798 lines
20 KiB
C
798 lines
20 KiB
C
/*
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* drivers/w1/masters/omap_hdq.c
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*
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* Copyright (C) 2007,2012 Texas Instruments, Inc.
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*
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* This file is licensed under the terms of the GNU General Public License
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* version 2. This program is licensed "as is" without any warranty of any
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* kind, whether express or implied.
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*
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*/
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/platform_device.h>
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#include <linux/interrupt.h>
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#include <linux/slab.h>
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#include <linux/err.h>
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#include <linux/io.h>
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#include <linux/sched.h>
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#include <linux/pm_runtime.h>
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#include <linux/of.h>
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#include "../w1.h"
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#include "../w1_int.h"
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#define MOD_NAME "OMAP_HDQ:"
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#define OMAP_HDQ_REVISION 0x00
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#define OMAP_HDQ_TX_DATA 0x04
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#define OMAP_HDQ_RX_DATA 0x08
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#define OMAP_HDQ_CTRL_STATUS 0x0c
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#define OMAP_HDQ_CTRL_STATUS_SINGLE BIT(7)
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#define OMAP_HDQ_CTRL_STATUS_INTERRUPTMASK BIT(6)
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#define OMAP_HDQ_CTRL_STATUS_CLOCKENABLE BIT(5)
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#define OMAP_HDQ_CTRL_STATUS_GO BIT(4)
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#define OMAP_HDQ_CTRL_STATUS_PRESENCE BIT(3)
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#define OMAP_HDQ_CTRL_STATUS_INITIALIZATION BIT(2)
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#define OMAP_HDQ_CTRL_STATUS_DIR BIT(1)
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#define OMAP_HDQ_INT_STATUS 0x10
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#define OMAP_HDQ_INT_STATUS_TXCOMPLETE BIT(2)
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#define OMAP_HDQ_INT_STATUS_RXCOMPLETE BIT(1)
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#define OMAP_HDQ_INT_STATUS_TIMEOUT BIT(0)
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#define OMAP_HDQ_SYSCONFIG 0x14
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#define OMAP_HDQ_SYSCONFIG_SOFTRESET BIT(1)
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#define OMAP_HDQ_SYSCONFIG_AUTOIDLE BIT(0)
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#define OMAP_HDQ_SYSCONFIG_NOIDLE 0x0
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#define OMAP_HDQ_SYSSTATUS 0x18
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#define OMAP_HDQ_SYSSTATUS_RESETDONE BIT(0)
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#define OMAP_HDQ_FLAG_CLEAR 0
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#define OMAP_HDQ_FLAG_SET 1
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#define OMAP_HDQ_TIMEOUT (HZ/5)
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#define OMAP_HDQ_MAX_USER 4
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static DECLARE_WAIT_QUEUE_HEAD(hdq_wait_queue);
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static int w1_id;
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struct hdq_data {
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struct device *dev;
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void __iomem *hdq_base;
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/* lock status update */
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struct mutex hdq_mutex;
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int hdq_usecount;
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u8 hdq_irqstatus;
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/* device lock */
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spinlock_t hdq_spinlock;
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/*
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* Used to control the call to omap_hdq_get and omap_hdq_put.
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* HDQ Protocol: Write the CMD|REG_address first, followed by
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* the data wrire or read.
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*/
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int init_trans;
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int rrw;
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/* mode: 0-HDQ 1-W1 */
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int mode;
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};
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static int omap_hdq_probe(struct platform_device *pdev);
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static int omap_hdq_remove(struct platform_device *pdev);
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static const struct of_device_id omap_hdq_dt_ids[] = {
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{ .compatible = "ti,omap3-1w" },
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{ .compatible = "ti,am4372-hdq" },
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{}
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};
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MODULE_DEVICE_TABLE(of, omap_hdq_dt_ids);
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static struct platform_driver omap_hdq_driver = {
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.probe = omap_hdq_probe,
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.remove = omap_hdq_remove,
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.driver = {
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.name = "omap_hdq",
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.of_match_table = omap_hdq_dt_ids,
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},
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};
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static u8 omap_w1_read_byte(void *_hdq);
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static void omap_w1_write_byte(void *_hdq, u8 byte);
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static u8 omap_w1_reset_bus(void *_hdq);
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static struct w1_bus_master omap_w1_master = {
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.read_byte = omap_w1_read_byte,
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.write_byte = omap_w1_write_byte,
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.reset_bus = omap_w1_reset_bus,
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};
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/* HDQ register I/O routines */
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static inline u8 hdq_reg_in(struct hdq_data *hdq_data, u32 offset)
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{
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return __raw_readl(hdq_data->hdq_base + offset);
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}
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static inline void hdq_reg_out(struct hdq_data *hdq_data, u32 offset, u8 val)
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{
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__raw_writel(val, hdq_data->hdq_base + offset);
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}
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static inline u8 hdq_reg_merge(struct hdq_data *hdq_data, u32 offset,
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u8 val, u8 mask)
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{
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u8 new_val = (__raw_readl(hdq_data->hdq_base + offset) & ~mask)
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| (val & mask);
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__raw_writel(new_val, hdq_data->hdq_base + offset);
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return new_val;
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}
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static void hdq_disable_interrupt(struct hdq_data *hdq_data, u32 offset,
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u32 mask)
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{
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u32 ie;
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ie = readl(hdq_data->hdq_base + offset);
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writel(ie & mask, hdq_data->hdq_base + offset);
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}
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/*
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* Wait for one or more bits in flag change.
