From: vaibhav.hiremath@linaro.org (Vaibhav Hiremath)
To: linux-arm-kernel@lists.infradead.org
Subject: [PATCH-V2 08/12] i2c: pxa: enable/disable i2c module across msg xfer
Date: Mon, 15 Jun 2015 21:19:55 +0530 [thread overview]
Message-ID: <1434383399-2370-9-git-send-email-vaibhav.hiremath@linaro.org> (raw)
In-Reply-To: <1434383399-2370-1-git-send-email-vaibhav.hiremath@linaro.org>
From: Yi Zhang <yizhang@marvell.com>
Enable i2c module/unit before transmission and disable when it finishes.
why?
It's because the i2c bus may be distrubed if the slave device,
typically a touch, powers on.
As we do not want to break slave mode support, this patch introduces
DT property to control disable of the I2C module after xfer in master mode
of operation.
i2c-disable-after-xfer : If set, driver will disable I2C module after msg xfer
Signed-off-by: Yi Zhang <yizhang@marvell.com>
Signed-off-by: Vaibhav Hiremath <vaibhav.hiremath@linaro.org>
---
drivers/i2c/busses/i2c-pxa.c | 41 +++++++++++++++++++++++++++++++++++++++--
1 file changed, 39 insertions(+), 2 deletions(-)
diff --git a/drivers/i2c/busses/i2c-pxa.c b/drivers/i2c/busses/i2c-pxa.c
index 0a8b3bb..c753411 100644
--- a/drivers/i2c/busses/i2c-pxa.c
+++ b/drivers/i2c/busses/i2c-pxa.c
@@ -161,6 +161,7 @@ struct pxa_i2c {
unsigned char master_code;
unsigned long rate;
bool highmode_enter;
+ bool disable_after_xfer;
};
#define _IBMR(i2c) ((i2c)->reg_ibmr)
@@ -286,6 +287,22 @@ static void i2c_pxa_scream_blue_murder(struct pxa_i2c *i2c, const char *why)
static void i2c_pxa_master_complete(struct pxa_i2c *i2c, int ret);
static irqreturn_t i2c_pxa_handler(int this_irq, void *dev_id);
+/* enable/disable i2c unit */
+static inline int i2c_pxa_is_enabled(struct pxa_i2c *i2c)
+{
+ return (readl(_ICR(i2c)) & ICR_IUE);
+}
+
+static inline void i2c_pxa_enable(struct pxa_i2c *i2c, bool enable)
+{
+ if (enable && !i2c_pxa_is_enabled(i2c)) {
+ writel(readl(_ICR(i2c)) | ICR_IUE, _ICR(i2c));
+ udelay(100);
+ } else {
+ writel(readl(_ICR(i2c)) & ~ICR_IUE, _ICR(i2c));
+ }
+}
+
static inline int i2c_pxa_is_slavemode(struct pxa_i2c *i2c)
{
return !(readl(_ICR(i2c)) & ICR_SCLE);
@@ -482,8 +499,7 @@ static void i2c_pxa_reset(struct pxa_i2c *i2c)
i2c_pxa_set_slave(i2c, 0);
/* enable unit */
- writel(readl(_ICR(i2c)) | ICR_IUE, _ICR(i2c));
- udelay(100);
+ i2c_pxa_enable(i2c, true);
}
@@ -840,6 +856,9 @@ static int i2c_pxa_pio_xfer(struct i2c_adapter *adap,
struct pxa_i2c *i2c = adap->algo_data;
int ret, i;
+ /* Enable i2c unit */
+ i2c_pxa_enable(i2c, true);
+
/* If the I2C controller is disabled we need to reset it
(probably due to a suspend/resume destroying state). We do
this here as we can then avoid worrying about resuming the
@@ -860,6 +879,11 @@ static int i2c_pxa_pio_xfer(struct i2c_adapter *adap,
ret = -EREMOTEIO;
out:
i2c_pxa_set_slave(i2c, ret);
+
+ /* disable i2c unit */
+ if (i2c->disable_after_xfer)
+ i2c_pxa_enable(i2c, false);
+
return ret;
}
@@ -1075,6 +1099,9 @@ static int i2c_pxa_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num
struct pxa_i2c *i2c = adap->algo_data;
int ret, i;
