[PATCH 0/4] i2c: i2c-au1550 updates

[PATCH 0/4] i2c: i2c-au1550 updates

[Manuel Lauss]

The following patches remove some bit-rot from the i2c-au1550 driver.
(Patch #3 supersedes the one I sent on 2011-06-12:
 "i2c-au1550: increase timeout waiting for transactions to finish").

#1 gets rid of all instances of the "volatile" keyword,
#2 removes an unused context member,
#3 fixes i2c on the db1300 board
#4 updates PM methods.

All run- and pm-tested on db1200 and db1300 hardware.

Please consider for 3.1.

Manuel Lauss (4):
  i2c/au1550: remove usage of volatile keyword
  i2c/au1550: remove unused ack_timeout
  i2c/au1550: increase timeout limit
  i2c/au1550: dev_pm_ops conversion

 arch/mips/include/asm/mach-au1x00/au1xxx_psc.h |   13 -
 drivers/i2c/busses/i2c-au1550.c                |  280 ++++++++++--------------
 2 files changed, 114 insertions(+), 179 deletions(-)

-- 
1.7.6

[PATCH 1/4] i2c/au1550: remove usage of volatile keyword

[Manuel Lauss]

Replace the usage of "volatile"s with register accessor functions.

Signed-off-by: Manuel Lauss <manuel.lauss-gM/Ye1E23mwN+BqQ9rBEUg@public.gmane.org>
---
 arch/mips/include/asm/mach-au1x00/au1xxx_psc.h |   13 --
 drivers/i2c/busses/i2c-au1550.c                |  252 +++++++++--------------
 2 files changed, 99 insertions(+), 166 deletions(-)

diff --git a/arch/mips/include/asm/mach-au1x00/au1xxx_psc.h b/arch/mips/include/asm/mach-au1x00/au1xxx_psc.h
index 892b7f1..5a5cb73 100644
--- a/arch/mips/include/asm/mach-au1x00/au1xxx_psc.h
+++ b/arch/mips/include/asm/mach-au1x00/au1xxx_psc.h
@@ -394,19 +394,6 @@ typedef struct	psc_spi {
 #define PSC_SPITXRX_LC		(1 << 29)
 #define PSC_SPITXRX_SR		(1 << 28)
 
-/* PSC in SMBus (I2C) Mode. */
-typedef struct	psc_smb {
-	u32	psc_sel;
-	u32	psc_ctrl;
-	u32	psc_smbcfg;
-	u32	psc_smbmsk;
-	u32	psc_smbpcr;
-	u32	psc_smbstat;
-	u32	psc_smbevnt;
-	u32	psc_smbtxrx;
-	u32	psc_smbtmr;
-} psc_smb_t;
-
 /* SMBus Config Register. */
 #define PSC_SMBCFG_RT_MASK	(3 << 30)
 #define PSC_SMBCFG_RT_FIFO1	(0 << 30)
diff --git a/drivers/i2c/busses/i2c-au1550.c b/drivers/i2c/busses/i2c-au1550.c
index 532828b..70b027c 100644
--- a/drivers/i2c/busses/i2c-au1550.c
+++ b/drivers/i2c/busses/i2c-au1550.c
@@ -39,29 +39,42 @@
 #include <asm/mach-au1x00/au1xxx.h>
 #include <asm/mach-au1x00/au1xxx_psc.h>
 
+#define PSC_SEL		0x00
+#define PSC_CTRL	0x04
+#define PSC_SMBCFG	0x08
+#define PSC_SMBMSK	0x0C
+#define PSC_SMBPCR	0x10
+#define PSC_SMBSTAT	0x14
+#define PSC_SMBEVNT	0x18
+#define PSC_SMBTXRX	0x1C
+#define PSC_SMBTMR	0x20
+
 struct i2c_au1550_data {
-	u32	psc_base;
+	void __iomem *psc_base;
 	int	xfer_timeout;
 	int	ack_timeout;
 	struct i2c_adapter adap;
 	struct resource *ioarea;
 };
 
