perf tools: Don't clone maps from parent when synthesizing forks

[linux/fpc-iii.git] / drivers / hwmon / npcm750-pwm-fan.c

// SPDX-License-Identifier: GPL-2.0
// Copyright (c) 2014-2018 Nuvoton Technology corporation.

#include <linux/clk.h>
#include <linux/device.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>
#include <linux/interrupt.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/of_address.h>
#include <linux/of_irq.h>
#include <linux/platform_device.h>
#include <linux/spinlock.h>
#include <linux/sysfs.h>
#include <linux/thermal.h>

/* NPCM7XX PWM registers */
#define NPCM7XX_PWM_REG_BASE(base, n)    ((base) + ((n) * 0x1000L))

#define NPCM7XX_PWM_REG_PR(base, n)     (NPCM7XX_PWM_REG_BASE(base, n) + 0x00)
#define NPCM7XX_PWM_REG_CSR(base, n)    (NPCM7XX_PWM_REG_BASE(base, n) + 0x04)
#define NPCM7XX_PWM_REG_CR(base, n)     (NPCM7XX_PWM_REG_BASE(base, n) + 0x08)
#define NPCM7XX_PWM_REG_CNRx(base, n, ch) \
                        (NPCM7XX_PWM_REG_BASE(base, n) + 0x0C + (12 * (ch)))
#define NPCM7XX_PWM_REG_CMRx(base, n, ch) \
                        (NPCM7XX_PWM_REG_BASE(base, n) + 0x10 + (12 * (ch)))
#define NPCM7XX_PWM_REG_PDRx(base, n, ch) \
                        (NPCM7XX_PWM_REG_BASE(base, n) + 0x14 + (12 * (ch)))
#define NPCM7XX_PWM_REG_PIER(base, n)   (NPCM7XX_PWM_REG_BASE(base, n) + 0x3C)
#define NPCM7XX_PWM_REG_PIIR(base, n)   (NPCM7XX_PWM_REG_BASE(base, n) + 0x40)

#define NPCM7XX_PWM_CTRL_CH0_MODE_BIT           BIT(3)
#define NPCM7XX_PWM_CTRL_CH1_MODE_BIT           BIT(11)
#define NPCM7XX_PWM_CTRL_CH2_MODE_BIT           BIT(15)
#define NPCM7XX_PWM_CTRL_CH3_MODE_BIT           BIT(19)

#define NPCM7XX_PWM_CTRL_CH0_INV_BIT            BIT(2)
#define NPCM7XX_PWM_CTRL_CH1_INV_BIT            BIT(10)
#define NPCM7XX_PWM_CTRL_CH2_INV_BIT            BIT(14)
#define NPCM7XX_PWM_CTRL_CH3_INV_BIT            BIT(18)

#define NPCM7XX_PWM_CTRL_CH0_EN_BIT             BIT(0)
#define NPCM7XX_PWM_CTRL_CH1_EN_BIT             BIT(8)
#define NPCM7XX_PWM_CTRL_CH2_EN_BIT             BIT(12)
#define NPCM7XX_PWM_CTRL_CH3_EN_BIT             BIT(16)

/* Define the maximum PWM channel number */
#define NPCM7XX_PWM_MAX_CHN_NUM                 8
#define NPCM7XX_PWM_MAX_CHN_NUM_IN_A_MODULE     4
#define NPCM7XX_PWM_MAX_MODULES                 2

/* Define the Counter Register, value = 100 for match 100% */
#define NPCM7XX_PWM_COUNTER_DEFAULT_NUM         255
#define NPCM7XX_PWM_CMR_DEFAULT_NUM             255
#define NPCM7XX_PWM_CMR_MAX                     255

/* default all PWM channels PRESCALE2 = 1 */
#define NPCM7XX_PWM_PRESCALE2_DEFAULT_CH0       0x4
#define NPCM7XX_PWM_PRESCALE2_DEFAULT_CH1       0x40
#define NPCM7XX_PWM_PRESCALE2_DEFAULT_CH2       0x400
#define NPCM7XX_PWM_PRESCALE2_DEFAULT_CH3       0x4000

#define PWM_OUTPUT_FREQ_25KHZ                   25000
#define PWN_CNT_DEFAULT                         256
#define MIN_PRESCALE1                           2
#define NPCM7XX_PWM_PRESCALE_SHIFT_CH01         8

#define NPCM7XX_PWM_PRESCALE2_DEFAULT   (NPCM7XX_PWM_PRESCALE2_DEFAULT_CH0 | \
                                        NPCM7XX_PWM_PRESCALE2_DEFAULT_CH1 | \
                                        NPCM7XX_PWM_PRESCALE2_DEFAULT_CH2 | \
                                        NPCM7XX_PWM_PRESCALE2_DEFAULT_CH3)

#define NPCM7XX_PWM_CTRL_MODE_DEFAULT   (NPCM7XX_PWM_CTRL_CH0_MODE_BIT | \
                                        NPCM7XX_PWM_CTRL_CH1_MODE_BIT | \
                                        NPCM7XX_PWM_CTRL_CH2_MODE_BIT | \
                                        NPCM7XX_PWM_CTRL_CH3_MODE_BIT)

/* NPCM7XX FAN Tacho registers */
#define NPCM7XX_FAN_REG_BASE(base, n)   ((base) + ((n) * 0x1000L))