+ /* Enable i2c unit */
+ i2c_pxa_enable(i2c, true);
+
for (i = adap->retries; i >= 0; i--) {
ret = i2c_pxa_do_xfer(i2c, msgs, num);
if (ret != I2C_RETRY)
@@ -1088,6 +1115,10 @@ static int i2c_pxa_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num
ret = -EREMOTEIO;
out:
i2c_pxa_set_slave(i2c, ret);
+ /* disable i2c unit */
+ if (i2c->disable_after_xfer)
+ i2c_pxa_enable(i2c, false);
+
return ret;
}
@@ -1128,6 +1159,9 @@ static int i2c_pxa_probe_dt(struct platform_device *pdev, struct pxa_i2c *i2c,
/* For device tree we always use the dynamic or alias-assigned ID */
i2c->adap.nr = -1;
+ i2c->disable_after_xfer = of_property_read_bool(np,
+ "i2c-disable-after-xfer");
+
if (of_get_property(np, "mrvl,i2c-polling", NULL))
i2c->use_pio = 1;
if (of_get_property(np, "mrvl,i2c-fast-mode", NULL))
@@ -1278,6 +1312,9 @@ static int i2c_pxa_probe(struct platform_device *dev)
platform_set_drvdata(dev, i2c);
+ if (i2c->disable_after_xfer)
+ i2c_pxa_enable(i2c, false);
+
#ifdef CONFIG_I2C_PXA_SLAVE
dev_info(&i2c->adap.dev, " PXA I2C adapter, slave address %d\n",
i2c->slave_addr);
--
1.9.1
WARNING: multiple messages have this Message-ID (diff)
From: Vaibhav Hiremath <vaibhav.hiremath-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
To: linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
Cc: linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org,
wsa-z923LK4zBo2bacvFa/9K2g@public.gmane.org,
robert.jarzmik-GANU6spQydw@public.gmane.org,
Yi Zhang <yizhang-eYqpPyKDWXRBDgjK7y7TUQ@public.gmane.org>,
Vaibhav Hiremath
<vaibhav.hiremath-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
Subject: [PATCH-V2 08/12] i2c: pxa: enable/disable i2c module across msg xfer
Date: Mon, 15 Jun 2015 21:19:55 +0530 [thread overview]
Message-ID: <1434383399-2370-9-git-send-email-vaibhav.hiremath@linaro.org> (raw)
In-Reply-To: <1434383399-2370-1-git-send-email-vaibhav.hiremath-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
From: Yi Zhang <yizhang-eYqpPyKDWXRBDgjK7y7TUQ@public.gmane.org>
Enable i2c module/unit before transmission and disable when it finishes.
why?
It's because the i2c bus may be distrubed if the slave device,
typically a touch, powers on.
As we do not want to break slave mode support, this patch introduces
DT property to control disable of the I2C module after xfer in master mode
of operation.
i2c-disable-after-xfer : If set, driver will disable I2C module after msg xfer
Signed-off-by: Yi Zhang <yizhang-eYqpPyKDWXRBDgjK7y7TUQ@public.gmane.org>
Signed-off-by: Vaibhav Hiremath <vaibhav.hiremath-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org>
---
drivers/i2c/busses/i2c-pxa.c | 41 +++++++++++++++++++++++++++++++++++++++--
1 file changed, 39 insertions(+), 2 deletions(-)
diff --git a/drivers/i2c/busses/i2c-pxa.c b/drivers/i2c/busses/i2c-pxa.c
index 0a8b3bb..c753411 100644
--- a/drivers/i2c/busses/i2c-pxa.c
+++ b/drivers/i2c/busses/i2c-pxa.c
@@ -161,6 +161,7 @@ struct pxa_i2c {
unsigned char master_code;
unsigned long rate;
bool highmode_enter;
+ bool disable_after_xfer;
};
#define _IBMR(i2c) ((i2c)->reg_ibmr)