-static int
-wait_xfer_done(struct i2c_au1550_data *adap)
+static inline void WR(struct i2c_au1550_data *a, int r, unsigned long v)
 {
-	u32	stat;
-	int	i;
-	volatile psc_smb_t	*sp;
+	__raw_writel(v, a->psc_base + r);
+	wmb();
+}
 
-	sp = (volatile psc_smb_t *)(adap->psc_base);
+static inline unsigned long RD(struct i2c_au1550_data *a, int r)
+{
+	return __raw_readl(a->psc_base + r);
+}
 
-	/* Wait for Tx Buffer Empty
-	*/
+static int wait_xfer_done(struct i2c_au1550_data *adap)
+{
+	int i;
+
+	/* Wait for Tx Buffer Empty */
 	for (i = 0; i < adap->xfer_timeout; i++) {
-		stat = sp->psc_smbstat;
-		au_sync();
-		if ((stat & PSC_SMBSTAT_TE) != 0)
+		if (RD(adap, PSC_SMBSTAT) & PSC_SMBSTAT_TE)
 			return 0;
 
 		udelay(1);
@@ -70,41 +83,27 @@ wait_xfer_done(struct i2c_au1550_data *adap)
 	return -ETIMEDOUT;
 }
 
-static int
-wait_ack(struct i2c_au1550_data *adap)
+static int wait_ack(struct i2c_au1550_data *adap)
 {
-	u32	stat;
-	volatile psc_smb_t	*sp;
+	unsigned long stat;
 
 	if (wait_xfer_done(adap))
 		return -ETIMEDOUT;
 
-	sp = (volatile psc_smb_t *)(adap->psc_base);
-
-	stat = sp->psc_smbevnt;
-	au_sync();
-
+	stat = RD(adap, PSC_SMBEVNT);
 	if ((stat & (PSC_SMBEVNT_DN | PSC_SMBEVNT_AN | PSC_SMBEVNT_AL)) != 0)
 		return -ETIMEDOUT;
 
 	return 0;
 }
 
-static int
-wait_master_done(struct i2c_au1550_data *adap)
+static int wait_master_done(struct i2c_au1550_data *adap)
 {
-	u32	stat;
-	int	i;
-	volatile psc_smb_t	*sp;
+	int i;
 
-	sp = (volatile psc_smb_t *)(adap->psc_base);
-
-	/* Wait for Master Done.
-	*/
+	/* Wait for Master Done. */
 	for (i = 0; i < adap->xfer_timeout; i++) {
-		stat = sp->psc_smbevnt;
-		au_sync();
-		if ((stat & PSC_SMBEVNT_MD) != 0)
+		if ((RD(adap, PSC_SMBEVNT) & PSC_SMBEVNT_MD) != 0)
 			return 0;
 		udelay(1);
 	}
@@ -115,29 +114,20 @@ wait_master_done(struct i2c_au1550_data *adap)
 static int
 do_address(struct i2c_au1550_data *adap, unsigned int addr, int rd, int q)
 {
-	volatile psc_smb_t	*sp;
-	u32			stat;
+	unsigned long stat;
 
-	sp = (volatile psc_smb_t *)(adap->psc_base);
-
-	/* Reset the FIFOs, clear events.
-	*/
-	stat = sp->psc_smbstat;
-	sp->psc_smbevnt = PSC_SMBEVNT_ALLCLR;
-	au_sync();
+	/* Reset the FIFOs, clear events. */
+	stat = RD(adap, PSC_SMBSTAT);
+	WR(adap, PSC_SMBEVNT, PSC_SMBEVNT_ALLCLR);
 
 	if (!(stat & PSC_SMBSTAT_TE) || !(stat & PSC_SMBSTAT_RE)) {
-		sp->psc_smbpcr = PSC_SMBPCR_DC;
-		au_sync();
-		do {
-			stat = sp->psc_smbpcr;
-			au_sync();
-		} while ((stat & PSC_SMBPCR_DC) != 0);
+		WR(adap, PSC_SMBPCR, PSC_SMBPCR_DC);
+		while ((RD(adap, PSC_SMBPCR) & PSC_SMBPCR_DC) != 0)
+			cpu_relax();
 		udelay(50);
 	}
 
