|  | // SPDX-License-Identifier: GPL-2.0-only | 
|  | /* | 
|  | * Copyright (C) 2007,2012 Texas Instruments, Inc. | 
|  | */ | 
|  | #include <linux/kernel.h> | 
|  | #include <linux/module.h> | 
|  | #include <linux/platform_device.h> | 
|  | #include <linux/interrupt.h> | 
|  | #include <linux/slab.h> | 
|  | #include <linux/err.h> | 
|  | #include <linux/io.h> | 
|  | #include <linux/sched.h> | 
|  | #include <linux/pm_runtime.h> | 
|  | #include <linux/of.h> | 
|  |  | 
|  | #include <linux/w1.h> | 
|  |  | 
|  | #define	MOD_NAME	"OMAP_HDQ:" | 
|  |  | 
|  | #define OMAP_HDQ_REVISION			0x00 | 
|  | #define OMAP_HDQ_TX_DATA			0x04 | 
|  | #define OMAP_HDQ_RX_DATA			0x08 | 
|  | #define OMAP_HDQ_CTRL_STATUS			0x0c | 
|  | #define OMAP_HDQ_CTRL_STATUS_SINGLE		BIT(7) | 
|  | #define OMAP_HDQ_CTRL_STATUS_INTERRUPTMASK	BIT(6) | 
|  | #define OMAP_HDQ_CTRL_STATUS_CLOCKENABLE	BIT(5) | 
|  | #define OMAP_HDQ_CTRL_STATUS_GO                 BIT(4) | 
|  | #define OMAP_HDQ_CTRL_STATUS_PRESENCE		BIT(3) | 
|  | #define OMAP_HDQ_CTRL_STATUS_INITIALIZATION	BIT(2) | 
|  | #define OMAP_HDQ_CTRL_STATUS_DIR		BIT(1) | 
|  | #define OMAP_HDQ_INT_STATUS			0x10 | 
|  | #define OMAP_HDQ_INT_STATUS_TXCOMPLETE		BIT(2) | 
|  | #define OMAP_HDQ_INT_STATUS_RXCOMPLETE		BIT(1) | 
|  | #define OMAP_HDQ_INT_STATUS_TIMEOUT		BIT(0) | 
|  |  | 
|  | #define OMAP_HDQ_FLAG_CLEAR			0 | 
|  | #define OMAP_HDQ_FLAG_SET			1 | 
|  | #define OMAP_HDQ_TIMEOUT			(HZ/5) | 
|  |  | 
|  | #define OMAP_HDQ_MAX_USER			4 | 
|  |  | 
|  | static DECLARE_WAIT_QUEUE_HEAD(hdq_wait_queue); | 
|  |  | 
|  | static int w1_id; | 
|  | module_param(w1_id, int, 0400); | 
|  | MODULE_PARM_DESC(w1_id, "1-wire id for the slave detection in HDQ mode"); | 
|  |  | 
|  | struct hdq_data { | 
|  | struct device		*dev; | 
|  | void __iomem		*hdq_base; | 
|  | /* lock read/write/break operations */ | 
|  | struct  mutex		hdq_mutex; | 
|  | /* interrupt status and a lock for it */ | 
|  | u8			hdq_irqstatus; | 
|  | spinlock_t		hdq_spinlock; | 
|  | /* mode: 0-HDQ 1-W1 */ | 
|  | int                     mode; | 
|  |  | 
|  | }; | 
|  |  | 
|  | /* HDQ register I/O routines */ | 
|  | static inline u8 hdq_reg_in(struct hdq_data *hdq_data, u32 offset) | 
|  | { | 
|  | return __raw_readl(hdq_data->hdq_base + offset); | 
|  | } | 
|  |  | 
|  | static inline void hdq_reg_out(struct hdq_data *hdq_data, u32 offset, u8 val) | 
|  | { | 
|  | __raw_writel(val, hdq_data->hdq_base + offset); | 
|  | } | 
|  |  | 
|  | static inline u8 hdq_reg_merge(struct hdq_data *hdq_data, u32 offset, | 
|  | u8 val, u8 mask) | 
|  | { | 
|  | u8 new_val = (__raw_readl(hdq_data->hdq_base + offset) & ~mask) | 
|  | | (val & mask); | 
|  | __raw_writel(new_val, hdq_data->hdq_base + offset); | 
|  |  | 
|  | return new_val; | 