@@ -286,6 +287,22 @@ static void i2c_pxa_scream_blue_murder(struct pxa_i2c *i2c, const char *why)
static void i2c_pxa_master_complete(struct pxa_i2c *i2c, int ret);
static irqreturn_t i2c_pxa_handler(int this_irq, void *dev_id);
+/* enable/disable i2c unit */
+static inline int i2c_pxa_is_enabled(struct pxa_i2c *i2c)
+{
+ return (readl(_ICR(i2c)) & ICR_IUE);
+}
+
+static inline void i2c_pxa_enable(struct pxa_i2c *i2c, bool enable)
+{
+ if (enable && !i2c_pxa_is_enabled(i2c)) {
+ writel(readl(_ICR(i2c)) | ICR_IUE, _ICR(i2c));
+ udelay(100);
+ } else {
+ writel(readl(_ICR(i2c)) & ~ICR_IUE, _ICR(i2c));
+ }
+}
+
static inline int i2c_pxa_is_slavemode(struct pxa_i2c *i2c)
{
return !(readl(_ICR(i2c)) & ICR_SCLE);
@@ -482,8 +499,7 @@ static void i2c_pxa_reset(struct pxa_i2c *i2c)
i2c_pxa_set_slave(i2c, 0);
/* enable unit */
- writel(readl(_ICR(i2c)) | ICR_IUE, _ICR(i2c));
- udelay(100);
+ i2c_pxa_enable(i2c, true);
}
@@ -840,6 +856,9 @@ static int i2c_pxa_pio_xfer(struct i2c_adapter *adap,
struct pxa_i2c *i2c = adap->algo_data;
int ret, i;
+ /* Enable i2c unit */
+ i2c_pxa_enable(i2c, true);
+
/* If the I2C controller is disabled we need to reset it
(probably due to a suspend/resume destroying state). We do
this here as we can then avoid worrying about resuming the
@@ -860,6 +879,11 @@ static int i2c_pxa_pio_xfer(struct i2c_adapter *adap,
ret = -EREMOTEIO;
out:
i2c_pxa_set_slave(i2c, ret);
+
+ /* disable i2c unit */
+ if (i2c->disable_after_xfer)
+ i2c_pxa_enable(i2c, false);
+
return ret;
}
@@ -1075,6 +1099,9 @@ static int i2c_pxa_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num
struct pxa_i2c *i2c = adap->algo_data;
int ret, i;
+ /* Enable i2c unit */
+ i2c_pxa_enable(i2c, true);
+
for (i = adap->retries; i >= 0; i--) {
ret = i2c_pxa_do_xfer(i2c, msgs, num);
if (ret != I2C_RETRY)
@@ -1088,6 +1115,10 @@ static int i2c_pxa_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num
ret = -EREMOTEIO;
out:
i2c_pxa_set_slave(i2c, ret);
+ /* disable i2c unit */
+ if (i2c->disable_after_xfer)
+ i2c_pxa_enable(i2c, false);
+
return ret;
}
@@ -1128,6 +1159,9 @@ static int i2c_pxa_probe_dt(struct platform_device *pdev, struct pxa_i2c *i2c,
/* For device tree we always use the dynamic or alias-assigned ID */
i2c->adap.nr = -1;
+ i2c->disable_after_xfer = of_property_read_bool(np,
+ "i2c-disable-after-xfer");
+
if (of_get_property(np, "mrvl,i2c-polling", NULL))
i2c->use_pio = 1;
if (of_get_property(np, "mrvl,i2c-fast-mode", NULL))
@@ -1278,6 +1312,9 @@ static int i2c_pxa_probe(struct platform_device *dev)
platform_set_drvdata(dev, i2c);
+ if (i2c->disable_after_xfer)
+ i2c_pxa_enable(i2c, false);
+
#ifdef CONFIG_I2C_PXA_SLAVE
dev_info(&i2c->adap.dev, " PXA I2C adapter, slave address %d\n",
i2c->slave_addr);
--
1.9.1
next prev parent reply other threads:[~2015-06-15 15:49 UTC|newest]
Thread overview: 125+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <vaibhav.hiremath@linaro.org>
2015-06-02 18:45 ` [PATCH-RESEND 0/3] i2c: core/pxa: Add support for hardware lock Vaibhav Hiremath
2015-06-02 18:45 ` Vaibhav Hiremath