-	/* Write out the i2c chip address and specify operation
-	*/
+	/* Write out the i2c chip address and specify operation */
 	addr <<= 1;
 	if (rd)
 		addr |= 1;
@@ -146,56 +136,42 @@ do_address(struct i2c_au1550_data *adap, unsigned int addr, int rd, int q)
 	if (q)
 		addr |= PSC_SMBTXRX_STP;
 
-	/* Put byte into fifo, start up master.
-	*/
-	sp->psc_smbtxrx = addr;
-	au_sync();
-	sp->psc_smbpcr = PSC_SMBPCR_MS;
-	au_sync();
+	/* Put byte into fifo, start up master. */
+	WR(adap, PSC_SMBTXRX, addr);
+	WR(adap, PSC_SMBPCR, PSC_SMBPCR_MS);
 	if (wait_ack(adap))
 		return -EIO;
 	return (q) ? wait_master_done(adap) : 0;
 }
 
-static u32
-wait_for_rx_byte(struct i2c_au1550_data *adap, u32 *ret_data)
+static int wait_for_rx_byte(struct i2c_au1550_data *adap, unsigned char *out)
 {
-	int	j;
-	u32	data, stat;
-	volatile psc_smb_t	*sp;
+	int j;
 
 	if (wait_xfer_done(adap))
 		return -EIO;
 
-	sp = (volatile psc_smb_t *)(adap->psc_base);
-
 	j =  adap->xfer_timeout * 100;
 	do {
 		j--;
 		if (j <= 0)
 			return -EIO;
 
-		stat = sp->psc_smbstat;
-		au_sync();
-		if ((stat & PSC_SMBSTAT_RE) == 0)
+		if ((RD(adap, PSC_SMBSTAT) & PSC_SMBSTAT_RE) == 0)
 			j = 0;
 		else
 			udelay(1);
 	} while (j > 0);
-	data = sp->psc_smbtxrx;
-	au_sync();
-	*ret_data = data;
+
+	*out = RD(adap, PSC_SMBTXRX);
 
 	return 0;
 }
 
-static int
-i2c_read(struct i2c_au1550_data *adap, unsigned char *buf,
+static int i2c_read(struct i2c_au1550_data *adap, unsigned char *buf,
 		    unsigned int len)
 {
-	int	i;
-	u32	data;
-	volatile psc_smb_t	*sp;
+	int i;
 
 	if (len == 0)
 		return 0;
@@ -204,62 +180,46 @@ i2c_read(struct i2c_au1550_data *adap, unsigned char *buf,
 	 * zero bytes for timing, waiting for bytes to appear in the
 	 * receive fifo, then reading the bytes.
 	 */
-
-	sp = (volatile psc_smb_t *)(adap->psc_base);
-
 	i = 0;
-	while (i < (len-1)) {
-		sp->psc_smbtxrx = 0;
-		au_sync();
-		if (wait_for_rx_byte(adap, &data))
+	while (i < (len - 1)) {
+		WR(adap, PSC_SMBTXRX, 0);
+		if (wait_for_rx_byte(adap, &buf[i]))
 			return -EIO;
 
-		buf[i] = data;
 		i++;
 	}
 
-	/* The last byte has to indicate transfer done.
-	*/
-	sp->psc_smbtxrx = PSC_SMBTXRX_STP;
-	au_sync();
+	/* The last byte has to indicate transfer done. */
+	WR(adap, PSC_SMBTXRX, PSC_SMBTXRX_STP);
 	if (wait_master_done(adap))
 		return -EIO;
 
-	data = sp->psc_smbtxrx;
-	au_sync();
-	buf[i] = data;
+	buf[i] = (unsigned char)(RD(adap, PSC_SMBTXRX) & 0xff);
 	return 0;
 }
 
