[U-Boot] [PATCH 1/2] I2C: add Marvell TWSI simple driver

[U-Boot] [PATCH 1/2] I2C: add Marvell TWSI simple driver

[Albert Aribaud]

This driver is for the Marvell TWSI/I2C module found in
the orion and kirkwood families among others.

Signed-off-by: Albert Aribaud <albert.aribaud@free.fr>
---
While the 'kirkwood_i2c' driver for the Marvell TWSI module
is already available in u-boot, this one is 25% smaller, less
complex (no state machine) and much faster (i2c probe on an
ED Mini V2 takes no noticeable time vs. half a second).

 drivers/i2c/Makefile |    1 +
 drivers/i2c/mvtwsi.c |  419 ++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 420 insertions(+), 0 deletions(-)
 create mode 100644 drivers/i2c/mvtwsi.c

diff --git a/drivers/i2c/Makefile b/drivers/i2c/Makefile
index d2c2515..73c415d 100644
--- a/drivers/i2c/Makefile
+++ b/drivers/i2c/Makefile
@@ -30,6 +30,7 @@ COBJS-$(CONFIG_DRIVER_DAVINCI_I2C) += davinci_i2c.o
 COBJS-$(CONFIG_FSL_I2C) += fsl_i2c.o
 COBJS-$(CONFIG_I2C_KIRKWOOD) += kirkwood_i2c.o
 COBJS-$(CONFIG_I2C_MXC) += mxc_i2c.o
+COBJS-$(CONFIG_I2C_DRIVER_MVTWSI) += mvtwsi.o
 COBJS-$(CONFIG_DRIVER_OMAP1510_I2C) += omap1510_i2c.o
 COBJS-$(CONFIG_DRIVER_OMAP24XX_I2C) += omap24xx_i2c.o
 COBJS-$(CONFIG_DRIVER_OMAP34XX_I2C) += omap24xx_i2c.o
diff --git a/drivers/i2c/mvtwsi.c b/drivers/i2c/mvtwsi.c
new file mode 100644
index 0000000..b591328
--- /dev/null
+++ b/drivers/i2c/mvtwsi.c
@@ -0,0 +1,419 @@
+/*
+ * Driver for the TWSI (i2c) controller on the Marvell orion5x
+ *
+ * Author: Albert Aribaud <albert.aribaud@free.fr>
+ * 2005 (c) MontaVista, Software, Inc.
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+ * MA 02110-1301 USA
+ */
+ 
+#include <common.h>
+#include <i2c.h>
+#include <asm/errno.h>
+#include <asm/io.h>
+
+/*
+ * include a file that will provide CONFIG_I2C_MVTWSI_BASE
+ * and possibly other settings
+ */
+
+#if defined(CONFIG_ORION5X)
+#include <asm/arch/orion5x.h>
+#else
+#error Driver mvtwsi not supported by SoC or board
+#endif
+
+/*
+ * TWSI register structure
+ */
+
+struct  mvtwsi_registers {
+	u32 slave_address;
+	u32 data;
+	u32 control;
+	union {
+		u32 status;	/* when reading */
+		u32 baudrate;	/* when writing */
+	};
+	u32 extended_slave_address;
+	u32 reserved[2];
+	u32 soft_reset;
+};
+
+/*
+ * Control register fields
+ */
+
+#define	MVTWSI_CONTROL_ACK	0x00000004
+#define	MVTWSI_CONTROL_IFLG	0x00000008
+#define	MVTWSI_CONTROL_STOP	0x00000010
+#define	MVTWSI_CONTROL_START	0x00000020
+#define	MVTWSI_CONTROL_TWSIEN	0x00000040
+#define	MVTWSI_CONTROL_INTEN	0x00000080
+
+/*
+ * Status register values -- only those expected in normal master
+ * operation on non-10-bit-address devices; whatever status we don't
+ * expect in nominal conditions (bus errors, arbitration losses,
+ * missing ACKs...) we just pass back to the caller as an error
+ * code.
+ */
+
+#define	MVTWSI_STATUS_START		0x08
+#define	MVTWSI_STATUS_REPEATED_START	0x10
+#define	MVTWSI_STATUS_ADDR_W_ACK	0x18
+#define	MVTWSI_STATUS_DATA_W_ACK	0x28
+#define	MVTWSI_STATUS_ADDR_R_ACK	0x40
+#define	MVTWSI_STATUS_ADDR_R_NAK	0x48
+#define	MVTWSI_STATUS_DATA_R_ACK	0x50
+#define	MVTWSI_STATUS_DATA_R_NAK	0x58 /* our NAK, not the slave's */
+#define	MVTWSI_STATUS_IDLE		0xF8
+
+/*
+ * The single instance of the controller we'll be dealing with
+ */
+
+static struct  mvtwsi_registers *twsi =
+	(struct  mvtwsi_registers *) CONFIG_I2C_MVTWSI_BASE;
+
+/*
+ * Returned statuses are 0 for success and nonzero otherwise.
+ * Currently, cmd_i2c and cmd_eeprom do not interpret an error status.
+ * Thus to ease debugging, the return status contains some debug info:
+ * - bits 31..24 are an error class: 0x01 is timeout, 0x02 is 'status mismatch'.
+ * - bits 23..16 are the last value of the control register.
+ * - bits 15..8 are the last value of the status register.
+ * - bits 7..0 are the expected value of the status register.
+ */
+
+#define MVTWSI_ERROR_WRONG_STATUS	0x01
+#define MVTWSI_ERROR_TIMEOUT		0x02
+
+#define MVTWSI_ERROR(ec,lc,ls,es) ( ( (ec << 24) & 0xFF000000) | \
+	( (lc << 16) & 0x00FF0000) | ( (ls<<8) & 0x0000FF00) | (es & 0xFF) )
+
+/*
+ * Wait for IFLG to raise, or return 'timeout'; then if status is as expected,
+ * return 0 (ok) or return 'wrong status'.
+ */
+
+static int twsi_wait(int expected_status)
+{
+	int control,status;
+	int timeout = 1000;
+	do {
+		control = readl(&twsi->control);
+		if (control & MVTWSI_CONTROL_IFLG) {
+			status = readl(&twsi->status);
+			if (status==expected_status)
+				return 0;
+			else
+				return MVTWSI_ERROR(MVTWSI_ERROR_WRONG_STATUS,control, status,
+					expected_status);
+		}
+		udelay(10);
+	} while (timeout--);
+	status = readl(&twsi->status);
+	return MVTWSI_ERROR(MVTWSI_ERROR_TIMEOUT,control,status,expected_status);
+}
+
+/*
+ * These flags are ORed to any write to the control register
+ * They allow global setting of TWSIEN and ACK.
+ * By default none are set.
+ * twsi_start() sets TWSIEN (in case the controller was disabled)
+ * twsi_recv() sets ACK or resets it depending on expected status.
+ */
+
+static u8 twsi_control_flags = MVTWSI_CONTROL_TWSIEN;
+
+/*
+ * Assert the START condition, either in a single I2C transaction
+ * or inside back-to-back ones (repeated starts).
+ */
+
+static int twsi_start(int expected_status)
+{
+	/* globally set TWSIEN in case it was not */
+	twsi_control_flags |= MVTWSI_CONTROL_TWSIEN;
+	/* assert START */
+	writel(twsi_control_flags | MVTWSI_CONTROL_START, &twsi->control);
+	/* wait for controller to process START */
+	return twsi_wait(expected_status);
+}
+
+/*
+ * Send a byte (i2c address or data).
+ */
+
+static int twsi_send(u8 byte, int expected_status)
+{
+	/* put byte in data register for sending */
+	writel(byte, &twsi->data);
+	/* clear any pending interrupt -- that'll cause sending */
+	writel(twsi_control_flags, &twsi->control);
+	/* wait for controller to receive byte and check ACK */
+	return twsi_wait(expected_status);
+}
+
+/*
+ * Receive a byte.
+ * Global mvtwsi_control_flags variable says if we should ack or nak.
+ */
+
+static int twsi_recv(u8 *byte)
+{
+	int expected_status, status;
+	/* compute expected status based on ACK bit in global control flags */
+	if (twsi_control_flags & MVTWSI_CONTROL_ACK)
+		expected_status = MVTWSI_STATUS_DATA_R_ACK;
+	else
+		expected_status = MVTWSI_STATUS_DATA_R_NAK;
+	/* acknowledge *previous state* and launch receive */
+	writel(twsi_control_flags, &twsi->control);
+	/* wait for controller to receive byte and assert ACK or NAK */
+	status = twsi_wait(expected_status);
+	/* if we did receive expected byte then store it */
