drivers/spi/spi-sprd-adi.c - pub/scm/linux/kernel/git/horms/ipvs-next - Git at Google

 /*
  * Copyright (C) 2017 Spreadtrum Communications Inc.
  *
  * SPDX-License-Identifier: GPL-2.0
  */

 #include <linux/delay.h>
 #include <linux/hwspinlock.h>
 #include <linux/init.h>
 #include <linux/io.h>
 #include <linux/kernel.h>
 #include <linux/module.h>
 #include <linux/of.h>
 #include <linux/of_device.h>
 #include <linux/platform_device.h>
 #include <linux/reboot.h>
 #include <linux/spi/spi.h>
 #include <linux/sizes.h>

 /* Registers definitions for ADI controller */
 #define REG_ADI_CTRL0			0x4
 #define REG_ADI_CHN_PRIL		0x8
 #define REG_ADI_CHN_PRIH		0xc
 #define REG_ADI_INT_EN			0x10
 #define REG_ADI_INT_RAW			0x14
 #define REG_ADI_INT_MASK		0x18
 #define REG_ADI_INT_CLR			0x1c
 #define REG_ADI_GSSI_CFG0		0x20
 #define REG_ADI_GSSI_CFG1		0x24
 #define REG_ADI_RD_CMD			0x28
 #define REG_ADI_RD_DATA			0x2c
 #define REG_ADI_ARM_FIFO_STS		0x30
 #define REG_ADI_STS			0x34
 #define REG_ADI_EVT_FIFO_STS		0x38
 #define REG_ADI_ARM_CMD_STS		0x3c
 #define REG_ADI_CHN_EN			0x40
 #define REG_ADI_CHN_ADDR(id)		(0x44 + (id - 2) * 4)
 #define REG_ADI_CHN_EN1			0x20c

 /* Bits definitions for register REG_ADI_GSSI_CFG0 */
 #define BIT_CLK_ALL_ON			BIT(30)

 /* Bits definitions for register REG_ADI_RD_DATA */
 #define BIT_RD_CMD_BUSY			BIT(31)
 #define RD_ADDR_SHIFT			16
 #define RD_VALUE_MASK			GENMASK(15, 0)
 #define RD_ADDR_MASK			GENMASK(30, 16)

 /* Bits definitions for register REG_ADI_ARM_FIFO_STS */
 #define BIT_FIFO_FULL			BIT(11)
 #define BIT_FIFO_EMPTY			BIT(10)

 /*
  * ADI slave devices include RTC, ADC, regulator, charger, thermal and so on.
  * The slave devices address offset is always 0x8000 and size is 4K.
  */
 #define ADI_SLAVE_ADDR_SIZE		SZ_4K
 #define ADI_SLAVE_OFFSET		0x8000

 /* Timeout (ms) for the trylock of hardware spinlocks */
 #define ADI_HWSPINLOCK_TIMEOUT		5000
 /*
  * ADI controller has 50 channels including 2 software channels
  * and 48 hardware channels.
  */
 #define ADI_HW_CHNS			50

 #define ADI_FIFO_DRAIN_TIMEOUT		1000
 #define ADI_READ_TIMEOUT		2000
 #define REG_ADDR_LOW_MASK		GENMASK(11, 0)

 /* Registers definitions for PMIC watchdog controller */
 #define REG_WDG_LOAD_LOW		0x80
 #define REG_WDG_LOAD_HIGH		0x84
 #define REG_WDG_CTRL			0x88
 #define REG_WDG_LOCK			0xa0

 /* Bits definitions for register REG_WDG_CTRL */
 #define BIT_WDG_RUN			BIT(1)
 #define BIT_WDG_RST			BIT(3)

 /* Registers definitions for PMIC */
 #define PMIC_RST_STATUS			0xee8
 #define PMIC_MODULE_EN			0xc08
 #define PMIC_CLK_EN			0xc18
 #define BIT_WDG_EN			BIT(2)

 /* Definition of PMIC reset status register */
 #define HWRST_STATUS_RECOVERY		0x20
 #define HWRST_STATUS_NORMAL		0x40
 #define HWRST_STATUS_ALARM		0x50
 #define HWRST_STATUS_SLEEP		0x60
 #define HWRST_STATUS_FASTBOOT		0x30
 #define HWRST_STATUS_SPECIAL		0x70
 #define HWRST_STATUS_PANIC		0x80
 #define HWRST_STATUS_CFTREBOOT		0x90
 #define HWRST_STATUS_AUTODLOADER	0xa0
 #define HWRST_STATUS_IQMODE		0xb0
 #define HWRST_STATUS_SPRDISK		0xc0