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* HDQ_FLAG_SET: wait until any bit in the flag is set.
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* HDQ_FLAG_CLEAR: wait until all bits in the flag are cleared.
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* return 0 on success and -ETIMEDOUT in the case of timeout.
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*/
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static int hdq_wait_for_flag(struct hdq_data *hdq_data, u32 offset,
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u8 flag, u8 flag_set, u8 *status)
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{
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int ret = 0;
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unsigned long timeout = jiffies + OMAP_HDQ_TIMEOUT;
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if (flag_set == OMAP_HDQ_FLAG_CLEAR) {
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/* wait for the flag clear */
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while (((*status = hdq_reg_in(hdq_data, offset)) & flag)
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&& time_before(jiffies, timeout)) {
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schedule_timeout_uninterruptible(1);
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}
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if (*status & flag)
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ret = -ETIMEDOUT;
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} else if (flag_set == OMAP_HDQ_FLAG_SET) {
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/* wait for the flag set */
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while (!((*status = hdq_reg_in(hdq_data, offset)) & flag)
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&& time_before(jiffies, timeout)) {
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schedule_timeout_uninterruptible(1);
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}
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if (!(*status & flag))
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ret = -ETIMEDOUT;
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} else
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return -EINVAL;
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return ret;
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}
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/* write out a byte and fill *status with HDQ_INT_STATUS */
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static int hdq_write_byte(struct hdq_data *hdq_data, u8 val, u8 *status)
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{
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int ret;
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u8 tmp_status;
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unsigned long irqflags;
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*status = 0;
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spin_lock_irqsave(&hdq_data->hdq_spinlock, irqflags);
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/* clear interrupt flags via a dummy read */
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hdq_reg_in(hdq_data, OMAP_HDQ_INT_STATUS);
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/* ISR loads it with new INT_STATUS */
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hdq_data->hdq_irqstatus = 0;
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spin_unlock_irqrestore(&hdq_data->hdq_spinlock, irqflags);
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hdq_reg_out(hdq_data, OMAP_HDQ_TX_DATA, val);
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/* set the GO bit */
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hdq_reg_merge(hdq_data, OMAP_HDQ_CTRL_STATUS, OMAP_HDQ_CTRL_STATUS_GO,
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OMAP_HDQ_CTRL_STATUS_DIR | OMAP_HDQ_CTRL_STATUS_GO);
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/* wait for the TXCOMPLETE bit */
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ret = wait_event_timeout(hdq_wait_queue,
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hdq_data->hdq_irqstatus, OMAP_HDQ_TIMEOUT);
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if (ret == 0) {
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dev_dbg(hdq_data->dev, "TX wait elapsed\n");
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ret = -ETIMEDOUT;
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goto out;
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}
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*status = hdq_data->hdq_irqstatus;
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/* check irqstatus */
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if (!(*status & OMAP_HDQ_INT_STATUS_TXCOMPLETE)) {
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dev_dbg(hdq_data->dev, "timeout waiting for"
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" TXCOMPLETE/RXCOMPLETE, %x", *status);
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ret = -ETIMEDOUT;
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goto out;
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}
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/* wait for the GO bit return to zero */
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ret = hdq_wait_for_flag(hdq_data, OMAP_HDQ_CTRL_STATUS,
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OMAP_HDQ_CTRL_STATUS_GO,
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OMAP_HDQ_FLAG_CLEAR, &tmp_status);
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if (ret) {
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dev_dbg(hdq_data->dev, "timeout waiting GO bit"
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" return to zero, %x", tmp_status);
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}
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out:
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return ret;
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}