+	if (status==0)
+		*byte = readl(&twsi->data);
+	/* return status */
+	return status;
+}
+
+/*
+ * Assert the STOP condition.
+ * This is also used to force the bus back in idle (SDA=SCL=1).
+ */
+
+static int twsi_stop(void)
+{
+	int control,status;
+	int timeout = 1000;
+	/* assert STOP */
+	control = MVTWSI_CONTROL_TWSIEN | MVTWSI_CONTROL_STOP;
+	writel(control, &twsi->control);
+	/* wait for idle condition. There won't be an IFLG so we cannot use twsi_wait(). */
+	do {
+		status = readl(&twsi->status);
+		if (status==MVTWSI_STATUS_IDLE)
+			return 0;
+		udelay(10);
+	} while (timeout--);
+	control = readl(&twsi->control);
+	return MVTWSI_ERROR(MVTWSI_ERROR_TIMEOUT,control,status,MVTWSI_STATUS_IDLE);
+}
+
+/*
+ * Ugly formula to convert m and n values to a frequency comes from
+ * TWSI specifications
+ */
+
+#define TWSI_FREQUENCY(m,n) \
+	( (u8) (CONFIG_SYS_TCLK / (10 * (m + 1) * 2 * (1 << n))) )
+
+/*
+ * These are required to be reprogrammed before enabling the controller
+ * because a reset loses them.
+ * Default values come from the spec, but a twsi_reset will change them.
+ */
+
+static u8 twsi_baud_rate = 0x44;
+static u8 twsi_actual_speed = TWSI_FREQUENCY(4,4);
+static u8 twsi_slave_address = 0;
+
+/*
+ * Reset controller.
+ * Called@end of i2c_init unsuccessful i2c transactions.
+ * Controller reset also resets the baud rate and slave address, so
+ * re-establish them.
+ */
+
+static void twsi_reset(void)
+{
+	/* ensure controller will be enabled by any twsi*() function */
+	twsi_control_flags = MVTWSI_CONTROL_TWSIEN;
+	/* reset controller */
+	writel(0, &twsi->soft_reset);
+	/* wait 2 ms -- this is what the Marvell LSP does */
+	udelay(20000);
+	/* set baud rate */
+	writel(twsi_baud_rate, &twsi->baudrate);
+	/* set slave address even though we don't use it */
+	writel(twsi_slave_address, &twsi->slave_address);
+	writel(0, &twsi->extended_slave_address);
+	/* assert STOP but don't care for the result */
+	(void) twsi_stop();
+}
+
+/*
+ * I2C init called by cmd_i2c when doing 'i2c reset'.
+ * Sets baud to the highest possible value not exceeding requested one.
+ */
+
+void i2c_init(int requested_speed, int slaveadd)
+{
+	int	tmp_speed, highest_speed, n, m;
+	int	baud = 0x44; /* value at controller reset */
+	/* use actual speed to collect progressively higher values */
+	highest_speed = 0;
+	/* compute m,n setting for highest speed not above requested speed */
+	for (n = 0; n < 8; n++) {
+		for (m = 0; m < 16; m++) {
+			tmp_speed = TWSI_FREQUENCY(m,n);
+			if (tmp_speed <= requested_speed)
+			if (tmp_speed > highest_speed) {
+				highest_speed = tmp_speed;
+				baud = (m << 3) | n;
+			}
+		}
+	}
+	/* save baud rate and slave for later calls to twsi_reset */
+	twsi_baud_rate = baud;
+	twsi_actual_speed = highest_speed;
+	twsi_slave_address = slaveadd;
+	/* reset controller */
+	twsi_reset();
+}
+
+/*
+ * Begin I2C transaction with expected start status,@given address.
+ * Common to i2c_probe, i2c_read and i2c_write.
+ * Expected address status will derive from direction bit (bit 0) in addr.
+ */
+
+static int i2c_begin(int expected_start_status, u8 addr)
+{
+	int status, expected_addr_status;
+	/* compute expected address status from direction bit in addr */
+	if (addr & 1) /* reading */
+		expected_addr_status = MVTWSI_STATUS_ADDR_R_ACK;
+	else /* writing */
+		expected_addr_status = MVTWSI_STATUS_ADDR_W_ACK;
+	/* assert START */
+	status = twsi_start(expected_start_status);
+	/* send out the address if the start went well */
+	if (status == 0)
+		status = twsi_send(addr, expected_addr_status);
+	/* return ok or status of first failure to caller */
+	return status;
+}
+
+/*
+ * End I2C transaction, of which the current status is given.
+ * Common to i2c_probe, i2c_read and i2c_write.
+ */
+
+static int i2c_end(int status)
+{
+	/* if transaction went well so far, try to assert a STOP */
+	/*if (status == 0)*/
+		twsi_stop();
+	/* if anything went wrong (including the STOP we tried), do a reset */
+	/*else
+		twsi_reset();*/
+	/* return ok or status of first failure to caller */
+	return status;
+}
+
+/*
+ * I2C probe called by cmd_i2c when doing 'i2c probe'.
+ * Begin read, nak data byte, end.
+ */
+
+int i2c_probe(uchar chip)
+{
+	u8 dummy_byte;
+	int status;
+	/* begin i2c read */
+	status = i2c_begin(MVTWSI_STATUS_START, (chip << 1) | 1 );
+	/* dummy read was accepted: receive byte but NAK it. */
+	if (status==0)
+		status = twsi_recv( &dummy_byte);
+	/* We expected either 0 (ok) or MVTWSI_STATUS_ADDR_R_NAK */
+	return i2c_end( (status==MVTWSI_STATUS_ADDR_R_NAK) ? 0: status);
+}
+
+/*
+ * I2C read called by cmd_i2c when doing 'i2c read' and by cmd_eeprom.c
+ * Begin write, send address byte(s), begin read, receive data bytes, end.
+ */
+
+int i2c_read(u8 dev, uint addr, int alen, u8 *data, int length)
+{
+	int status;
+	/* begin i2c write to send the address bytes */
+	status = i2c_begin(MVTWSI_STATUS_START, (dev << 1) );
+	/* send addr bytes */
+	while ( (status==0) && alen--)
+		status = twsi_send(addr >> (8*alen), MVTWSI_STATUS_DATA_W_ACK);
+	/* NOTE: should we send a stop before a start? That's eeprom-level stuff */
+	/* begin i2c read to receive eeprom data bytes */
+	if (status == 0)
+		status = i2c_begin(MVTWSI_STATUS_REPEATED_START, (dev << 1) | 1);
+	/* prepare ACK if@least one byte must be received */
+	if (length > 0)
+		twsi_control_flags |= MVTWSI_CONTROL_ACK;
+	/* now receive actual bytes */
+	while ( (status==0) && length-- ) {
+		/* reset NAK if we if no more to read now */
+		if (length == 0)
+			twsi_control_flags &= ~MVTWSI_CONTROL_ACK;
+		/* read current byte */
+		status = twsi_recv(data++);
+	}
+	/* end i2c transaction */
+	return i2c_end(status);
+}
+
+/*
+ * I2C write called by cmd_i2c when doing 'i2c write' and by cmd_eeprom.c
+ * Begin write, send address byte(s), send data bytes, end.
+ */
+
+int i2c_write(u8 dev, uint addr, int alen, u8 *data, int length)
+{
+	int status;
+	/* begin i2c write to send the eeprom adress bytes then data bytes */
+	status = i2c_begin(MVTWSI_STATUS_START, (dev << 1) );
+	/* send addr bytes */
+	while ( (status==0) && alen--)
+		status = twsi_send(addr >> (8*alen), MVTWSI_STATUS_DATA_W_ACK);
+	/* send data bytes */
+	while ( (status==0) && (length-->0) )
+		status = twsi_send(*(data++), MVTWSI_STATUS_DATA_W_ACK);
+	/* end i2c transaction */
+	return i2c_end(status);
+}
+
+/*
+ * Bus set/get routines: we only support bus 0.
+ */
+
+int i2c_set_bus_num(unsigned int bus)
+{
+	if (bus > 0) {
+		return -1;
+	}
+	return 0;
+}
+
+unsigned int i2c_get_bus_num(void)
+{
+	return 0;
+}
-- 
1.7.1