-static int
-i2c_write(struct i2c_au1550_data *adap, unsigned char *buf,
+static int i2c_write(struct i2c_au1550_data *adap, unsigned char *buf,
 		     unsigned int len)
 {
-	int	i;
-	u32	data;
-	volatile psc_smb_t	*sp;
+	int i;
+	unsigned long data;
 
 	if (len == 0)
 		return 0;
 
-	sp = (volatile psc_smb_t *)(adap->psc_base);
-
 	i = 0;
 	while (i < (len-1)) {
 		data = buf[i];
-		sp->psc_smbtxrx = data;
-		au_sync();
+		WR(adap, PSC_SMBTXRX, data);
 		if (wait_ack(adap))
 			return -EIO;
 		i++;
 	}
 
-	/* The last byte has to indicate transfer done.
-	*/
+	/* The last byte has to indicate transfer done. */
 	data = buf[i];
 	data |= PSC_SMBTXRX_STP;
-	sp->psc_smbtxrx = data;
-	au_sync();
+	WR(adap, PSC_SMBTXRX, data);
 	if (wait_master_done(adap))
 		return -EIO;
 	return 0;
@@ -269,12 +229,10 @@ static int
 au1550_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg *msgs, int num)
 {
 	struct i2c_au1550_data *adap = i2c_adap->algo_data;
-	volatile psc_smb_t *sp = (volatile psc_smb_t *)adap->psc_base;
 	struct i2c_msg *p;
 	int i, err = 0;
 
-	sp->psc_ctrl = PSC_CTRL_ENABLE;
-	au_sync();
+	WR(adap, PSC_CTRL, PSC_CTRL_ENABLE);
 
 	for (i = 0; !err && i < num; i++) {
 		p = &msgs[i];
@@ -293,14 +251,12 @@ au1550_xfer(struct i2c_adapter *i2c_adap, struct i2c_msg *msgs, int num)
 	if (err == 0)
 		err = num;
 
-	sp->psc_ctrl = PSC_CTRL_SUSPEND;
-	au_sync();
+	WR(adap, PSC_CTRL, PSC_CTRL_SUSPEND);
 
 	return err;
 }
 
-static u32
-au1550_func(struct i2c_adapter *adap)
+static u32 au1550_func(struct i2c_adapter *adap)
 {
 	return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL;
 }
@@ -312,57 +268,45 @@ static const struct i2c_algorithm au1550_algo = {
 
 static void i2c_au1550_setup(struct i2c_au1550_data *priv)
 {
-	volatile psc_smb_t *sp = (volatile psc_smb_t *)priv->psc_base;
-	u32 stat;
-
-	sp->psc_ctrl = PSC_CTRL_DISABLE;
-	au_sync();
-	sp->psc_sel = PSC_SEL_PS_SMBUSMODE;
-	sp->psc_smbcfg = 0;
-	au_sync();
-	sp->psc_ctrl = PSC_CTRL_ENABLE;
-	au_sync();
-	do {
-		stat = sp->psc_smbstat;
-		au_sync();
-	} while ((stat & PSC_SMBSTAT_SR) == 0);
+	unsigned long cfg;
 
-	sp->psc_smbcfg = (PSC_SMBCFG_RT_FIFO8 | PSC_SMBCFG_TT_FIFO8 |
-				PSC_SMBCFG_DD_DISABLE);
+	WR(priv, PSC_CTRL, PSC_CTRL_DISABLE);
+	WR(priv, PSC_SEL, PSC_SEL_PS_SMBUSMODE);
+	WR(priv, PSC_SMBCFG, 0);
+	WR(priv, PSC_CTRL, PSC_CTRL_ENABLE);
+	while ((RD(priv, PSC_SMBSTAT) & PSC_SMBSTAT_SR) == 0)
+		cpu_relax();
+
+	cfg = PSC_SMBCFG_RT_FIFO8 | PSC_SMBCFG_TT_FIFO8 | PSC_SMBCFG_DD_DISABLE;
+	WR(priv, PSC_SMBCFG, cfg);
 