|  | } | 
|  |  | 
|  | /* | 
|  | * Wait for one or more bits in flag change. | 
|  | * HDQ_FLAG_SET: wait until any bit in the flag is set. | 
|  | * HDQ_FLAG_CLEAR: wait until all bits in the flag are cleared. | 
|  | * return 0 on success and -ETIMEDOUT in the case of timeout. | 
|  | */ | 
|  | static int hdq_wait_for_flag(struct hdq_data *hdq_data, u32 offset, | 
|  | u8 flag, u8 flag_set, u8 *status) | 
|  | { | 
|  | int ret = 0; | 
|  | unsigned long timeout = jiffies + OMAP_HDQ_TIMEOUT; | 
|  |  | 
|  | if (flag_set == OMAP_HDQ_FLAG_CLEAR) { | 
|  | /* wait for the flag clear */ | 
|  | while (((*status = hdq_reg_in(hdq_data, offset)) & flag) | 
|  | && time_before(jiffies, timeout)) { | 
|  | schedule_timeout_uninterruptible(1); | 
|  | } | 
|  | if (*status & flag) | 
|  | ret = -ETIMEDOUT; | 
|  | } else if (flag_set == OMAP_HDQ_FLAG_SET) { | 
|  | /* wait for the flag set */ | 
|  | while (!((*status = hdq_reg_in(hdq_data, offset)) & flag) | 
|  | && time_before(jiffies, timeout)) { | 
|  | schedule_timeout_uninterruptible(1); | 
|  | } | 
|  | if (!(*status & flag)) | 
|  | ret = -ETIMEDOUT; | 
|  | } else | 
|  | return -EINVAL; | 
|  |  | 
|  | return ret; | 
|  | } | 
|  |  | 
|  | /* Clear saved irqstatus after using an interrupt */ | 
|  | static u8 hdq_reset_irqstatus(struct hdq_data *hdq_data, u8 bits) | 
|  | { | 
|  | unsigned long irqflags; | 
|  | u8 status; | 
|  |  | 
|  | spin_lock_irqsave(&hdq_data->hdq_spinlock, irqflags); | 
|  | status = hdq_data->hdq_irqstatus; | 
|  | /* this is a read-modify-write */ | 
|  | hdq_data->hdq_irqstatus &= ~bits; | 
|  | spin_unlock_irqrestore(&hdq_data->hdq_spinlock, irqflags); | 
|  |  | 
|  | return status; | 
|  | } | 
|  |  | 
|  | /* write out a byte and fill *status with HDQ_INT_STATUS */ | 
|  | static int hdq_write_byte(struct hdq_data *hdq_data, u8 val, u8 *status) | 
|  | { | 
|  | int ret; | 
|  | u8 tmp_status; | 
|  |  | 
|  | ret = mutex_lock_interruptible(&hdq_data->hdq_mutex); | 
|  | if (ret < 0) { | 
|  | ret = -EINTR; | 
|  | goto rtn; | 
|  | } | 
|  |  | 
|  | if (hdq_data->hdq_irqstatus) | 
|  | dev_err(hdq_data->dev, "TX irqstatus not cleared (%02x)\n", | 
|  | hdq_data->hdq_irqstatus); | 
|  |  | 
|  | *status = 0; | 
|  |  | 
|  | hdq_reg_out(hdq_data, OMAP_HDQ_TX_DATA, val); | 
|  |  | 
|  | /* set the GO bit */ | 
|  | hdq_reg_merge(hdq_data, OMAP_HDQ_CTRL_STATUS, OMAP_HDQ_CTRL_STATUS_GO, | 
|  | OMAP_HDQ_CTRL_STATUS_DIR | OMAP_HDQ_CTRL_STATUS_GO); | 
|  | /* wait for the TXCOMPLETE bit */ | 
|  | ret = wait_event_timeout(hdq_wait_queue, | 
|  | (hdq_data->hdq_irqstatus & OMAP_HDQ_INT_STATUS_TXCOMPLETE), | 
|  | OMAP_HDQ_TIMEOUT); | 
|  | *status = hdq_reset_irqstatus(hdq_data, OMAP_HDQ_INT_STATUS_TXCOMPLETE); | 