#define NPCM7XX_FAN_REG_TCNT1(base, n)    (NPCM7XX_FAN_REG_BASE(base, n) + 0x00)
#define NPCM7XX_FAN_REG_TCRA(base, n)     (NPCM7XX_FAN_REG_BASE(base, n) + 0x02)
#define NPCM7XX_FAN_REG_TCRB(base, n)     (NPCM7XX_FAN_REG_BASE(base, n) + 0x04)
#define NPCM7XX_FAN_REG_TCNT2(base, n)    (NPCM7XX_FAN_REG_BASE(base, n) + 0x06)
#define NPCM7XX_FAN_REG_TPRSC(base, n)    (NPCM7XX_FAN_REG_BASE(base, n) + 0x08)
#define NPCM7XX_FAN_REG_TCKC(base, n)     (NPCM7XX_FAN_REG_BASE(base, n) + 0x0A)
#define NPCM7XX_FAN_REG_TMCTRL(base, n)   (NPCM7XX_FAN_REG_BASE(base, n) + 0x0C)
#define NPCM7XX_FAN_REG_TICTRL(base, n)   (NPCM7XX_FAN_REG_BASE(base, n) + 0x0E)
#define NPCM7XX_FAN_REG_TICLR(base, n)    (NPCM7XX_FAN_REG_BASE(base, n) + 0x10)
#define NPCM7XX_FAN_REG_TIEN(base, n)     (NPCM7XX_FAN_REG_BASE(base, n) + 0x12)
#define NPCM7XX_FAN_REG_TCPA(base, n)     (NPCM7XX_FAN_REG_BASE(base, n) + 0x14)
#define NPCM7XX_FAN_REG_TCPB(base, n)     (NPCM7XX_FAN_REG_BASE(base, n) + 0x16)
#define NPCM7XX_FAN_REG_TCPCFG(base, n)   (NPCM7XX_FAN_REG_BASE(base, n) + 0x18)
#define NPCM7XX_FAN_REG_TINASEL(base, n)  (NPCM7XX_FAN_REG_BASE(base, n) + 0x1A)
#define NPCM7XX_FAN_REG_TINBSEL(base, n)  (NPCM7XX_FAN_REG_BASE(base, n) + 0x1C)

#define NPCM7XX_FAN_TCKC_CLKX_NONE      0
#define NPCM7XX_FAN_TCKC_CLK1_APB       BIT(0)
#define NPCM7XX_FAN_TCKC_CLK2_APB       BIT(3)

#define NPCM7XX_FAN_TMCTRL_TBEN         BIT(6)
#define NPCM7XX_FAN_TMCTRL_TAEN         BIT(5)
#define NPCM7XX_FAN_TMCTRL_TBEDG        BIT(4)
#define NPCM7XX_FAN_TMCTRL_TAEDG        BIT(3)
#define NPCM7XX_FAN_TMCTRL_MODE_5       BIT(2)

#define NPCM7XX_FAN_TICLR_CLEAR_ALL     GENMASK(5, 0)
#define NPCM7XX_FAN_TICLR_TFCLR         BIT(5)
#define NPCM7XX_FAN_TICLR_TECLR         BIT(4)
#define NPCM7XX_FAN_TICLR_TDCLR         BIT(3)
#define NPCM7XX_FAN_TICLR_TCCLR         BIT(2)
#define NPCM7XX_FAN_TICLR_TBCLR         BIT(1)
#define NPCM7XX_FAN_TICLR_TACLR         BIT(0)

#define NPCM7XX_FAN_TIEN_ENABLE_ALL     GENMASK(5, 0)
#define NPCM7XX_FAN_TIEN_TFIEN          BIT(5)
#define NPCM7XX_FAN_TIEN_TEIEN          BIT(4)
#define NPCM7XX_FAN_TIEN_TDIEN          BIT(3)
#define NPCM7XX_FAN_TIEN_TCIEN          BIT(2)
#define NPCM7XX_FAN_TIEN_TBIEN          BIT(1)
#define NPCM7XX_FAN_TIEN_TAIEN          BIT(0)

#define NPCM7XX_FAN_TICTRL_TFPND        BIT(5)
#define NPCM7XX_FAN_TICTRL_TEPND        BIT(4)
#define NPCM7XX_FAN_TICTRL_TDPND        BIT(3)
#define NPCM7XX_FAN_TICTRL_TCPND        BIT(2)
#define NPCM7XX_FAN_TICTRL_TBPND        BIT(1)
#define NPCM7XX_FAN_TICTRL_TAPND        BIT(0)

#define NPCM7XX_FAN_TCPCFG_HIBEN        BIT(7)
#define NPCM7XX_FAN_TCPCFG_EQBEN        BIT(6)
#define NPCM7XX_FAN_TCPCFG_LOBEN        BIT(5)
#define NPCM7XX_FAN_TCPCFG_CPBSEL       BIT(4)
#define NPCM7XX_FAN_TCPCFG_HIAEN        BIT(3)
#define NPCM7XX_FAN_TCPCFG_EQAEN        BIT(2)
#define NPCM7XX_FAN_TCPCFG_LOAEN        BIT(1)
#define NPCM7XX_FAN_TCPCFG_CPASEL       BIT(0)

/* FAN General Definition */
/* Define the maximum FAN channel number */
#define NPCM7XX_FAN_MAX_MODULE                  8
#define NPCM7XX_FAN_MAX_CHN_NUM_IN_A_MODULE     2
#define NPCM7XX_FAN_MAX_CHN_NUM                 16

/*
 * Get Fan Tach Timeout (base on clock 214843.75Hz, 1 cnt = 4.654us)
 * Timeout 94ms ~= 0x5000
 * (The minimum FAN speed could to support ~640RPM/pulse 1,
 * 320RPM/pulse 2, ...-- 10.6Hz)
 */
#define NPCM7XX_FAN_TIMEOUT     0x5000
#define NPCM7XX_FAN_TCNT        0xFFFF
#define NPCM7XX_FAN_TCPA        (NPCM7XX_FAN_TCNT - NPCM7XX_FAN_TIMEOUT)
#define NPCM7XX_FAN_TCPB        (NPCM7XX_FAN_TCNT - NPCM7XX_FAN_TIMEOUT)

