[PATCH 2/4] i2c-imx: ported to u-boot-v2
Sascha Hauer
s.hauer at pengutronix.de
Tue Nov 24 03:13:53 EST 2009
Hi Marc,
Generally this driver is *very* verbose for the debug case. can we limit
the output to some sensible level?
Some more comments inline.
Sascha
On Mon, Nov 23, 2009 at 01:20:08PM +0100, Marc Kleine-Budde wrote:
> Signed-off-by: Marc Kleine-Budde <mkl at pengutronix.de>
> ---
> drivers/i2c/Kconfig | 8 +
> drivers/i2c/Makefile | 2 +
> drivers/i2c/i2c-imx.c | 543 +++++++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 553 insertions(+), 0 deletions(-)
> create mode 100644 drivers/i2c/i2c-imx.c
>
> diff --git a/drivers/i2c/Kconfig b/drivers/i2c/Kconfig
> index 4d0f8da..aeae450 100644
> --- a/drivers/i2c/Kconfig
> +++ b/drivers/i2c/Kconfig
> @@ -1,2 +1,10 @@
> menuconfig I2C
> bool "I2C drivers "
> +
> +if I2C
> +
> +config DRIVER_I2C_IMX
> + bool "i.MX I2C Master driver"
> + depends on ARCH_IMX
> +
> +endif
> diff --git a/drivers/i2c/Makefile b/drivers/i2c/Makefile
> index 9a37393..bf16153 100644
> --- a/drivers/i2c/Makefile
> +++ b/drivers/i2c/Makefile
> @@ -1 +1,3 @@
> obj-$(CONFIG_I2C) += i2c.o
> +
> +obj-$(CONFIG_DRIVER_I2C_IMX) += i2c-imx.o
> diff --git a/drivers/i2c/i2c-imx.c b/drivers/i2c/i2c-imx.c
> new file mode 100644
> index 0000000..09066fa
> --- /dev/null
> +++ b/drivers/i2c/i2c-imx.c
> @@ -0,0 +1,543 @@
> +/*
> + * Copyright (C) 2002 Motorola GSG-China
> + *
> + * 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
> + * USA.
> + *
> + * Author:
> + * Darius Augulis, Teltonika Inc.
> + *
> + * Desc.:
> + * Implementation of I2C Adapter/Algorithm Driver
> + * for I2C Bus integrated in Freescale i.MX/MXC processors
> + *
> + * Derived from Motorola GSG China I2C example driver
> + *
> + * Copyright (C) 2005 Torsten Koschorrek <koschorrek at synertronixx.de
> + * Copyright (C) 2005 Matthias Blaschke <blaschke at synertronixx.de
> + * Copyright (C) 2007 RightHand Technologies, Inc.
> + * Copyright (C) 2008 Darius Augulis <darius.augulis at teltonika.lt>
> + *
> + */
> +
> +/** Includes *******************************************************************
> +*******************************************************************************/
> +
> +#include <clock.h>
> +#include <common.h>
> +#include <driver.h>
> +#include <gpio.h>
> +#include <init.h>
> +#include <malloc.h>
> +#include <types.h>
> +#include <xfuncs.h>
> +
> +#include <linux/err.h>
> +
> +#include <asm/io.h>
> +#include <i2c/i2c.h>
> +#include <mach/generic.h>
> +#include <mach/clock.h>
> +
> +/** Defines ********************************************************************
> +*******************************************************************************/
> +
> +/* This will be the driver name the kernel reports */
> +#define DRIVER_NAME "i2c-imx"