|  | if (ret == 0) { | 
|  | dev_dbg(hdq_data->dev, "TX wait elapsed\n"); | 
|  | ret = -ETIMEDOUT; | 
|  | goto out; | 
|  | } | 
|  |  | 
|  | /* check irqstatus */ | 
|  | if (!(*status & OMAP_HDQ_INT_STATUS_TXCOMPLETE)) { | 
|  | dev_dbg(hdq_data->dev, "timeout waiting for" | 
|  | " TXCOMPLETE/RXCOMPLETE, %x\n", *status); | 
|  | ret = -ETIMEDOUT; | 
|  | goto out; | 
|  | } | 
|  |  | 
|  | /* wait for the GO bit return to zero */ | 
|  | ret = hdq_wait_for_flag(hdq_data, OMAP_HDQ_CTRL_STATUS, | 
|  | OMAP_HDQ_CTRL_STATUS_GO, | 
|  | OMAP_HDQ_FLAG_CLEAR, &tmp_status); | 
|  | if (ret) { | 
|  | dev_dbg(hdq_data->dev, "timeout waiting GO bit" | 
|  | " return to zero, %x\n", tmp_status); | 
|  | } | 
|  |  | 
|  | out: | 
|  | mutex_unlock(&hdq_data->hdq_mutex); | 
|  | rtn: | 
|  | return ret; | 
|  | } | 
|  |  | 
|  | /* HDQ Interrupt service routine */ | 
|  | static irqreturn_t hdq_isr(int irq, void *_hdq) | 
|  | { | 
|  | struct hdq_data *hdq_data = _hdq; | 
|  | unsigned long irqflags; | 
|  |  | 
|  | spin_lock_irqsave(&hdq_data->hdq_spinlock, irqflags); | 
|  | hdq_data->hdq_irqstatus |= hdq_reg_in(hdq_data, OMAP_HDQ_INT_STATUS); | 
|  | spin_unlock_irqrestore(&hdq_data->hdq_spinlock, irqflags); | 
|  | dev_dbg(hdq_data->dev, "hdq_isr: %x\n", hdq_data->hdq_irqstatus); | 
|  |  | 
|  | if (hdq_data->hdq_irqstatus & | 
|  | (OMAP_HDQ_INT_STATUS_TXCOMPLETE | OMAP_HDQ_INT_STATUS_RXCOMPLETE | 
|  | | OMAP_HDQ_INT_STATUS_TIMEOUT)) { | 
|  | /* wake up sleeping process */ | 
|  | wake_up(&hdq_wait_queue); | 
|  | } | 
|  |  | 
|  | return IRQ_HANDLED; | 
|  | } | 
|  |  | 
|  | /* W1 search callback function  in HDQ mode */ | 
|  | static void omap_w1_search_bus(void *_hdq, struct w1_master *master_dev, | 
|  | u8 search_type, w1_slave_found_callback slave_found) | 
|  | { | 
|  | u64 module_id, rn_le, cs, id; | 
|  |  | 
|  | if (w1_id) | 
|  | module_id = w1_id; | 
|  | else | 
|  | module_id = 0x1; | 
|  |  | 
|  | rn_le = cpu_to_le64(module_id); | 
|  | /* | 
|  | * HDQ might not obey truly the 1-wire spec. | 
|  | * So calculate CRC based on module parameter. | 
|  | */ | 
|  | cs = w1_calc_crc8((u8 *)&rn_le, 7); | 
|  | id = (cs << 56) | module_id; | 
|  |  | 
|  | slave_found(master_dev, id); | 
|  | } | 
|  |  | 
|  | /* Issue break pulse to the device */ | 
|  | static int omap_hdq_break(struct hdq_data *hdq_data) | 
|  | { | 
|  | int ret = 0; | 
|  | u8 tmp_status; | 
|  |  | 
|  | ret = mutex_lock_interruptible(&hdq_data->hdq_mutex); | 
|  | if (ret < 0) { | 
|  | dev_dbg(hdq_data->dev, "Could not acquire mutex\n"); | 
|  | ret = -EINTR; | 
|  | goto rtn; | 
|  | } | 
|  |  | 
|  | if (hdq_data->hdq_irqstatus) | 
|  | dev_err(hdq_data->dev, "break irqstatus not cleared (%02x)\n", | 
|  | hdq_data->hdq_irqstatus); | 
