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Merge branch 'for-linus/2639/i2c-1' of git://git.fluff.org/bjdooks/linux

Browse Source 
* 'for-linus/2639/i2c-1' of git://git.fluff.org/bjdooks/linux:
  i2c-mpc: Add support for 64bit system
  i2c: add driver for Freescale i.MX28
  i2c: tegra: Add i2c support
This commit is contained in:
Linus Torvalds 2011-03-17 17:10:19 -07:00
commit 02e4c627d8
5 changed files with 1157 additions and 1 deletions
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19
drivers/i2c/busses/Kconfig
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@ -433,7 +433,7 @@ config I2C_IXP2000
config I2C_MPC
tristate "MPC107/824x/85xx/512x/52xx/83xx/86xx"
depends on PPC32
depends on PPC
help
If you say yes to this option, support will be included for the
built-in I2C interface on the MPC107, Tsi107, MPC512x, MPC52xx,
@ -452,6 +452,16 @@ config I2C_MV64XXX
This driver can also be built as a module. If so, the module
will be called i2c-mv64xxx.
config I2C_MXS
tristate "Freescale i.MX28 I2C interface"
depends on SOC_IMX28
help
Say Y here if you want to use the I2C bus controller on
the Freescale i.MX28 processors.
This driver can also be built as a module. If so, the module
will be called i2c-mxs.
config I2C_NOMADIK
tristate "ST-Ericsson Nomadik/Ux500 I2C Controller"
depends on PLAT_NOMADIK
@ -618,6 +628,13 @@ config I2C_STU300
This driver can also be built as a module. If so, the module
will be called i2c-stu300.
config I2C_TEGRA
tristate "NVIDIA Tegra internal I2C controller"
depends on ARCH_TEGRA
help
If you say yes to this option, support will be included for the
I2C controller embedded in NVIDIA Tegra SOCs
config I2C_VERSATILE
tristate "ARM Versatile/Realview I2C bus support"
depends on ARCH_VERSATILE || ARCH_REALVIEW || ARCH_VEXPRESS

2
drivers/i2c/busses/Makefile
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@ -43,6 +43,7 @@ obj-$(CONFIG_I2C_IOP3XX) += i2c-iop3xx.o
obj-$(CONFIG_I2C_IXP2000) += i2c-ixp2000.o
obj-$(CONFIG_I2C_MPC) += i2c-mpc.o
obj-$(CONFIG_I2C_MV64XXX) += i2c-mv64xxx.o
obj-$(CONFIG_I2C_MXS) += i2c-mxs.o
obj-$(CONFIG_I2C_NOMADIK) += i2c-nomadik.o
obj-$(CONFIG_I2C_NUC900) += i2c-nuc900.o
obj-$(CONFIG_I2C_OCORES) += i2c-ocores.o
@ -59,6 +60,7 @@ obj-$(CONFIG_I2C_SH7760) += i2c-sh7760.o
obj-$(CONFIG_I2C_SH_MOBILE) += i2c-sh_mobile.o
obj-$(CONFIG_I2C_SIMTEC) += i2c-simtec.o
obj-$(CONFIG_I2C_STU300) += i2c-stu300.o
obj-$(CONFIG_I2C_TEGRA) += i2c-tegra.o
obj-$(CONFIG_I2C_VERSATILE) += i2c-versatile.o
obj-$(CONFIG_I2C_OCTEON) += i2c-octeon.o
obj-$(CONFIG_I2C_XILINX) += i2c-xiic.o

412
drivers/i2c/busses/i2c-mxs.c Normal file
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@ -0,0 +1,412 @@
/*
* Freescale MXS I2C bus driver
*
* Copyright (C) 2011 Wolfram Sang, Pengutronix e.K.
*
* based on a (non-working) driver which was:
*
* Copyright (C) 2009-2010 Freescale Semiconductor, Inc. All Rights Reserved.
*
* TODO: add dma-support if platform-support for it is available
*
* 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.