> +
> +/* Default value */
> +#define IMX_I2C_BIT_RATE 100000 /* 100kHz */
> +
> +/* IMX I2C registers */
> +#define IMX_I2C_IADR 0x00 /* i2c slave address */
> +#define IMX_I2C_IFDR 0x04 /* i2c frequency divider */
> +#define IMX_I2C_I2CR 0x08 /* i2c control */
> +#define IMX_I2C_I2SR 0x0C /* i2c status */
> +#define IMX_I2C_I2DR 0x10 /* i2c transfer data */
> +
> +/* Bits of IMX I2C registers */
> +#define I2SR_RXAK 0x01
> +#define I2SR_IIF 0x02
> +#define I2SR_SRW 0x04
> +#define I2SR_IAL 0x10
> +#define I2SR_IBB 0x20
> +#define I2SR_IAAS 0x40
> +#define I2SR_ICF 0x80
> +#define I2CR_RSTA 0x04
> +#define I2CR_TXAK 0x08
> +#define I2CR_MTX 0x10
> +#define I2CR_MSTA 0x20
> +#define I2CR_IIEN 0x40
> +#define I2CR_IEN 0x80
> +
> +/** Variables ******************************************************************
> +*******************************************************************************/
> +
> +/*
> + * sorted list of clock divider, register value pairs
> + * taken from table 26-5, p.26-9, Freescale i.MX
> + * Integrated Portable System Processor Reference Manual
> + * Document Number: MC9328MXLRM, Rev. 5.1, 06/2007
> + *
> + * Duplicated divider values removed from list
> + */
> +
> +static u16 i2c_clk_div[50][2] = {
> + { 22, 0x20 }, { 24, 0x21 }, { 26, 0x22 }, { 28, 0x23 },
> + { 30, 0x00 }, { 32, 0x24 }, { 36, 0x25 }, { 40, 0x26 },
> + { 42, 0x03 }, { 44, 0x27 }, { 48, 0x28 }, { 52, 0x05 },
> + { 56, 0x29 }, { 60, 0x06 }, { 64, 0x2A }, { 72, 0x2B },
> + { 80, 0x2C }, { 88, 0x09 }, { 96, 0x2D }, { 104, 0x0A },
> + { 112, 0x2E }, { 128, 0x2F }, { 144, 0x0C }, { 160, 0x30 },
> + { 192, 0x31 }, { 224, 0x32 }, { 240, 0x0F }, { 256, 0x33 },
> + { 288, 0x10 }, { 320, 0x34 }, { 384, 0x35 }, { 448, 0x36 },
> + { 480, 0x13 }, { 512, 0x37 }, { 576, 0x14 }, { 640, 0x38 },
> + { 768, 0x39 }, { 896, 0x3A }, { 960, 0x17 }, { 1024, 0x3B },
> + { 1152, 0x18 }, { 1280, 0x3C }, { 1536, 0x3D }, { 1792, 0x3E },
> + { 1920, 0x1B }, { 2048, 0x3F }, { 2304, 0x1C }, { 2560, 0x1D },
> + { 3072, 0x1E }, { 3840, 0x1F }
> +};
> +
> +struct imx_i2c_struct {
> + struct i2c_adapter adapter;
> + unsigned int disable_delay;
> + int stopped;
> + unsigned int ifdr; /* IMX_I2C_IFDR */
> +};
> +#define to_imx_i2c_struct(a) container_of(a, struct imx_i2c_struct, adapter)
> +
> +/** Functions for IMX I2C adapter driver ***************************************
> +*******************************************************************************/
> +
> +#ifdef CONFIG_I2C_DEBUG
> +static void i2c_imx_dump_reg(struct i2c_adapter *adapter)
> +{
> + unsigned long base = adapter->dev->map_base;
> + u32 reg_cr, reg_sr;
> +
> + reg_cr = readb(base + IMX_I2C_I2CR);
> + reg_sr = readb(base + IMX_I2C_I2SR);
> +
> + dev_dbg(adapter->dev, "CONTROL:\t"
