Patchwork [U-Boot,05/11] I2C: add Marvell TWSI simple driver

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Submitter Rogan Dawes
Date March 18, 2011, 8:04 a.m.
Message ID <1300435500-4909-6-git-send-email-rogan@dawes.za.net>
Download mbox | patch
Permalink /patch/87493/
State Not Applicable
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Rogan Dawes - March 18, 2011, 8:04 a.m.
From: Albert Aribaud <albert.aribaud@free.fr>

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>
---
 drivers/i2c/Makefile |    1 +
 drivers/i2c/mvtwsi.c |  419 ++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 420 insertions(+), 0 deletions(-)
 create mode 100644 drivers/i2c/mvtwsi.c
Heiko Schocher - March 18, 2011, 8:29 a.m.
Hello rogan@dawes.za.net,

rogan@dawes.za.net wrote:
> From: Albert Aribaud <albert.aribaud@free.fr>
> 
> 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>
> ---
>  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

This patch could not be against current head! There is no
more this CONFIG_I2C_KIRKWOOD define. Instead this driver
was renamed to mvtwsi.c from Albert Aribaud, see commits:

01ec99d9693929fc56e630c10499b1bfce3e3693

and

306563a773f1111c6beff8d1855d5b2a2137aebd

So, sorry, Nack for this patch. But could you rebase
to current head and try the existing driver?

bye,
Heiko
Rogan Dawes - March 18, 2011, 8:41 a.m.
On 2011/03/18 10:29 AM, Heiko Schocher wrote:
> Hello rogan@dawes.za.net,
> 

> This patch could not be against current head! There is no
> more this CONFIG_I2C_KIRKWOOD define. Instead this driver
> was renamed to mvtwsi.c from Albert Aribaud, see commits:
> 
> 01ec99d9693929fc56e630c10499b1bfce3e3693
> 
> and
> 
> 306563a773f1111c6beff8d1855d5b2a2137aebd
> 
> So, sorry, Nack for this patch. But could you rebase
> to current head and try the existing driver?
> 
> bye,
> Heiko

Hi Heiko,

Sorry, I'm afraid you misunderstood the intention of the posting. My
cover letter stated that it was a functional port of U-Boot to the
DNS323, based on a (VERY) old starting point, prior to the relocation
work. I was posting it to show that I DO have a working port for the
DNS323, and to contrast that with the non-working post-relocation port,
which I am asking for help with.

Regards,

Rogan
Heiko Schocher - March 18, 2011, 9:22 a.m.
Hello Rogan,

Rogan Dawes wrote:
> On 2011/03/18 10:29 AM, Heiko Schocher wrote:
>> Hello rogan@dawes.za.net,
>>
> 
>> This patch could not be against current head! There is no
>> more this CONFIG_I2C_KIRKWOOD define. Instead this driver
>> was renamed to mvtwsi.c from Albert Aribaud, see commits:
>>
>> 01ec99d9693929fc56e630c10499b1bfce3e3693
>>
>> and
>>
>> 306563a773f1111c6beff8d1855d5b2a2137aebd
>>
>> So, sorry, Nack for this patch. But could you rebase
>> to current head and try the existing driver?
>>
>> bye,
>> Heiko
> 
> Hi Heiko,
> 
> Sorry, I'm afraid you misunderstood the intention of the posting. My
> cover letter stated that it was a functional port of U-Boot to the
> DNS323, based on a (VERY) old starting point, prior to the relocation
> work. I was posting it to show that I DO have a working port for the
> DNS323, and to contrast that with the non-working post-relocation port,
> which I am asking for help with.

Ah, I see.

Sorry I only parsed the i2c patch ;-)

Hmm.. I couldn;t find a config file for your dns323 port, nor an
"dns323" or "DNS323" entry in boards.cfg. Which board config file do
you use?

bye,
Heiko
Rogan Dawes - March 18, 2011, 11:14 a.m.
On 2011/03/18 11:22 AM, Heiko Schocher wrote:
> Hello Rogan,
> 
> Rogan Dawes wrote:
>> On 2011/03/18 10:29 AM, Heiko Schocher wrote:
>>> Hello rogan@dawes.za.net,
>>>
>>
>>> This patch could not be against current head! There is no
>>> more this CONFIG_I2C_KIRKWOOD define. Instead this driver
>>> was renamed to mvtwsi.c from Albert Aribaud, see commits:
>>>
>>> 01ec99d9693929fc56e630c10499b1bfce3e3693
>>>
>>> and
>>>
>>> 306563a773f1111c6beff8d1855d5b2a2137aebd
>>>
>>> So, sorry, Nack for this patch. But could you rebase
>>> to current head and try the existing driver?
>>>
>>> bye,
>>> Heiko
>>
>> Hi Heiko,
>>
>> Sorry, I'm afraid you misunderstood the intention of the posting. My
>> cover letter stated that it was a functional port of U-Boot to the
>> DNS323, based on a (VERY) old starting point, prior to the relocation
>> work. I was posting it to show that I DO have a working port for the
>> DNS323, and to contrast that with the non-working post-relocation port,
>> which I am asking for help with.
> 
> Ah, I see.
> 
> Sorry I only parsed the i2c patch ;-)
> 
> Hmm.. I couldn;t find a config file for your dns323 port, nor an
> "dns323" or "DNS323" entry in boards.cfg. Which board config file do
> you use?
> 
> bye,
> Heiko

Introduced in patch 11 of that series, or patch 7 or the "non-working"
series.

They've both been held up by the list because they are larger than
100kB. Any moderators around?

Rogan
Wolfgang Denk - March 18, 2011, 4:19 p.m.
Dear Rogan Dawes,

In message <4D831A9C.2020106@dawes.za.net> you wrote:
> 
> Sorry, I'm afraid you misunderstood the intention of the posting. My

You made it difficult NOT to misunderstand it.

A posting with "[PATCH]" in the subject _is_ supposed to be apatch
against current mainline.

If you post it for other purpoesen, then you must not use "PATCH"
in the subject.


Best regards,

Wolfgang Denk

Patch

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 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)*/
+		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 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;
+}