*
*/
#include <linux/slab.h>
#include <linux/device.h>
#include <linux/module.h>
#include <linux/i2c.h>
#include <linux/err.h>
#include <linux/interrupt.h>
#include <linux/completion.h>
#include <linux/platform_device.h>
#include <linux/jiffies.h>
#include <linux/io.h>
#include <mach/common.h>
#define DRIVER_NAME "mxs-i2c"
#define MXS_I2C_CTRL0 (0x00)
#define MXS_I2C_CTRL0_SET (0x04)
#define MXS_I2C_CTRL0_SFTRST 0x80000000
#define MXS_I2C_CTRL0_SEND_NAK_ON_LAST 0x02000000
#define MXS_I2C_CTRL0_RETAIN_CLOCK 0x00200000
#define MXS_I2C_CTRL0_POST_SEND_STOP 0x00100000
#define MXS_I2C_CTRL0_PRE_SEND_START 0x00080000
#define MXS_I2C_CTRL0_MASTER_MODE 0x00020000
#define MXS_I2C_CTRL0_DIRECTION 0x00010000
#define MXS_I2C_CTRL0_XFER_COUNT(v) ((v) & 0x0000FFFF)
#define MXS_I2C_CTRL1 (0x40)
#define MXS_I2C_CTRL1_SET (0x44)
#define MXS_I2C_CTRL1_CLR (0x48)
#define MXS_I2C_CTRL1_BUS_FREE_IRQ 0x80
#define MXS_I2C_CTRL1_DATA_ENGINE_CMPLT_IRQ 0x40
#define MXS_I2C_CTRL1_NO_SLAVE_ACK_IRQ 0x20
#define MXS_I2C_CTRL1_OVERSIZE_XFER_TERM_IRQ 0x10
#define MXS_I2C_CTRL1_EARLY_TERM_IRQ 0x08
#define MXS_I2C_CTRL1_MASTER_LOSS_IRQ 0x04
#define MXS_I2C_CTRL1_SLAVE_STOP_IRQ 0x02
#define MXS_I2C_CTRL1_SLAVE_IRQ 0x01
#define MXS_I2C_IRQ_MASK (MXS_I2C_CTRL1_DATA_ENGINE_CMPLT_IRQ | \
MXS_I2C_CTRL1_NO_SLAVE_ACK_IRQ | \
MXS_I2C_CTRL1_EARLY_TERM_IRQ | \
MXS_I2C_CTRL1_MASTER_LOSS_IRQ | \
MXS_I2C_CTRL1_SLAVE_STOP_IRQ | \
MXS_I2C_CTRL1_SLAVE_IRQ)
#define MXS_I2C_QUEUECTRL (0x60)
#define MXS_I2C_QUEUECTRL_SET (0x64)
#define MXS_I2C_QUEUECTRL_CLR (0x68)
#define MXS_I2C_QUEUECTRL_QUEUE_RUN 0x20
#define MXS_I2C_QUEUECTRL_PIO_QUEUE_MODE 0x04
#define MXS_I2C_QUEUESTAT (0x70)
#define MXS_I2C_QUEUESTAT_RD_QUEUE_EMPTY 0x00002000
#define MXS_I2C_QUEUECMD (0x80)
#define MXS_I2C_QUEUEDATA (0x90)
#define MXS_I2C_DATA (0xa0)
#define MXS_CMD_I2C_SELECT (MXS_I2C_CTRL0_RETAIN_CLOCK | \
MXS_I2C_CTRL0_PRE_SEND_START | \
MXS_I2C_CTRL0_MASTER_MODE | \
MXS_I2C_CTRL0_DIRECTION | \
MXS_I2C_CTRL0_XFER_COUNT(1))
#define MXS_CMD_I2C_WRITE (MXS_I2C_CTRL0_PRE_SEND_START | \
MXS_I2C_CTRL0_MASTER_MODE | \
MXS_I2C_CTRL0_DIRECTION)
#define MXS_CMD_I2C_READ (MXS_I2C_CTRL0_SEND_NAK_ON_LAST | \
MXS_I2C_CTRL0_MASTER_MODE)
/**
* struct mxs_i2c_dev - per device, private MXS-I2C data
*
* @dev: driver model device node
* @regs: IO registers pointer
* @cmd_complete: completion object for transaction wait
* @cmd_err: error code for last transaction
* @adapter: i2c subsystem adapter node
*/
struct mxs_i2c_dev {
struct device *dev;
void __iomem *regs;
struct completion cmd_complete;
u32 cmd_err;
struct i2c_adapter adapter;
};
/*
* TODO: check if calls to here are really needed. If not, we could get rid of
* mxs_reset_block and the mach-dependency. Needs an I2C analyzer, probably.