> + "IEN =%d, IIEN=%d, MSTA=%d, MTX =%d, TXAK=%d, RSTA=%d\n",
> + (reg_cr & I2CR_IEN ? 1 : 0), (reg_cr & I2CR_IIEN ? 1 : 0),
> + (reg_cr & I2CR_MSTA ? 1 : 0), (reg_cr & I2CR_MTX ? 1 : 0),
> + (reg_cr & I2CR_TXAK ? 1 : 0), (reg_cr & I2CR_RSTA ? 1 : 0));
> +
> + dev_dbg(adapter->dev, "STATUS:\t"
> + "ICF =%d, IAAS=%d, IB =%d, IAL =%d, SRW =%d, IIF =%d, RXAK=%d\n",
> + (reg_sr & I2SR_ICF ? 1 : 0), (reg_sr & I2SR_IAAS ? 1 : 0),
> + (reg_sr & I2SR_IBB ? 1 : 0), (reg_sr & I2SR_IAL ? 1 : 0),
> + (reg_sr & I2SR_SRW ? 1 : 0), (reg_sr & I2SR_IIF ? 1 : 0),
> + (reg_sr & I2SR_RXAK ? 1 : 0));
> +}
> +#else
> +static inline void i2c_imx_dump_reg(struct i2c_adapter *adapter)
> +{
> + return;
> +}
> +#endif
> +
> +static int i2c_imx_bus_busy(struct i2c_adapter *adapter, int for_busy)
> +{
> + unsigned long base = adapter->dev->map_base;
> + uint64_t start;
> + unsigned int temp;
> +
> + dev_dbg(adapter->dev, "<%s>\n", __func__);
> +
> + start = get_time_ns();
> + while (1) {
> + temp = readb(base + IMX_I2C_I2SR);
> + if (for_busy && (temp & I2SR_IBB))
> + break;
> + if (!for_busy && !(temp & I2SR_IBB))
> + break;
> + if (is_timeout(start, 1000 * 1000)) { /* 1 us */
Resolution is in nanoseconds, so this would be 1ms. Please use the
USECOND or MSECOND define here instead.
> + dev_warn(adapter->dev, "<%s> I2C bus is busy\n", __func__);
> + return -EIO;
> + }
> + }
> +
> + return 0;
> +}
> +
> +static int i2c_imx_trx_complete(struct i2c_adapter *adapter)
> +{
> + unsigned long base = adapter->dev->map_base;
> + uint64_t start;
> +
> + dev_dbg(adapter->dev, "<%s>\n", __func__);
> +
> + start = get_time_ns();
> + while (1) {
> + unsigned int reg = readb(base + IMX_I2C_I2SR);
> + if (reg & I2SR_ICF) {
> + break;
> + }
> +
> + if (is_timeout(start, 100 * 1000 * 1000)) { /* 100 ms */
100 * MSECOND
> + dev_warn(adapter->dev, "<%s> TXR timeout\n", __func__);
> + return -EIO;
> + }
> +
> + writeb(0x0, base + IMX_I2C_I2SR); /* FIXME */
Fix what?
> + }
> + dev_dbg(adapter->dev, "<%s> TRX complete\n", __func__);
> +
> + return 0;
> +}
> +
> +static int i2c_imx_wait_iif(struct i2c_adapter *adapter) {
> + unsigned long base = adapter->dev->map_base;
> + uint64_t start;
> +
> + start = get_time_ns();
> + while (1) {
> + unsigned int reg = readb(base + IMX_I2C_I2SR);
> + if (reg & I2SR_IIF) {
> + break;
> + }
> +
> + if (is_timeout(start, 100 * 1000 * 1000)) { /* 100 ms */
> + dev_warn(adapter->dev, "<%s> IIF timeout\n", __func__);
> + return -EIO;
> + }
> + }
> + dev_dbg(adapter->dev, "<%s> IIF complete\n", __func__);
> +
> + return 0;
> +}
> +
> +static int i2c_imx_acked(struct i2c_adapter *adapter)
> +{
> + unsigned long base = adapter->dev->map_base;
> +
> + if (readb(base + IMX_I2C_I2SR) & I2SR_RXAK) {
> + dev_notice(adapter->dev, "<%s> No ACK\n", __func__);