|  |  | 
|  | /* set the INIT and GO bit */ | 
|  | hdq_reg_merge(hdq_data, OMAP_HDQ_CTRL_STATUS, | 
|  | OMAP_HDQ_CTRL_STATUS_INITIALIZATION | OMAP_HDQ_CTRL_STATUS_GO, | 
|  | OMAP_HDQ_CTRL_STATUS_DIR | OMAP_HDQ_CTRL_STATUS_INITIALIZATION | | 
|  | OMAP_HDQ_CTRL_STATUS_GO); | 
|  |  | 
|  | /* wait for the TIMEOUT bit */ | 
|  | ret = wait_event_timeout(hdq_wait_queue, | 
|  | (hdq_data->hdq_irqstatus & OMAP_HDQ_INT_STATUS_TIMEOUT), | 
|  | OMAP_HDQ_TIMEOUT); | 
|  | tmp_status = hdq_reset_irqstatus(hdq_data, OMAP_HDQ_INT_STATUS_TIMEOUT); | 
|  | if (ret == 0) { | 
|  | dev_dbg(hdq_data->dev, "break wait elapsed\n"); | 
|  | ret = -EINTR; | 
|  | goto out; | 
|  | } | 
|  |  | 
|  | /* check irqstatus */ | 
|  | if (!(tmp_status & OMAP_HDQ_INT_STATUS_TIMEOUT)) { | 
|  | dev_dbg(hdq_data->dev, "timeout waiting for TIMEOUT, %x\n", | 
|  | tmp_status); | 
|  | ret = -ETIMEDOUT; | 
|  | goto out; | 
|  | } | 
|  |  | 
|  | /* | 
|  | * check for the presence detect bit to get | 
|  | * set to show that the slave is responding | 
|  | */ | 
|  | if (!(hdq_reg_in(hdq_data, OMAP_HDQ_CTRL_STATUS) & | 
|  | OMAP_HDQ_CTRL_STATUS_PRESENCE)) { | 
|  | dev_dbg(hdq_data->dev, "Presence bit not set\n"); | 
|  | ret = -ETIMEDOUT; | 
|  | goto out; | 
|  | } | 
|  |  | 
|  | /* | 
|  | * wait for both INIT and GO bits rerurn to zero. | 
|  | * zero wait time expected for interrupt mode. | 
|  | */ | 
|  | ret = hdq_wait_for_flag(hdq_data, OMAP_HDQ_CTRL_STATUS, | 
|  | OMAP_HDQ_CTRL_STATUS_INITIALIZATION | | 
|  | OMAP_HDQ_CTRL_STATUS_GO, OMAP_HDQ_FLAG_CLEAR, | 
|  | &tmp_status); | 
|  | if (ret) | 
|  | dev_dbg(hdq_data->dev, "timeout waiting INIT&GO bits" | 
|  | " return to zero, %x\n", tmp_status); | 
|  |  | 
|  | out: | 
|  | mutex_unlock(&hdq_data->hdq_mutex); | 
|  | rtn: | 
|  | return ret; | 
|  | } | 
|  |  | 
|  | static int hdq_read_byte(struct hdq_data *hdq_data, u8 *val) | 
|  | { | 
|  | int ret = 0; | 
|  | u8 status; | 
|  |  | 
|  | ret = mutex_lock_interruptible(&hdq_data->hdq_mutex); | 
|  | if (ret < 0) { | 
|  | ret = -EINTR; | 
|  | goto rtn; | 
|  | } | 
|  |  | 
|  | if (pm_runtime_suspended(hdq_data->dev)) { | 
|  | ret = -EINVAL; | 
|  | goto out; | 
|  | } | 
|  |  | 
|  | if (!(hdq_data->hdq_irqstatus & OMAP_HDQ_INT_STATUS_RXCOMPLETE)) { | 
|  | hdq_reg_merge(hdq_data, OMAP_HDQ_CTRL_STATUS, | 
|  | OMAP_HDQ_CTRL_STATUS_DIR | OMAP_HDQ_CTRL_STATUS_GO, | 
|  | OMAP_HDQ_CTRL_STATUS_DIR | OMAP_HDQ_CTRL_STATUS_GO); | 
|  | /* | 
|  | * The RX comes immediately after TX. | 
|  | */ | 
|  | wait_event_timeout(hdq_wait_queue, | 
|  | (hdq_data->hdq_irqstatus | 
|  | & (OMAP_HDQ_INT_STATUS_RXCOMPLETE | | 
|  | OMAP_HDQ_INT_STATUS_TIMEOUT)), | 
|  | OMAP_HDQ_TIMEOUT); | 
|  | status = hdq_reset_irqstatus(hdq_data, | 