 	/* Divide by 8 to get a 6.25 MHz clock.  The later protocol
 	 * timings are based on this clock.
 	 */
-	sp->psc_smbcfg |= PSC_SMBCFG_SET_DIV(PSC_SMBCFG_DIV8);
-	sp->psc_smbmsk = PSC_SMBMSK_ALLMASK;
-	au_sync();
+	cfg |= PSC_SMBCFG_SET_DIV(PSC_SMBCFG_DIV8);
+	WR(priv, PSC_SMBCFG, cfg);
+	WR(priv, PSC_SMBMSK, PSC_SMBMSK_ALLMASK);
 
 	/* Set the protocol timer values.  See Table 71 in the
 	 * Au1550 Data Book for standard timing values.
 	 */
-	sp->psc_smbtmr = PSC_SMBTMR_SET_TH(0) | PSC_SMBTMR_SET_PS(15) | \
+	WR(priv, PSC_SMBTMR, PSC_SMBTMR_SET_TH(0) | PSC_SMBTMR_SET_PS(15) | \
 		PSC_SMBTMR_SET_PU(15) | PSC_SMBTMR_SET_SH(15) | \
 		PSC_SMBTMR_SET_SU(15) | PSC_SMBTMR_SET_CL(15) | \
-		PSC_SMBTMR_SET_CH(15);
-	au_sync();
+		PSC_SMBTMR_SET_CH(15));
 
-	sp->psc_smbcfg |= PSC_SMBCFG_DE_ENABLE;
-	do {
-		stat = sp->psc_smbstat;
-		au_sync();
-	} while ((stat & PSC_SMBSTAT_SR) == 0);
+	cfg |= PSC_SMBCFG_DE_ENABLE;
+	WR(priv, PSC_SMBCFG, cfg);
+	while ((RD(priv, PSC_SMBSTAT) & PSC_SMBSTAT_SR) == 0)
+		cpu_relax();
 
-	sp->psc_ctrl = PSC_CTRL_SUSPEND;
-	au_sync();
+	WR(priv, PSC_CTRL, PSC_CTRL_SUSPEND);
 }
 
 static void i2c_au1550_disable(struct i2c_au1550_data *priv)
 {
-	volatile psc_smb_t *sp = (volatile psc_smb_t *)priv->psc_base;
-
-	sp->psc_smbcfg = 0;
-	sp->psc_ctrl = PSC_CTRL_DISABLE;
-	au_sync();
+	WR(priv, PSC_SMBCFG, 0);
+	WR(priv, PSC_CTRL, PSC_CTRL_DISABLE);
 }
 
 /*
@@ -396,7 +340,11 @@ i2c_au1550_probe(struct platform_device *pdev)
 		goto out_mem;
 	}
 
-	priv->psc_base = CKSEG1ADDR(r->start);
+	priv->psc_base = ioremap(r->start, resource_size(r));
+	if (!priv->psc_base) {
+		ret = -EIO;
+		goto out_map;
+	}
 	priv->xfer_timeout = 200;
 	priv->ack_timeout = 200;
 
@@ -406,8 +354,7 @@ i2c_au1550_probe(struct platform_device *pdev)
 	priv->adap.dev.parent = &pdev->dev;
 	strlcpy(priv->adap.name, "Au1xxx PSC I2C", sizeof(priv->adap.name));
 
-	/* Now, set up the PSC for SMBus PIO mode.
-	*/
+	/* Now, set up the PSC for SMBus PIO mode. */
 	i2c_au1550_setup(priv);
 
 	ret = i2c_add_numbered_adapter(&priv->adap);
@@ -417,7 +364,8 @@ i2c_au1550_probe(struct platform_device *pdev)
 	}
 
 	i2c_au1550_disable(priv);
-
+	iounmap(priv->psc_base);
+out_map:
 	release_resource(priv->ioarea);
 	kfree(priv->ioarea);
 out_mem:
@@ -426,14 +374,14 @@ out:
 	return ret;
 }
 