 /* Use default timeout 50 ms that converts to watchdog values */
 #define WDG_LOAD_VAL			((50 * 1000) / 32768)
 #define WDG_LOAD_MASK			GENMASK(15, 0)
 #define WDG_UNLOCK_KEY			0xe551

 struct sprd_adi {
 	struct spi_controller	*ctlr;
 	struct device		*dev;
 	void __iomem		*base;
 	struct hwspinlock	*hwlock;
 	unsigned long		slave_vbase;
 	unsigned long		slave_pbase;
 	struct notifier_block	restart_handler;
 };

 static int sprd_adi_check_paddr(struct sprd_adi *sadi, u32 paddr)
 {
 	if (paddr < sadi->slave_pbase || paddr >
 	    (sadi->slave_pbase + ADI_SLAVE_ADDR_SIZE)) {
 		dev_err(sadi->dev,
 			"slave physical address is incorrect, addr = 0x%x\n",
 			paddr);
 		return -EINVAL;
 	}

 	return 0;
 }

 static unsigned long sprd_adi_to_vaddr(struct sprd_adi *sadi, u32 paddr)
 {
 	return (paddr - sadi->slave_pbase + sadi->slave_vbase);
 }

 static int sprd_adi_drain_fifo(struct sprd_adi *sadi)
 {
 	u32 timeout = ADI_FIFO_DRAIN_TIMEOUT;
 	u32 sts;

 	do {
 		sts = readl_relaxed(sadi->base + REG_ADI_ARM_FIFO_STS);
 		if (sts & BIT_FIFO_EMPTY)
 			break;

 		cpu_relax();
 	} while (--timeout);

 	if (timeout == 0) {
 		dev_err(sadi->dev, "drain write fifo timeout\n");
 		return -EBUSY;
 	}

 	return 0;
 }

 static int sprd_adi_fifo_is_full(struct sprd_adi *sadi)
 {
 	return readl_relaxed(sadi->base + REG_ADI_ARM_FIFO_STS) & BIT_FIFO_FULL;
 }

 static int sprd_adi_read(struct sprd_adi *sadi, u32 reg_paddr, u32 *read_val)
 {
 	int read_timeout = ADI_READ_TIMEOUT;
 	unsigned long flags;
 	u32 val, rd_addr;
 	int ret;

 	ret = hwspin_lock_timeout_irqsave(sadi->hwlock,
 					  ADI_HWSPINLOCK_TIMEOUT,
 					  &flags);
 	if (ret) {
 		dev_err(sadi->dev, "get the hw lock failed\n");
 		return ret;
 	}

 	/*
 	 * Set the physical register address need to read into RD_CMD register,
 	 * then ADI controller will start to transfer automatically.
 	 */
 	writel_relaxed(reg_paddr, sadi->base + REG_ADI_RD_CMD);

 	/*
 	 * Wait read operation complete, the BIT_RD_CMD_BUSY will be set
 	 * simultaneously when writing read command to register, and the
 	 * BIT_RD_CMD_BUSY will be cleared after the read operation is
 	 * completed.
 	 */
 	do {
 		val = readl_relaxed(sadi->base + REG_ADI_RD_DATA);
 		if (!(val & BIT_RD_CMD_BUSY))
 			break;

 		cpu_relax();
 	} while (--read_timeout);

 	if (read_timeout == 0) {
 		dev_err(sadi->dev, "ADI read timeout\n");
 		ret = -EBUSY;
 		goto out;
 	}

 	/*
 	 * The return value includes data and read register address, from bit 0
 	 * to bit 15 are data, and from bit 16 to bit 30 are read register
 	 * address. Then we can check the returned register address to validate
 	 * data.
 	 */
 	rd_addr = (val & RD_ADDR_MASK ) >> RD_ADDR_SHIFT;

 	if (rd_addr != (reg_paddr & REG_ADDR_LOW_MASK)) {
 		dev_err(sadi->dev, "read error, reg addr = 0x%x, val = 0x%x\n",
 			reg_paddr, val);
 		ret = -EIO;
 		goto out;
 	}

 	*read_val = val & RD_VALUE_MASK;

 out:
 	hwspin_unlock_irqrestore(sadi->hwlock, &flags);
 	return ret;
 }

 static int sprd_adi_write(struct sprd_adi *sadi, u32 reg_paddr, u32 val)
 {
 	unsigned long reg = sprd_adi_to_vaddr(sadi, reg_paddr);
 	u32 timeout = ADI_FIFO_DRAIN_TIMEOUT;
 	unsigned long flags;
 	int ret;

 	ret = hwspin_lock_timeout_irqsave(sadi->hwlock,
 					  ADI_HWSPINLOCK_TIMEOUT,
 					  &flags);
 	if (ret) {
 		dev_err(sadi->dev, "get the hw lock failed\n");
 		return ret;
 	}

 	ret = sprd_adi_drain_fifo(sadi);
 	if (ret < 0)
 		goto out;

 	/*
 	 * we should wait for write fifo is empty before writing data to PMIC
 	 * registers.
 	 */
 	do {
 		if (!sprd_adi_fifo_is_full(sadi)) {
 			writel_relaxed(val, (void __iomem *)reg);
 			break;
 		}

 		cpu_relax();
 	} while (--timeout);

 	if (timeout == 0) {
 		dev_err(sadi->dev, "write fifo is full\n");
 		ret = -EBUSY;
 	}

 out:
 	hwspin_unlock_irqrestore(sadi->hwlock, &flags);
 	return ret;
 }

 static int sprd_adi_transfer_one(struct spi_controller *ctlr,
 				 struct spi_device *spi_dev,
 				 struct spi_transfer *t)
 {
 	struct sprd_adi *sadi = spi_controller_get_devdata(ctlr);
 	u32 phy_reg, val;
 	int ret;

 	if (t->rx_buf) {
 		phy_reg = *(u32 *)t->rx_buf + sadi->slave_pbase;

 		ret = sprd_adi_check_paddr(sadi, phy_reg);
 		if (ret)
 			return ret;

 		ret = sprd_adi_read(sadi, phy_reg, &val);
 		if (ret)
 			return ret;