*/
static void mxs_i2c_reset(struct mxs_i2c_dev *i2c)
{
mxs_reset_block(i2c->regs);
writel(MXS_I2C_IRQ_MASK << 8, i2c->regs + MXS_I2C_CTRL1_SET);
}
static void mxs_i2c_pioq_setup_read(struct mxs_i2c_dev *i2c, u8 addr, int len,
int flags)
{
u32 data;
writel(MXS_CMD_I2C_SELECT, i2c->regs + MXS_I2C_QUEUECMD);
data = (addr << 1) | I2C_SMBUS_READ;
writel(data, i2c->regs + MXS_I2C_DATA);
data = MXS_CMD_I2C_READ | MXS_I2C_CTRL0_XFER_COUNT(len) | flags;
writel(data, i2c->regs + MXS_I2C_QUEUECMD);
}
static void mxs_i2c_pioq_setup_write(struct mxs_i2c_dev *i2c,
u8 addr, u8 *buf, int len, int flags)
{
u32 data;
int i, shifts_left;
data = MXS_CMD_I2C_WRITE | MXS_I2C_CTRL0_XFER_COUNT(len + 1) | flags;
writel(data, i2c->regs + MXS_I2C_QUEUECMD);
/*
* We have to copy the slave address (u8) and buffer (arbitrary number
* of u8) into the data register (u32). To achieve that, the u8 are put
* into the MSBs of 'data' which is then shifted for the next u8. When
* apropriate, 'data' is written to MXS_I2C_DATA. So, the first u32
* looks like this:
*
* 3 2 1 0
* 10987654|32109876|54321098|76543210
* --------+--------+--------+--------
* buffer+2|buffer+1|buffer+0|slave_addr
*/
data = ((addr << 1) | I2C_SMBUS_WRITE) << 24;
for (i = 0; i < len; i++) {
data >>= 8;
data |= buf[i] << 24;
if ((i & 3) == 2)
writel(data, i2c->regs + MXS_I2C_DATA);
}
/* Write out the remaining bytes if any */
shifts_left = 24 - (i & 3) * 8;
if (shifts_left)
writel(data >> shifts_left, i2c->regs + MXS_I2C_DATA);
}
/*
* TODO: should be replaceable with a waitqueue and RD_QUEUE_IRQ (setting the
* rd_threshold to 1). Couldn't get this to work, though.
*/
static int mxs_i2c_wait_for_data(struct mxs_i2c_dev *i2c)
{
unsigned long timeout = jiffies + msecs_to_jiffies(1000);
while (readl(i2c->regs + MXS_I2C_QUEUESTAT)
& MXS_I2C_QUEUESTAT_RD_QUEUE_EMPTY) {
if (time_after(jiffies, timeout))
return -ETIMEDOUT;
cond_resched();
}
return 0;
}
static int mxs_i2c_finish_read(struct mxs_i2c_dev *i2c, u8 *buf, int len)
{
u32 data;
int i;
for (i = 0; i < len; i++) {
if ((i & 3) == 0) {
if (mxs_i2c_wait_for_data(i2c))
return -ETIMEDOUT;
data = readl(i2c->regs + MXS_I2C_QUEUEDATA);
}
buf[i] = data & 0xff;
data >>= 8;
}
return 0;
}
/*
* Low level master read/write transaction.
