nqx_dev->reg,
		nqx_dev->pdata->vdd_levels[0],
		nqx_dev->pdata->vdd_levels[1]);
		if (ret < 0) {
		dev_err(dev, "%s:set voltage failed\n", __func__);
		return ret;
		}

		/* pass expected current from NFC in uA */
		ret = regulator_set_load(nqx_dev->reg, nqx_dev->pdata->max_current);
		if (ret < 0) {
		dev_err(dev, "%s:set load failed\n", __func__);
		return ret;
		}

		ret = regulator_enable(nqx_dev->reg);
		if (ret < 0)
		dev_err(dev, "%s:regulator_enable failed\n", __func__);
		else
		nqx_dev->is_vreg_enabled = true;
		return ret;
		}

		/**
		* nfc_ldo_config()
		* @client: I2C client instance, containing node to read DT entry
		* @nqx_dev: NFC device containing regulator handle
		*
		* Configure LDO if entry is present in DT file otherwise
		* with success as it's optional
		*
		* Return: 0 on success and -ve on failure
		*/
		static int nfc_ldo_config(struct i2c_client client, struct nqx_dev nqx_dev)
		{
		int r;

		if (of_get_property(client->dev.of_node, NFC_LDO_SUPPLY_NAME, NULL)) {
		// Get the regulator handle
		nqx_dev->reg = regulator_get(&client->dev,
		NFC_LDO_SUPPLY_DT_NAME);
		if (IS_ERR(nqx_dev->reg)) {
		r = PTR_ERR(nqx_dev->reg);
		nqx_dev->reg = NULL;
		dev_err(&client->dev,
		"%s: regulator_get failed, ret = %d\n",
		__func__, r);
		return r;
		}
		} else {
		nqx_dev->reg = NULL;
		dev_err(&client->dev,
		"%s: regulator entry not present\n", __func__);
		// return success as it's optional to configure LDO
		return 0;
		}

		// LDO config supported by platform DT
		r = nfc_ldo_vote(nqx_dev);
		if (r < 0) {
		dev_err(&client->dev,
		"%s: LDO voting failed, ret = %d\n", __func__, r);
		regulator_put(nqx_dev->reg);
		}
		return r;
		}

		/**
		* nfc_ldo_unvote()
		* @nqx_dev: NFC device containing regulator handle
		*
		* set voltage and load to zero and disable regulator
		*
		* Return: 0 on success and -ve on failure
		*/
		static int nfc_ldo_unvote(struct nqx_dev *nqx_dev)
		{
		struct device *dev = &nqx_dev->client->dev;
		int ret;

		if (!nqx_dev->is_vreg_enabled) {
		dev_err(dev, "%s: regulator already disabled\n", __func__);
		return -EINVAL;
		}

		ret = regulator_disable(nqx_dev->reg);
		if (ret < 0) {
		dev_err(dev, "%s:regulator_disable failed\n", __func__);
		return ret;
		}
		nqx_dev->is_vreg_enabled = false;

		ret = regulator_set_voltage(nqx_dev->reg, 0, NFC_VDDIO_MAX);
		if (ret < 0) {
		dev_err(dev, "%s:set voltage failed\n", __func__);
		return ret;
		}

		ret = regulator_set_load(nqx_dev->reg, 0);
		if (ret < 0)
		dev_err(dev, "%s:set load failed\n", __func__);
		return ret;
		}

		static int nfc_open(struct inode inode, struct file filp)
		{
		struct nqx_dev *nqx_dev = container_of(inode->i_cdev,
		@@ -1219,9 +1344,29 @@ static int nfc_parse_dt(struct device dev, struct nqx_platform_data pdata)
		else
		pdata->clk_pin_voting = true;

		// optional property
		r = of_property_read_u32_array(np, NFC_LDO_VOL_DT_NAME,
		(u32 *) pdata->vdd_levels,
		ARRAY_SIZE(pdata->vdd_levels));
		if (r) {
		dev_err(dev, "error reading NFC VDDIO min and max value\n");
		// set default as per datasheet
		pdata->vdd_levels[0] = NFC_VDDIO_MIN;
		pdata->vdd_levels[1] = NFC_VDDIO_MAX;
		}