[U-Boot] [PATCH 2/2] edminiv2: add I2C support using mvtwsi driver

[Albert Aribaud]

Signed-off-by: Albert Aribaud <albert.aribaud@free.fr>
---
 include/configs/edminiv2.h |    9 +++++++++
 1 files changed, 9 insertions(+), 0 deletions(-)

diff --git a/include/configs/edminiv2.h b/include/configs/edminiv2.h
index 57dd165..36ed392 100644
--- a/include/configs/edminiv2.h
+++ b/include/configs/edminiv2.h
@@ -182,6 +182,15 @@
 #endif /* CMD_IDE */
 
 /*
+ * I2C related stuff
+ */
+#define CONFIG_I2C_DRIVER_MVTWSI
+#define CONFIG_I2C_MVTWSI_BASE		ORION5X_TWSI_BASE
+#define CONFIG_SYS_I2C_SLAVE		0x0
+#define CONFIG_SYS_I2C_SPEED		100000
+#define CONFIG_CMD_I2C
+
+/*
  *  Environment variables configurations
  */
 #define CONFIG_ENV_IS_IN_FLASH		1
-- 
1.7.1

[U-Boot] [PATCH 1/2] I2C: add Marvell TWSI simple driver

[Albert ARIBAUD]

Reviewing myself, as a blatant copy-paste mistake only hit my eyes right 
after the patch was posted. :(

Le 25/08/2010 16:23, Albert Aribaud a ?crit :

> diff --git a/drivers/i2c/mvtwsi.c b/drivers/i2c/mvtwsi.c

> @@ -0,0 +1,419 @@
> +/*
> + * Driver for the TWSI (i2c) controller on the Marvell orion5x
> + *
> + * Author: Albert Aribaud<albert.aribaud@free.fr>
> + * 2005 (c) MontaVista, Software, Inc.

This code is not (c) Montavista originally; it is a completely new 
implementation, with the license notice copied from the kirkwood file. 
I'll remove this line in patch V2.

Amicalement,
-- 
Albert.

[U-Boot] [PATCH 1/2] I2C: add Marvell TWSI simple driver

[Prafulla Wadaskar]

 

> -----Original Message-----
> From: u-boot-bounces at lists.denx.de 
> [mailto:u-boot-bounces at lists.denx.de] On Behalf Of Albert Aribaud
> Sent: Wednesday, August 25, 2010 7:54 PM
> To: u-boot at lists.denx.de
> Subject: [U-Boot] [PATCH 1/2] I2C: add Marvell TWSI simple driver
> 
> This driver is for the Marvell TWSI/I2C module found in
> the orion and kirkwood families among others.
> 
> Signed-off-by: Albert Aribaud <albert.aribaud@free.fr>
> ---
> While the 'kirkwood_i2c' driver for the Marvell TWSI module
> is already available in u-boot, this one is 25% smaller, less
> complex (no state machine) and much faster (i2c probe on an
> ED Mini V2 takes no noticeable time vs. half a second).