 		*(u32 *)t->rx_buf = val;
 	} else if (t->tx_buf) {
 		u32 *p = (u32 *)t->tx_buf;

 		/*
 		 * Get the physical register address need to write and convert
 		 * the physical address to virtual address. Since we need
 		 * virtual register address to write.
 		 */
 		phy_reg = *p++ + sadi->slave_pbase;
 		ret = sprd_adi_check_paddr(sadi, phy_reg);
 		if (ret)
 			return ret;

 		val = *p;
 		ret = sprd_adi_write(sadi, phy_reg, val);
 		if (ret)
 			return ret;
 	} else {
 		dev_err(sadi->dev, "no buffer for transfer\n");
 		return -EINVAL;
 	}

 	return 0;
 }

 static int sprd_adi_restart_handler(struct notifier_block *this,
 				    unsigned long mode, void *cmd)
 {
 	struct sprd_adi *sadi = container_of(this, struct sprd_adi,
 					     restart_handler);
 	u32 val, reboot_mode = 0;

 	if (!cmd)
 		reboot_mode = HWRST_STATUS_NORMAL;
 	else if (!strncmp(cmd, "recovery", 8))
 		reboot_mode = HWRST_STATUS_RECOVERY;
 	else if (!strncmp(cmd, "alarm", 5))
 		reboot_mode = HWRST_STATUS_ALARM;
 	else if (!strncmp(cmd, "fastsleep", 9))
 		reboot_mode = HWRST_STATUS_SLEEP;
 	else if (!strncmp(cmd, "bootloader", 10))
 		reboot_mode = HWRST_STATUS_FASTBOOT;
 	else if (!strncmp(cmd, "panic", 5))
 		reboot_mode = HWRST_STATUS_PANIC;
 	else if (!strncmp(cmd, "special", 7))
 		reboot_mode = HWRST_STATUS_SPECIAL;
 	else if (!strncmp(cmd, "cftreboot", 9))
 		reboot_mode = HWRST_STATUS_CFTREBOOT;
 	else if (!strncmp(cmd, "autodloader", 11))
 		reboot_mode = HWRST_STATUS_AUTODLOADER;
 	else if (!strncmp(cmd, "iqmode", 6))
 		reboot_mode = HWRST_STATUS_IQMODE;
 	else if (!strncmp(cmd, "sprdisk", 7))
 		reboot_mode = HWRST_STATUS_SPRDISK;
 	else
 		reboot_mode = HWRST_STATUS_NORMAL;

 	/* Record the reboot mode */
 	sprd_adi_read(sadi, sadi->slave_pbase + PMIC_RST_STATUS, &val);
 	val |= reboot_mode;
 	sprd_adi_write(sadi, sadi->slave_pbase + PMIC_RST_STATUS, val);

 	/* Enable the interface clock of the watchdog */
 	sprd_adi_read(sadi, sadi->slave_pbase + PMIC_MODULE_EN, &val);
 	val |= BIT_WDG_EN;
 	sprd_adi_write(sadi, sadi->slave_pbase + PMIC_MODULE_EN, val);

 	/* Enable the work clock of the watchdog */
 	sprd_adi_read(sadi, sadi->slave_pbase + PMIC_CLK_EN, &val);
 	val |= BIT_WDG_EN;
 	sprd_adi_write(sadi, sadi->slave_pbase + PMIC_CLK_EN, val);

 	/* Unlock the watchdog */
 	sprd_adi_write(sadi, sadi->slave_pbase + REG_WDG_LOCK, WDG_UNLOCK_KEY);

 	/* Load the watchdog timeout value, 50ms is always enough. */
 	sprd_adi_write(sadi, sadi->slave_pbase + REG_WDG_LOAD_LOW,
 		       WDG_LOAD_VAL & WDG_LOAD_MASK);
 	sprd_adi_write(sadi, sadi->slave_pbase + REG_WDG_LOAD_HIGH, 0);

 	/* Start the watchdog to reset system */
 	sprd_adi_read(sadi, sadi->slave_pbase + REG_WDG_CTRL, &val);
 	val |= BIT_WDG_RUN | BIT_WDG_RST;
 	sprd_adi_write(sadi, sadi->slave_pbase + REG_WDG_CTRL, val);

 	mdelay(1000);

 	dev_emerg(sadi->dev, "Unable to restart system\n");
 	return NOTIFY_DONE;
 }

 static void sprd_adi_hw_init(struct sprd_adi *sadi)
 {
 	struct device_node *np = sadi->dev->of_node;
 	int i, size, chn_cnt;
 	const __be32 *list;
 	u32 tmp;

 	/* Address bits select default 12 bits */
 	writel_relaxed(0, sadi->base + REG_ADI_CTRL0);

