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w1: masters: omap_hdq: add support for 1-wire mode 

This patches makes following changes to omap_hdq driver
 - Enable 1-wire mode.
 - Implement w1_triplet callback to facilitate search rom
   procedure and auto detection of 1-wire slaves.
 - Proper enabling and disabling of interrupt.
 - Cleanups (formatting and return value checks).

HDQ mode remains unchanged.

Signed-off-by: Vignesh R <vigneshr@ti.com>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Ian Campbell <ijc+devicetree@hellion.org.uk>
Cc: Kumar Gala <galak@codeaurora.org>
Acked-by: Evgeniy Polyakov <zbr@ioremap.net>
Cc: Jonathan Corbet <corbet@lwn.net>
CC: Tony Lindgren <tony@atomide.com>
Cc: Vignesh R <vigneshr@ti.com>
Cc: NeilBrown <neilb@suse.de>
Cc: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Vignesh R 2015-09-14 10:54:33 -07:00 committed by Greg Kroah-Hartman
parent 5052436dcb
commit e93762bbf6
3 changed files with 203 additions and 34 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

7
Documentation/devicetree/bindings/w1/omap-hdq.txt
View File

@ -1,11 +1,15 @@
* OMAP HDQ One wire bus master controller
Required properties:
- compatible : should be "ti,omap3-1w"
- compatible : should be "ti,omap3-1w" or "ti,am4372-hdq"
- reg : Address and length of the register set for the device
- interrupts : interrupt line.
- ti,hwmods : "hdq1w"
Optional properties:
- ti,mode: should be "hdq": HDQ mode "1w": one-wire mode.
If not specified HDQ mode is implied.
Example:
- From omap3.dtsi
@ -14,4 +18,5 @@ Example:
reg = <0x480b2000 0x1000>;
interrupts = <58>;
ti,hwmods = "hdq1w";
ti,mode = "hdq";
};

6
Documentation/w1/masters/omap-hdq
View File

@ -44,3 +44,9 @@ e.g:
insmod omap_hdq.ko W1_ID=2
inamod w1_bq27000.ko F_ID=2
The driver also supports 1-wire mode. In this mode, there is no need to
pass slave ID as parameter. The driver will auto-detect slaves connected
to the bus using SEARCH_ROM procedure. 1-wire mode can be selected by
setting "ti,mode" property to "1w" in DT (see
Documentation/devicetree/bindings/w1/omap-hdq.txt for more details).
By default driver is in HDQ mode.