*/
static int mxs_i2c_xfer_msg(struct i2c_adapter *adap, struct i2c_msg *msg,
int stop)
{
struct mxs_i2c_dev *i2c = i2c_get_adapdata(adap);
int ret;
int flags;
init_completion(&i2c->cmd_complete);
dev_dbg(i2c->dev, "addr: 0x%04x, len: %d, flags: 0x%x, stop: %d\n",
msg->addr, msg->len, msg->flags, stop);
if (msg->len == 0)
return -EINVAL;
flags = stop ? MXS_I2C_CTRL0_POST_SEND_STOP : 0;
if (msg->flags & I2C_M_RD)
mxs_i2c_pioq_setup_read(i2c, msg->addr, msg->len, flags);
else
mxs_i2c_pioq_setup_write(i2c, msg->addr, msg->buf, msg->len,
flags);
writel(MXS_I2C_QUEUECTRL_QUEUE_RUN,
i2c->regs + MXS_I2C_QUEUECTRL_SET);
ret = wait_for_completion_timeout(&i2c->cmd_complete,
msecs_to_jiffies(1000));
if (ret == 0)
goto timeout;
if ((!i2c->cmd_err) && (msg->flags & I2C_M_RD)) {
ret = mxs_i2c_finish_read(i2c, msg->buf, msg->len);
if (ret)
goto timeout;
}
if (i2c->cmd_err == -ENXIO)
mxs_i2c_reset(i2c);
dev_dbg(i2c->dev, "Done with err=%d\n", i2c->cmd_err);
return i2c->cmd_err;
timeout:
dev_dbg(i2c->dev, "Timeout!\n");
mxs_i2c_reset(i2c);
return -ETIMEDOUT;
}
static int mxs_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[],
int num)
{
int i;
int err;
for (i = 0; i < num; i++) {
err = mxs_i2c_xfer_msg(adap, &msgs[i], i == (num - 1));
if (err)
return err;
}
return num;
}
static u32 mxs_i2c_func(struct i2c_adapter *adap)
{
return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK);
}
static irqreturn_t mxs_i2c_isr(int this_irq, void *dev_id)
{
struct mxs_i2c_dev *i2c = dev_id;
u32 stat = readl(i2c->regs + MXS_I2C_CTRL1) & MXS_I2C_IRQ_MASK;
if (!stat)
return IRQ_NONE;
if (stat & MXS_I2C_CTRL1_NO_SLAVE_ACK_IRQ)
i2c->cmd_err = -ENXIO;
else if (stat & (MXS_I2C_CTRL1_EARLY_TERM_IRQ |
MXS_I2C_CTRL1_MASTER_LOSS_IRQ |
MXS_I2C_CTRL1_SLAVE_STOP_IRQ | MXS_I2C_CTRL1_SLAVE_IRQ))
/* MXS_I2C_CTRL1_OVERSIZE_XFER_TERM_IRQ is only for slaves */
i2c->cmd_err = -EIO;
else
i2c->cmd_err = 0;
complete(&i2c->cmd_complete);
writel(stat, i2c->regs + MXS_I2C_CTRL1_CLR);
return IRQ_HANDLED;
}
static const struct i2c_algorithm mxs_i2c_algo = {
.master_xfer = mxs_i2c_xfer,
.functionality = mxs_i2c_func,
};
static int __devinit mxs_i2c_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct mxs_i2c_dev *i2c;
struct i2c_adapter *adap;
struct resource *res;
resource_size_t res_size;
int err, irq;
i2c = devm_kzalloc(dev, sizeof(struct mxs_i2c_dev), GFP_KERNEL);
if (!i2c)
return -ENOMEM;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res)
return -ENOENT;
res_size = resource_size(res);
if (!devm_request_mem_region(dev, res->start, res_size, res->name))
return -EBUSY;
i2c->regs = devm_ioremap_nocache(dev, res->start, res_size);
if (!i2c->regs)
return -EBUSY;
irq = platform_get_irq(pdev, 0);
if (irq < 0)
return irq;
err = devm_request_irq(dev, irq, mxs_i2c_isr, 0, dev_name(dev), i2c);
if (err)
return err;
i2c->dev = dev;
platform_set_drvdata(pdev, i2c);
/* Do reset to enforce correct startup after pinmuxing */
mxs_i2c_reset(i2c);
writel(MXS_I2C_QUEUECTRL_PIO_QUEUE_MODE,
i2c->regs + MXS_I2C_QUEUECTRL_SET);
adap = &i2c->adapter;
strlcpy(adap->name, "MXS I2C adapter", sizeof(adap->name));