-static int __devexit
-i2c_au1550_remove(struct platform_device *pdev)
+static int __devexit i2c_au1550_remove(struct platform_device *pdev)
 {
 	struct i2c_au1550_data *priv = platform_get_drvdata(pdev);
 
 	platform_set_drvdata(pdev, NULL);
 	i2c_del_adapter(&priv->adap);
 	i2c_au1550_disable(priv);
+	iounmap(priv->psc_base);
 	release_resource(priv->ioarea);
 	kfree(priv->ioarea);
 	kfree(priv);
@@ -476,14 +424,12 @@ static struct platform_driver au1xpsc_smbus_driver = {
 	.resume		= i2c_au1550_resume,
 };
 
-static int __init
-i2c_au1550_init(void)
+static int __init i2c_au1550_init(void)
 {
 	return platform_driver_register(&au1xpsc_smbus_driver);
 }
 
-static void __exit
-i2c_au1550_exit(void)
+static void __exit i2c_au1550_exit(void)
 {
 	platform_driver_unregister(&au1xpsc_smbus_driver);
 }
-- 
1.7.6

[PATCH 2/4] i2c/au1550: remove unused ack_timeout

[Manuel Lauss]

The ack_timeout context member is unused, get rid of it.

Signed-off-by: Manuel Lauss <manuel.lauss-gM/Ye1E23mwN+BqQ9rBEUg@public.gmane.org>
---
 drivers/i2c/busses/i2c-au1550.c |    2 --
 1 files changed, 0 insertions(+), 2 deletions(-)

diff --git a/drivers/i2c/busses/i2c-au1550.c b/drivers/i2c/busses/i2c-au1550.c
index 70b027c..98ee11a 100644
--- a/drivers/i2c/busses/i2c-au1550.c
+++ b/drivers/i2c/busses/i2c-au1550.c
@@ -52,7 +52,6 @@
 struct i2c_au1550_data {
 	void __iomem *psc_base;
 	int	xfer_timeout;
-	int	ack_timeout;
 	struct i2c_adapter adap;
 	struct resource *ioarea;
 };
@@ -346,7 +345,6 @@ i2c_au1550_probe(struct platform_device *pdev)
 		goto out_map;
 	}
 	priv->xfer_timeout = 200;
-	priv->ack_timeout = 200;
 
 	priv->adap.nr = pdev->id;
 	priv->adap.algo = &au1550_algo;
-- 
1.7.6

[PATCH 3/4] i2c/au1550: increase timeout limit

[Manuel Lauss]

The timeout waiting for various events to occur is tailored for
a module clock of 50MHz.  On the DB1300 board only 48MHz can be
supplied to the i2c module, which results in the timeout aborting
complex transfers to slaves slightly too early if they employ
for example clock stretching.

With this change the WM8731 codec on the DB1300 board is correctly
detected and initialized.

Signed-off-by: Manuel Lauss <manuel.lauss-gM/Ye1E23mwN+BqQ9rBEUg@public.gmane.org>
---
 drivers/i2c/busses/i2c-au1550.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/drivers/i2c/busses/i2c-au1550.c b/drivers/i2c/busses/i2c-au1550.c
index 98ee11a..36d1b29 100644
--- a/drivers/i2c/busses/i2c-au1550.c
+++ b/drivers/i2c/busses/i2c-au1550.c
@@ -344,7 +344,7 @@ i2c_au1550_probe(struct platform_device *pdev)
 		ret = -EIO;
 		goto out_map;
 	}
-	priv->xfer_timeout = 200;
+	priv->xfer_timeout = 400;
 
 	priv->adap.nr = pdev->id;
 	priv->adap.algo = &au1550_algo;
-- 
1.7.6

Re: Fwd: [PATCH 3/4] i2c/au1550: increase timeout limit

[Shubhrajyoti]