224
drivers/w1/masters/omap_hdq.c
View File

@ -17,6 +17,7 @@
#include <linux/io.h>
#include <linux/sched.h>
#include <linux/pm_runtime.h>
#include <linux/of.h>
#include "../w1.h"
#include "../w1_int.h"
@ -27,21 +28,23 @@
#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_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 (1<<2)
#define OMAP_HDQ_INT_STATUS_RXCOMPLETE (1<<1)
#define OMAP_HDQ_INT_STATUS_TIMEOUT (1<<0)
#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_SYSCONFIG 0x14
#define OMAP_HDQ_SYSCONFIG_SOFTRESET (1<<1)
#define OMAP_HDQ_SYSCONFIG_AUTOIDLE (1<<0)
#define OMAP_HDQ_SYSCONFIG_SOFTRESET BIT(1)
#define OMAP_HDQ_SYSCONFIG_AUTOIDLE BIT(0)
#define OMAP_HDQ_SYSCONFIG_NOIDLE 0x0
#define OMAP_HDQ_SYSSTATUS 0x18
#define OMAP_HDQ_SYSSTATUS_RESETDONE (1<<0)
#define OMAP_HDQ_SYSSTATUS_RESETDONE BIT(0)
#define OMAP_HDQ_FLAG_CLEAR 0
#define OMAP_HDQ_FLAG_SET 1
@ -67,6 +70,10 @@ struct hdq_data {
* the data wrire or read.
*/
int init_trans;
int rrw;
/* mode: 0-HDQ 1-W1 */
int mode;
};
static int omap_hdq_probe(struct platform_device *pdev);
@ -74,6 +81,7 @@ static int omap_hdq_remove(struct platform_device *pdev);
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);
@ -90,15 +98,12 @@ static struct platform_driver omap_hdq_driver = {
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 */
@ -122,6 +127,15 @@ static inline u8 hdq_reg_merge(struct hdq_data *hdq_data, u32 offset,
return new_val;
}
static void hdq_disable_interrupt(struct hdq_data *hdq_data, u32 offset,
u32 mask)
{
u32 ie;
ie = readl(hdq_data->hdq_base + offset);
writel(ie & mask, hdq_data->hdq_base + offset);
}
/*
* Wait for one or more bits in flag change.
* HDQ_FLAG_SET: wait until any bit in the flag is set.
@ -229,13 +243,7 @@ static irqreturn_t hdq_isr(int irq, void *_hdq)
return IRQ_HANDLED;
}
/* HDQ Mode: always return success */
static u8 omap_w1_reset_bus(void *_hdq)
{
return 0;
}
/* W1 search callback function */
/* 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)
{
@ -262,9 +270,10 @@ 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);
hdq_reg_out(hdq_data, OMAP_HDQ_SYSCONFIG,
OMAP_HDQ_SYSCONFIG_SOFTRESET);
/*
* Select HDQ mode & enable clocks.
* Select HDQ/1W 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.
@ -282,7 +291,8 @@ static int _omap_hdq_reset(struct hdq_data *hdq_data)
else {
hdq_reg_out(hdq_data, OMAP_HDQ_CTRL_STATUS,
OMAP_HDQ_CTRL_STATUS_CLOCKENABLE |
OMAP_HDQ_CTRL_STATUS_INTERRUPTMASK);
OMAP_HDQ_CTRL_STATUS_INTERRUPTMASK |
hdq_data->mode);
hdq_reg_out(hdq_data, OMAP_HDQ_SYSCONFIG,
OMAP_HDQ_SYSCONFIG_AUTOIDLE);
}
@ -334,6 +344,18 @@ static int omap_hdq_break(struct hdq_data *hdq_data)
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.
@ -368,6 +390,8 @@ static int hdq_read_byte(struct hdq_data *hdq_data, u8 *val)
goto out;
}
hdq_data->hdq_irqstatus = 0;
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,
@ -400,7 +424,7 @@ rtn:
}
/* Enable clocks and set the controller to HDQ mode */
/* Enable clocks and set the controller to HDQ/1W mode */
static int omap_hdq_get(struct hdq_data *hdq_data)
{
int ret = 0;
@ -422,7 +446,7 @@ static int omap_hdq_get(struct hdq_data *hdq_data)
pm_runtime_get_sync(hdq_data->dev);
/* make sure HDQ is out of reset */
/* make sure HDQ/1W is out of reset */
if (!(hdq_reg_in(hdq_data, OMAP_HDQ_SYSSTATUS) &
OMAP_HDQ_SYSSTATUS_RESETDONE)) {
ret = _omap_hdq_reset(hdq_data);
@ -430,12 +454,13 @@ static int omap_hdq_get(struct hdq_data *hdq_data)
/* back up the count */
hdq_data->hdq_usecount--;
} else {
/* select HDQ mode & enable clocks */
/* 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);
OMAP_HDQ_CTRL_STATUS_INTERRUPTMASK |
hdq_data->mode);
hdq_reg_out(hdq_data, OMAP_HDQ_SYSCONFIG,
OMAP_HDQ_SYSCONFIG_AUTOIDLE);
OMAP_HDQ_SYSCONFIG_NOIDLE);
hdq_reg_in(hdq_data, OMAP_HDQ_INT_STATUS);
}
}
@ -456,6 +481,8 @@ static int omap_hdq_put(struct hdq_data *hdq_data)
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");
@ -471,6 +498,100 @@ static int omap_hdq_put(struct hdq_data *hdq_data)
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)
{
@ -478,6 +599,10 @@ static u8 omap_w1_read_byte(void *_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);
@ -491,6 +616,10 @@ static u8 omap_w1_read_byte(void *_hdq)
return -1;
}
hdq_disable_interrupt(hdq_data, OMAP_HDQ_CTRL_STATUS,
~OMAP_HDQ_CTRL_STATUS_INTERRUPTMASK);
hdq_data->hdq_usecount = 0;
/* Write followed by a read, release the module */
if (hdq_data->init_trans) {
ret = mutex_lock_interruptible(&hdq_data->hdq_mutex);
@ -517,6 +646,14 @@ static void omap_w1_write_byte(void *_hdq, u8 byte)
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");
@ -551,6 +688,7 @@ static int omap_hdq_probe(struct platform_device *pdev)
struct resource *res;
int ret, irq;
u8 rev;
const char *mode;
hdq_data = devm_kzalloc(dev, sizeof(*hdq_data), GFP_KERNEL);
if (!hdq_data) {
@ -567,10 +705,21 @@ static int omap_hdq_probe(struct platform_device *pdev)
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);
pm_runtime_get_sync(&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");
return -EINVAL;
}
rev = hdq_reg_in(hdq_data, OMAP_HDQ_REVISION);
dev_info(&pdev->dev, "OMAP HDQ Hardware Rev %c.%c. Driver in %s mode\n",
@ -594,6 +743,15 @@ static int omap_hdq_probe(struct platform_device *pdev)
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);
@ -635,8 +793,8 @@ static int omap_hdq_remove(struct platform_device *pdev)
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_PARM_DESC(w1_id, "1-wire id for the slave detection in HDQ mode");
MODULE_AUTHOR("Texas Instruments");
MODULE_DESCRIPTION("HDQ driver Library");
MODULE_DESCRIPTION("HDQ-1W driver Library");
MODULE_LICENSE("GPL");