#define NPCM7XX_FAN_POLL_TIMER_200MS                    200
#define NPCM7XX_FAN_DEFAULT_PULSE_PER_REVOLUTION        2
#define NPCM7XX_FAN_TINASEL_FANIN_DEFAULT               0
#define NPCM7XX_FAN_CLK_PRESCALE                        255

#define NPCM7XX_FAN_CMPA                                0
#define NPCM7XX_FAN_CMPB                                1

/* Obtain the fan number */
#define NPCM7XX_FAN_INPUT(fan, cmp)             (((fan) << 1) + (cmp))

/* fan sample status */
#define FAN_DISABLE                             0xFF
#define FAN_INIT                                0x00
#define FAN_PREPARE_TO_GET_FIRST_CAPTURE        0x01
#define FAN_ENOUGH_SAMPLE                       0x02

struct npcm7xx_fan_dev {
        u8 fan_st_flg;
        u8 fan_pls_per_rev;
        u16 fan_cnt;
        u32 fan_cnt_tmp;
};

struct npcm7xx_cooling_device {
        char name[THERMAL_NAME_LENGTH];
        struct npcm7xx_pwm_fan_data *data;
        struct thermal_cooling_device *tcdev;
        int pwm_port;
        u8 *cooling_levels;
        u8 max_state;
        u8 cur_state;
};

struct npcm7xx_pwm_fan_data {
        void __iomem *pwm_base;
        void __iomem *fan_base;
        unsigned long pwm_clk_freq;
        unsigned long fan_clk_freq;
        struct clk *pwm_clk;
        struct clk *fan_clk;
        struct mutex pwm_lock[NPCM7XX_PWM_MAX_MODULES];
        spinlock_t fan_lock[NPCM7XX_FAN_MAX_MODULE];
        int fan_irq[NPCM7XX_FAN_MAX_MODULE];
        bool pwm_present[NPCM7XX_PWM_MAX_CHN_NUM];
        bool fan_present[NPCM7XX_FAN_MAX_CHN_NUM];
        u32 input_clk_freq;
        struct timer_list fan_timer;
        struct npcm7xx_fan_dev fan_dev[NPCM7XX_FAN_MAX_CHN_NUM];
        struct npcm7xx_cooling_device *cdev[NPCM7XX_PWM_MAX_CHN_NUM];
        u8 fan_select;
};

static int npcm7xx_pwm_config_set(struct npcm7xx_pwm_fan_data *data,
                                  int channel, u16 val)
{
        u32 pwm_ch = (channel % NPCM7XX_PWM_MAX_CHN_NUM_IN_A_MODULE);
        u32 module = (channel / NPCM7XX_PWM_MAX_CHN_NUM_IN_A_MODULE);
        u32 tmp_buf, ctrl_en_bit, env_bit;

        /*
         * Config PWM Comparator register for setting duty cycle
         */
        mutex_lock(&data->pwm_lock[module]);

        /* write new CMR value  */
        iowrite32(val, NPCM7XX_PWM_REG_CMRx(data->pwm_base, module, pwm_ch));
        tmp_buf = ioread32(NPCM7XX_PWM_REG_CR(data->pwm_base, module));

        switch (pwm_ch) {
        case 0:
                ctrl_en_bit = NPCM7XX_PWM_CTRL_CH0_EN_BIT;
                env_bit = NPCM7XX_PWM_CTRL_CH0_INV_BIT;
                break;
        case 1:
                ctrl_en_bit = NPCM7XX_PWM_CTRL_CH1_EN_BIT;
                env_bit = NPCM7XX_PWM_CTRL_CH1_INV_BIT;
                break;
        case 2:
                ctrl_en_bit = NPCM7XX_PWM_CTRL_CH2_EN_BIT;
                env_bit = NPCM7XX_PWM_CTRL_CH2_INV_BIT;
                break;
        case 3:
                ctrl_en_bit = NPCM7XX_PWM_CTRL_CH3_EN_BIT;
                env_bit = NPCM7XX_PWM_CTRL_CH3_INV_BIT;
                break;
        default:
                mutex_unlock(&data->pwm_lock[module]);
                return -ENODEV;
        }

        if (val == 0) {
                /* Disable PWM */
                tmp_buf &= ~ctrl_en_bit;
                tmp_buf |= env_bit;
        } else {
                /* Enable PWM */
                tmp_buf |= ctrl_en_bit;
                tmp_buf &= ~env_bit;
        }

        iowrite32(tmp_buf, NPCM7XX_PWM_REG_CR(data->pwm_base, module));
        mutex_unlock(&data->pwm_lock[module]);

        return 0;
}

static inline void npcm7xx_fan_start_capture(struct npcm7xx_pwm_fan_data *data,
                                             u8 fan, u8 cmp)
{
        u8 fan_id;
        u8 reg_mode;
        u8 reg_int;
        unsigned long flags;

        fan_id = NPCM7XX_FAN_INPUT(fan, cmp);

        /* to check whether any fan tach is enable */
        if (data->fan_dev[fan_id].fan_st_flg != FAN_DISABLE) {
                /* reset status */
                spin_lock_irqsave(&data->fan_lock[fan], flags);

                data->fan_dev[fan_id].fan_st_flg = FAN_INIT;
                reg_int = ioread8(NPCM7XX_FAN_REG_TIEN(data->fan_base, fan));

                /*
                 * the interrupt enable bits do not need to be cleared before
                 * it sets, the interrupt enable bits are cleared only on reset.
                 * the clock unit control register is behaving in the same
                 * manner that the interrupt enable register behave.
                 */
                if (cmp == NPCM7XX_FAN_CMPA) {
                        /* enable interrupt */
                        iowrite8(reg_int | (NPCM7XX_FAN_TIEN_TAIEN |
                                            NPCM7XX_FAN_TIEN_TEIEN),
                                 NPCM7XX_FAN_REG_TIEN(data->fan_base, fan));