adap->owner = THIS_MODULE;
adap->algo = &mxs_i2c_algo;
adap->dev.parent = dev;
adap->nr = pdev->id;
i2c_set_adapdata(adap, i2c);
err = i2c_add_numbered_adapter(adap);
if (err) {
dev_err(dev, "Failed to add adapter (%d)\n", err);
writel(MXS_I2C_CTRL0_SFTRST,
i2c->regs + MXS_I2C_CTRL0_SET);
return err;
}
return 0;
}
static int __devexit mxs_i2c_remove(struct platform_device *pdev)
{
struct mxs_i2c_dev *i2c = platform_get_drvdata(pdev);
int ret;
ret = i2c_del_adapter(&i2c->adapter);
if (ret)
return -EBUSY;
writel(MXS_I2C_QUEUECTRL_QUEUE_RUN,
i2c->regs + MXS_I2C_QUEUECTRL_CLR);
writel(MXS_I2C_CTRL0_SFTRST, i2c->regs + MXS_I2C_CTRL0_SET);
platform_set_drvdata(pdev, NULL);
return 0;
}
static struct platform_driver mxs_i2c_driver = {
.driver = {
.name = DRIVER_NAME,
.owner = THIS_MODULE,
},
.remove = __devexit_p(mxs_i2c_remove),
};
static int __init mxs_i2c_init(void)
{
return platform_driver_probe(&mxs_i2c_driver, mxs_i2c_probe);
}
subsys_initcall(mxs_i2c_init);
static void __exit mxs_i2c_exit(void)
{
platform_driver_unregister(&mxs_i2c_driver);
}
module_exit(mxs_i2c_exit);
MODULE_AUTHOR("Wolfram Sang <w.sang@pengutronix.de>");
MODULE_DESCRIPTION("MXS I2C Bus Driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:" DRIVER_NAME);

700
drivers/i2c/busses/i2c-tegra.c Normal file
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@ -0,0 +1,700 @@
/*
* drivers/i2c/busses/i2c-tegra.c
*
* Copyright (C) 2010 Google, Inc.
* Author: Colin Cross <ccross@android.com>
*
* This software is licensed under the terms of the GNU General Public
* License version 2, as published by the Free Software Foundation, and
* may be copied, distributed, and modified under those terms.
*
* 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.
*
*/
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/platform_device.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/io.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/i2c-tegra.h>
#include <asm/unaligned.h>
#include <mach/clk.h>
#define TEGRA_I2C_TIMEOUT (msecs_to_jiffies(1000))
#define BYTES_PER_FIFO_WORD 4
#define I2C_CNFG 0x000
#define I2C_CNFG_PACKET_MODE_EN (1<<10)
#define I2C_CNFG_NEW_MASTER_FSM (1<<11)
#define I2C_SL_CNFG 0x020
#define I2C_SL_CNFG_NEWSL (1<<2)
#define I2C_SL_ADDR1 0x02c
#define I2C_TX_FIFO 0x050
#define I2C_RX_FIFO 0x054
#define I2C_PACKET_TRANSFER_STATUS 0x058
#define I2C_FIFO_CONTROL 0x05c
#define I2C_FIFO_CONTROL_TX_FLUSH (1<<1)
#define I2C_FIFO_CONTROL_RX_FLUSH (1<<0)
#define I2C_FIFO_CONTROL_TX_TRIG_SHIFT 5
#define I2C_FIFO_CONTROL_RX_TRIG_SHIFT 2
#define I2C_FIFO_STATUS 0x060
#define I2C_FIFO_STATUS_TX_MASK 0xF0
#define I2C_FIFO_STATUS_TX_SHIFT 4
#define I2C_FIFO_STATUS_RX_MASK 0x0F
#define I2C_FIFO_STATUS_RX_SHIFT 0
#define I2C_INT_MASK 0x064
#define I2C_INT_STATUS 0x068
#define I2C_INT_PACKET_XFER_COMPLETE (1<<7)
#define I2C_INT_ALL_PACKETS_XFER_COMPLETE (1<<6)
#define I2C_INT_TX_FIFO_OVERFLOW (1<<5)
#define I2C_INT_RX_FIFO_UNDERFLOW (1<<4)
#define I2C_INT_NO_ACK (1<<3)
#define I2C_INT_ARBITRATION_LOST (1<<2)
#define I2C_INT_TX_FIFO_DATA_REQ (1<<1)
#define I2C_INT_RX_FIFO_DATA_REQ (1<<0)