Hi Albert
This will be very good enhancement indeed.

> 
>  drivers/i2c/Makefile |    1 +
>  drivers/i2c/mvtwsi.c |  419

Can you pls follow the same strategy as we followed for mvgbe, mvsata?
Please rename and enhance current kirkwood_i2c driver support,
and then add support for Orion followed by board support for edminiv2

Regards..
Prafulla .. 

[U-Boot] [PATCH 1/2] I2C: add Marvell TWSI simple driver

[Heiko Schocher]

Hello Albert,

Albert Aribaud wrote:
> This driver is for the Marvell TWSI/I2C module found in
> the orion and kirkwood families among others.
> 
> Signed-off-by: Albert Aribaud <albert.aribaud@free.fr>
> ---
> While the 'kirkwood_i2c' driver for the Marvell TWSI module
> is already available in u-boot, this one is 25% smaller, less
> complex (no state machine) and much faster (i2c probe on an
> ED Mini V2 takes no noticeable time vs. half a second).

Great!

As the kirkwood_i2c driver is actually not used in any board,
we should remove it completely, can you add this for v2?

Beside of that, I have just some minor codstyling comments:

>  drivers/i2c/Makefile |    1 +
>  drivers/i2c/mvtwsi.c |  419 ++++++++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 420 insertions(+), 0 deletions(-)
>  create mode 100644 drivers/i2c/mvtwsi.c
> 
> diff --git a/drivers/i2c/Makefile b/drivers/i2c/Makefile
> index d2c2515..73c415d 100644
> --- a/drivers/i2c/Makefile
> +++ b/drivers/i2c/Makefile
> @@ -30,6 +30,7 @@ COBJS-$(CONFIG_DRIVER_DAVINCI_I2C) += davinci_i2c.o
>  COBJS-$(CONFIG_FSL_I2C) += fsl_i2c.o
>  COBJS-$(CONFIG_I2C_KIRKWOOD) += kirkwood_i2c.o
>  COBJS-$(CONFIG_I2C_MXC) += mxc_i2c.o
> +COBJS-$(CONFIG_I2C_DRIVER_MVTWSI) += mvtwsi.o
>  COBJS-$(CONFIG_DRIVER_OMAP1510_I2C) += omap1510_i2c.o
>  COBJS-$(CONFIG_DRIVER_OMAP24XX_I2C) += omap24xx_i2c.o
>  COBJS-$(CONFIG_DRIVER_OMAP34XX_I2C) += omap24xx_i2c.o
> diff --git a/drivers/i2c/mvtwsi.c b/drivers/i2c/mvtwsi.c
> new file mode 100644
> index 0000000..b591328
> --- /dev/null
> +++ b/drivers/i2c/mvtwsi.c
> @@ -0,0 +1,419 @@
> +/*
> + * Driver for the TWSI (i2c) controller on the Marvell orion5x
> + *
> + * Author: Albert Aribaud <albert.aribaud@free.fr>
> + * 2005 (c) MontaVista, Software, Inc.
> + *
> + * See file CREDITS for list of people who contributed to this
> + * project.
> + *
> + * This program is free software; you can redistribute it and/or
> + * modify it under the terms of the GNU General Public License as
> + * published by the Free Software Foundation; either version 2 of
> + * the License, or (at your option) any later version.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program; if not, write to the Free Software
> + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
> + * MA 02110-1301 USA
> + */
> + 
> +#include <common.h>
> +#include <i2c.h>
> +#include <asm/errno.h>
> +#include <asm/io.h>
> +
> +/*
> + * include a file that will provide CONFIG_I2C_MVTWSI_BASE
> + * and possibly other settings
> + */
> +
> +#if defined(CONFIG_ORION5X)
> +#include <asm/arch/orion5x.h>
> +#else
> +#error Driver mvtwsi not supported by SoC or board
> +#endif
> +
> +/*
> + * TWSI register structure
> + */
> +
> +struct  mvtwsi_registers {
> +	u32 slave_address;
> +	u32 data;
> +	u32 control;
> +	union {
> +		u32 status;	/* when reading */
> +		u32 baudrate;	/* when writing */
> +	};
> +	u32 extended_slave_address;
> +	u32 reserved[2];
> +	u32 soft_reset;
> +};
> +
> +/*
> + * Control register fields
> + */
> +
> +#define	MVTWSI_CONTROL_ACK	0x00000004
> +#define	MVTWSI_CONTROL_IFLG	0x00000008
> +#define	MVTWSI_CONTROL_STOP	0x00000010
> +#define	MVTWSI_CONTROL_START	0x00000020
> +#define	MVTWSI_CONTROL_TWSIEN	0x00000040
> +#define	MVTWSI_CONTROL_INTEN	0x00000080
> +
> +/*
> + * Status register values -- only those expected in normal master
> + * operation on non-10-bit-address devices; whatever status we don't
> + * expect in nominal conditions (bus errors, arbitration losses,
> + * missing ACKs...) we just pass back to the caller as an error
> + * code.
> + */
> +
> +#define	MVTWSI_STATUS_START		0x08
> +#define	MVTWSI_STATUS_REPEATED_START	0x10
> +#define	MVTWSI_STATUS_ADDR_W_ACK	0x18
> +#define	MVTWSI_STATUS_DATA_W_ACK	0x28
> +#define	MVTWSI_STATUS_ADDR_R_ACK	0x40
> +#define	MVTWSI_STATUS_ADDR_R_NAK	0x48
> +#define	MVTWSI_STATUS_DATA_R_ACK	0x50
> +#define	MVTWSI_STATUS_DATA_R_NAK	0x58 /* our NAK, not the slave's */

line too long.

> +#define	MVTWSI_STATUS_IDLE		0xF8
> +
> +/*
> + * The single instance of the controller we'll be dealing with
> + */
> +
> +static struct  mvtwsi_registers *twsi =
> +	(struct  mvtwsi_registers *) CONFIG_I2C_MVTWSI_BASE;
> +
> +/*
> + * Returned statuses are 0 for success and nonzero otherwise.
> + * Currently, cmd_i2c and cmd_eeprom do not interpret an error status.
> + * Thus to ease debugging, the return status contains some debug info:
> + * - bits 31..24 are an error class: 0x01 is timeout, 0x02 is 'status mismatch'.
> + * - bits 23..16 are the last value of the control register.
> + * - bits 15..8 are the last value of the status register.
> + * - bits 7..0 are the expected value of the status register.
> + */
> +
> +#define MVTWSI_ERROR_WRONG_STATUS	0x01
> +#define MVTWSI_ERROR_TIMEOUT		0x02
> +
> +#define MVTWSI_ERROR(ec,lc,ls,es) ( ( (ec << 24) & 0xFF000000) | \
> +	( (lc << 16) & 0x00FF0000) | ( (ls<<8) & 0x0000FF00) | (es & 0xFF) )
> +
> +/*
> + * Wait for IFLG to raise, or return 'timeout'; then if status is as expected,
> + * return 0 (ok) or return 'wrong status'.
> + */
> +

blank line not necessary.

