diff options
Diffstat (limited to 'drivers/w1/masters/omap_hdq.c')
| -rw-r--r-- | drivers/w1/masters/omap_hdq.c | 642 |
1 files changed, 642 insertions, 0 deletions
diff --git a/drivers/w1/masters/omap_hdq.c b/drivers/w1/masters/omap_hdq.c new file mode 100644 index 000000000..e7d448963 --- /dev/null +++ b/drivers/w1/masters/omap_hdq.c @@ -0,0 +1,642 @@ +/* + * drivers/w1/masters/omap_hdq.c + * + * Copyright (C) 2007,2012 Texas Instruments, Inc. + * + * This file is licensed under the terms of the GNU General Public License + * version 2. This program is licensed "as is" without any warranty of any + * kind, whether express or implied. + * + */ +#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 "../w1.h" +#include "../w1_int.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_INTERRUPTMASK (1<<6) +#define OMAP_HDQ_CTRL_STATUS_CLOCKENABLE (1<<5) +#define OMAP_HDQ_CTRL_STATUS_GO (1<<4) +#define OMAP_HDQ_CTRL_STATUS_INITIALIZATION (1<<2) +#define OMAP_HDQ_CTRL_STATUS_DIR (1<<1) +#define OMAP_HDQ_CTRL_STATUS_MODE (1<<0) +#define OMAP_HDQ_INT_STATUS 0x10 +#define OMAP_HDQ_INT_STATUS_TXCOMPLETE (1<<2) +#define OMAP_HDQ_INT_STATUS_RXCOMPLETE (1<<1) +#define OMAP_HDQ_INT_STATUS_TIMEOUT (1<<0) +#define OMAP_HDQ_SYSCONFIG 0x14 +#define OMAP_HDQ_SYSCONFIG_SOFTRESET (1<<1) +#define OMAP_HDQ_SYSCONFIG_AUTOIDLE (1<<0) +#define OMAP_HDQ_SYSSTATUS 0x18 +#define OMAP_HDQ_SYSSTATUS_RESETDONE (1<<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; + +struct hdq_data { + struct device *dev; + void __iomem *hdq_base; + /* lock status update */ + struct mutex hdq_mutex; + int hdq_usecount; + u8 hdq_irqstatus; + /* device lock */ + spinlock_t hdq_spinlock; + /* + * Used to control the call to omap_hdq_get and omap_hdq_put. + * HDQ Protocol: Write the CMD|REG_address first, followed by + * the data wrire or read. + */ + int init_trans; +}; + +static int omap_hdq_probe(struct platform_device *pdev); +static int omap_hdq_remove(struct platform_device *pdev); + +static const struct of_device_id omap_hdq_dt_ids[] = { + { .compatible = "ti,omap3-1w" }, + {} +}; +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, + }, +}; + +static u8 omap_w1_read_byte(void *_hdq); +static void omap_w1_write_byte(void *_hdq, u8 byte); +static u8 omap_w1_reset_bus(void *_hdq); +static void omap_w1_search_bus(void *_hdq, struct w1_master *master_dev, + u8 search_type, w1_slave_found_callback slave_found); + + +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, + .search = omap_w1_search_bus, +}; + +/* 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; +} + +/* 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; + unsigned long irqflags; + + *status = 0; + + spin_lock_irqsave(&hdq_data->hdq_spinlock, irqflags); + /* clear interrupt flags via a dummy read */ + hdq_reg_in(hdq_data, OMAP_HDQ_INT_STATUS); + /* ISR loads it with new INT_STATUS */ + hdq_data->hdq_irqstatus = 0; + spin_unlock_irqrestore(&hdq_data->hdq_spinlock, irqflags); + + 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_TIMEOUT); + if (ret == 0) { + dev_dbg(hdq_data->dev, "TX wait elapsed\n"); + ret = -ETIMEDOUT; + goto out; + } + + *status = hdq_data->hdq_irqstatus; + /* check irqstatus */ + if (!