 	/* Set all channels as default priority */
 	writel_relaxed(0, sadi->base + REG_ADI_CHN_PRIL);
 	writel_relaxed(0, sadi->base + REG_ADI_CHN_PRIH);

 	/* Set clock auto gate mode */
 	tmp = readl_relaxed(sadi->base + REG_ADI_GSSI_CFG0);
 	tmp &= ~BIT_CLK_ALL_ON;
 	writel_relaxed(tmp, sadi->base + REG_ADI_GSSI_CFG0);

 	/* Set hardware channels setting */
 	list = of_get_property(np, "sprd,hw-channels", &size);
 	if (!list || !size) {
 		dev_info(sadi->dev, "no hw channels setting in node\n");
 		return;
 	}

 	chn_cnt = size / 8;
 	for (i = 0; i < chn_cnt; i++) {
 		u32 value;
 		u32 chn_id = be32_to_cpu(*list++);
 		u32 chn_config = be32_to_cpu(*list++);

 		/* Channel 0 and 1 are software channels */
 		if (chn_id < 2)
 			continue;

 		writel_relaxed(chn_config, sadi->base +
 			       REG_ADI_CHN_ADDR(chn_id));

 		if (chn_id < 32) {
 			value = readl_relaxed(sadi->base + REG_ADI_CHN_EN);
 			value |= BIT(chn_id);
 			writel_relaxed(value, sadi->base + REG_ADI_CHN_EN);
 		} else if (chn_id < ADI_HW_CHNS) {
 			value = readl_relaxed(sadi->base + REG_ADI_CHN_EN1);
 			value |= BIT(chn_id - 32);
 			writel_relaxed(value, sadi->base + REG_ADI_CHN_EN1);
 		}
 	}
 }

 static int sprd_adi_probe(struct platform_device *pdev)
 {
 	struct device_node *np = pdev->dev.of_node;
 	struct spi_controller *ctlr;
 	struct sprd_adi *sadi;
 	struct resource *res;
 	u32 num_chipselect;
 	int ret;

 	if (!np) {
 		dev_err(&pdev->dev, "can not find the adi bus node\n");
 		return -ENODEV;
 	}

 	pdev->id = of_alias_get_id(np, "spi");
 	num_chipselect = of_get_child_count(np);

 	ctlr = spi_alloc_master(&pdev->dev, sizeof(struct sprd_adi));
 	if (!ctlr)
 		return -ENOMEM;

 	dev_set_drvdata(&pdev->dev, ctlr);
 	sadi = spi_controller_get_devdata(ctlr);

 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	sadi->base = devm_ioremap_resource(&pdev->dev, res);
 	if (IS_ERR(sadi->base)) {
 		ret = PTR_ERR(sadi->base);
 		goto put_ctlr;
 	}

 	sadi->slave_vbase = (unsigned long)sadi->base + ADI_SLAVE_OFFSET;
 	sadi->slave_pbase = res->start + ADI_SLAVE_OFFSET;
 	sadi->ctlr = ctlr;
 	sadi->dev = &pdev->dev;
 	ret = of_hwspin_lock_get_id_byname(np, "adi");
 	if (ret < 0) {
 		dev_err(&pdev->dev, "can not get the hardware spinlock\n");
 		goto put_ctlr;
 	}

 	sadi->hwlock = devm_hwspin_lock_request_specific(&pdev->dev, ret);
 	if (!sadi->hwlock) {
 		ret = -ENXIO;
 		goto put_ctlr;
 	}

 	sprd_adi_hw_init(sadi);

 	ctlr->dev.of_node = pdev->dev.of_node;
 	ctlr->bus_num = pdev->id;
 	ctlr->num_chipselect = num_chipselect;
 	ctlr->flags = SPI_MASTER_HALF_DUPLEX;
 	ctlr->bits_per_word_mask = 0;
 	ctlr->transfer_one = sprd_adi_transfer_one;

 	ret = devm_spi_register_controller(&pdev->dev, ctlr);
 	if (ret) {
 		dev_err(&pdev->dev, "failed to register SPI controller\n");
 		goto put_ctlr;
 	}

 	sadi->restart_handler.notifier_call = sprd_adi_restart_handler;
 	sadi->restart_handler.priority = 128;
 	ret = register_restart_handler(&sadi->restart_handler);
 	if (ret) {
 		dev_err(&pdev->dev, "can not register restart handler\n");
 		goto put_ctlr;
 	}

 	return 0;

 put_ctlr:
 	spi_controller_put(ctlr);
 	return ret;
 }

 static int sprd_adi_remove(struct platform_device *pdev)
 {
 	struct spi_controller *ctlr = dev_get_drvdata(&pdev->dev);
 	struct sprd_adi *sadi = spi_controller_get_devdata(ctlr);

 	unregister_restart_handler(&sadi->restart_handler);
 	return 0;
 }

 static const struct of_device_id sprd_adi_of_match[] = {
 	{
 		.compatible = "sprd,sc9860-adi",
 	},
 	{ },
 };
 MODULE_DEVICE_TABLE(of, sprd_adi_of_match);

 static struct platform_driver sprd_adi_driver = {
 	.driver = {
 		.name = "sprd-adi",
 		.of_match_table = sprd_adi_of_match,
 	},
 	.probe = sprd_adi_probe,
 	.remove = sprd_adi_remove,
 };
 module_platform_driver(sprd_adi_driver);