|  | OMAP_HDQ_INT_STATUS_RXCOMPLETE | | 
|  | OMAP_HDQ_INT_STATUS_TIMEOUT); | 
|  | hdq_reg_merge(hdq_data, OMAP_HDQ_CTRL_STATUS, 0, | 
|  | OMAP_HDQ_CTRL_STATUS_DIR); | 
|  |  | 
|  | /* check irqstatus */ | 
|  | if (!(status & OMAP_HDQ_INT_STATUS_RXCOMPLETE)) { | 
|  | dev_dbg(hdq_data->dev, "timeout waiting for" | 
|  | " RXCOMPLETE, %x", status); | 
|  | ret = -ETIMEDOUT; | 
|  | goto out; | 
|  | } | 
|  | } else { /* interrupt had occurred before hdq_read_byte was called */ | 
|  | hdq_reset_irqstatus(hdq_data, OMAP_HDQ_INT_STATUS_RXCOMPLETE); | 
|  | } | 
|  | /* the data is ready. Read it in! */ | 
|  | *val = hdq_reg_in(hdq_data, OMAP_HDQ_RX_DATA); | 
|  | out: | 
|  | mutex_unlock(&hdq_data->hdq_mutex); | 
|  | rtn: | 
|  | return ret; | 
|  |  | 
|  | } | 
|  |  | 
|  | /* | 
|  | * W1 triplet callback function - used for searching ROM addresses. | 
|  | * Registered only when controller is in 1-wire mode. | 
|  | */ | 
|  | static u8 omap_w1_triplet(void *_hdq, u8 bdir) | 
|  | { | 
|  | u8 id_bit, comp_bit; | 
|  | int err; | 
|  | u8 ret = 0x3; /* no slaves responded */ | 
|  | struct hdq_data *hdq_data = _hdq; | 
|  | u8 ctrl = OMAP_HDQ_CTRL_STATUS_SINGLE | OMAP_HDQ_CTRL_STATUS_GO | | 
|  | OMAP_HDQ_CTRL_STATUS_INTERRUPTMASK; | 
|  | u8 mask = ctrl | OMAP_HDQ_CTRL_STATUS_DIR; | 
|  |  | 
|  | err = pm_runtime_get_sync(hdq_data->dev); | 
|  | if (err < 0) { | 
|  | pm_runtime_put_noidle(hdq_data->dev); | 
|  |  | 
|  | return err; | 
|  | } | 
|  |  | 
|  | err = mutex_lock_interruptible(&hdq_data->hdq_mutex); | 
|  | if (err < 0) { | 
|  | dev_dbg(hdq_data->dev, "Could not acquire mutex\n"); | 
|  | goto rtn; | 
|  | } | 
|  |  | 
|  | /* read id_bit */ | 
|  | hdq_reg_merge(_hdq, OMAP_HDQ_CTRL_STATUS, | 
|  | ctrl | OMAP_HDQ_CTRL_STATUS_DIR, mask); | 
|  | err = wait_event_timeout(hdq_wait_queue, | 
|  | (hdq_data->hdq_irqstatus | 
|  | & OMAP_HDQ_INT_STATUS_RXCOMPLETE), | 
|  | OMAP_HDQ_TIMEOUT); | 
|  | /* Must clear irqstatus for another RXCOMPLETE interrupt */ | 
|  | hdq_reset_irqstatus(hdq_data, OMAP_HDQ_INT_STATUS_RXCOMPLETE); | 
|  |  | 
|  | if (err == 0) { | 
|  | dev_dbg(hdq_data->dev, "RX wait elapsed\n"); | 
|  | goto out; | 
|  | } | 
|  | id_bit = (hdq_reg_in(_hdq, OMAP_HDQ_RX_DATA) & 0x01); | 
|  |  | 
|  | /* read comp_bit */ | 
|  | hdq_reg_merge(_hdq, OMAP_HDQ_CTRL_STATUS, | 
|  | ctrl | OMAP_HDQ_CTRL_STATUS_DIR, mask); | 
|  | err = wait_event_timeout(hdq_wait_queue, | 
|  | (hdq_data->hdq_irqstatus | 
|  | & OMAP_HDQ_INT_STATUS_RXCOMPLETE), | 
|  | OMAP_HDQ_TIMEOUT); | 
|  | /* Must clear irqstatus for another RXCOMPLETE interrupt */ | 
|  | hdq_reset_irqstatus(hdq_data, OMAP_HDQ_INT_STATUS_RXCOMPLETE); | 
|  |  | 
|  | if (err == 0) { | 
|  | dev_dbg(hdq_data->dev, "RX wait elapsed\n"); | 