> + return -EIO;
> + }
> +
> + dev_dbg(adapter->dev, "<%s> ACK received\n", __func__);
> + return 0;
> +}
> +
> +static int i2c_imx_start(struct i2c_adapter *adapter)
> +{
> + struct imx_i2c_struct *i2c_imx = to_imx_i2c_struct(adapter);
> + unsigned long base = adapter->dev->map_base;
> + unsigned int temp = 0;
> + int result;
> +
> + dev_dbg(adapter->dev, "<%s>\n", __func__);
> +
> + writeb(i2c_imx->ifdr, base + IMX_I2C_IFDR);
> + /* Enable I2C controller */
> + writeb(0, base + IMX_I2C_I2SR);
> + writeb(I2CR_IEN, base + IMX_I2C_I2CR);
> +
> + /* Wait controller to be stable */
> + udelay(100);
> +
> + /* Start I2C transaction */
> + temp = readb(base + IMX_I2C_I2CR);
> + temp |= I2CR_MSTA;
> + writeb(temp, base + IMX_I2C_I2CR);
> +
> + result = i2c_imx_bus_busy(adapter, 1);
> + if (result)
> + return result;
> +
> + i2c_imx->stopped = 0;
> +
> + temp |= I2CR_MTX | I2CR_TXAK;
> + writeb(temp, base + IMX_I2C_I2CR);
> +
> + return result;
> +}
> +
> +static void i2c_imx_stop(struct i2c_adapter *adapter)
> +{
> + struct imx_i2c_struct *i2c_imx = to_imx_i2c_struct(adapter);
> + unsigned long base = adapter->dev->map_base;
> + unsigned int temp = 0;
> +
> + if (!i2c_imx->stopped) {
> + /* Stop I2C transaction */
> + dev_dbg(adapter->dev, "<%s>\n", __func__);
> + temp = readb(base + IMX_I2C_I2CR);
> + temp &= ~(I2CR_MSTA | I2CR_MTX);
> + writeb(temp, base + IMX_I2C_I2CR);
> + i2c_imx->stopped = 1;
> + }
> + if (cpu_is_mx1()) {
> + /*
> + * This delay caused by an i.MXL hardware bug.
> + * If no (or too short) delay, no "STOP" bit will be generated.
> + */
> + udelay(i2c_imx->disable_delay);
> + }
> +
> + if (!i2c_imx->stopped)
> + i2c_imx_bus_busy(adapter, 0);
> +
> + /* Disable I2C controller */
> + writeb(0, base + IMX_I2C_I2CR);
> +}
> +
> +static void __init i2c_imx_set_clk(struct imx_i2c_struct *i2c_imx,
> + unsigned int rate)
> +{
> + unsigned int i2c_clk_rate;
> + unsigned int div;
> + int i;
> +
> + /* Divider value calculation */
> + i2c_clk_rate = imx_get_i2cclk();
> + div = (i2c_clk_rate + rate - 1) / rate;
> + if (div < i2c_clk_div[0][0])
> + i = 0;
> + else if (div > i2c_clk_div[ARRAY_SIZE(i2c_clk_div) - 1][0])
> + i = ARRAY_SIZE(i2c_clk_div) - 1;
> + else
> + for (i = 0; i2c_clk_div[i][0] < div; i++);
> +
> + /* Store divider value */
> + i2c_imx->ifdr = i2c_clk_div[i][1];
> +
> + /*
> + * There dummy delay is calculated.
> + * It should be about one I2C clock period long.
> + * This delay is used in I2C bus disable function
> + * to fix chip hardware bug.
> + */
> + i2c_imx->disable_delay = (500000U * i2c_clk_div[i][0]
> + + (i2c_clk_rate / 2) - 1) / (i2c_clk_rate / 2);
> +
> + /* dev_dbg() can't be used, because adapter is not yet registered */
This isn't true here. Can you replace this with dev_dbg?