 MODULE_DESCRIPTION("Spreadtrum ADI Controller Driver");
 MODULE_AUTHOR("Baolin Wang <Baolin.Wang@spreadtrum.com>");
 MODULE_LICENSE("GPL v2");
	/*
	* Copyright (C) 2017 Spreadtrum Communications Inc.
	*
	* SPDX-License-Identifier: GPL-2.0
	*/

	#include <linux/delay.h>
	#include <linux/hwspinlock.h>
	#include <linux/init.h>
	#include <linux/io.h>
	#include <linux/kernel.h>
	#include <linux/module.h>
	#include <linux/of.h>
	#include <linux/of_device.h>
	#include <linux/platform_device.h>
	#include <linux/reboot.h>
	#include <linux/spi/spi.h>
	#include <linux/sizes.h>

	/* Registers definitions for ADI controller */
	#define REG_ADI_CTRL0 0x4
	#define REG_ADI_CHN_PRIL 0x8
	#define REG_ADI_CHN_PRIH 0xc
	#define REG_ADI_INT_EN 0x10
	#define REG_ADI_INT_RAW 0x14
	#define REG_ADI_INT_MASK 0x18
	#define REG_ADI_INT_CLR 0x1c
	#define REG_ADI_GSSI_CFG0 0x20
	#define REG_ADI_GSSI_CFG1 0x24
	#define REG_ADI_RD_CMD 0x28
	#define REG_ADI_RD_DATA 0x2c
	#define REG_ADI_ARM_FIFO_STS 0x30
	#define REG_ADI_STS 0x34
	#define REG_ADI_EVT_FIFO_STS 0x38
	#define REG_ADI_ARM_CMD_STS 0x3c
	#define REG_ADI_CHN_EN 0x40
	#define REG_ADI_CHN_ADDR(id) (0x44 + (id - 2) * 4)
	#define REG_ADI_CHN_EN1 0x20c

	/* Bits definitions for register REG_ADI_GSSI_CFG0 */
	#define BIT_CLK_ALL_ON BIT(30)

	/* Bits definitions for register REG_ADI_RD_DATA */
	#define BIT_RD_CMD_BUSY BIT(31)
	#define RD_ADDR_SHIFT 16
	#define RD_VALUE_MASK GENMASK(15, 0)
	#define RD_ADDR_MASK GENMASK(30, 16)

	/* Bits definitions for register REG_ADI_ARM_FIFO_STS */
	#define BIT_FIFO_FULL BIT(11)
	#define BIT_FIFO_EMPTY BIT(10)

	/*
	* ADI slave devices include RTC, ADC, regulator, charger, thermal and so on.
	* The slave devices address offset is always 0x8000 and size is 4K.
	*/
	#define ADI_SLAVE_ADDR_SIZE SZ_4K
	#define ADI_SLAVE_OFFSET 0x8000

	/* Timeout (ms) for the trylock of hardware spinlocks */
	#define ADI_HWSPINLOCK_TIMEOUT 5000
	/*
	* ADI controller has 50 channels including 2 software channels
	* and 48 hardware channels.
	*/
	#define ADI_HW_CHNS 50

	#define ADI_FIFO_DRAIN_TIMEOUT 1000
	#define ADI_READ_TIMEOUT 2000
	#define REG_ADDR_LOW_MASK GENMASK(11, 0)

	/* Registers definitions for PMIC watchdog controller */
	#define REG_WDG_LOAD_LOW 0x80
	#define REG_WDG_LOAD_HIGH 0x84
	#define REG_WDG_CTRL 0x88
	#define REG_WDG_LOCK 0xa0

	/* Bits definitions for register REG_WDG_CTRL */
	#define BIT_WDG_RUN BIT(1)
	#define BIT_WDG_RST BIT(3)

	/* Registers definitions for PMIC */
	#define PMIC_RST_STATUS 0xee8
	#define PMIC_MODULE_EN 0xc08
	#define PMIC_CLK_EN 0xc18
	#define BIT_WDG_EN BIT(2)

	/* Definition of PMIC reset status register */
	#define HWRST_STATUS_RECOVERY 0x20
	#define HWRST_STATUS_NORMAL 0x40
	#define HWRST_STATUS_ALARM 0x50
	#define HWRST_STATUS_SLEEP 0x60
	#define HWRST_STATUS_FASTBOOT 0x30
	#define HWRST_STATUS_SPECIAL 0x70
	#define HWRST_STATUS_PANIC 0x80
	#define HWRST_STATUS_CFTREBOOT 0x90
	#define HWRST_STATUS_AUTODLOADER 0xa0
	#define HWRST_STATUS_IQMODE 0xb0
	#define HWRST_STATUS_SPRDISK 0xc0