|  | goto out; | 
|  | } | 
|  | comp_bit = (hdq_reg_in(_hdq, OMAP_HDQ_RX_DATA) & 0x01); | 
|  |  | 
|  | if (id_bit && comp_bit) { | 
|  | ret = 0x03;  /* no slaves responded */ | 
|  | goto out; | 
|  | } | 
|  | if (!id_bit && !comp_bit) { | 
|  | /* Both bits are valid, take the direction given */ | 
|  | ret = bdir ? 0x04 : 0; | 
|  | } else { | 
|  | /* Only one bit is valid, take that direction */ | 
|  | bdir = id_bit; | 
|  | ret = id_bit ? 0x05 : 0x02; | 
|  | } | 
|  |  | 
|  | /* write bdir bit */ | 
|  | hdq_reg_out(_hdq, OMAP_HDQ_TX_DATA, bdir); | 
|  | hdq_reg_merge(_hdq, OMAP_HDQ_CTRL_STATUS, ctrl, mask); | 
|  | err = wait_event_timeout(hdq_wait_queue, | 
|  | (hdq_data->hdq_irqstatus | 
|  | & OMAP_HDQ_INT_STATUS_TXCOMPLETE), | 
|  | OMAP_HDQ_TIMEOUT); | 
|  | /* Must clear irqstatus for another TXCOMPLETE interrupt */ | 
|  | hdq_reset_irqstatus(hdq_data, OMAP_HDQ_INT_STATUS_TXCOMPLETE); | 
|  |  | 
|  | if (err == 0) { | 
|  | dev_dbg(hdq_data->dev, "TX wait elapsed\n"); | 
|  | goto out; | 
|  | } | 
|  |  | 
|  | hdq_reg_merge(_hdq, OMAP_HDQ_CTRL_STATUS, 0, | 
|  | OMAP_HDQ_CTRL_STATUS_SINGLE); | 
|  |  | 
|  | out: | 
|  | mutex_unlock(&hdq_data->hdq_mutex); | 
|  | rtn: | 
|  | pm_runtime_mark_last_busy(hdq_data->dev); | 
|  | pm_runtime_put_autosuspend(hdq_data->dev); | 
|  |  | 
|  | return ret; | 
|  | } | 
|  |  | 
|  | /* reset callback */ | 
|  | static u8 omap_w1_reset_bus(void *_hdq) | 
|  | { | 
|  | struct hdq_data *hdq_data = _hdq; | 
|  | int err; | 
|  |  | 
|  | err = pm_runtime_get_sync(hdq_data->dev); | 
|  | if (err < 0) { | 
|  | pm_runtime_put_noidle(hdq_data->dev); | 
|  |  | 
|  | return err; | 
|  | } | 
|  |  | 
|  | omap_hdq_break(hdq_data); | 
|  |  | 
|  | pm_runtime_mark_last_busy(hdq_data->dev); | 
|  | pm_runtime_put_autosuspend(hdq_data->dev); | 
|  |  | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | /* Read a byte of data from the device */ | 
|  | static u8 omap_w1_read_byte(void *_hdq) | 
|  | { | 
|  | struct hdq_data *hdq_data = _hdq; | 
|  | u8 val = 0; | 
|  | int ret; | 
|  |  | 
|  | ret = pm_runtime_get_sync(hdq_data->dev); | 
|  | if (ret < 0) { | 
|  | pm_runtime_put_noidle(hdq_data->dev); | 
|  |  | 
|  | return -1; | 
|  | } | 
|  |  | 
|  | ret = hdq_read_byte(hdq_data, &val); | 
|  | if (ret) | 
|  | val = -1; | 
|  |  | 
|  | pm_runtime_mark_last_busy(hdq_data->dev); | 
|  | pm_runtime_put_autosuspend(hdq_data->dev); | 
|  |  | 
|  | return val; | 
|  | } | 
|  |  | 
|  | /* Write a byte of data to the device */ | 
|  | static void omap_w1_write_byte(void *_hdq, u8 byte) | 
|  | { | 
|  | struct hdq_data *hdq_data = _hdq; | 
|  | int ret; | 
|  | u8 status; | 
|  |  | 
|  | ret = pm_runtime_get_sync(hdq_data->dev); | 
|  | if (ret < 0) { | 