Hi Manuel,
> From: *Manuel Lauss* <manuel.lauss-gM/Ye1E23mwN+BqQ9rBEUg@public.gmane.org 
> <mailto:manuel.lauss-gM/Ye1E23mwN+BqQ9rBEUg@public.gmane.org>>
> Date: Thu, Jul 14, 2011 at 2:26 PM
> Subject: [PATCH 3/4] i2c/au1550: increase timeout limit
> To: Linux-I2C <linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org 
> <mailto:linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>>, Ben Dooks <ben-linux-elnMNo+KYs3YtjvyW6yDsg@public.gmane.org 
> <mailto:ben-linux-elnMNo+KYs3YtjvyW6yDsg@public.gmane.org>>
> Cc: Manuel Lauss <manuel.lauss-gM/Ye1E23mwN+BqQ9rBEUg@public.gmane.org 
> <mailto:manuel.lauss-gM/Ye1E23mwN+BqQ9rBEUg@public.gmane.org>>
>
>
> The timeout waiting for various events to occur is tailored for
> a module clock of 50MHz.  On the DB1300 board only 48MHz can be
> supplied to the i2c module, which results in the timeout aborting
> complex transfers to slaves slightly too early if they employ
> for example clock stretching.
>
> With this change the WM8731 codec on the DB1300 board is correctly
> detected and initialized.
>
> Signed-off-by: Manuel Lauss <manuel.lauss-gM/Ye1E23mwN+BqQ9rBEUg@public.gmane.org 
> <mailto:manuel.lauss-gM/Ye1E23mwN+BqQ9rBEUg@public.gmane.org>>
> ---
>  drivers/i2c/busses/i2c-au1550.c |    2 +-
>  1 files changed, 1 insertions(+), 1 deletions(-)
>
> diff --git a/drivers/i2c/busses/i2c-au1550.c 
> b/drivers/i2c/busses/i2c-au1550.c
> index 98ee11a..36d1b29 100644
> --- a/drivers/i2c/busses/i2c-au1550.c
> +++ b/drivers/i2c/busses/i2c-au1550.c
> @@ -344,7 +344,7 @@ i2c_au1550_probe(struct platform_device *pdev)
>                ret = -EIO;
>                goto out_map;
>        }
> -       priv->xfer_timeout = 200;
> +       priv->xfer_timeout = 400;
What is the unit of the timeout. If it is in usec then how is it 
dependent on the clock
supplied to the i2c module.

Am I missing something.
>
>        priv->adap.nr <http://adap.nr> = pdev->id;
>        priv->adap.algo = &au1550_algo;
> --
> 1.7.6
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-i2c" in
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> <mailto:majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>

Re: Fwd: [PATCH 3/4] i2c/au1550: increase timeout limit

[Manuel Lauss]

On Mon, Jul 18, 2011 at 11:31 AM, Shubhrajyoti <shubhrajyoti-l0cyMroinI0@public.gmane.org> wrote:
> Hi Manuel,
>>
>> From: *Manuel Lauss* <manuel.lauss-gM/Ye1E23mwN+BqQ9rBEUg@public.gmane.org
>> <mailto:manuel.lauss-gM/Ye1E23mwN+BqQ9rBEUg@public.gmane.org>>
>> Date: Thu, Jul 14, 2011 at 2:26 PM
>> Subject: [PATCH 3/4] i2c/au1550: increase timeout limit
>> To: Linux-I2C <linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
>> <mailto:linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org>>, Ben Dooks <ben-linux-elnMNo+KYs3YtjvyW6yDsg@public.gmane.org
>> <mailto:ben-linux-elnMNo+KYs3YtjvyW6yDsg@public.gmane.org>>
>> Cc: Manuel Lauss <manuel.lauss-gM/Ye1E23mwN+BqQ9rBEUg@public.gmane.org
>> <mailto:manuel.lauss-gM/Ye1E23mwN+BqQ9rBEUg@public.gmane.org>>
>>
>>
>> The timeout waiting for various events to occur is tailored for
>> a module clock of 50MHz.  On the DB1300 board only 48MHz can be
>> supplied to the i2c module, which results in the timeout aborting
>> complex transfers to slaves slightly too early if they employ
>> for example clock stretching.
>>
>> With this change the WM8731 codec on the DB1300 board is correctly
>> detected and initialized.
>>
>> Signed-off-by: Manuel Lauss <manuel.lauss-gM/Ye1E23mwN+BqQ9rBEUg@public.gmane.org
>> <mailto:manuel.lauss-gM/Ye1E23mwN+BqQ9rBEUg@public.gmane.org>>
>> ---
>>  drivers/i2c/busses/i2c-au1550.c |    2 +-
>>  1 files changed, 1 insertions(+), 1 deletions(-)
>>
>> diff --git a/drivers/i2c/busses/i2c-au1550.c
>> b/drivers/i2c/busses/i2c-au1550.c
>> index 98ee11a..36d1b29 100644
>> --- a/drivers/i2c/busses/i2c-au1550.c
>> +++ b/drivers/i2c/busses/i2c-au1550.c
>> @@ -344,7 +344,7 @@ i2c_au1550_probe(struct platform_device *pdev)
>>               ret = -EIO;
>>               goto out_map;
>>       }
>> -       priv->xfer_timeout = 200;
>> +       priv->xfer_timeout = 400;
>
> What is the unit of the timeout. If it is in usec then how is it dependent
> on the clock
> supplied to the i2c module.
>
> Am I missing something.