> +static int twsi_wait(int expected_status)
> +{
> +	int control,status;
> +	int timeout = 1000;

please insert a blank line, check this on other places too.

> +	do {
> +		control = readl(&twsi->control);
> +		if (control & MVTWSI_CONTROL_IFLG) {
> +			status = readl(&twsi->status);
> +			if (status==expected_status)

please insert a space between "=="

> +				return 0;
> +			else
> +				return MVTWSI_ERROR(MVTWSI_ERROR_WRONG_STATUS,control, status,

line too long, also please insert a space after a ","
Please check this for the whole file.

> +					expected_status);
> +		}
> +		udelay(10);
> +	} while (timeout--);
> +	status = readl(&twsi->status);
> +	return MVTWSI_ERROR(MVTWSI_ERROR_TIMEOUT,control,status,expected_status);
> +}
> +
> +/*
> + * These flags are ORed to any write to the control register
> + * They allow global setting of TWSIEN and ACK.
> + * By default none are set.
> + * twsi_start() sets TWSIEN (in case the controller was disabled)
> + * twsi_recv() sets ACK or resets it depending on expected status.
> + */
> +

blank line not necessary. Please check the whole file

> +static u8 twsi_control_flags = MVTWSI_CONTROL_TWSIEN;
> +
> +/*
> + * Assert the START condition, either in a single I2C transaction
> + * or inside back-to-back ones (repeated starts).
> + */
> +
> +static int twsi_start(int expected_status)
> +{
> +	/* globally set TWSIEN in case it was not */
> +	twsi_control_flags |= MVTWSI_CONTROL_TWSIEN;
> +	/* assert START */
> +	writel(twsi_control_flags | MVTWSI_CONTROL_START, &twsi->control);
> +	/* wait for controller to process START */
> +	return twsi_wait(expected_status);
> +}
> +
> +/*
> + * Send a byte (i2c address or data).
> + */
> +
> +static int twsi_send(u8 byte, int expected_status)
> +{
> +	/* put byte in data register for sending */
> +	writel(byte, &twsi->data);
> +	/* clear any pending interrupt -- that'll cause sending */
> +	writel(twsi_control_flags, &twsi->control);
> +	/* wait for controller to receive byte and check ACK */
> +	return twsi_wait(expected_status);
> +}
> +
> +/*
> + * Receive a byte.
> + * Global mvtwsi_control_flags variable says if we should ack or nak.
> + */
> +
> +static int twsi_recv(u8 *byte)
> +{
> +	int expected_status, status;
> +	/* compute expected status based on ACK bit in global control flags */
> +	if (twsi_control_flags & MVTWSI_CONTROL_ACK)
> +		expected_status = MVTWSI_STATUS_DATA_R_ACK;
> +	else
> +		expected_status = MVTWSI_STATUS_DATA_R_NAK;
> +	/* acknowledge *previous state* and launch receive */
> +	writel(twsi_control_flags, &twsi->control);
> +	/* wait for controller to receive byte and assert ACK or NAK */
> +	status = twsi_wait(expected_status);
> +	/* if we did receive expected byte then store it */
> +	if (status==0)
> +		*byte = readl(&twsi->data);
> +	/* return status */

comment not necessary.

> +	return status;
> +}
> +
> +/*
> + * Assert the STOP condition.
> + * This is also used to force the bus back in idle (SDA=SCL=1).
> + */
> +
> +static int twsi_stop(void)
> +{
> +	int control,status;
> +	int timeout = 1000;
> +	/* assert STOP */
> +	control = MVTWSI_CONTROL_TWSIEN | MVTWSI_CONTROL_STOP;
> +	writel(control, &twsi->control);
> +	/* wait for idle condition. There won't be an IFLG so we cannot use twsi_wait(). */
> +	do {
> +		status = readl(&twsi->status);
> +		if (status==MVTWSI_STATUS_IDLE)
> +			return 0;
> +		udelay(10);
> +	} while (timeout--);
> +	control = readl(&twsi->control);
> +	return MVTWSI_ERROR(MVTWSI_ERROR_TIMEOUT,control,status,MVTWSI_STATUS_IDLE);
> +}
> +
> +/*
> + * Ugly formula to convert m and n values to a frequency comes from
> + * TWSI specifications
> + */
> +
> +#define TWSI_FREQUENCY(m,n) \
> +	( (u8) (CONFIG_SYS_TCLK / (10 * (m + 1) * 2 * (1 << n))) )
> +
> +/*
> + * These are required to be reprogrammed before enabling the controller
> + * because a reset loses them.
> + * Default values come from the spec, but a twsi_reset will change them.
> + */
> +
> +static u8 twsi_baud_rate = 0x44;
> +static u8 twsi_actual_speed = TWSI_FREQUENCY(4,4);
> +static u8 twsi_slave_address = 0;
> +
> +/*
> + * Reset controller.
> + * Called at end of i2c_init unsuccessful i2c transactions.
> + * Controller reset also resets the baud rate and slave address, so
> + * re-establish them.
> + */
> +
> +static void twsi_reset(void)
> +{
> +	/* ensure controller will be enabled by any twsi*() function */
> +	twsi_control_flags = MVTWSI_CONTROL_TWSIEN;
> +	/* reset controller */
> +	writel(0, &twsi->soft_reset);
> +	/* wait 2 ms -- this is what the Marvell LSP does */
> +	udelay(20000);
> +	/* set baud rate */
> +	writel(twsi_baud_rate, &twsi->baudrate);
> +	/* set slave address even though we don't use it */
> +	writel(twsi_slave_address, &twsi->slave_address);
> +	writel(0, &twsi->extended_slave_address);
> +	/* assert STOP but don't care for the result */
> +	(void) twsi_stop();
> +}
> +
> +/*
> + * I2C init called by cmd_i2c when doing 'i2c reset'.
> + * Sets baud to the highest possible value not exceeding requested one.
> + */
> +
> +void i2c_init(int requested_speed, int slaveadd)
> +{
> +	int	tmp_speed, highest_speed, n, m;
> +	int	baud = 0x44; /* value at controller reset */
> +	/* use actual speed to collect progressively higher values */
> +	highest_speed = 0;
> +	/* compute m,n setting for highest speed not above requested speed */
> +	for (n = 0; n < 8; n++) {
> +		for (m = 0; m < 16; m++) {
> +			tmp_speed = TWSI_FREQUENCY(m,n);
> +			if (tmp_speed <= requested_speed)
> +			if (tmp_speed > highest_speed) {
> +				highest_speed = tmp_speed;
> +				baud = (m << 3) | n;
> +			}
> +		}
> +	}
> +	/* save baud rate and slave for later calls to twsi_reset */
> +	twsi_baud_rate = baud;
> +	twsi_actual_speed = highest_speed;
> +	twsi_slave_address = slaveadd;
> +	/* reset controller */
> +	twsi_reset();
> +}
> +
> +/*
> + * Begin I2C transaction with expected start status, at given address.
> + * Common to i2c_probe, i2c_read and i2c_write.
> + * Expected address status will derive from direction bit (bit 0) in addr.
> + */
> +
> +static int i2c_begin(int expected_start_status, u8 addr)
> +{
> +	int status, expected_addr_status;
> +	/* compute expected address status from direction bit in addr */
> +	if (addr & 1) /* reading */
> +		expected_addr_status = MVTWSI_STATUS_ADDR_R_ACK;
> +	else /* writing */
> +		expected_addr_status = MVTWSI_STATUS_ADDR_W_ACK;
> +	/* assert START */
> +	status = twsi_start(expected_start_status);
> +	/* send out the address if the start went well */
> +	if (status == 0)
> +		status = twsi_send(addr, expected_addr_status);
> +	/* return ok or status of first failure to caller */
> +	return status;
> +}
> +
> +/*
> + * End I2C transaction, of which the current status is given.
> + * Common to i2c_probe, i2c_read and i2c_write.
> + */
> +
> +static int i2c_end(int status)
> +{
> +	/* if transaction went well so far, try to assert a STOP */
> +	/*if (status == 0)*/

