Re: [PATCH v2 2/3] w1: masters: omap_hdq: Add support for 1-wire mode
From: Vignesh R
Date: Thu Mar 19 2015 - 23:59:47 EST
Gentle Ping ....
On Monday 02 March 2015 04:19 PM, Vignesh R wrote:
> 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@xxxxxx>
> ---
>
> Change log:
> v2:
> * Change compatible to "ti,am4372-hdq" as Arnd suggested.
>
> Documentation/devicetree/bindings/w1/omap-hdq.txt | 7 +-
> Documentation/w1/masters/omap-hdq | 6 +
> drivers/w1/masters/omap_hdq.c | 209 ++++++++++++++++++----
> 3 files changed, 188 insertions(+), 34 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/w1/omap-hdq.txt b/Documentation/devicetree/bindings/w1/omap-hdq.txt
> index fef794741bd1..913c5f91a0f9 100644
> --- a/Documentation/devicetree/bindings/w1/omap-hdq.txt
> +++ b/Documentation/devicetree/bindings/w1/omap-hdq.txt
> @@ -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";
> };
> diff --git a/Documentation/w1/masters/omap-hdq b/Documentation/w1/masters/omap-hdq
> index 884dc284b215..234522709a5f 100644
> --- a/Documentation/w1/masters/omap-hdq
> +++ b/Documentation/w1/masters/omap-hdq
> @@ -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.
> diff --git a/drivers/w1/masters/omap_hdq.c b/drivers/w1/masters/omap_hdq.c
> index 03321d6a2684..325b46905657 100644
> --- a/drivers/w1/masters/omap_hdq.c
> +++ b/drivers/w1/masters/omap_hdq.c
> @@ -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 BIT(0)
> #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 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,
> + u8 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 +498,85 @@ 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 ret, id_bit, comp_bit;
> + 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);
> +
> + ret = mutex_lock_interruptible(&hdq_data->hdq_mutex);
> + if (ret < 0) {
> + ret = -EINTR;
> + 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);
> + wait_event_timeout(hdq_wait_queue,
> + (hdq_data->hdq_irqstatus
> + & OMAP_HDQ_INT_STATUS_RXCOMPLETE),
> + OMAP_HDQ_TIMEOUT);
> + 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);
> + wait_event_timeout(hdq_wait_queue,
> + (hdq_data->hdq_irqstatus
> + & OMAP_HDQ_INT_STATUS_RXCOMPLETE),
> + OMAP_HDQ_TIMEOUT);
> + comp_bit = (hdq_reg_in(_hdq, OMAP_HDQ_RX_DATA) & 0x01);
> +
> + if (id_bit && comp_bit) {
> + ret = 0x03; /* error */
> + goto rtn;
> + }
> + 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);
> + wait_event_timeout(hdq_wait_queue,
> + (hdq_data->hdq_irqstatus
> + & OMAP_HDQ_INT_STATUS_TXCOMPLETE),
> + OMAP_HDQ_TIMEOUT);
> +
> + hdq_reg_merge(_hdq, OMAP_HDQ_CTRL_STATUS, 0,
> + OMAP_HDQ_CTRL_STATUS_SINGLE);
> +
> +rtn:
> + mutex_unlock(&hdq_data->hdq_mutex);
> + 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 +584,10 @@ 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 +601,10 @@ 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 +631,14 @@ 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 +673,7 @@ 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 +690,21 @@ 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 +728,15 @@ 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 +778,8 @@ 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");
>
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