	/* Use default timeout 50 ms that converts to watchdog values */
	#define WDG_LOAD_VAL ((50 * 1000) / 32768)
	#define WDG_LOAD_MASK GENMASK(15, 0)
	#define WDG_UNLOCK_KEY 0xe551

	struct sprd_adi {
	struct spi_controller *ctlr;
	struct device *dev;
	void __iomem *base;
	struct hwspinlock *hwlock;
	unsigned long slave_vbase;
	unsigned long slave_pbase;
	struct notifier_block restart_handler;
	};

	static int sprd_adi_check_paddr(struct sprd_adi *sadi, u32 paddr)
	{
	if (paddr < sadi->slave_pbase \|\| paddr >
	(sadi->slave_pbase + ADI_SLAVE_ADDR_SIZE)) {
	dev_err(sadi->dev,
	"slave physical address is incorrect, addr = 0x%x\n",
	paddr);
	return -EINVAL;
	}

	return 0;
	}

	static unsigned long sprd_adi_to_vaddr(struct sprd_adi *sadi, u32 paddr)
	{
	return (paddr - sadi->slave_pbase + sadi->slave_vbase);
	}

	static int sprd_adi_drain_fifo(struct sprd_adi *sadi)
	{
	u32 timeout = ADI_FIFO_DRAIN_TIMEOUT;
	u32 sts;

	do {
	sts = readl_relaxed(sadi->base + REG_ADI_ARM_FIFO_STS);
	if (sts & BIT_FIFO_EMPTY)
	break;

	cpu_relax();
	} while (--timeout);

	if (timeout == 0) {
	dev_err(sadi->dev, "drain write fifo timeout\n");
	return -EBUSY;
	}

	return 0;
	}

	static int sprd_adi_fifo_is_full(struct sprd_adi *sadi)
	{
	return readl_relaxed(sadi->base + REG_ADI_ARM_FIFO_STS) & BIT_FIFO_FULL;
	}

	static int sprd_adi_read(struct sprd_adi sadi, u32 reg_paddr, u32 read_val)
	{
	int read_timeout = ADI_READ_TIMEOUT;
	unsigned long flags;
	u32 val, rd_addr;
	int ret;

	ret = hwspin_lock_timeout_irqsave(sadi->hwlock,
	ADI_HWSPINLOCK_TIMEOUT,
	&flags);
	if (ret) {
	dev_err(sadi->dev, "get the hw lock failed\n");
	return ret;
	}

	/*
	* Set the physical register address need to read into RD_CMD register,
	* then ADI controller will start to transfer automatically.
	*/
	writel_relaxed(reg_paddr, sadi->base + REG_ADI_RD_CMD);

	/*
	* Wait read operation complete, the BIT_RD_CMD_BUSY will be set
	* simultaneously when writing read command to register, and the
	* BIT_RD_CMD_BUSY will be cleared after the read operation is
	* completed.
	*/
	do {
	val = readl_relaxed(sadi->base + REG_ADI_RD_DATA);
	if (!(val & BIT_RD_CMD_BUSY))
	break;

	cpu_relax();
	} while (--read_timeout);

	if (read_timeout == 0) {
	dev_err(sadi->dev, "ADI read timeout\n");
	ret = -EBUSY;
	goto out;
	}

	/*
	* The return value includes data and read register address, from bit 0
	* to bit 15 are data, and from bit 16 to bit 30 are read register
	* address. Then we can check the returned register address to validate
	* data.
	*/
	rd_addr = (val & RD_ADDR_MASK ) >> RD_ADDR_SHIFT;

	if (rd_addr != (reg_paddr & REG_ADDR_LOW_MASK)) {
	dev_err(sadi->dev, "read error, reg addr = 0x%x, val = 0x%x\n",
	reg_paddr, val);
	ret = -EIO;
	goto out;
	}

	*read_val = val & RD_VALUE_MASK;

	out:
	hwspin_unlock_irqrestore(sadi->hwlock, &flags);
	return ret;
	}

	static int sprd_adi_write(struct sprd_adi *sadi, u32 reg_paddr, u32 val)
	{
	unsigned long reg = sprd_adi_to_vaddr(sadi, reg_paddr);
	u32 timeout = ADI_FIFO_DRAIN_TIMEOUT;
	unsigned long flags;
	int ret;

	ret = hwspin_lock_timeout_irqsave(sadi->hwlock,
	ADI_HWSPINLOCK_TIMEOUT,
	&flags);
	if (ret) {
	dev_err(sadi->dev, "get the hw lock failed\n");
	return ret;
	}

	ret = sprd_adi_drain_fifo(sadi);
	if (ret < 0)
	goto out;

	/*
	* we should wait for write fifo is empty before writing data to PMIC
	* registers.
	*/
	do {
	if (!sprd_adi_fifo_is_full(sadi)) {
	writel_relaxed(val, (void __iomem *)reg);
	break;
	}

	cpu_relax();
	} while (--timeout);

	if (timeout == 0) {
	dev_err(sadi->dev, "write fifo is full\n");
	ret = -EBUSY;
	}

	out:
	hwspin_unlock_irqrestore(sadi->hwlock, &flags);
	return ret;
	}

	static int sprd_adi_transfer_one(struct spi_controller *ctlr,
	struct spi_device *spi_dev,
	struct spi_transfer *t)
	{
	struct sprd_adi *sadi = spi_controller_get_devdata(ctlr);
	u32 phy_reg, val;
	int ret;

	if (t->rx_buf) {
	phy_reg = (u32 )t->rx_buf + sadi->slave_pbase;

	ret = sprd_adi_check_paddr(sadi, phy_reg);
	if (ret)
	return ret;

	ret = sprd_adi_read(sadi, phy_reg, &val);
	if (ret)
	return ret;