(*status & OMAP_HDQ_INT_STATUS_TXCOMPLETE)) { + dev_dbg(hdq_data->dev, "timeout waiting for" + " TXCOMPLETE/RXCOMPLETE, %x", *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", tmp_status); + } + +out: + 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", 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; +} + +/* HDQ Mode: always return success */ +static u8 omap_w1_reset_bus(void *_hdq) +{ + return 0; +} + +/* W1 search callback function */ +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); +} + +static int _omap_hdq_reset(struct hdq_data *hdq_data) +{ + int ret; + u8 tmp_status; + + hdq_reg_out(hdq_data, OMAP_HDQ_SYSCONFIG, OMAP_HDQ_SYSCONFIG_SOFTRESET); + /* + * Select HDQ mode & enable clocks. + * It is observed that INT flags can't be cleared via a read and GO/INIT + * won't return to zero if interrupt is disabled. So we always enable + * interrupt. + */ + hdq_reg_out(hdq_data, OMAP_HDQ_CTRL_STATUS, + OMAP_HDQ_CTRL_STATUS_CLOCKENABLE | + OMAP_HDQ_CTRL_STATUS_INTERRUPTMASK); + + /* wait for reset to complete */ + ret = hdq_wait_for_flag(hdq_data, OMAP_HDQ_SYSSTATUS, + OMAP_HDQ_SYSSTATUS_RESETDONE, OMAP_HDQ_FLAG_SET, &tmp_status); + if (ret) + dev_dbg(hdq_data->dev, "timeout waiting HDQ reset, %x", + tmp_status); + else { + hdq_reg_out(hdq_data, OMAP_HDQ_CTRL_STATUS, + OMAP_HDQ_CTRL_STATUS_CLOCKENABLE | + OMAP_HDQ_CTRL_STATUS_INTERRUPTMASK); + hdq_reg_out(hdq_data, OMAP_HDQ_SYSCONFIG, + OMAP_HDQ_SYSCONFIG_AUTOIDLE); + } + + return ret; +} + +/* Issue break pulse to the device */ +static int omap_hdq_break(struct hdq_data *hdq_data) +{ + int ret = 0; + u8 tmp_status; + unsigned long irqflags; + + 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; + } + + spin_lock_irqsave(&hdq_data->hdq_spinlock, irqflags); + /* clear interrupt flags via a dummy read */ + hdq_reg_in(hdq_data, OMAP_HDQ_INT_STATUS); + /* ISR loads it with new INT_STATUS */ + hdq_data->hdq_irqstatus = 0; + spin_unlock_irqrestore(&hdq_data->hdq_spinlock, irqflags); + + /* 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_TIMEOUT); + if (ret == 0) { + dev_dbg(hdq_data->dev, "break wait elapsed\n"); + ret = -EINTR; + goto out; + } + + tmp_status = hdq_data->hdq_irqstatus; + /* check irqstatus */ + if (!(tmp_status & OMAP_HDQ_INT_STATUS_TIMEOUT)) { + dev_dbg(hdq_data->dev, "timeout waiting for TIMEOUT, %x", + tmp_status); + 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", 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 (!hdq_data->hdq_usecount) { + 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_TIMEOUT); + + hdq_reg_merge(hdq_data, OMAP_HDQ_CTRL_STATUS, 0, + OMAP_HDQ_CTRL_STATUS_DIR); + status = hdq_data->hdq_irqstatus; + /* check irqstatus */ + if (!(status & OMAP_HDQ_INT_STATUS_RXCOMPLETE)) { + dev_dbg(hdq_data->dev, "timeout waiting for" + " RXCOMPLETE, %x", status); + ret = -ETIMEDOUT; + goto out; + } + } + /* 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; + +} + +/* Enable clocks and set the controller to HDQ mode */ +static int omap_hdq_get(struct hdq_data *hdq_data) +{ + int ret = 0; + + ret = mutex_lock_interruptible(&hdq_data->hdq_mutex); + if (ret < 0) { + ret = -EINTR; + goto rtn; + } + + if (OMAP_HDQ_MAX_USER == hdq_data->hdq_usecount) { + dev_dbg(hdq_data->dev, "attempt to exceed the max use count"); + ret = -EINVAL; + goto out; + } else { + hdq_data->hdq_usecount++; + try_module_get(THIS_MODULE); + if (1 == hdq_data->hdq_usecount) { + + pm_runtime_get_sync(hdq_data->dev); + + /* make sure HDQ is out of reset */ + if (!(hdq_reg_in(hdq_data, OMAP_HDQ_SYSSTATUS) & + OMAP_HDQ_SYSSTATUS_RESETDONE)) { + ret = _omap_hdq_reset(hdq_data); + if (ret) + /* back up the count */ + hdq_data->hdq_usecount--; + } else { + /* select HDQ mode & enable clocks */ + hdq_reg_out(hdq_data, OMAP_HDQ_CTRL_STATUS, + OMAP_HDQ_CTRL_STATUS_CLOCKENABLE | + OMAP_HDQ_CTRL_STATUS_INTERRUPTMASK); + hdq_reg_out(hdq_data, OMAP_HDQ_SYSCONFIG, + OMAP_HDQ_SYSCONFIG_AUTOIDLE); + hdq_reg_in(hdq_data, OMAP_HDQ_INT_STATUS); + } + } + } + +out: + mutex_unlock(&hdq_data->hdq_mutex); +rtn: + return ret; +} + +/* Disable clocks to the module */ +static int