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/* HDQ Interrupt service routine */
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static irqreturn_t hdq_isr(int irq, void *_hdq)
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{
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struct hdq_data *hdq_data = _hdq;
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unsigned long irqflags;
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spin_lock_irqsave(&hdq_data->hdq_spinlock, irqflags);
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hdq_data->hdq_irqstatus = hdq_reg_in(hdq_data, OMAP_HDQ_INT_STATUS);
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spin_unlock_irqrestore(&hdq_data->hdq_spinlock, irqflags);
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dev_dbg(hdq_data->dev, "hdq_isr: %x", hdq_data->hdq_irqstatus);
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if (hdq_data->hdq_irqstatus &
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(OMAP_HDQ_INT_STATUS_TXCOMPLETE | OMAP_HDQ_INT_STATUS_RXCOMPLETE
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| OMAP_HDQ_INT_STATUS_TIMEOUT)) {
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/* wake up sleeping process */
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wake_up(&hdq_wait_queue);
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}
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return IRQ_HANDLED;
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}
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/* W1 search callback function in HDQ mode */
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static void omap_w1_search_bus(void *_hdq, struct w1_master *master_dev,
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u8 search_type, w1_slave_found_callback slave_found)
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{
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u64 module_id, rn_le, cs, id;
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if (w1_id)
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module_id = w1_id;
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else
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module_id = 0x1;
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rn_le = cpu_to_le64(module_id);
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/*
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* HDQ might not obey truly the 1-wire spec.
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* So calculate CRC based on module parameter.
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*/
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cs = w1_calc_crc8((u8 *)&rn_le, 7);
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id = (cs << 56) | module_id;
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slave_found(master_dev, id);
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}
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static int _omap_hdq_reset(struct hdq_data *hdq_data)
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{
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int ret;
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u8 tmp_status;
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hdq_reg_out(hdq_data, OMAP_HDQ_SYSCONFIG,
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OMAP_HDQ_SYSCONFIG_SOFTRESET);
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/*
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* Select HDQ/1W mode & enable clocks.
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* It is observed that INT flags can't be cleared via a read and GO/INIT
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* won't return to zero if interrupt is disabled. So we always enable
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* interrupt.
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*/
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hdq_reg_out(hdq_data, OMAP_HDQ_CTRL_STATUS,
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OMAP_HDQ_CTRL_STATUS_CLOCKENABLE |
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OMAP_HDQ_CTRL_STATUS_INTERRUPTMASK);
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/* wait for reset to complete */
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ret = hdq_wait_for_flag(hdq_data, OMAP_HDQ_SYSSTATUS,
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OMAP_HDQ_SYSSTATUS_RESETDONE, OMAP_HDQ_FLAG_SET, &tmp_status);
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if (ret)
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dev_dbg(hdq_data->dev, "timeout waiting HDQ reset, %x",
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tmp_status);
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else {
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hdq_reg_out(hdq_data, OMAP_HDQ_CTRL_STATUS,
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OMAP_HDQ_CTRL_STATUS_CLOCKENABLE |
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OMAP_HDQ_CTRL_STATUS_INTERRUPTMASK |
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hdq_data->mode);
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hdq_reg_out(hdq_data, OMAP_HDQ_SYSCONFIG,
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OMAP_HDQ_SYSCONFIG_AUTOIDLE);
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}
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return ret;
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}
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/* Issue break pulse to the device */
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static int omap_hdq_break(struct hdq_data *hdq_data)
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{
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int ret = 0;
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u8 tmp_status;
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unsigned long irqflags;
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ret = mutex_lock_interruptible(&hdq_data->hdq_mutex);
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if (ret < 0) {