Don;t add dead code.

> +		twsi_stop();
> +	/* if anything went wrong (including the STOP we tried), do a reset */
> +	/*else
> +		twsi_reset();*/

here too.

> +	/* return ok or status of first failure to caller */
> +	return status;
> +}
> +
> +/*
> + * I2C probe called by cmd_i2c when doing 'i2c probe'.
> + * Begin read, nak data byte, end.
> + */
> +
> +int i2c_probe(uchar chip)
> +{
> +	u8 dummy_byte;
> +	int status;
> +	/* begin i2c read */
> +	status = i2c_begin(MVTWSI_STATUS_START, (chip << 1) | 1 );
> +	/* dummy read was accepted: receive byte but NAK it. */
> +	if (status==0)
> +		status = twsi_recv( &dummy_byte);
> +	/* We expected either 0 (ok) or MVTWSI_STATUS_ADDR_R_NAK */
> +	return i2c_end( (status==MVTWSI_STATUS_ADDR_R_NAK) ? 0: status);
> +}
> +
> +/*
> + * I2C read called by cmd_i2c when doing 'i2c read' and by cmd_eeprom.c
> + * Begin write, send address byte(s), begin read, receive data bytes, end.
> + */
> +
> +int i2c_read(u8 dev, uint addr, int alen, u8 *data, int length)
> +{
> +	int status;
> +	/* begin i2c write to send the address bytes */
> +	status = i2c_begin(MVTWSI_STATUS_START, (dev << 1) );
> +	/* send addr bytes */
> +	while ( (status==0) && alen--)
> +		status = twsi_send(addr >> (8*alen), MVTWSI_STATUS_DATA_W_ACK);
> +	/* NOTE: should we send a stop before a start? That's eeprom-level stuff */
> +	/* begin i2c read to receive eeprom data bytes */
> +	if (status == 0)
> +		status = i2c_begin(MVTWSI_STATUS_REPEATED_START, (dev << 1) | 1);
> +	/* prepare ACK if at least one byte must be received */
> +	if (length > 0)
> +		twsi_control_flags |= MVTWSI_CONTROL_ACK;
> +	/* now receive actual bytes */
> +	while ( (status==0) && length-- ) {
> +		/* reset NAK if we if no more to read now */
> +		if (length == 0)
> +			twsi_control_flags &= ~MVTWSI_CONTROL_ACK;
> +		/* read current byte */
> +		status = twsi_recv(data++);
> +	}
> +	/* end i2c transaction */
> +	return i2c_end(status);
> +}
> +
> +/*
> + * I2C write called by cmd_i2c when doing 'i2c write' and by cmd_eeprom.c
> + * Begin write, send address byte(s), send data bytes, end.
> + */
> +
> +int i2c_write(u8 dev, uint addr, int alen, u8 *data, int length)
> +{
> +	int status;
> +	/* begin i2c write to send the eeprom adress bytes then data bytes */
> +	status = i2c_begin(MVTWSI_STATUS_START, (dev << 1) );
> +	/* send addr bytes */
> +	while ( (status==0) && alen--)
> +		status = twsi_send(addr >> (8*alen), MVTWSI_STATUS_DATA_W_ACK);
> +	/* send data bytes */
> +	while ( (status==0) && (length-->0) )
> +		status = twsi_send(*(data++), MVTWSI_STATUS_DATA_W_ACK);
> +	/* end i2c transaction */
> +	return i2c_end(status);
> +}
> +
> +/*
> + * Bus set/get routines: we only support bus 0.
> + */
> +
> +int i2c_set_bus_num(unsigned int bus)
> +{
> +	if (bus > 0) {
> +		return -1;
> +	}
> +	return 0;
> +}
> +
> +unsigned int i2c_get_bus_num(void)
> +{
> +	return 0;
> +}

[U-Boot] [PATCH 1/2] I2C: add Marvell TWSI simple driver

[Albert ARIBAUD]

(adding Heiko, custodian of I2C/EEPROM and committer of kirkwood_i2c)

Le 26/08/2010 06:33, Prafulla Wadaskar a ?crit :
>
>
>> -----Original Message-----
>> From: u-boot-bounces at lists.denx.de
>> [mailto:u-boot-bounces at lists.denx.de] On Behalf Of Albert Aribaud
>> Sent: Wednesday, August 25, 2010 7:54 PM
>> To: u-boot at lists.denx.de
>> Subject: [U-Boot] [PATCH 1/2] I2C: add Marvell TWSI simple driver
>>
>> This driver is for the Marvell TWSI/I2C module found in
>> the orion and kirkwood families among others.
>>
>> Signed-off-by: Albert Aribaud<albert.aribaud@free.fr>
>> ---
>> While the 'kirkwood_i2c' driver for the Marvell TWSI module
>> is already available in u-boot, this one is 25% smaller, less
>> complex (no state machine) and much faster (i2c probe on an
>> ED Mini V2 takes no noticeable time vs. half a second).
>
> Hi Albert
> This will be very good enhancement indeed.
>
>>
>>   drivers/i2c/Makefile |    1 +
>>   drivers/i2c/mvtwsi.c |  419
>
> Can you pls follow the same strategy as we followed for mvgbe, mvsata?
> Please rename and enhance current kirkwood_i2c driver support,
> and then add support for Orion followed by board support for edminiv2
>
> Regards..
> Prafulla ..