> +#ifdef CONFIG_I2C_DEBUG
> + printk(KERN_DEBUG "I2C: <%s> I2C_CLK=%d, REQ DIV=%d\n",
> + __func__, i2c_clk_rate, div);
> + printk(KERN_DEBUG "I2C: <%s> IFDR[IC]=0x%x, REAL DIV=%d\n",
> + __func__, i2c_clk_div[i][1], i2c_clk_div[i][0]);
> +#endif
> +}
> +
> +static int i2c_imx_write(struct i2c_adapter *adapter, struct i2c_msg *msgs)
> +{
> + unsigned long base = adapter->dev->map_base;
> + int i, result;
> +
> + dev_dbg(adapter->dev, "<%s> write slave address: addr=0x%x\n",
> + __func__, msgs->addr << 1);
> +
> + /* write slave address */
> + writeb(msgs->addr << 1, base + IMX_I2C_I2DR);
> +
> + result = i2c_imx_trx_complete(adapter);
> + if (result)
> + return result;
> + result = i2c_imx_acked(adapter);
> + if (result)
> + return result;
> +
> + dev_dbg(adapter->dev, "<%s> write data\n", __func__);
> +
> + /* write data */
> + for (i = 0; i < msgs->len; i++) {
> + dev_dbg(adapter->dev,
> + "<%s> write byte: B%d=0x%02X\n",
> + __func__, i, msgs->buf[i]);
> + writeb(msgs->buf[i], base + IMX_I2C_I2DR);
> +
> + result = i2c_imx_trx_complete(adapter);
> + if (result)
> + return result;
> + result = i2c_imx_acked(adapter);
> + if (result)
> + return result;
> + }
> + return 0;
> +}
> +
> +static int i2c_imx_read(struct i2c_adapter *adapter, struct i2c_msg *msgs)
> +{
> + struct imx_i2c_struct *i2c_imx = to_imx_i2c_struct(adapter);
> + unsigned long base = adapter->dev->map_base;
> + int i, result;
> + unsigned int temp;
> +
> + dev_dbg(adapter->dev,
> + "<%s> write slave address: addr=0x%x\n",
> + __func__, (msgs->addr << 1) | 0x01);
> +
> + /* write slave address */
> + writeb((msgs->addr << 1) | 0x01, base + IMX_I2C_I2DR);
> +
> + result = i2c_imx_trx_complete(adapter);
> + if (result)
> + return result;
> + result = i2c_imx_acked(adapter);
> + if (result)
> + return result;
> +
> + result = i2c_imx_wait_iif(adapter);
> + if (result)
> + return result;
> +
> + /* setup bus to read data */
> + temp = readb(base + IMX_I2C_I2CR);
> + temp &= ~I2CR_MTX;
> + if (msgs->len - 1)
> + temp &= ~I2CR_TXAK;
> + writeb(temp, base + IMX_I2C_I2CR);
> +
> + readb(base + IMX_I2C_I2DR); /* dummy read */
> +
> + dev_dbg(adapter->dev, "<%s> read data\n", __func__);
> +
> + /* read data */
> + for (i = 0; i < msgs->len; i++) {
> + result = i2c_imx_trx_complete(adapter);
> + if (result)
> + return result;
> +
> + if (i == (msgs->len - 1)) {
> + /*
> + * It must generate STOP before read I2DR to prevent
> + * controller from generating another clock cycle
> + */
> + dev_dbg(adapter->dev, "<%s> clear MSTA\n", __func__);
> + temp = readb(base + IMX_I2C_I2CR);
> + temp &= ~(I2CR_MSTA | I2CR_MTX);
> + writeb(temp, base + IMX_I2C_I2CR);
> + i2c_imx_bus_busy(adapter, 0);
> + i2c_imx->stopped = 1;
> + } else if (i == (msgs->len - 2)) {
> + dev_dbg(adapter->dev, "<%s> set TXAK\n", __func__);
> + temp = readb(base + IMX_I2C_I2CR);
> + temp |= I2CR_TXAK;
> + writeb(temp, base + IMX_I2C_I2CR);