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dev_dbg(hdq_data->dev, "Could not acquire mutex\n");
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ret = -EINTR;
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goto rtn;
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}
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spin_lock_irqsave(&hdq_data->hdq_spinlock, irqflags);
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/* clear interrupt flags via a dummy read */
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hdq_reg_in(hdq_data, OMAP_HDQ_INT_STATUS);
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/* ISR loads it with new INT_STATUS */
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hdq_data->hdq_irqstatus = 0;
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spin_unlock_irqrestore(&hdq_data->hdq_spinlock, irqflags);
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/* set the INIT and GO bit */
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hdq_reg_merge(hdq_data, OMAP_HDQ_CTRL_STATUS,
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OMAP_HDQ_CTRL_STATUS_INITIALIZATION | OMAP_HDQ_CTRL_STATUS_GO,
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OMAP_HDQ_CTRL_STATUS_DIR | OMAP_HDQ_CTRL_STATUS_INITIALIZATION |
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OMAP_HDQ_CTRL_STATUS_GO);
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/* wait for the TIMEOUT bit */
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ret = wait_event_timeout(hdq_wait_queue,
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hdq_data->hdq_irqstatus, OMAP_HDQ_TIMEOUT);
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if (ret == 0) {
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dev_dbg(hdq_data->dev, "break wait elapsed\n");
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ret = -EINTR;
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goto out;
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}
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tmp_status = hdq_data->hdq_irqstatus;
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/* check irqstatus */
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if (!(tmp_status & OMAP_HDQ_INT_STATUS_TIMEOUT)) {
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dev_dbg(hdq_data->dev, "timeout waiting for TIMEOUT, %x",
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tmp_status);
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ret = -ETIMEDOUT;
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goto out;
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}
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/*
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* check for the presence detect bit to get
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* set to show that the slave is responding
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*/
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if (!(hdq_reg_in(hdq_data, OMAP_HDQ_CTRL_STATUS) &
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OMAP_HDQ_CTRL_STATUS_PRESENCE)) {
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dev_dbg(hdq_data->dev, "Presence bit not set\n");
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ret = -ETIMEDOUT;
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goto out;
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}
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/*
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* wait for both INIT and GO bits rerurn to zero.
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* zero wait time expected for interrupt mode.
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*/
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ret = hdq_wait_for_flag(hdq_data, OMAP_HDQ_CTRL_STATUS,
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OMAP_HDQ_CTRL_STATUS_INITIALIZATION |
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OMAP_HDQ_CTRL_STATUS_GO, OMAP_HDQ_FLAG_CLEAR,
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&tmp_status);
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if (ret)
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dev_dbg(hdq_data->dev, "timeout waiting INIT&GO bits"
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" return to zero, %x", tmp_status);
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out:
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mutex_unlock(&hdq_data->hdq_mutex);
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rtn:
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return ret;
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}
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static int hdq_read_byte(struct hdq_data *hdq_data, u8 *val)
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{
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int ret = 0;
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u8 status;
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ret = mutex_lock_interruptible(&hdq_data->hdq_mutex);
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if (ret < 0) {
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ret = -EINTR;
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goto rtn;
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}
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if (!hdq_data->hdq_usecount) {
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ret = -EINVAL;
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goto out;
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}
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if (!(hdq_data->hdq_irqstatus & OMAP_HDQ_INT_STATUS_RXCOMPLETE)) {
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hdq_reg_merge(hdq_data, OMAP_HDQ_CTRL_STATUS,
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OMAP_HDQ_CTRL_STATUS_DIR | OMAP_HDQ_CTRL_STATUS_GO,
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OMAP_HDQ_CTRL_STATUS_DIR | OMAP_HDQ_CTRL_STATUS_GO);
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/*
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* The RX comes immediately after TX.