	(u32 )t->rx_buf = val;
	} else if (t->tx_buf) {
	u32 p = (u32 )t->tx_buf;

	/*
	* Get the physical register address need to write and convert
	* the physical address to virtual address. Since we need
	* virtual register address to write.
	*/
	phy_reg = *p++ + sadi->slave_pbase;
	ret = sprd_adi_check_paddr(sadi, phy_reg);
	if (ret)
	return ret;

	val = *p;
	ret = sprd_adi_write(sadi, phy_reg, val);
	if (ret)
	return ret;
	} else {
	dev_err(sadi->dev, "no buffer for transfer\n");
	return -EINVAL;
	}

	return 0;
	}

	static int sprd_adi_restart_handler(struct notifier_block *this,
	unsigned long mode, void *cmd)
	{
	struct sprd_adi *sadi = container_of(this, struct sprd_adi,
	restart_handler);
	u32 val, reboot_mode = 0;

	if (!cmd)
	reboot_mode = HWRST_STATUS_NORMAL;
	else if (!strncmp(cmd, "recovery", 8))
	reboot_mode = HWRST_STATUS_RECOVERY;
	else if (!strncmp(cmd, "alarm", 5))
	reboot_mode = HWRST_STATUS_ALARM;
	else if (!strncmp(cmd, "fastsleep", 9))
	reboot_mode = HWRST_STATUS_SLEEP;
	else if (!strncmp(cmd, "bootloader", 10))
	reboot_mode = HWRST_STATUS_FASTBOOT;
	else if (!strncmp(cmd, "panic", 5))
	reboot_mode = HWRST_STATUS_PANIC;
	else if (!strncmp(cmd, "special", 7))
	reboot_mode = HWRST_STATUS_SPECIAL;
	else if (!strncmp(cmd, "cftreboot", 9))
	reboot_mode = HWRST_STATUS_CFTREBOOT;
	else if (!strncmp(cmd, "autodloader", 11))
	reboot_mode = HWRST_STATUS_AUTODLOADER;
	else if (!strncmp(cmd, "iqmode", 6))
	reboot_mode = HWRST_STATUS_IQMODE;
	else if (!strncmp(cmd, "sprdisk", 7))
	reboot_mode = HWRST_STATUS_SPRDISK;
	else
	reboot_mode = HWRST_STATUS_NORMAL;

	/* Record the reboot mode */
	sprd_adi_read(sadi, sadi->slave_pbase + PMIC_RST_STATUS, &val);
	val \|= reboot_mode;
	sprd_adi_write(sadi, sadi->slave_pbase + PMIC_RST_STATUS, val);

	/* Enable the interface clock of the watchdog */
	sprd_adi_read(sadi, sadi->slave_pbase + PMIC_MODULE_EN, &val);
	val \|= BIT_WDG_EN;
	sprd_adi_write(sadi, sadi->slave_pbase + PMIC_MODULE_EN, val);

	/* Enable the work clock of the watchdog */
	sprd_adi_read(sadi, sadi->slave_pbase + PMIC_CLK_EN, &val);
	val \|= BIT_WDG_EN;
	sprd_adi_write(sadi, sadi->slave_pbase + PMIC_CLK_EN, val);

	/* Unlock the watchdog */
	sprd_adi_write(sadi, sadi->slave_pbase + REG_WDG_LOCK, WDG_UNLOCK_KEY);

	/* Load the watchdog timeout value, 50ms is always enough. */
	sprd_adi_write(sadi, sadi->slave_pbase + REG_WDG_LOAD_LOW,
	WDG_LOAD_VAL & WDG_LOAD_MASK);
	sprd_adi_write(sadi, sadi->slave_pbase + REG_WDG_LOAD_HIGH, 0);

	/* Start the watchdog to reset system */
	sprd_adi_read(sadi, sadi->slave_pbase + REG_WDG_CTRL, &val);
	val \|= BIT_WDG_RUN \| BIT_WDG_RST;
	sprd_adi_write(sadi, sadi->slave_pbase + REG_WDG_CTRL, val);

	mdelay(1000);

	dev_emerg(sadi->dev, "Unable to restart system\n");
	return NOTIFY_DONE;
	}

	static void sprd_adi_hw_init(struct sprd_adi *sadi)
	{
	struct device_node *np = sadi->dev->of_node;
	int i, size, chn_cnt;
	const __be32 *list;
	u32 tmp;

	/* Address bits select default 12 bits */
	writel_relaxed(0, sadi->base + REG_ADI_CTRL0);

	/* Set all channels as default priority */
	writel_relaxed(0, sadi->base + REG_ADI_CHN_PRIL);
	writel_relaxed(0, sadi->base + REG_ADI_CHN_PRIH);