2015-06-02 18:45 ` [PATCH-RESEND 1/3] i2c: core: append hardware lock with bus lock Vaibhav Hiremath
2015-06-02 18:45 ` Vaibhav Hiremath
2015-06-02 18:45 ` [PATCH-RESEND 2/3] i2c: pxa: Add support for hardware lock Vaibhav Hiremath
2015-06-02 18:45 ` Vaibhav Hiremath
2015-06-02 18:45 ` [PATCH-RESEND 3/3] i2c: pxa: Add pin ctrl support for CP core access Vaibhav Hiremath
2015-06-02 18:45 ` Vaibhav Hiremath
2015-06-16 8:28 ` [PATCH-RESEND 0/3] i2c: core/pxa: Add support for hardware lock Vaibhav Hiremath
2015-06-16 8:28 ` Vaibhav Hiremath
2015-07-07 6:43 ` Vaibhav Hiremath
2015-07-07 6:43 ` Vaibhav Hiremath
2015-10-25 9:52 ` Wolfram Sang
2015-10-25 9:52 ` Wolfram Sang
2015-06-15 15:49 ` [PATCH-V2 00/12] i2c: pxa: Fixes, cleanup and support for pxa910 family Vaibhav Hiremath
2015-06-15 15:49 ` Vaibhav Hiremath
2015-06-15 15:49 ` [PATCH-V2 01/12] i2c: pxa: keep i2c irq ON in suspend Vaibhav Hiremath
2015-06-15 15:49 ` Vaibhav Hiremath
2015-06-15 15:49 ` [PATCH-V2 02/12] i2c: pxa: No need to set slave addr for i2c master mode reset Vaibhav Hiremath
2015-06-15 15:49 ` Vaibhav Hiremath
2015-07-03 20:58 ` Robert Jarzmik
2015-07-03 20:58 ` Robert Jarzmik
2015-06-15 15:49 ` [PATCH-V2 03/12] i2c: pxa: Return I2C_RETRY when timeout in pio mode Vaibhav Hiremath
2015-06-15 15:49 ` Vaibhav Hiremath
2015-06-16 5:31 ` Shubhrajyoti Datta
2015-06-16 5:31 ` Shubhrajyoti Datta
2015-06-16 7:41 ` Vaibhav Hiremath
2015-06-16 7:41 ` Vaibhav Hiremath
2015-07-03 21:07 ` Robert Jarzmik
2015-07-03 21:07 ` Robert Jarzmik
2015-06-15 15:49 ` [PATCH-V2 04/12] i2c: pxa: Reset i2c controller on timeout in interrupt and " Vaibhav Hiremath
2015-06-15 15:49 ` Vaibhav Hiremath
2015-07-03 15:27 ` Robert Jarzmik
2015-07-03 15:27 ` Robert Jarzmik
2015-07-03 18:13 ` Vaibhav Hiremath
2015-07-03 18:13 ` Vaibhav Hiremath
2015-06-15 15:49 ` [PATCH-V2 05/12] i2c: pxa: Remove compile warnning in 64bit mode Vaibhav Hiremath
2015-06-15 15:49 ` Vaibhav Hiremath
2015-06-15 15:49 ` [PATCH-V2 06/12] i2c: pxa: Update debug function to dump more info on error Vaibhav Hiremath
2015-06-15 15:49 ` Vaibhav Hiremath
2015-06-15 15:49 ` [PATCH-V2 07/12] i2c:pxa: Use devm_ variants in probe function Vaibhav Hiremath
2015-06-15 15:49 ` Vaibhav Hiremath
2015-07-03 15:28 ` Robert Jarzmik
2015-07-03 15:28 ` Robert Jarzmik
2015-07-03 18:14 ` Vaibhav Hiremath
2015-07-03 18:14 ` Vaibhav Hiremath
2015-06-15 15:49 ` Vaibhav Hiremath [this message]
2015-06-15 15:49 ` [PATCH-V2 08/12] i2c: pxa: enable/disable i2c module across msg xfer Vaibhav Hiremath
2015-07-03 15:28 ` Robert Jarzmik
2015-07-03 15:28 ` Robert Jarzmik
2015-07-03 18:23 ` Vaibhav Hiremath
2015-07-03 18:23 ` Vaibhav Hiremath
2015-07-03 18:48 ` Vaibhav Hiremath
2015-07-03 18:48 ` Vaibhav Hiremath
2015-07-03 19:44 ` Robert Jarzmik
2015-07-03 19:44 ` Robert Jarzmik
2015-06-15 15:49 ` [PATCH-V2 09/12] Documentation: binding: add new property 'disable_after_xfer' to i2c-pxa Vaibhav Hiremath
2015-06-15 15:49 ` Vaibhav Hiremath
2015-06-15 15:49 ` [PATCH-V2 10/12] i2c: pxa: Add support for pxa910/988 & new configuration features Vaibhav Hiremath