		// optional property
		r = of_property_read_u32(np, NFC_LDO_CUR_DT_NAME, &pdata->max_current);
		if (r) {
		dev_err(dev, "error reading NFC current value\n");
		// set default as per datasheet
		pdata->max_current = NFC_CURRENT_MAX;
		}

		pdata->clkreq_gpio = of_get_named_gpio(np, "qcom,nq-clkreq", 0);

		return r;
		// return success as above properties are optional
		return 0;
		}

		static inline int gpio_input_init(const struct device * const dev,
		@@ -1466,6 +1611,12 @@ static int nqx_probe(struct i2c_client *client,
		}
		nqx_disable_irq(nqx_dev);

		r = nfc_ldo_config(client, nqx_dev);
		if (r) {
		dev_err(&client->dev, "%s: LDO config failed\n", __func__);
		goto err_ldo_config_failed;
		}

		/*
		* To be efficient we need to test whether nfcc hardware is physically
		* present before attempting further hardware initialisation.
		@@ -1507,6 +1658,7 @@ static int nqx_probe(struct i2c_client *client,
		nqx_dev->irq_wake_up = false;
		nqx_dev->cold_reset_rsp_pending = false;
		nqx_dev->nfc_enabled = false;
		nqx_dev->is_ese_session_active = false;

		dev_err(&client->dev,
		"%s: probing NFCC NQxxx exited successfully\n",
		@@ -1518,6 +1670,11 @@ static int nqx_probe(struct i2c_client *client,
		unregister_reboot_notifier(&nfcc_notifier);
		#endif
		err_request_hw_check_failed:
		if (nqx_dev->reg) {
		nfc_ldo_unvote(nqx_dev);
		regulator_put(nqx_dev->reg);
		}
		err_ldo_config_failed:
		free_irq(client->irq, nqx_dev);
		err_request_irq_failed:
		device_destroy(nqx_dev->nqx_class, nqx_dev->devno);
		@@ -1568,6 +1725,13 @@ static int nqx_remove(struct i2c_client *client)
		goto err;
		}

		gpio_set_value(nqx_dev->en_gpio, 0);
		// HW dependent delay before LDO goes into LPM mode
		usleep_range(10000, 10100);
		if (nqx_dev->reg) {
		ret = nfc_ldo_unvote(nqx_dev);
		regulator_put(nqx_dev->reg);
		}
		unregister_reboot_notifier(&nfcc_notifier);
		free_irq(client->irq, nqx_dev);
		cdev_del(&nqx_dev->c_dev);

drivers/nfc/nq-nci.h

+10 −1

Original line number	Diff line number	Diff line
		/* SPDX-License-Identifier: GPL-2.0-only */
		/*
		* Copyright (c) 2015-2019, The Linux Foundation. All rights reserved.
		* Copyright (c) 2015-2020, The Linux Foundation. All rights reserved.
		*/

		#ifndef __NQ_NCI_H
		@@ -50,6 +50,15 @@
		#define PAYLOAD_LENGTH_MAX (256)
		#define BYTE (0x8)
		#define NCI_IDENTIFIER (0x10)
		#define NFC_LDO_SUPPLY_DT_NAME "qcom,nq-vdd-1p8"
		#define NFC_LDO_SUPPLY_NAME "qcom,nq-vdd-1p8-supply"
		#define NFC_LDO_VOL_DT_NAME "qcom,nq-vdd-1p8-voltage"
		#define NFC_LDO_CUR_DT_NAME "qcom,nq-vdd-1p8-current"

		//as per SN1x0 datasheet
		#define NFC_VDDIO_MIN 1650000 //in uV
		#define NFC_VDDIO_MAX 1950000 //in uV
		#define NFC_CURRENT_MAX 157000 //in uA

		enum ese_ioctl_request {
		/* eSE POWER ON */