                        reg_mode = NPCM7XX_FAN_TCKC_CLK1_APB
                                | ioread8(NPCM7XX_FAN_REG_TCKC(data->fan_base,
                                                               fan));

                        /* start to Capture */
                        iowrite8(reg_mode, NPCM7XX_FAN_REG_TCKC(data->fan_base,
                                                                fan));
                } else {
                        /* enable interrupt */
                        iowrite8(reg_int | (NPCM7XX_FAN_TIEN_TBIEN |
                                            NPCM7XX_FAN_TIEN_TFIEN),
                                 NPCM7XX_FAN_REG_TIEN(data->fan_base, fan));

                        reg_mode =
                                NPCM7XX_FAN_TCKC_CLK2_APB
                                | ioread8(NPCM7XX_FAN_REG_TCKC(data->fan_base,
                                                               fan));

                        /* start to Capture */
                        iowrite8(reg_mode,
                                 NPCM7XX_FAN_REG_TCKC(data->fan_base, fan));
                }

                spin_unlock_irqrestore(&data->fan_lock[fan], flags);
        }
}

/*
 * Enable a background timer to poll fan tach value, (200ms * 4)
 * to polling all fan
 */
static void npcm7xx_fan_polling(struct timer_list *t)
{
        struct npcm7xx_pwm_fan_data *data;
        int i;

        data = from_timer(data, t, fan_timer);

        /*
         * Polling two module per one round,
         * FAN01 & FAN89 / FAN23 & FAN1011 / FAN45 & FAN1213 / FAN67 & FAN1415
         */
        for (i = data->fan_select; i < NPCM7XX_FAN_MAX_MODULE;
              i = i + 4) {
                /* clear the flag and reset the counter (TCNT) */
                iowrite8(NPCM7XX_FAN_TICLR_CLEAR_ALL,
                         NPCM7XX_FAN_REG_TICLR(data->fan_base, i));

                if (data->fan_present[i * 2]) {
                        iowrite16(NPCM7XX_FAN_TCNT,
                                  NPCM7XX_FAN_REG_TCNT1(data->fan_base, i));
                        npcm7xx_fan_start_capture(data, i, NPCM7XX_FAN_CMPA);
                }
                if (data->fan_present[(i * 2) + 1]) {
                        iowrite16(NPCM7XX_FAN_TCNT,
                                  NPCM7XX_FAN_REG_TCNT2(data->fan_base, i));
                        npcm7xx_fan_start_capture(data, i, NPCM7XX_FAN_CMPB);
                }
        }

        data->fan_select++;
        data->fan_select &= 0x3;

        /* reset the timer interval */
        data->fan_timer.expires = jiffies +
                msecs_to_jiffies(NPCM7XX_FAN_POLL_TIMER_200MS);
        add_timer(&data->fan_timer);
}

static inline void npcm7xx_fan_compute(struct npcm7xx_pwm_fan_data *data,
                                       u8 fan, u8 cmp, u8 fan_id, u8 flag_int,
                                       u8 flag_mode, u8 flag_clear)
{
        u8  reg_int;
        u8  reg_mode;
        u16 fan_cap;

        if (cmp == NPCM7XX_FAN_CMPA)
                fan_cap = ioread16(NPCM7XX_FAN_REG_TCRA(data->fan_base, fan));
        else
                fan_cap = ioread16(NPCM7XX_FAN_REG_TCRB(data->fan_base, fan));

        /* clear capature flag, H/W will auto reset the NPCM7XX_FAN_TCNTx */
        iowrite8(flag_clear, NPCM7XX_FAN_REG_TICLR(data->fan_base, fan));

        if (data->fan_dev[fan_id].fan_st_flg == FAN_INIT) {
                /* First capture, drop it */
                data->fan_dev[fan_id].fan_st_flg =
                        FAN_PREPARE_TO_GET_FIRST_CAPTURE;

                /* reset counter */
                data->fan_dev[fan_id].fan_cnt_tmp = 0;
        } else if (data->fan_dev[fan_id].fan_st_flg < FAN_ENOUGH_SAMPLE) {
                /*
                 * collect the enough sample,
                 * (ex: 2 pulse fan need to get 2 sample)
                 */
                data->fan_dev[fan_id].fan_cnt_tmp +=
                        (NPCM7XX_FAN_TCNT - fan_cap);

                data->fan_dev[fan_id].fan_st_flg++;
        } else {
                /* get enough sample or fan disable */
                if (data->fan_dev[fan_id].fan_st_flg == FAN_ENOUGH_SAMPLE) {
                        data->fan_dev[fan_id].fan_cnt_tmp +=
                                (NPCM7XX_FAN_TCNT - fan_cap);

                        /* compute finial average cnt per pulse */
                        data->fan_dev[fan_id].fan_cnt =
                                data->fan_dev[fan_id].fan_cnt_tmp /
                                FAN_ENOUGH_SAMPLE;

                        data->fan_dev[fan_id].fan_st_flg = FAN_INIT;
                }

                reg_int =  ioread8(NPCM7XX_FAN_REG_TIEN(data->fan_base, fan));

                /* disable interrupt */
                iowrite8((reg_int & ~flag_int),
                         NPCM7XX_FAN_REG_TIEN(data->fan_base, fan));
                reg_mode =  ioread8(NPCM7XX_FAN_REG_TCKC(data->fan_base, fan));