#define I2C_CLK_DIVISOR 0x06c
#define DVC_CTRL_REG1 0x000
#define DVC_CTRL_REG1_INTR_EN (1<<10)
#define DVC_CTRL_REG2 0x004
#define DVC_CTRL_REG3 0x008
#define DVC_CTRL_REG3_SW_PROG (1<<26)
#define DVC_CTRL_REG3_I2C_DONE_INTR_EN (1<<30)
#define DVC_STATUS 0x00c
#define DVC_STATUS_I2C_DONE_INTR (1<<30)
#define I2C_ERR_NONE 0x00
#define I2C_ERR_NO_ACK 0x01
#define I2C_ERR_ARBITRATION_LOST 0x02
#define PACKET_HEADER0_HEADER_SIZE_SHIFT 28
#define PACKET_HEADER0_PACKET_ID_SHIFT 16
#define PACKET_HEADER0_CONT_ID_SHIFT 12
#define PACKET_HEADER0_PROTOCOL_I2C (1<<4)
#define I2C_HEADER_HIGHSPEED_MODE (1<<22)
#define I2C_HEADER_CONT_ON_NAK (1<<21)
#define I2C_HEADER_SEND_START_BYTE (1<<20)
#define I2C_HEADER_READ (1<<19)
#define I2C_HEADER_10BIT_ADDR (1<<18)
#define I2C_HEADER_IE_ENABLE (1<<17)
#define I2C_HEADER_REPEAT_START (1<<16)
#define I2C_HEADER_MASTER_ADDR_SHIFT 12
#define I2C_HEADER_SLAVE_ADDR_SHIFT 1
/**
* struct tegra_i2c_dev - per device i2c context
* @dev: device reference for power management
* @adapter: core i2c layer adapter information
* @clk: clock reference for i2c controller
* @i2c_clk: clock reference for i2c bus
* @iomem: memory resource for registers
* @base: ioremapped registers cookie
* @cont_id: i2c controller id, used for for packet header
* @irq: irq number of transfer complete interrupt
* @is_dvc: identifies the DVC i2c controller, has a different register layout
* @msg_complete: transfer completion notifier
* @msg_err: error code for completed message
* @msg_buf: pointer to current message data
* @msg_buf_remaining: size of unsent data in the message buffer
* @msg_read: identifies read transfers
* @bus_clk_rate: current i2c bus clock rate
* @is_suspended: prevents i2c controller accesses after suspend is called
*/
struct tegra_i2c_dev {
struct device *dev;
struct i2c_adapter adapter;
struct clk *clk;
struct clk *i2c_clk;
struct resource *iomem;
void __iomem *base;
int cont_id;
int irq;
int is_dvc;
struct completion msg_complete;
int msg_err;
u8 *msg_buf;
size_t msg_buf_remaining;
int msg_read;
unsigned long bus_clk_rate;
bool is_suspended;
};
static void dvc_writel(struct tegra_i2c_dev *i2c_dev, u32 val, unsigned long reg)
{
writel(val, i2c_dev->base + reg);
}
static u32 dvc_readl(struct tegra_i2c_dev *i2c_dev, unsigned long reg)
{
return readl(i2c_dev->base + reg);
}
/*
* i2c_writel and i2c_readl will offset the register if necessary to talk
* to the I2C block inside the DVC block
*/
static unsigned long tegra_i2c_reg_addr(struct tegra_i2c_dev *i2c_dev,
unsigned long reg)
{
if (i2c_dev->is_dvc)
reg += (reg >= I2C_TX_FIFO) ? 0x10 : 0x40;
return reg;
}
static void i2c_writel(struct tegra_i2c_dev *i2c_dev, u32 val,
unsigned long reg)
{
writel(val, i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg));
}
static u32 i2c_readl(struct tegra_i2c_dev *i2c_dev, unsigned long reg)
{
return readl(i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg));
}
static void i2c_writesl(struct tegra_i2c_dev *i2c_dev, void *data,
unsigned long reg, int len)
{
writesl(i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg), data, len);