	/* Set clock auto gate mode */
	tmp = readl_relaxed(sadi->base + REG_ADI_GSSI_CFG0);
	tmp &= ~BIT_CLK_ALL_ON;
	writel_relaxed(tmp, sadi->base + REG_ADI_GSSI_CFG0);

	/* Set hardware channels setting */
	list = of_get_property(np, "sprd,hw-channels", &size);
	if (!list \|\| !size) {
	dev_info(sadi->dev, "no hw channels setting in node\n");
	return;
	}

	chn_cnt = size / 8;
	for (i = 0; i < chn_cnt; i++) {
	u32 value;
	u32 chn_id = be32_to_cpu(*list++);
	u32 chn_config = be32_to_cpu(*list++);

	/* Channel 0 and 1 are software channels */
	if (chn_id < 2)
	continue;

	writel_relaxed(chn_config, sadi->base +
	REG_ADI_CHN_ADDR(chn_id));

	if (chn_id < 32) {
	value = readl_relaxed(sadi->base + REG_ADI_CHN_EN);
	value \|= BIT(chn_id);
	writel_relaxed(value, sadi->base + REG_ADI_CHN_EN);
	} else if (chn_id < ADI_HW_CHNS) {
	value = readl_relaxed(sadi->base + REG_ADI_CHN_EN1);
	value \|= BIT(chn_id - 32);
	writel_relaxed(value, sadi->base + REG_ADI_CHN_EN1);
	}
	}
	}

	static int sprd_adi_probe(struct platform_device *pdev)
	{
	struct device_node *np = pdev->dev.of_node;
	struct spi_controller *ctlr;
	struct sprd_adi *sadi;
	struct resource *res;
	u32 num_chipselect;
	int ret;

	if (!np) {
	dev_err(&pdev->dev, "can not find the adi bus node\n");
	return -ENODEV;
	}

	pdev->id = of_alias_get_id(np, "spi");
	num_chipselect = of_get_child_count(np);

	ctlr = spi_alloc_master(&pdev->dev, sizeof(struct sprd_adi));
	if (!ctlr)
	return -ENOMEM;

	dev_set_drvdata(&pdev->dev, ctlr);
	sadi = spi_controller_get_devdata(ctlr);

	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
	sadi->base = devm_ioremap_resource(&pdev->dev, res);
	if (IS_ERR(sadi->base)) {
	ret = PTR_ERR(sadi->base);
	goto put_ctlr;
	}

	sadi->slave_vbase = (unsigned long)sadi->base + ADI_SLAVE_OFFSET;
	sadi->slave_pbase = res->start + ADI_SLAVE_OFFSET;
	sadi->ctlr = ctlr;
	sadi->dev = &pdev->dev;
	ret = of_hwspin_lock_get_id_byname(np, "adi");
	if (ret < 0) {
	dev_err(&pdev->dev, "can not get the hardware spinlock\n");
	goto put_ctlr;
	}

	sadi->hwlock = devm_hwspin_lock_request_specific(&pdev->dev, ret);
	if (!sadi->hwlock) {
	ret = -ENXIO;
	goto put_ctlr;
	}

	sprd_adi_hw_init(sadi);

	ctlr->dev.of_node = pdev->dev.of_node;
	ctlr->bus_num = pdev->id;
	ctlr->num_chipselect = num_chipselect;
	ctlr->flags = SPI_MASTER_HALF_DUPLEX;
	ctlr->bits_per_word_mask = 0;
	ctlr->transfer_one = sprd_adi_transfer_one;

	ret = devm_spi_register_controller(&pdev->dev, ctlr);
	if (ret) {
	dev_err(&pdev->dev, "failed to register SPI controller\n");
	goto put_ctlr;
	}

	sadi->restart_handler.notifier_call = sprd_adi_restart_handler;
	sadi->restart_handler.priority = 128;
	ret = register_restart_handler(&sadi->restart_handler);
	if (ret) {
	dev_err(&pdev->dev, "can not register restart handler\n");
	goto put_ctlr;
	}

	return 0;

	put_ctlr:
	spi_controller_put(ctlr);
	return ret;
	}

	static int sprd_adi_remove(struct platform_device *pdev)
	{
	struct spi_controller *ctlr = dev_get_drvdata(&pdev->dev);
	struct sprd_adi *sadi = spi_controller_get_devdata(ctlr);

	unregister_restart_handler(&sadi->restart_handler);
	return 0;
	}

	static const struct of_device_id sprd_adi_of_match[] = {
	{
	.compatible = "sprd,sc9860-adi",
	},
	{ },
	};
	MODULE_DEVICE_TABLE(of, sprd_adi_of_match);

	static struct platform_driver sprd_adi_driver = {
	.driver = {
	.name = "sprd-adi",
	.of_match_table = sprd_adi_of_match,
	},
	.probe = sprd_adi_probe,
	.remove = sprd_adi_remove,
	};
	module_platform_driver(sprd_adi_driver);

	MODULE_DESCRIPTION("Spreadtrum ADI Controller Driver");
	MODULE_AUTHOR("Baolin Wang <Baolin.Wang@spreadtrum.com>");
	MODULE_LICENSE("GPL v2");