[PATCH V2] i2c: s3c2410 : Add polling mode support
Yuvaraj Cd
yuvaraj.lkml at gmail.com
Thu Jan 2 00:01:38 EST 2014
Ping..
On Fri, Dec 13, 2013 at 2:51 PM, Yuvaraj Kumar <yuvaraj.cd at gmail.com> wrote:
> Dear Wolfram,
> Can you take this into your tree?
>
> On Fri, Nov 22, 2013 at 11:32 AM, Yuvaraj Kumar <yuvaraj.cd at gmail.com> wrote:
>> Any comments on this patch?
>>
>> On Mon, Nov 11, 2013 at 4:50 PM, Yuvaraj Kumar C D <yuvaraj.cd at gmail.com> wrote:
>>> From: Vasanth Ananthan <vasanthananthan at gmail.com>
>>>
>>> This patch adds polling mode support for i2c-s3c2410 driver.The
>>> SATA PHY controller's CMU and TRSV block's are of I2C register
>>> map in exynos5250.These blocks can be configured using i2c.
>>>
>>> But i2c controller instance on which these block's sits lacks an
>>> interrupt line.Also the current i2c-s3c2410 driver is only interrupt
>>> driven, thus a polling mode support is required in the driver for
>>> supporting this controller. This patch adds this support to the driver.
>>>
>>> Changes from V1:
>>> 1.Changed the is_ack() to have even period b/w polls and
>>> used usleep_range() instead of udelay().
>>>
>>> Signed-off-by: Vasanth Ananthan <vasanth.a at samsung.com>
>>> Signed-off-by: Yuvaraj Kumar C D <yuvaraj.cd at samsung.com>
>>> ---
>>> .../devicetree/bindings/i2c/i2c-s3c2410.txt | 2 +
>>> drivers/i2c/busses/i2c-s3c2410.c | 66 +++++++++++++++++---
>>> 2 files changed, 58 insertions(+), 10 deletions(-)
>>>
>>> diff --git a/Documentation/devicetree/bindings/i2c/i2c-s3c2410.txt b/Documentation/devicetree/bindings/i2c/i2c-s3c2410.txt
>>> index 296eb45..278de8e 100644
>>> --- a/Documentation/devicetree/bindings/i2c/i2c-s3c2410.txt
>>> +++ b/Documentation/devicetree/bindings/i2c/i2c-s3c2410.txt
>>> @@ -10,6 +10,8 @@ Required properties:
>>> inside HDMIPHY block found on several samsung SoCs
>>> (d) "samsung, exynos5440-i2c", for s3c2440-like i2c used
>>> on EXYNOS5440 which does not need GPIO configuration.
>>> + (e) "samsung, exynos5-sata-phy-i2c", for s3c2440-like i2c used as
>>> + a host to SATA PHY controller on an internal bus.
>>> - reg: physical base address of the controller and length of memory mapped
>>> region.
>>> - interrupts: interrupt number to the cpu.
>>> diff --git a/drivers/i2c/busses/i2c-s3c2410.c b/drivers/i2c/busses/i2c-s3c2410.c
>>> index 3747b9b..08ed126 100644
>>> --- a/drivers/i2c/busses/i2c-s3c2410.c
>>> +++ b/drivers/i2c/busses/i2c-s3c2410.c
>>> @@ -85,6 +85,7 @@
>>> #define QUIRK_S3C2440 (1 << 0)
>>> #define QUIRK_HDMIPHY (1 << 1)
>>> #define QUIRK_NO_GPIO (1 << 2)
>>> +#define QUIRK_POLL (1 << 3)
>>>
>>> /* Max time to wait for bus to become idle after a xfer (in us) */
>>> #define S3C2410_IDLE_TIMEOUT 5000
>>> @@ -141,6 +142,8 @@ static struct platform_device_id s3c24xx_driver_ids[] = {
>>> };
>>> MODULE_DEVICE_TABLE(platform, s3c24xx_driver_ids);
>>>
>>> +static int i2c_s3c_irq_nextbyte(struct s3c24xx_i2c *i2c, unsigned long iicstat);
>>> +
>>> #ifdef CONFIG_OF
>>> static const struct of_device_id s3c24xx_i2c_match[] = {
>>> { .compatible = "samsung,s3c2410-i2c", .data = (void *)0 },
>>> @@ -149,6 +152,8 @@ static const struct of_device_id s3c24xx_i2c_match[] = {
>>> .data = (void *)(QUIRK_S3C2440 | QUIRK_HDMIPHY | QUIRK_NO_GPIO) },
>>> { .compatible = "samsung,exynos5440-i2c",
>>> .data = (void *)(QUIRK_S3C2440 | QUIRK_NO_GPIO) },
>>> + { .compatible = "samsung,exynos5-sata-phy-i2c",