}
static void i2c_readsl(struct tegra_i2c_dev *i2c_dev, void *data,
unsigned long reg, int len)
{
readsl(i2c_dev->base + tegra_i2c_reg_addr(i2c_dev, reg), data, len);
}
static void tegra_i2c_mask_irq(struct tegra_i2c_dev *i2c_dev, u32 mask)
{
u32 int_mask = i2c_readl(i2c_dev, I2C_INT_MASK);
int_mask &= ~mask;
i2c_writel(i2c_dev, int_mask, I2C_INT_MASK);
}
static void tegra_i2c_unmask_irq(struct tegra_i2c_dev *i2c_dev, u32 mask)
{
u32 int_mask = i2c_readl(i2c_dev, I2C_INT_MASK);
int_mask |= mask;
i2c_writel(i2c_dev, int_mask, I2C_INT_MASK);
}
static int tegra_i2c_flush_fifos(struct tegra_i2c_dev *i2c_dev)
{
unsigned long timeout = jiffies + HZ;
u32 val = i2c_readl(i2c_dev, I2C_FIFO_CONTROL);
val |= I2C_FIFO_CONTROL_TX_FLUSH | I2C_FIFO_CONTROL_RX_FLUSH;
i2c_writel(i2c_dev, val, I2C_FIFO_CONTROL);
while (i2c_readl(i2c_dev, I2C_FIFO_CONTROL) &
(I2C_FIFO_CONTROL_TX_FLUSH | I2C_FIFO_CONTROL_RX_FLUSH)) {
if (time_after(jiffies, timeout)) {
dev_warn(i2c_dev->dev, "timeout waiting for fifo flush\n");
return -ETIMEDOUT;
}
msleep(1);
}
return 0;
}
static int tegra_i2c_empty_rx_fifo(struct tegra_i2c_dev *i2c_dev)
{
u32 val;
int rx_fifo_avail;
u8 *buf = i2c_dev->msg_buf;
size_t buf_remaining = i2c_dev->msg_buf_remaining;
int words_to_transfer;
val = i2c_readl(i2c_dev, I2C_FIFO_STATUS);
rx_fifo_avail = (val & I2C_FIFO_STATUS_RX_MASK) >>
I2C_FIFO_STATUS_RX_SHIFT;
/* Rounds down to not include partial word at the end of buf */
words_to_transfer = buf_remaining / BYTES_PER_FIFO_WORD;
if (words_to_transfer > rx_fifo_avail)
words_to_transfer = rx_fifo_avail;
i2c_readsl(i2c_dev, buf, I2C_RX_FIFO, words_to_transfer);
buf += words_to_transfer * BYTES_PER_FIFO_WORD;
buf_remaining -= words_to_transfer * BYTES_PER_FIFO_WORD;
rx_fifo_avail -= words_to_transfer;
/*
* If there is a partial word at the end of buf, handle it manually to
* prevent overwriting past the end of buf
*/
if (rx_fifo_avail > 0 && buf_remaining > 0) {
BUG_ON(buf_remaining > 3);
val = i2c_readl(i2c_dev, I2C_RX_FIFO);
memcpy(buf, &val, buf_remaining);
buf_remaining = 0;
rx_fifo_avail--;
}
BUG_ON(rx_fifo_avail > 0 && buf_remaining > 0);
i2c_dev->msg_buf_remaining = buf_remaining;
i2c_dev->msg_buf = buf;
return 0;
}
static int tegra_i2c_fill_tx_fifo(struct tegra_i2c_dev *i2c_dev)
{
u32 val;
int tx_fifo_avail;
u8 *buf = i2c_dev->msg_buf;
size_t buf_remaining = i2c_dev->msg_buf_remaining;
int words_to_transfer;
val = i2c_readl(i2c_dev, I2C_FIFO_STATUS);
tx_fifo_avail = (val & I2C_FIFO_STATUS_TX_MASK) >>
I2C_FIFO_STATUS_TX_SHIFT;
/* Rounds down to not include partial word at the end of buf */
words_to_transfer = buf_remaining / BYTES_PER_FIFO_WORD;
if (words_to_transfer > tx_fifo_avail)
words_to_transfer = tx_fifo_avail;
i2c_writesl(i2c_dev, buf, I2C_TX_FIFO, words_to_transfer);
buf += words_to_transfer * BYTES_PER_FIFO_WORD;
buf_remaining -= words_to_transfer * BYTES_PER_FIFO_WORD;
tx_fifo_avail -= words_to_transfer;
/*
* If there is a partial word at the end of buf, handle it manually to
* prevent reading past the end of buf, which could cross a page
* boundary and fault.