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*/
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wait_event_timeout(hdq_wait_queue,
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(hdq_data->hdq_irqstatus
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& OMAP_HDQ_INT_STATUS_RXCOMPLETE),
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OMAP_HDQ_TIMEOUT);
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hdq_reg_merge(hdq_data, OMAP_HDQ_CTRL_STATUS, 0,
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OMAP_HDQ_CTRL_STATUS_DIR);
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status = hdq_data->hdq_irqstatus;
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/* check irqstatus */
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if (!(status & OMAP_HDQ_INT_STATUS_RXCOMPLETE)) {
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dev_dbg(hdq_data->dev, "timeout waiting for"
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" RXCOMPLETE, %x", status);
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ret = -ETIMEDOUT;
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goto out;
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}
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}
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/* the data is ready. Read it in! */
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*val = hdq_reg_in(hdq_data, OMAP_HDQ_RX_DATA);
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out:
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mutex_unlock(&hdq_data->hdq_mutex);
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rtn:
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return ret;
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}
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/* Enable clocks and set the controller to HDQ/1W mode */
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static int omap_hdq_get(struct hdq_data *hdq_data)
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{
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int ret = 0;
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ret = mutex_lock_interruptible(&hdq_data->hdq_mutex);
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if (ret < 0) {
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ret = -EINTR;
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goto rtn;
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}
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if (OMAP_HDQ_MAX_USER == hdq_data->hdq_usecount) {
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dev_dbg(hdq_data->dev, "attempt to exceed the max use count");
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ret = -EINVAL;
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goto out;
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} else {
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hdq_data->hdq_usecount++;
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try_module_get(THIS_MODULE);
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if (1 == hdq_data->hdq_usecount) {
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pm_runtime_get_sync(hdq_data->dev);
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/* make sure HDQ/1W is out of reset */
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if (!(hdq_reg_in(hdq_data, OMAP_HDQ_SYSSTATUS) &
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OMAP_HDQ_SYSSTATUS_RESETDONE)) {
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ret = _omap_hdq_reset(hdq_data);
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if (ret)
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/* back up the count */
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hdq_data->hdq_usecount--;
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} else {
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/* select HDQ/1W mode & enable clocks */
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hdq_reg_out(hdq_data, OMAP_HDQ_CTRL_STATUS,
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OMAP_HDQ_CTRL_STATUS_CLOCKENABLE |
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OMAP_HDQ_CTRL_STATUS_INTERRUPTMASK |
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hdq_data->mode);
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hdq_reg_out(hdq_data, OMAP_HDQ_SYSCONFIG,
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OMAP_HDQ_SYSCONFIG_NOIDLE);
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hdq_reg_in(hdq_data, OMAP_HDQ_INT_STATUS);
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}
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}
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}
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out:
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mutex_unlock(&hdq_data->hdq_mutex);
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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;
|
|
|
|
hdq_reg_out(hdq_data, OMAP_HDQ_SYSCONFIG,
|
|
OMAP_HDQ_SYSCONFIG_AUTOIDLE);
|
|
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;
|
|
}
|
|
|
|
/*
|
|
* 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;
|
|
|
|
omap_hdq_get(_hdq);
|
|
|
|
err = mutex_lock_interruptible(&hdq_data->hdq_mutex);
|
|
if (err < 0) {
|
|
dev_dbg(hdq_data->dev, "Could not acquire mutex\n");
|
|
goto rtn;
|
|
}
|
|
|
|
hdq_data->hdq_irqstatus = 0;
|
|
/* 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);
|
|
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);
|
|
|
|
hdq_data->hdq_irqstatus = 0;
|
|
/* 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);
|
|
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);
|
|
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:
|
|
omap_hdq_put(_hdq);
|
|
return ret;
|
|
}
|
|
|
|
/* reset callback */
|
|
static u8 omap_w1_reset_bus(void *_hdq)
|
|
{
|
|
omap_hdq_get(_hdq);
|
|
omap_hdq_break(_hdq);
|
|
omap_hdq_put(_hdq);
|
|
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;
|
|
|
|
/* First write to initialize the transfer */
|
|
if (hdq_data->init_trans == 0)
|
|
omap_hdq_get(hdq_data);
|
|
|
|
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;
|
|
}
|
|
|
|
hdq_disable_interrupt(hdq_data, OMAP_HDQ_CTRL_STATUS,
|
|
~OMAP_HDQ_CTRL_STATUS_INTERRUPTMASK);
|
|
|
|
/* 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);
|
|
|
|
/*
|
|
* 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 = 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;
|
|
const char *mode;
|
|
|
|
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;
|
|
hdq_data->rrw = 0;
|
|
mutex_init(&hdq_data->hdq_mutex);
|
|
|
|
pm_runtime_enable(&pdev->dev);
|
|
ret = pm_runtime_get_sync(&pdev->dev);
|
|
if (ret < 0) {
|
|
dev_dbg(&pdev->dev, "pm_runtime_get_sync failed\n");
|
|
goto err_w1;
|
|
}
|
|
|
|
ret = _omap_hdq_reset(hdq_data);
|
|
if (ret) {
|
|
dev_dbg(&pdev->dev, "reset failed\n");
|
|
goto err_irq;
|
|
}
|
|
|
|
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);
|
|
|
|
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;
|
|
}
|
|
|
|
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 in HDQ mode");
|
|
|
|
MODULE_AUTHOR("Texas Instruments");
|
|
MODULE_DESCRIPTION("HDQ-1W driver Library");
|
|
MODULE_LICENSE("GPL");
|