>>> + .data = (void *)(QUIRK_S3C2440 | QUIRK_POLL | QUIRK_NO_GPIO) },
>>> {},
>>> };
>>> MODULE_DEVICE_TABLE(of, s3c24xx_i2c_match);
>>> @@ -187,7 +192,8 @@ static inline void s3c24xx_i2c_master_complete(struct s3c24xx_i2c *i2c, int ret)
>>> if (ret)
>>> i2c->msg_idx = ret;
>>>
>>> - wake_up(&i2c->wait);
>>> + if (!(i2c->quirks & QUIRK_POLL))
>>> + wake_up(&i2c->wait);
>>> }
>>>
>>> static inline void s3c24xx_i2c_disable_ack(struct s3c24xx_i2c *i2c)
>>> @@ -224,6 +230,22 @@ static inline void s3c24xx_i2c_enable_irq(struct s3c24xx_i2c *i2c)
>>> writel(tmp | S3C2410_IICCON_IRQEN, i2c->regs + S3C2410_IICCON);
>>> }
>>>
>>> +static bool is_ack(struct s3c24xx_i2c *i2c)
>>> +{
>>> + int tries;
>>> +
>>> + for (tries = 50; tries; --tries) {
>>> + if (readl(i2c->regs + S3C2410_IICCON)
>>> + & S3C2410_IICCON_IRQPEND) {
>>> + if (!(readl(i2c->regs + S3C2410_IICSTAT)
>>> + & S3C2410_IICSTAT_LASTBIT))
>>> + return true;
>>> + }
>>> + usleep_range(1000, 2000);
>>> + }
>>> + dev_err(i2c->dev, "ack was not recieved\n");
>>> + return false;
>>> +}
>>>
>>> /* s3c24xx_i2c_message_start
>>> *
>>> @@ -268,6 +290,16 @@ static void s3c24xx_i2c_message_start(struct s3c24xx_i2c *i2c,
>>>
>>> stat |= S3C2410_IICSTAT_START;
>>> writel(stat, i2c->regs + S3C2410_IICSTAT);
>>> +
>>> + if (i2c->quirks & QUIRK_POLL) {
>>> + while ((i2c->msg_num != 0) && is_ack(i2c)) {
>>> + i2c_s3c_irq_nextbyte(i2c, stat);
>>> + stat = readl(i2c->regs + S3C2410_IICSTAT);
>>> +
>>> + if (stat & S3C2410_IICSTAT_ARBITR)
>>> + dev_err(i2c->dev, "deal with arbitration loss\n");
>>> + }
>>> + }
>>> }
>>>
>>> static inline void s3c24xx_i2c_stop(struct s3c24xx_i2c *i2c, int ret)
>>> @@ -675,6 +707,15 @@ static int s3c24xx_i2c_doxfer(struct s3c24xx_i2c *i2c,
>>> s3c24xx_i2c_enable_irq(i2c);
>>> s3c24xx_i2c_message_start(i2c, msgs);
>>>
>>> + if (i2c->quirks & QUIRK_POLL) {
>>> + ret = i2c->msg_idx;
>>> +
>>> + if (ret != num)
>>> + dev_dbg(i2c->dev, "incomplete xfer (%d)\n", ret);
>>> +
>>> + goto out;
>>> + }
>>> +
>>> timeout = wait_event_timeout(i2c->wait, i2c->msg_num == 0, HZ * 5);
>>>
>>> ret = i2c->msg_idx;
>>> @@ -820,6 +861,9 @@ static int s3c24xx_i2c_clockrate(struct s3c24xx_i2c *i2c, unsigned int *got)
>>> if (div1 == 512)
>>> iiccon |= S3C2410_IICCON_TXDIV_512;
>>>
>>> + if (i2c->quirks & QUIRK_POLL)
>>> + iiccon |= S3C2410_IICCON_SCALE(2);
>>> +
>>> writel(iiccon, i2c->regs + S3C2410_IICCON);
>>>
>>> if (i2c->quirks & QUIRK_S3C2440) {
>>> @@ -1117,18 +1161,20 @@ static int s3c24xx_i2c_probe(struct platform_device *pdev)
>>> * ensure no current IRQs pending
>>> */
>>>
>>> - i2c->irq = ret = platform_get_irq(pdev, 0);
>>> - if (ret <= 0) {
>>> - dev_err(&pdev->dev, "cannot find IRQ\n");
>>> - return ret;
>>> - }
>>> + if (!(i2c->quirks & QUIRK_POLL)) {
>>> + i2c->irq = ret = platform_get_irq(pdev, 0);
>>> + if (ret <= 0) {
>>> + dev_err(&pdev->dev, "cannot find IRQ\n");
>>> + return ret;
>>> + }
>>>
>>> ret = devm_request_irq(&pdev->dev, i2c->irq, s3c24xx_i2c_irq, 0,
>>> - dev_name(&pdev->dev), i2c);
>>> + dev_name(&pdev->dev), i2c);
>>>
>>> - if (ret != 0) {
>>> - dev_err(&pdev->dev, "cannot claim IRQ %d\n", i2c->irq);
>>> - return ret;
>>> + if (ret != 0) {
>>> + dev_err(&pdev->dev, "cannot claim IRQ %d\n", i2c->irq);
>>> + return ret;
>>> + }
>>> }
>>>
>>> ret = s3c24xx_i2c_register_cpufreq(i2c);
>>> --
>>> 1.7.9.5
>>>
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