                /* stop capturing */
                iowrite8((reg_mode & ~flag_mode),
                         NPCM7XX_FAN_REG_TCKC(data->fan_base, fan));
        }
}

static inline void npcm7xx_check_cmp(struct npcm7xx_pwm_fan_data *data,
                                     u8 fan, u8 cmp, u8 flag)
{
        u8 reg_int;
        u8 reg_mode;
        u8 flag_timeout;
        u8 flag_cap;
        u8 flag_clear;
        u8 flag_int;
        u8 flag_mode;
        u8 fan_id;

        fan_id = NPCM7XX_FAN_INPUT(fan, cmp);

        if (cmp == NPCM7XX_FAN_CMPA) {
                flag_cap = NPCM7XX_FAN_TICTRL_TAPND;
                flag_timeout = NPCM7XX_FAN_TICTRL_TEPND;
                flag_int = NPCM7XX_FAN_TIEN_TAIEN | NPCM7XX_FAN_TIEN_TEIEN;
                flag_mode = NPCM7XX_FAN_TCKC_CLK1_APB;
                flag_clear = NPCM7XX_FAN_TICLR_TACLR | NPCM7XX_FAN_TICLR_TECLR;
        } else {
                flag_cap = NPCM7XX_FAN_TICTRL_TBPND;
                flag_timeout = NPCM7XX_FAN_TICTRL_TFPND;
                flag_int = NPCM7XX_FAN_TIEN_TBIEN | NPCM7XX_FAN_TIEN_TFIEN;
                flag_mode = NPCM7XX_FAN_TCKC_CLK2_APB;
                flag_clear = NPCM7XX_FAN_TICLR_TBCLR | NPCM7XX_FAN_TICLR_TFCLR;
        }

        if (flag & flag_timeout) {
                reg_int =  ioread8(NPCM7XX_FAN_REG_TIEN(data->fan_base, fan));

                /* disable interrupt */
                iowrite8((reg_int & ~flag_int),
                         NPCM7XX_FAN_REG_TIEN(data->fan_base, fan));

                /* clear interrupt flag */
                iowrite8(flag_clear,
                         NPCM7XX_FAN_REG_TICLR(data->fan_base, fan));

                reg_mode =  ioread8(NPCM7XX_FAN_REG_TCKC(data->fan_base, fan));

                /* stop capturing */
                iowrite8((reg_mode & ~flag_mode),
                         NPCM7XX_FAN_REG_TCKC(data->fan_base, fan));

                /*
                 *  If timeout occurs (NPCM7XX_FAN_TIMEOUT), the fan doesn't
                 *  connect or speed is lower than 10.6Hz (320RPM/pulse2).
                 *  In these situation, the RPM output should be zero.
                 */
                data->fan_dev[fan_id].fan_cnt = 0;
        } else {
            /* input capture is occurred */
                if (flag & flag_cap)
                        npcm7xx_fan_compute(data, fan, cmp, fan_id, flag_int,
                                            flag_mode, flag_clear);
        }
}

static irqreturn_t npcm7xx_fan_isr(int irq, void *dev_id)
{
        struct npcm7xx_pwm_fan_data *data = dev_id;
        unsigned long flags;
        int module;
        u8 flag;

        module = irq - data->fan_irq[0];
        spin_lock_irqsave(&data->fan_lock[module], flags);

        flag = ioread8(NPCM7XX_FAN_REG_TICTRL(data->fan_base, module));
        if (flag > 0) {
                npcm7xx_check_cmp(data, module, NPCM7XX_FAN_CMPA, flag);
                npcm7xx_check_cmp(data, module, NPCM7XX_FAN_CMPB, flag);
                spin_unlock_irqrestore(&data->fan_lock[module], flags);
                return IRQ_HANDLED;
        }

        spin_unlock_irqrestore(&data->fan_lock[module], flags);

        return IRQ_NONE;
}

static int npcm7xx_read_pwm(struct device *dev, u32 attr, int channel,
                            long *val)
{
        struct npcm7xx_pwm_fan_data *data = dev_get_drvdata(dev);
        u32 pmw_ch = (channel % NPCM7XX_PWM_MAX_CHN_NUM_IN_A_MODULE);
        u32 module = (channel / NPCM7XX_PWM_MAX_CHN_NUM_IN_A_MODULE);

        switch (attr) {
        case hwmon_pwm_input:
                *val = ioread32
                        (NPCM7XX_PWM_REG_CMRx(data->pwm_base, module, pmw_ch));
                return 0;
        default:
                return -EOPNOTSUPP;
        }
}

static int npcm7xx_write_pwm(struct device *dev, u32 attr, int channel,
                             long val)
{
        struct npcm7xx_pwm_fan_data *data = dev_get_drvdata(dev);
        int err;

        switch (attr) {
        case hwmon_pwm_input:
                if (val < 0 || val > NPCM7XX_PWM_CMR_MAX)
                        return -EINVAL;
                err = npcm7xx_pwm_config_set(data, channel, (u16)val);
                break;
        default:
                err = -EOPNOTSUPP;
                break;
        }

        return err;
}

static umode_t npcm7xx_pwm_is_visible(const void *_data, u32 attr, int channel)
{
        const struct npcm7xx_pwm_fan_data *data = _data;

        if (!data->pwm_present[channel])
                return 0;

        switch (attr) {
        case hwmon_pwm_input:
                return 0644;
        default:
                return 0;
        }
}

static int npcm7xx_read_fan(struct device *dev, u32 attr, int channel,
                            long *val)
{
        struct npcm7xx_pwm_fan_data *data = dev_get_drvdata(dev);

        switch (attr) {
        case hwmon_fan_input:
                *val = 0;
                if (data->fan_dev[channel].fan_cnt <= 0)
                        return data->fan_dev[channel].fan_cnt;