|  | pm_runtime_put_noidle(hdq_data->dev); | 
|  |  | 
|  | return; | 
|  | } | 
|  |  | 
|  | /* | 
|  | * We need to reset the slave before | 
|  | * issuing the SKIP ROM command, else | 
|  | * the slave will not work. | 
|  | */ | 
|  | if (byte == W1_SKIP_ROM) | 
|  | omap_hdq_break(hdq_data); | 
|  |  | 
|  | ret = hdq_write_byte(hdq_data, byte, &status); | 
|  | if (ret < 0) { | 
|  | dev_dbg(hdq_data->dev, "TX failure:Ctrl status %x\n", status); | 
|  | goto out_err; | 
|  | } | 
|  |  | 
|  | out_err: | 
|  | pm_runtime_mark_last_busy(hdq_data->dev); | 
|  | pm_runtime_put_autosuspend(hdq_data->dev); | 
|  | } | 
|  |  | 
|  | static struct w1_bus_master omap_w1_master = { | 
|  | .read_byte	= omap_w1_read_byte, | 
|  | .write_byte	= omap_w1_write_byte, | 
|  | .reset_bus	= omap_w1_reset_bus, | 
|  | }; | 
|  |  | 
|  | static int __maybe_unused omap_hdq_runtime_suspend(struct device *dev) | 
|  | { | 
|  | struct hdq_data *hdq_data = dev_get_drvdata(dev); | 
|  |  | 
|  | hdq_reg_out(hdq_data, 0, hdq_data->mode); | 
|  | hdq_reg_in(hdq_data, OMAP_HDQ_INT_STATUS); | 
|  |  | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | static int __maybe_unused omap_hdq_runtime_resume(struct device *dev) | 
|  | { | 
|  | struct hdq_data *hdq_data = dev_get_drvdata(dev); | 
|  |  | 
|  | /* select HDQ/1W mode & enable clocks */ | 
|  | hdq_reg_out(hdq_data, OMAP_HDQ_CTRL_STATUS, | 
|  | OMAP_HDQ_CTRL_STATUS_CLOCKENABLE | | 
|  | OMAP_HDQ_CTRL_STATUS_INTERRUPTMASK | | 
|  | hdq_data->mode); | 
|  | hdq_reg_in(hdq_data, OMAP_HDQ_INT_STATUS); | 
|  |  | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | static const struct dev_pm_ops omap_hdq_pm_ops = { | 
|  | SET_RUNTIME_PM_OPS(omap_hdq_runtime_suspend, | 
|  | omap_hdq_runtime_resume, NULL) | 
|  | }; | 
|  |  | 
|  | static int omap_hdq_probe(struct platform_device *pdev) | 
|  | { | 
|  | struct device *dev = &pdev->dev; | 
|  | struct hdq_data *hdq_data; | 
|  | int ret, irq; | 
|  | u8 rev; | 
|  | const char *mode; | 
|  |  | 
|  | hdq_data = devm_kzalloc(dev, sizeof(*hdq_data), GFP_KERNEL); | 
|  | if (!hdq_data) | 
|  | return -ENOMEM; | 
|  |  | 
|  | hdq_data->dev = dev; | 
|  | platform_set_drvdata(pdev, hdq_data); | 
|  |  | 
|  | hdq_data->hdq_base = devm_platform_ioremap_resource(pdev, 0); | 
|  | if (IS_ERR(hdq_data->hdq_base)) | 
|  | return PTR_ERR(hdq_data->hdq_base); | 
|  |  | 
|  | mutex_init(&hdq_data->hdq_mutex); | 
|  |  | 
|  | ret = of_property_read_string(pdev->dev.of_node, "ti,mode", &mode); | 
|  | if (ret < 0 || !strcmp(mode, "hdq")) { | 
|  | hdq_data->mode = 0; | 
|  | omap_w1_master.search = omap_w1_search_bus; | 
|  | } else { | 
|  | hdq_data->mode = 1; | 
|  | omap_w1_master.triplet = omap_w1_triplet; | 
|  | } | 
|  |  | 
|  | pm_runtime_enable(&pdev->dev); | 