I can do this of course; however I felt that I was not fixing an 
existing driver (as I did with mvgbe) or adding support (as I did with 
mvsata where there was no existing driver) but introducing competition 
(as kirkwood_i2c exists and is functional) and I did not want to rudely 
stomp the existing driver.

Besides, as mvtwsi is new code, and even though I tested it (probe, 
read, write) with the ED Mini V2 EEPROM and RTC, until we are sure that 
it works we might want to keep the older kirkwood_i2c code around and be 
able to switch from one to the other -- having two different drivers for 
the same HW IP and selecting at config time is done in 
include/configs/km_arm.h where an option can be set to use either the 
soft I2C driver or the kirkwood one.

Finally, we can always remove the kirkwood_i2c driver later on if we 
want, in a separate patch (which will also switch km_arm to using mvtwsi).

Anyway, this mvtwsi patch will require Heiko's ACK as well as yours; 
let's hear from him (when he is back) on whether I should add mvtwsi or 
replace kirkwood_i2c.

Amicalement,
-- 
Albert.

[U-Boot] [PATCH 1/2] I2C: add Marvell TWSI simple driver

[Albert ARIBAUD]

Le 26/08/2010 08:30, Heiko Schocher a ?crit :

> As the kirkwood_i2c driver is actually not used in any board,
> we should remove it completely, can you add this for v2?

That answers the questions I *just* asked on the list :) -- Wilco.

> Beside of that, I have just some minor codstyling comments:
>
>[...]

Will apply these. Thanks!

Amicalement,
-- 
Albert.

[U-Boot] [PATCH 1/2] I2C: add Marvell TWSI simple driver

[Heiko Schocher]

Hello Albert,

Albert ARIBAUD wrote:
> (adding Heiko, custodian of I2C/EEPROM and committer of kirkwood_i2c)
> 
> Le 26/08/2010 06:33, Prafulla Wadaskar a ?crit :
>>
>>> -----Original Message-----
>>> From: u-boot-bounces at lists.denx.de
>>> [mailto:u-boot-bounces at lists.denx.de] On Behalf Of Albert Aribaud
>>> Sent: Wednesday, August 25, 2010 7:54 PM
>>> To: u-boot at lists.denx.de
>>> Subject: [U-Boot] [PATCH 1/2] I2C: add Marvell TWSI simple driver
>>>
>>> This driver is for the Marvell TWSI/I2C module found in
>>> the orion and kirkwood families among others.
>>>
>>> Signed-off-by: Albert Aribaud<albert.aribaud@free.fr>
>>> ---
>>> While the 'kirkwood_i2c' driver for the Marvell TWSI module
>>> is already available in u-boot, this one is 25% smaller, less
>>> complex (no state machine) and much faster (i2c probe on an
>>> ED Mini V2 takes no noticeable time vs. half a second).
>> Hi Albert
>> This will be very good enhancement indeed.
>>
>>>   drivers/i2c/Makefile |    1 +
>>>   drivers/i2c/mvtwsi.c |  419
>> Can you pls follow the same strategy as we followed for mvgbe, mvsata?
>> Please rename and enhance current kirkwood_i2c driver support,
>> and then add support for Orion followed by board support for edminiv2
>>
>> Regards..
>> Prafulla ..
> 
> I can do this of course; however I felt that I was not fixing an 
> existing driver (as I did with mvgbe) or adding support (as I did with 
> mvsata where there was no existing driver) but introducing competition 
> (as kirkwood_i2c exists and is functional) and I did not want to rudely 
> stomp the existing driver.
> 
> Besides, as mvtwsi is new code, and even though I tested it (probe, 
> read, write) with the ED Mini V2 EEPROM and RTC, until we are sure that 
> it works we might want to keep the older kirkwood_i2c code around and be 
> able to switch from one to the other -- having two different drivers for 
> the same HW IP and selecting at config time is done in 
> include/configs/km_arm.h where an option can be set to use either the 
> soft I2C driver or the kirkwood one.

We use only soft i2c on this board, so please remove the kirkwood_i2c.c
driver completely. So we have only your driver in tree, which is used and
working.

bye
Heiko
-- 
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany

[U-Boot] [PATCH 1/2] I2C: add Marvell TWSI simple driver

[Prafulla Wadaskar]

 