                /* Convert the raw reading to RPM */
                if (data->fan_dev[channel].fan_cnt > 0 &&
                    data->fan_dev[channel].fan_pls_per_rev > 0)
                        *val = ((data->input_clk_freq * 60) /
                                (data->fan_dev[channel].fan_cnt *
                                 data->fan_dev[channel].fan_pls_per_rev));
                return 0;
        default:
                return -EOPNOTSUPP;
        }
}

static umode_t npcm7xx_fan_is_visible(const void *_data, u32 attr, int channel)
{
        const struct npcm7xx_pwm_fan_data *data = _data;

        if (!data->fan_present[channel])
                return 0;

        switch (attr) {
        case hwmon_fan_input:
                return 0444;
        default:
                return 0;
        }
}

static int npcm7xx_read(struct device *dev, enum hwmon_sensor_types type,
                        u32 attr, int channel, long *val)
{
        switch (type) {
        case hwmon_pwm:
                return npcm7xx_read_pwm(dev, attr, channel, val);
        case hwmon_fan:
                return npcm7xx_read_fan(dev, attr, channel, val);
        default:
                return -EOPNOTSUPP;
        }
}

static int npcm7xx_write(struct device *dev, enum hwmon_sensor_types type,
                         u32 attr, int channel, long val)
{
        switch (type) {
        case hwmon_pwm:
                return npcm7xx_write_pwm(dev, attr, channel, val);
        default:
                return -EOPNOTSUPP;
        }
}

static umode_t npcm7xx_is_visible(const void *data,
                                  enum hwmon_sensor_types type,
                                  u32 attr, int channel)
{
        switch (type) {
        case hwmon_pwm:
                return npcm7xx_pwm_is_visible(data, attr, channel);
        case hwmon_fan:
                return npcm7xx_fan_is_visible(data, attr, channel);
        default:
                return 0;
        }
}

static const u32 npcm7xx_pwm_config[] = {
        HWMON_PWM_INPUT,
        HWMON_PWM_INPUT,
        HWMON_PWM_INPUT,
        HWMON_PWM_INPUT,
        HWMON_PWM_INPUT,
        HWMON_PWM_INPUT,
        HWMON_PWM_INPUT,
        HWMON_PWM_INPUT,
        0
};

static const struct hwmon_channel_info npcm7xx_pwm = {
        .type = hwmon_pwm,
        .config = npcm7xx_pwm_config,
};

static const u32 npcm7xx_fan_config[] = {
        HWMON_F_INPUT,
        HWMON_F_INPUT,
        HWMON_F_INPUT,
        HWMON_F_INPUT,
        HWMON_F_INPUT,
        HWMON_F_INPUT,
        HWMON_F_INPUT,
        HWMON_F_INPUT,
        HWMON_F_INPUT,
        HWMON_F_INPUT,
        HWMON_F_INPUT,
        HWMON_F_INPUT,
        HWMON_F_INPUT,
        HWMON_F_INPUT,
        HWMON_F_INPUT,
        HWMON_F_INPUT,
        0
};

static const struct hwmon_channel_info npcm7xx_fan = {
        .type = hwmon_fan,
        .config = npcm7xx_fan_config,
};

static const struct hwmon_channel_info *npcm7xx_info[] = {
        &npcm7xx_pwm,
        &npcm7xx_fan,
        NULL
};

static const struct hwmon_ops npcm7xx_hwmon_ops = {
        .is_visible = npcm7xx_is_visible,
        .read = npcm7xx_read,
        .write = npcm7xx_write,
};

static const struct hwmon_chip_info npcm7xx_chip_info = {
        .ops = &npcm7xx_hwmon_ops,
        .info = npcm7xx_info,
};

static u32 npcm7xx_pwm_init(struct npcm7xx_pwm_fan_data *data)
{
        int m, ch;
        u32 prescale_val, output_freq;

        data->pwm_clk_freq = clk_get_rate(data->pwm_clk);

        /* Adjust NPCM7xx PWMs output frequency to ~25Khz */
        output_freq = data->pwm_clk_freq / PWN_CNT_DEFAULT;
        prescale_val = DIV_ROUND_CLOSEST(output_freq, PWM_OUTPUT_FREQ_25KHZ);

        /* If prescale_val = 0, then the prescale output clock is stopped */
        if (prescale_val < MIN_PRESCALE1)
                prescale_val = MIN_PRESCALE1;
        /*
         * prescale_val need to decrement in one because in the PWM Prescale
         * register the Prescale value increment by one
         */
        prescale_val--;

        /* Setting PWM Prescale Register value register to both modules */
        prescale_val |= (prescale_val << NPCM7XX_PWM_PRESCALE_SHIFT_CH01);

        for (m = 0; m < NPCM7XX_PWM_MAX_MODULES  ; m++) {
                iowrite32(prescale_val, NPCM7XX_PWM_REG_PR(data->pwm_base, m));
                iowrite32(NPCM7XX_PWM_PRESCALE2_DEFAULT,
                          NPCM7XX_PWM_REG_CSR(data->pwm_base, m));
                iowrite32(NPCM7XX_PWM_CTRL_MODE_DEFAULT,
                          NPCM7XX_PWM_REG_CR(data->pwm_base, m));

                for (ch = 0; ch < NPCM7XX_PWM_MAX_CHN_NUM_IN_A_MODULE; ch++) {
                        iowrite32(NPCM7XX_PWM_COUNTER_DEFAULT_NUM,
                                  NPCM7XX_PWM_REG_CNRx(data->pwm_base, m, ch));
                }
        }

        return output_freq / ((prescale_val & 0xf) + 1);
}

static void npcm7xx_fan_init(struct npcm7xx_pwm_fan_data *data)
{
        int md;
        int ch;
        int i;
        u32 apb_clk_freq;

        for (md = 0; md < NPCM7XX_FAN_MAX_MODULE; md++) {
                /* stop FAN0~7 clock */
                iowrite8(NPCM7XX_FAN_TCKC_CLKX_NONE,
                         NPCM7XX_FAN_REG_TCKC(data->fan_base, md));

                /* disable all interrupt */
                iowrite8(0x00, NPCM7XX_FAN_REG_TIEN(data->fan_base, md));

                /* clear all interrupt */
                iowrite8(NPCM7XX_FAN_TICLR_CLEAR_ALL,
                         NPCM7XX_FAN_REG_TICLR(data->fan_base, md));

