Linux 5.1.15

[linux/fpc-iii.git] / drivers / spi / spi-sprd-adi.c

/*
 * 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");