omap_hdq_put(struct hdq_data *hdq_data) +{ + int ret = 0; + + ret = mutex_lock_interruptible(&hdq_data->hdq_mutex); + if (ret < 0) + return -EINTR; + + if (0 == hdq_data->hdq_usecount) { + dev_dbg(hdq_data->dev, "attempt to decrement use count" + " when it is zero"); + ret = -EINVAL; + } else { + hdq_data->hdq_usecount--; + module_put(THIS_MODULE); + if (0 == hdq_data->hdq_usecount) + pm_runtime_put_sync(hdq_data->dev); + } + mutex_unlock(&hdq_data->hdq_mutex); + + return ret; +} + +/* 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 = hdq_read_byte(hdq_data, &val); + if (ret) { + ret = mutex_lock_interruptible(&hdq_data->hdq_mutex); + if (ret < 0) { + dev_dbg(hdq_data->dev, "Could not acquire mutex\n"); + return -EINTR; + } + hdq_data->init_trans = 0; + mutex_unlock(&hdq_data->hdq_mutex); + omap_hdq_put(hdq_data); + return -1; + } + + /* Write followed by a read, release the module */ + if (hdq_data->init_trans) { + ret = mutex_lock_interruptible(&hdq_data->hdq_mutex); + if (ret < 0) { + dev_dbg(hdq_data->dev, "Could not acquire mutex\n"); + return -EINTR; + } + hdq_data->init_trans = 0; + mutex_unlock(&hdq_data->hdq_mutex); + omap_hdq_put(hdq_data); + } + + 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; + + /* First write to initialize the transfer */ + if (hdq_data->init_trans == 0) + omap_hdq_get(hdq_data); + + ret = mutex_lock_interruptible(&hdq_data->hdq_mutex); + if (ret < 0) { + dev_dbg(hdq_data->dev, "Could not acquire mutex\n"); + return; + } + hdq_data->init_trans++; + mutex_unlock(&hdq_data->hdq_mutex); + + ret = hdq_write_byte(hdq_data, byte, &status); + if (ret < 0) { + dev_dbg(hdq_data->dev, "TX failure:Ctrl status %x\n", status); + return; + } + + /* Second write, data transferred. Release the module */ + if (hdq_data->init_trans > 1) { + omap_hdq_put(hdq_data); + ret = mutex_lock_interruptible(&hdq_data->hdq_mutex); + if (ret < 0) { + dev_dbg(hdq_data->dev, "Could not acquire mutex\n"); + return; + } + hdq_data->init_trans = 0; + mutex_unlock(&hdq_data->hdq_mutex); + } +} + +static int omap_hdq_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct hdq_data *hdq_data; + struct resource *res; + int ret, irq; + u8 rev; + + hdq_data = devm_kzalloc(dev, sizeof(*hdq_data), GFP_KERNEL); + if (!hdq_data) { + dev_dbg(&pdev->dev, "unable to allocate memory\n"); + return -ENOMEM; + } + + hdq_data->dev = dev; + platform_set_drvdata(pdev, hdq_data); + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + hdq_data->hdq_base = devm_ioremap_resource(dev, res); + if (IS_ERR(hdq_data->hdq_base)) + return PTR_ERR(hdq_data->hdq_base); + + hdq_data->hdq_usecount = 0; + mutex_init(&hdq_data->hdq_mutex); + + pm_runtime_enable(&pdev->dev); + pm_runtime_get_sync(&pdev->dev); + + 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) { + ret = -ENXIO; + 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_put_sync(&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_disable(&pdev->dev); + + return ret; +} + +static int omap_hdq_remove(struct platform_device *pdev) +{ + struct hdq_data *hdq_data = platform_get_drvdata(pdev); + + mutex_lock(&hdq_data->hdq_mutex); + + if (hdq_data->hdq_usecount) { + dev_dbg(&pdev->dev, "removed when use count is not zero\n"); + mutex_unlock(&hdq_data->hdq_mutex); + return -EBUSY; + } + + mutex_unlock(&hdq_data->hdq_mutex); + + /* remove module dependency */ + pm_runtime_disable(&pdev->dev); + + return 0; +} + +module_platform_driver(omap_hdq_driver); + +module_param(w1_id, int, S_IRUSR); +MODULE_PARM_DESC(w1_id, "1-wire id for the slave detection"); + +MODULE_AUTHOR("Texas Instruments"); +MODULE_DESCRIPTION("HDQ driver Library"); +MODULE_LICENSE("GPL"); |