                /* set FAN0~7 clock prescaler */
                iowrite8(NPCM7XX_FAN_CLK_PRESCALE,
                         NPCM7XX_FAN_REG_TPRSC(data->fan_base, md));

                /* set FAN0~7 mode (high-to-low transition) */
                iowrite8((NPCM7XX_FAN_TMCTRL_MODE_5 | NPCM7XX_FAN_TMCTRL_TBEN |
                          NPCM7XX_FAN_TMCTRL_TAEN),
                         NPCM7XX_FAN_REG_TMCTRL(data->fan_base, md));

                /* set FAN0~7 Initial Count/Cap */
                iowrite16(NPCM7XX_FAN_TCNT,
                          NPCM7XX_FAN_REG_TCNT1(data->fan_base, md));
                iowrite16(NPCM7XX_FAN_TCNT,
                          NPCM7XX_FAN_REG_TCNT2(data->fan_base, md));

                /* set FAN0~7 compare (equal to count) */
                iowrite8((NPCM7XX_FAN_TCPCFG_EQAEN | NPCM7XX_FAN_TCPCFG_EQBEN),
                         NPCM7XX_FAN_REG_TCPCFG(data->fan_base, md));

                /* set FAN0~7 compare value */
                iowrite16(NPCM7XX_FAN_TCPA,
                          NPCM7XX_FAN_REG_TCPA(data->fan_base, md));
                iowrite16(NPCM7XX_FAN_TCPB,
                          NPCM7XX_FAN_REG_TCPB(data->fan_base, md));

                /* set FAN0~7 fan input FANIN 0~15 */
                iowrite8(NPCM7XX_FAN_TINASEL_FANIN_DEFAULT,
                         NPCM7XX_FAN_REG_TINASEL(data->fan_base, md));
                iowrite8(NPCM7XX_FAN_TINASEL_FANIN_DEFAULT,
                         NPCM7XX_FAN_REG_TINBSEL(data->fan_base, md));

                for (i = 0; i < NPCM7XX_FAN_MAX_CHN_NUM_IN_A_MODULE; i++) {
                        ch = md * NPCM7XX_FAN_MAX_CHN_NUM_IN_A_MODULE + i;
                        data->fan_dev[ch].fan_st_flg = FAN_DISABLE;
                        data->fan_dev[ch].fan_pls_per_rev =
                                NPCM7XX_FAN_DEFAULT_PULSE_PER_REVOLUTION;
                        data->fan_dev[ch].fan_cnt = 0;
                }
        }

        apb_clk_freq = clk_get_rate(data->fan_clk);

        /* Fan tach input clock = APB clock / prescalar, default is 255. */
        data->input_clk_freq = apb_clk_freq / (NPCM7XX_FAN_CLK_PRESCALE + 1);
}

static int
npcm7xx_pwm_cz_get_max_state(struct thermal_cooling_device *tcdev,
                             unsigned long *state)
{
        struct npcm7xx_cooling_device *cdev = tcdev->devdata;

        *state = cdev->max_state;

        return 0;
}

static int
npcm7xx_pwm_cz_get_cur_state(struct thermal_cooling_device *tcdev,
                             unsigned long *state)
{
        struct npcm7xx_cooling_device *cdev = tcdev->devdata;

        *state = cdev->cur_state;

        return 0;
}

static int
npcm7xx_pwm_cz_set_cur_state(struct thermal_cooling_device *tcdev,
                             unsigned long state)
{
        struct npcm7xx_cooling_device *cdev = tcdev->devdata;
        int ret;

        if (state > cdev->max_state)
                return -EINVAL;

        cdev->cur_state = state;
        ret = npcm7xx_pwm_config_set(cdev->data, cdev->pwm_port,
                                     cdev->cooling_levels[cdev->cur_state]);

        return ret;
}

static const struct thermal_cooling_device_ops npcm7xx_pwm_cool_ops = {
        .get_max_state = npcm7xx_pwm_cz_get_max_state,
        .get_cur_state = npcm7xx_pwm_cz_get_cur_state,
        .set_cur_state = npcm7xx_pwm_cz_set_cur_state,
};

static int npcm7xx_create_pwm_cooling(struct device *dev,
                                      struct device_node *child,
                                      struct npcm7xx_pwm_fan_data *data,
                                      u32 pwm_port, u8 num_levels)
{
        int ret;
        struct npcm7xx_cooling_device *cdev;

        cdev = devm_kzalloc(dev, sizeof(*cdev), GFP_KERNEL);
        if (!cdev)
                return -ENOMEM;

        cdev->cooling_levels = devm_kzalloc(dev, num_levels, GFP_KERNEL);
        if (!cdev->cooling_levels)
                return -ENOMEM;

        cdev->max_state = num_levels - 1;
        ret = of_property_read_u8_array(child, "cooling-levels",
                                        cdev->cooling_levels,
                                        num_levels);
        if (ret) {
                dev_err(dev, "Property 'cooling-levels' cannot be read.\n");
                return ret;
        }
        snprintf(cdev->name, THERMAL_NAME_LENGTH, "%pOFn%d", child,
                 pwm_port);

        cdev->tcdev = thermal_of_cooling_device_register(child,
                                                         cdev->name,
                                                         cdev,
                                                         &npcm7xx_pwm_cool_ops);
        if (IS_ERR(cdev->tcdev))
                return PTR_ERR(cdev->tcdev);

        cdev->data = data;
        cdev->pwm_port = pwm_port;

        data->cdev[pwm_port] = cdev;

        return 0;
}

static int npcm7xx_en_pwm_fan(struct device *dev,
                              struct device_node *child,
                              struct npcm7xx_pwm_fan_data *data)
{
        u8 *fan_ch;
        u32 pwm_port;
        int ret, fan_cnt;
        u8 index, ch;

        ret = of_property_read_u32(child, "reg", &pwm_port);
        if (ret)
                return ret;