> + }
> + msgs->buf[i] = readb(base + IMX_I2C_I2DR);
> + dev_dbg(adapter->dev, "<%s> read byte: B%d=0x%02X\n",
> + __func__, i, msgs->buf[i]);
> + }
> + return 0;
> +}
> +
> +static int i2c_imx_xfer(struct i2c_adapter *adapter,
> + struct i2c_msg *msgs, int num)
> +{
> + unsigned long base = adapter->dev->map_base;
> + unsigned int i, temp;
> + int result;
> +
> + dev_dbg(adapter->dev, "<%s>\n", __func__);
> +
> + /* Start I2C transfer */
> + result = i2c_imx_start(adapter);
> + if (result)
> + goto fail0;
> +
> + /* read/write data */
> + for (i = 0; i < num; i++) {
> + if (i) {
> + dev_dbg(adapter->dev,
> + "<%s> repeated start\n", __func__);
> +
> + temp = readb(base + IMX_I2C_I2CR);
> + temp |= I2CR_RSTA;
> + writeb(temp, base + IMX_I2C_I2CR);
> +
> + result = i2c_imx_bus_busy(adapter, 1);
> + if (result)
> + goto fail0;
> + }
> + dev_dbg(adapter->dev, "<%s> transfer message: %d\n", __func__, i);
> +
> + i2c_imx_dump_reg(adapter);
> +
> + /* write/read data */
> + if (msgs[i].flags & I2C_M_RD)
> + result = i2c_imx_read(adapter, &msgs[i]);
> + else
> + result = i2c_imx_write(adapter, &msgs[i]);
> + }
> +
> +fail0:
> + /* Stop I2C transfer */
> + i2c_imx_stop(adapter);
> +
> + dev_dbg(adapter->dev, "<%s> exit with: %s: %d\n", __func__,
> + (result < 0) ? "error" : "success msg",
> + (result < 0) ? result : num);
> + return (result < 0) ? result : num;
> +}
> +
> +
> +
> +static int __init i2c_imx_probe(struct device_d *pdev)
> +{
> + struct imx_i2c_struct *i2c_imx;
> + struct i2c_platform_data *pdata;
> + unsigned long base = pdev->map_base;
> + int ret;
> +
> + dev_dbg(pdev, "<%s>\n", __func__);
> +
> + pdata = pdev->platform_data;
> +
> + i2c_imx = kzalloc(sizeof(struct imx_i2c_struct), GFP_KERNEL);
> +
> + /* Setup i2c_imx driver structure */
> + i2c_imx->adapter.master_xfer = i2c_imx_xfer;
> + i2c_imx->adapter.nr = pdev->id;
> + i2c_imx->adapter.dev = pdev;
> +
> + /* Set up clock divider */
> + if (pdata && pdata->bitrate)
> + i2c_imx_set_clk(i2c_imx, pdata->bitrate);
> + else
> + i2c_imx_set_clk(i2c_imx, IMX_I2C_BIT_RATE);
> +
> + /* Set up chip registers to defaults */
> + writeb(0, base + IMX_I2C_I2CR);
> + writeb(0, base + IMX_I2C_I2SR);
> +
> + /* Add I2C adapter */
> + ret = i2c_add_numbered_adapter(&i2c_imx->adapter);
> + if (ret < 0) {
> + dev_err(pdev, "registration failed\n");
> + goto fail;
> + }
> +
> + return 0;
> +
> +fail:
> + kfree(i2c_imx);
> + return ret;
> +}
> +
> +static struct driver_d i2c_imx_driver = {
> + .probe = i2c_imx_probe,
> + .name = DRIVER_NAME,
> +};
> +
> +static int __init i2c_adap_imx_init(void)
> +{
> + return register_driver(&i2c_imx_driver);
> +}
> +device_initcall(i2c_adap_imx_init);
> --
> 1.6.5.2
>
>
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> u-boot-v2 at lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/u-boot-v2
>
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