2015-06-15 15:49 ` Vaibhav Hiremath
2015-06-15 15:49 ` [PATCH-V2 11/12] i2c: pxa: Add ILCR (tLow & tHigh) configuration support Vaibhav Hiremath
2015-06-15 15:49 ` Vaibhav Hiremath
2015-07-03 15:28 ` Robert Jarzmik
2015-07-03 15:28 ` Robert Jarzmik
2015-07-03 18:17 ` Vaibhav Hiremath
2015-07-03 18:17 ` Vaibhav Hiremath
2015-06-15 15:49 ` [PATCH-V2 12/12] Documentation: binding: add sclk adjustment properties to i2c-pxa Vaibhav Hiremath
2015-06-15 15:49 ` Vaibhav Hiremath
2015-06-16 13:22 ` Rob Herring
2015-06-16 13:22 ` Rob Herring
2015-06-16 14:25 ` Vaibhav Hiremath
2015-06-16 14:25 ` Vaibhav Hiremath
2015-06-29 8:52 ` [PATCH-V2 00/12] i2c: pxa: Fixes, cleanup and support for pxa910 family Vaibhav Hiremath
2015-06-29 8:52 ` Vaibhav Hiremath
2015-07-02 16:54 ` Vaibhav Hiremath
2015-07-02 16:54 ` Vaibhav Hiremath
2015-06-17 18:58 [PATCH-v2 0/3] mfd: 88pm800: Add Device tree support Vaibhav Hiremath
2015-06-17 18:58 ` Vaibhav Hiremath
2015-06-17 18:58 ` [rtc-linux] " Vaibhav Hiremath
2015-06-17 18:58 ` [PATCH-v2 1/3] mfd: 88pm800: Add device " Vaibhav Hiremath
2015-06-17 18:58 ` Vaibhav Hiremath
2015-06-17 18:58 ` [rtc-linux] " Vaibhav Hiremath
2015-06-17 18:58 ` Vaibhav Hiremath
2015-06-17 18:58 ` [PATCH-v2] rtc: 88pm80x: add " Vaibhav Hiremath
2015-06-17 18:58 ` Vaibhav Hiremath
2015-06-17 18:58 ` [rtc-linux] " Vaibhav Hiremath
2015-06-20 0:43 ` Alexandre Belloni
2015-06-20 0:43 ` Alexandre Belloni
2015-06-20 0:43 ` Alexandre Belloni
2015-06-20 0:43 ` Alexandre Belloni
2015-06-25 7:46 ` Vaibhav Hiremath
2015-06-25 7:46 ` Vaibhav Hiremath
2015-06-25 7:46 ` Vaibhav Hiremath
2015-06-25 7:46 ` Vaibhav Hiremath
2015-07-07 6:37 ` Vaibhav Hiremath
2015-07-07 6:37 ` Vaibhav Hiremath
2015-07-07 6:37 ` Vaibhav Hiremath
2015-07-07 6:37 ` Vaibhav Hiremath
2015-06-17 18:58 ` [PATCH-v2 2/3] mfd: 88pm800: Allow configuration of interrupt clear method Vaibhav Hiremath
2015-06-17 18:58 ` Vaibhav Hiremath
2015-06-17 18:58 ` [rtc-linux] " Vaibhav Hiremath
2015-06-17 18:58 ` Vaibhav Hiremath
2015-06-17 18:58 ` [PATCH-v2 3/3] mfd: devicetree: bindings: Add new 88pm800 mfd binding Vaibhav Hiremath
2015-06-17 18:58 ` Vaibhav Hiremath
2015-06-17 18:58 ` [rtc-linux] " Vaibhav Hiremath
2015-06-17 18:58 ` Vaibhav Hiremath
2015-06-23 15:37 ` Rob Herring
2015-06-23 15:37 ` Rob Herring
2015-06-23 15:37 ` [rtc-linux] " Rob Herring
2015-06-23 15:37 ` Rob Herring
2015-06-23 17:02 ` Vaibhav Hiremath
2015-06-23 17:02 ` Vaibhav Hiremath
2015-06-23 17:02 ` [rtc-linux] " Vaibhav Hiremath
2015-06-24 0:29 ` Krzysztof Kozlowski
2015-06-24 0:29 ` Krzysztof Kozlowski
2015-06-24 0:29 ` [rtc-linux] " Krzysztof Kozlowski
2015-06-24 0:29 ` Krzysztof Kozlowski
2015-06-24 5:19 ` Vaibhav Hiremath
2015-06-24 5:19 ` Vaibhav Hiremath
2015-06-24 5:19 ` [rtc-linux] " Vaibhav Hiremath
2015-06-24 5:19 ` Vaibhav Hiremath
2015-06-23 5:07 ` [PATCH-v2 0/3] mfd: 88pm800: Add Device tree support Vaibhav Hiremath
2015-06-23 5:07 ` Vaibhav Hiremath
2015-06-23 5:07 ` [rtc-linux] " Vaibhav Hiremath
2015-06-23 5:07 ` Vaibhav Hiremath
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