        data->pwm_present[pwm_port] = true;
        ret = npcm7xx_pwm_config_set(data, pwm_port,
                                     NPCM7XX_PWM_CMR_DEFAULT_NUM);

        ret = of_property_count_u8_elems(child, "cooling-levels");
        if (ret > 0) {
                ret = npcm7xx_create_pwm_cooling(dev, child, data, pwm_port,
                                                 ret);
                if (ret)
                        return ret;
        }

        fan_cnt = of_property_count_u8_elems(child, "fan-tach-ch");
        if (fan_cnt < 1)
                return -EINVAL;

        fan_ch = devm_kcalloc(dev, fan_cnt, sizeof(*fan_ch), GFP_KERNEL);
        if (!fan_ch)
                return -ENOMEM;

        ret = of_property_read_u8_array(child, "fan-tach-ch", fan_ch, fan_cnt);
        if (ret)
                return ret;

        for (ch = 0; ch < fan_cnt; ch++) {
                index = fan_ch[ch];
                data->fan_present[index] = true;
                data->fan_dev[index].fan_st_flg = FAN_INIT;
        }

        return 0;
}

static int npcm7xx_pwm_fan_probe(struct platform_device *pdev)
{
        struct device *dev = &pdev->dev;
        struct device_node *np, *child;
        struct npcm7xx_pwm_fan_data *data;
        struct resource *res;
        struct device *hwmon;
        char name[20];
        int ret, cnt;
        u32 output_freq;
        u32 i;

        np = dev->of_node;

        data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
        if (!data)
                return -ENOMEM;

        res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "pwm");
        if (!res) {
                dev_err(dev, "pwm resource not found\n");
                return -ENODEV;
        }

        data->pwm_base = devm_ioremap_resource(dev, res);
        dev_dbg(dev, "pwm base resource is %pR\n", res);
        if (IS_ERR(data->pwm_base))
                return PTR_ERR(data->pwm_base);

        data->pwm_clk = devm_clk_get(dev, "pwm");
        if (IS_ERR(data->pwm_clk)) {
                dev_err(dev, "couldn't get pwm clock\n");
                return PTR_ERR(data->pwm_clk);
        }

        res = platform_get_resource_byname(pdev, IORESOURCE_MEM, "fan");
        if (!res) {
                dev_err(dev, "fan resource not found\n");
                return -ENODEV;
        }

        data->fan_base = devm_ioremap_resource(dev, res);
        dev_dbg(dev, "fan base resource is %pR\n", res);
        if (IS_ERR(data->fan_base))
                return PTR_ERR(data->fan_base);

        data->fan_clk = devm_clk_get(dev, "fan");
        if (IS_ERR(data->fan_clk)) {
                dev_err(dev, "couldn't get fan clock\n");
                return PTR_ERR(data->fan_clk);
        }

        output_freq = npcm7xx_pwm_init(data);
        npcm7xx_fan_init(data);

        for (cnt = 0; cnt < NPCM7XX_PWM_MAX_MODULES  ; cnt++)
                mutex_init(&data->pwm_lock[cnt]);

        for (i = 0; i < NPCM7XX_FAN_MAX_MODULE; i++) {
                spin_lock_init(&data->fan_lock[i]);

                data->fan_irq[i] = platform_get_irq(pdev, i);
                if (data->fan_irq[i] < 0) {
                        dev_err(dev, "get IRQ fan%d failed\n", i);
                        return data->fan_irq[i];
                }

                sprintf(name, "NPCM7XX-FAN-MD%d", i);
                ret = devm_request_irq(dev, data->fan_irq[i], npcm7xx_fan_isr,
                                       0, name, (void *)data);
                if (ret) {
                        dev_err(dev, "register IRQ fan%d failed\n", i);
                        return ret;
                }
        }

        for_each_child_of_node(np, child) {
                ret = npcm7xx_en_pwm_fan(dev, child, data);
                if (ret) {
                        dev_err(dev, "enable pwm and fan failed\n");
                        of_node_put(child);
                        return ret;
                }
        }

        hwmon = devm_hwmon_device_register_with_info(dev, "npcm7xx_pwm_fan",
                                                     data, &npcm7xx_chip_info,
                                                     NULL);
        if (IS_ERR(hwmon)) {
                dev_err(dev, "unable to register hwmon device\n");
                return PTR_ERR(hwmon);
        }

        for (i = 0; i < NPCM7XX_FAN_MAX_CHN_NUM; i++) {
                if (data->fan_present[i]) {
                        /* fan timer initialization */
                        data->fan_timer.expires = jiffies +
                                msecs_to_jiffies(NPCM7XX_FAN_POLL_TIMER_200MS);
                        timer_setup(&data->fan_timer,
                                    npcm7xx_fan_polling, 0);
                        add_timer(&data->fan_timer);
                        break;
                }
        }

        pr_info("NPCM7XX PWM-FAN Driver probed, output Freq %dHz[PWM], input Freq %dHz[FAN]\n",
                output_freq, data->input_clk_freq);

        return 0;
}

static const struct of_device_id of_pwm_fan_match_table[] = {
        { .compatible = "nuvoton,npcm750-pwm-fan", },
        {},
};
MODULE_DEVICE_TABLE(of, of_pwm_fan_match_table);

static struct platform_driver npcm7xx_pwm_fan_driver = {
        .probe          = npcm7xx_pwm_fan_probe,
        .driver         = {
                .name   = "npcm7xx_pwm_fan",
                .of_match_table = of_pwm_fan_match_table,
        },
};

module_platform_driver(npcm7xx_pwm_fan_driver);

MODULE_DESCRIPTION("Nuvoton NPCM7XX PWM and Fan Tacho driver");
MODULE_AUTHOR("Tomer Maimon <tomer.maimon@nuvoton.com>");
MODULE_LICENSE("GPL v2");