|  | pm_runtime_use_autosuspend(&pdev->dev); | 
|  | pm_runtime_set_autosuspend_delay(&pdev->dev, 300); | 
|  | ret = pm_runtime_get_sync(&pdev->dev); | 
|  | if (ret < 0) { | 
|  | pm_runtime_put_noidle(&pdev->dev); | 
|  | dev_dbg(&pdev->dev, "pm_runtime_get_sync failed\n"); | 
|  | goto err_w1; | 
|  | } | 
|  |  | 
|  | rev = hdq_reg_in(hdq_data, OMAP_HDQ_REVISION); | 
|  | dev_info(&pdev->dev, "OMAP HDQ Hardware Rev %c.%c. Driver in %s mode\n", | 
|  | (rev >> 4) + '0', (rev & 0x0f) + '0', "Interrupt"); | 
|  |  | 
|  | spin_lock_init(&hdq_data->hdq_spinlock); | 
|  |  | 
|  | irq = platform_get_irq(pdev, 0); | 
|  | if (irq	< 0) { | 
|  | dev_dbg(&pdev->dev, "Failed to get IRQ: %d\n", irq); | 
|  | ret = irq; | 
|  | goto err_irq; | 
|  | } | 
|  |  | 
|  | ret = devm_request_irq(dev, irq, hdq_isr, 0, "omap_hdq", hdq_data); | 
|  | if (ret < 0) { | 
|  | dev_dbg(&pdev->dev, "could not request irq\n"); | 
|  | goto err_irq; | 
|  | } | 
|  |  | 
|  | omap_hdq_break(hdq_data); | 
|  |  | 
|  | pm_runtime_mark_last_busy(&pdev->dev); | 
|  | pm_runtime_put_autosuspend(&pdev->dev); | 
|  |  | 
|  | omap_w1_master.data = hdq_data; | 
|  |  | 
|  | ret = w1_add_master_device(&omap_w1_master); | 
|  | if (ret) { | 
|  | dev_dbg(&pdev->dev, "Failure in registering w1 master\n"); | 
|  | goto err_w1; | 
|  | } | 
|  |  | 
|  | return 0; | 
|  |  | 
|  | err_irq: | 
|  | pm_runtime_put_sync(&pdev->dev); | 
|  | err_w1: | 
|  | pm_runtime_dont_use_autosuspend(&pdev->dev); | 
|  | pm_runtime_disable(&pdev->dev); | 
|  |  | 
|  | return ret; | 
|  | } | 
|  |  | 
|  | static int omap_hdq_remove(struct platform_device *pdev) | 
|  | { | 
|  | int active; | 
|  |  | 
|  | active = pm_runtime_get_sync(&pdev->dev); | 
|  | if (active < 0) | 
|  | pm_runtime_put_noidle(&pdev->dev); | 
|  |  | 
|  | w1_remove_master_device(&omap_w1_master); | 
|  |  | 
|  | pm_runtime_dont_use_autosuspend(&pdev->dev); | 
|  | if (active >= 0) | 
|  | pm_runtime_put_sync(&pdev->dev); | 
|  | pm_runtime_disable(&pdev->dev); | 
|  |  | 
|  | return 0; | 
|  | } | 
|  |  | 
|  | static const struct of_device_id omap_hdq_dt_ids[] = { | 
|  | { .compatible = "ti,omap3-1w" }, | 
|  | { .compatible = "ti,am4372-hdq" }, | 
|  | {} | 
|  | }; | 
|  | MODULE_DEVICE_TABLE(of, omap_hdq_dt_ids); | 
|  |  | 
|  | static struct platform_driver omap_hdq_driver = { | 
|  | .probe = omap_hdq_probe, | 
|  | .remove = omap_hdq_remove, | 
|  | .driver = { | 
|  | .name =	"omap_hdq", | 
|  | .of_match_table = omap_hdq_dt_ids, | 
|  | .pm = &omap_hdq_pm_ops, | 
|  | }, | 
|  | }; | 
|  | module_platform_driver(omap_hdq_driver); | 
|  |  | 
|  | MODULE_AUTHOR("Texas Instruments"); | 
|  | MODULE_DESCRIPTION("HDQ-1W driver Library"); | 
|  | MODULE_LICENSE("GPL"); |