It's used as a loop counter, with udelay()s in the various loops.
On the DB1300 board I observed that the function "wait_master_done()"
returns an error due to the loop counter reaching zero when accessing
the WM8731; an adm1025 hwmon actually works without this patch.
That timeout is more or less a safeguard against busy waiting forever
on various event bits.

Manuel

[PATCH 4/4] i2c/au1550: dev_pm_ops conversion

[Manuel Lauss]

use newer dev_pm_ops for PM

Signed-off-by: Manuel Lauss <manuel.lauss-gM/Ye1E23mwN+BqQ9rBEUg@public.gmane.org>
---
 drivers/i2c/busses/i2c-au1550.c |   24 ++++++++++++++----------
 1 files changed, 14 insertions(+), 10 deletions(-)

diff --git a/drivers/i2c/busses/i2c-au1550.c b/drivers/i2c/busses/i2c-au1550.c
index 36d1b29..90a79f4 100644
--- a/drivers/i2c/busses/i2c-au1550.c
+++ b/drivers/i2c/busses/i2c-au1550.c
@@ -387,39 +387,43 @@ static int __devexit i2c_au1550_remove(struct platform_device *pdev)
 }
 
 #ifdef CONFIG_PM
-static int
-i2c_au1550_suspend(struct platform_device *pdev, pm_message_t state)
+static int i2c_au1550_suspend(struct device *dev)
 {
-	struct i2c_au1550_data *priv = platform_get_drvdata(pdev);
+	struct i2c_au1550_data *priv = dev_get_drvdata(dev);
 
 	i2c_au1550_disable(priv);
 
 	return 0;
 }
 
-static int
-i2c_au1550_resume(struct platform_device *pdev)
+static int i2c_au1550_resume(struct device *dev)
 {
-	struct i2c_au1550_data *priv = platform_get_drvdata(pdev);
+	struct i2c_au1550_data *priv = dev_get_drvdata(dev);
 
 	i2c_au1550_setup(priv);
 
 	return 0;
 }
+
+static const struct dev_pm_ops i2c_au1550_pmops = {
+	.suspend	= i2c_au1550_suspend,
+	.resume		= i2c_au1550_resume,
+};
+
+#define AU1XPSC_SMBUS_PMOPS (&i2c_au1550_pmops)
+
 #else
-#define i2c_au1550_suspend	NULL
-#define i2c_au1550_resume	NULL
+#define AU1XPSC_SMBUS_PMOPS NULL
 #endif
 
 static struct platform_driver au1xpsc_smbus_driver = {
 	.driver = {
 		.name	= "au1xpsc_smbus",
 		.owner	= THIS_MODULE,
+		.pm	= AU1XPSC_SMBUS_PMOPS,
 	},
 	.probe		= i2c_au1550_probe,
 	.remove		= __devexit_p(i2c_au1550_remove),
-	.suspend	= i2c_au1550_suspend,
-	.resume		= i2c_au1550_resume,
 };
 
 static int __init i2c_au1550_init(void)
-- 
1.7.6