> -----Original Message-----
> From: Heiko Schocher [mailto:hs at denx.de] 
> Sent: Thursday, August 26, 2010 12:17 PM
> To: Albert ARIBAUD
> Cc: Prafulla Wadaskar; u-boot at lists.denx.de; Heiko Schosher; 
> Ashish Karkare; Prabhanjan Sarnaik
> Subject: Re: [U-Boot] [PATCH 1/2] I2C: add Marvell TWSI simple driver
> 
> Hello Albert,
> 
> Albert ARIBAUD wrote:
> > (adding Heiko, custodian of I2C/EEPROM and committer of 
> kirkwood_i2c)
> > 
> > Le 26/08/2010 06:33, Prafulla Wadaskar a ?crit :
> >>
> >>> -----Original Message-----
> >>> From: u-boot-bounces at lists.denx.de
> >>> [mailto:u-boot-bounces at lists.denx.de] On Behalf Of Albert Aribaud
> >>> Sent: Wednesday, August 25, 2010 7:54 PM
> >>> To: u-boot at lists.denx.de
> >>> Subject: [U-Boot] [PATCH 1/2] I2C: add Marvell TWSI simple driver
> >>>
> >>> This driver is for the Marvell TWSI/I2C module found in
> >>> the orion and kirkwood families among others.
> >>>
> >>> Signed-off-by: Albert Aribaud<albert.aribaud@free.fr>
> >>> ---
> >>> While the 'kirkwood_i2c' driver for the Marvell TWSI module
> >>> is already available in u-boot, this one is 25% smaller, less
> >>> complex (no state machine) and much faster (i2c probe on an
> >>> ED Mini V2 takes no noticeable time vs. half a second).
> >> Hi Albert
> >> This will be very good enhancement indeed.
> >>
> >>>   drivers/i2c/Makefile |    1 +
> >>>   drivers/i2c/mvtwsi.c |  419
> >> Can you pls follow the same strategy as we followed for 
> mvgbe, mvsata?
> >> Please rename and enhance current kirkwood_i2c driver support,
> >> and then add support for Orion followed by board support 
> for edminiv2
> >>
> >> Regards..
> >> Prafulla ..
> > 
> > I can do this of course; however I felt that I was not fixing an 
> > existing driver (as I did with mvgbe) or adding support (as 
> I did with 
> > mvsata where there was no existing driver) but introducing 
> competition 
> > (as kirkwood_i2c exists and is functional) and I did not 
> want to rudely 
> > stomp the existing driver.
> > 
> > Besides, as mvtwsi is new code, and even though I tested it (probe, 
> > read, write) with the ED Mini V2 EEPROM and RTC, until we 
> are sure that 
> > it works we might want to keep the older kirkwood_i2c code 
> around and be 
> > able to switch from one to the other -- having two 
> different drivers for 
> > the same HW IP and selecting at config time is done in 
> > include/configs/km_arm.h where an option can be set to use 
> either the 
> > soft I2C driver or the kirkwood one.
> 
> We use only soft i2c on this board, so please remove the 
> kirkwood_i2c.c
> driver completely. So we have only your driver in tree, which 
> is used and
> working.

Ack.
Regards..
Prafulla . .

> 
> bye
> Heiko
> -- 
> DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
> HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany
> 

[U-Boot] [PATCH 1/2] I2C: add Marvell TWSI simple driver

[Albert ARIBAUD]

Le 26/08/2010 10:23, Prafulla Wadaskar a ?crit :

>> We use only soft i2c on this board, so please remove the
>> kirkwood_i2c.c
>> driver completely. So we have only your driver in tree, which
>> is used and
>> working.
>
> Ack.
> Regards..
> Prafulla . .

Wilco. As a safety and cleanliness measure, I'll prepend a patch to the 
set, which will remove the 'hard i2c' related options from km_arm since 
they aren't used, and won't build any more once the switch is done.

Amicalement,
-- 
Albert.

[U-Boot] [PATCH 1/2] I2C: add Marvell TWSI simple driver

[Albert ARIBAUD]

Le 26/08/2010 08:30, Heiko Schocher a ?crit :

> Beside of that, I have just some minor codstyling comments:

Meanwhile, I've run checkpatch on this file and fixed every warning and 
error, thus some of your comments were taken care of in the process. 
That left:

>> +#define	MVTWSI_STATUS_DATA_R_NAK	0x58 /* our NAK, not the slave's */
>
> line too long.

Checkpatch did not complain on this one. Is there a specific line length 
contraint beside passing checkpatch?

>> +/*
>> + * Wait for IFLG to raise, or return 'timeout'; then if status is as expected,
>> + * return 0 (ok) or return 'wrong status'.
>> + */
>> +
>
> blank line not necessary.

Which blank line exactly? Between the comment block and code? If so, 
does this apply everywhere, i.e. after the topmost license comment 
block, before blocks of #define, etc?

As a side note, if V2 gets Acked by Prafulla and you, can you add the 
commit to your i2c tree and ask for a new pull? Anyway, Wolfgang said he 
won't resume activity on u-boot before sep 5th.

Amicalement,
-- 
Albert.

[U-Boot] [PATCH 1/2] I2C: add Marvell TWSI simple driver

[Heiko Schocher]

Hello Albert,

Albert ARIBAUD wrote:
> Le 26/08/2010 08:30, Heiko Schocher a ?crit :
> 
>> Beside of that, I have just some minor codstyling comments:
> 
> Meanwhile, I've run checkpatch on this file and fixed every warning and
> error, thus some of your comments were taken care of in the process.
> That left:
> 
>>> +#define    MVTWSI_STATUS_DATA_R_NAK    0x58 /* our NAK, not the
>>> slave's */
>>
>> line too long.
> 
> Checkpatch did not complain on this one. Is there a specific line length
> contraint beside passing checkpatch?

Yep, 78 characters.

>>> +/*
>>> + * Wait for IFLG to raise, or return 'timeout'; then if status is as
>>> expected,
>>> + * return 0 (ok) or return 'wrong status'.
>>> + */
>>> +
>>
>> blank line not necessary.
> 
> Which blank line exactly? Between the comment block and code? If so,

Yes.

> does this apply everywhere, i.e. after the topmost license comment
> block, before blocks of #define, etc?

No, there, it is Ok.

> As a side note, if V2 gets Acked by Prafulla and you, can you add the
> commit to your i2c tree and ask for a new pull? Anyway, Wolfgang said he
> won't resume activity on u-boot before sep 5th.

Yes, if I and Prafulla accept it, this is the usual way.

bye,
Heiko

-- 
DENX Software Engineering GmbH,     MD: Wolfgang Denk & Detlev Zundel
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany

[U-Boot] [PATCH 1/2] I2C: add Marvell TWSI simple driver

[Albert ARIBAUD]

Le 27/08/2010 07:25, Heiko Schocher a ?crit :

>>>> +#define    MVTWSI_STATUS_DATA_R_NAK    0x58 /* our NAK, not the
>>>> slave's */
>>>
>>> line too long.
>>
>> Checkpatch did not complain on this one. Is there a specific line length
>> contraint beside passing checkpatch?
>
> Yep, 78 characters.

Ok. I added a possibility for checkpatch to accept a custom line length; 
I'll try and push that to the lkml. Meanwhile, it showed me three lines 
beyond 78 characters, fixed.

>> Which blank line exactly? Between the comment block and code? If so,
>
> Yes.

>> does this apply everywhere, i.e. after the topmost license comment
>> block, before blocks of #define, etc?
>
> No, there, it is Ok.

Fixed, thanks.

>> As a side note, if V2 gets Acked by Prafulla and you, can you add the
>> commit to your i2c tree and ask for a new pull? Anyway, Wolfgang said he
>> won't resume activity on u-boot before sep 5th.
>
> Yes, if I and Prafulla accept it, this is the usual way.

Here you go, then. :)

Thanks for your review.

Amicalement,
-- 
Albert.