*/
if (tx_fifo_avail > 0 && buf_remaining > 0) {
BUG_ON(buf_remaining > 3);
memcpy(&val, buf, buf_remaining);
i2c_writel(i2c_dev, val, I2C_TX_FIFO);
buf_remaining = 0;
tx_fifo_avail--;
}
BUG_ON(tx_fifo_avail > 0 && buf_remaining > 0);
i2c_dev->msg_buf_remaining = buf_remaining;
i2c_dev->msg_buf = buf;
return 0;
}
/*
* One of the Tegra I2C blocks is inside the DVC (Digital Voltage Controller)
* block. This block is identical to the rest of the I2C blocks, except that
* it only supports master mode, it has registers moved around, and it needs
* some extra init to get it into I2C mode. The register moves are handled
* by i2c_readl and i2c_writel
*/
static void tegra_dvc_init(struct tegra_i2c_dev *i2c_dev)
{
u32 val = 0;
val = dvc_readl(i2c_dev, DVC_CTRL_REG3);
val |= DVC_CTRL_REG3_SW_PROG;
val |= DVC_CTRL_REG3_I2C_DONE_INTR_EN;
dvc_writel(i2c_dev, val, DVC_CTRL_REG3);
val = dvc_readl(i2c_dev, DVC_CTRL_REG1);
val |= DVC_CTRL_REG1_INTR_EN;
dvc_writel(i2c_dev, val, DVC_CTRL_REG1);
}
static int tegra_i2c_init(struct tegra_i2c_dev *i2c_dev)
{
u32 val;
int err = 0;
clk_enable(i2c_dev->clk);
tegra_periph_reset_assert(i2c_dev->clk);
udelay(2);
tegra_periph_reset_deassert(i2c_dev->clk);
if (i2c_dev->is_dvc)
tegra_dvc_init(i2c_dev);
val = I2C_CNFG_NEW_MASTER_FSM | I2C_CNFG_PACKET_MODE_EN;
i2c_writel(i2c_dev, val, I2C_CNFG);
i2c_writel(i2c_dev, 0, I2C_INT_MASK);
clk_set_rate(i2c_dev->clk, i2c_dev->bus_clk_rate * 8);
val = 7 << I2C_FIFO_CONTROL_TX_TRIG_SHIFT |
0 << I2C_FIFO_CONTROL_RX_TRIG_SHIFT;
i2c_writel(i2c_dev, val, I2C_FIFO_CONTROL);
if (tegra_i2c_flush_fifos(i2c_dev))
err = -ETIMEDOUT;
clk_disable(i2c_dev->clk);
return err;
}
static irqreturn_t tegra_i2c_isr(int irq, void *dev_id)
{
u32 status;
const u32 status_err = I2C_INT_NO_ACK | I2C_INT_ARBITRATION_LOST;
struct tegra_i2c_dev *i2c_dev = dev_id;
status = i2c_readl(i2c_dev, I2C_INT_STATUS);
if (status == 0) {
dev_warn(i2c_dev->dev, "interrupt with no status\n");
return IRQ_NONE;
}
if (unlikely(status & status_err)) {
if (status & I2C_INT_NO_ACK)
i2c_dev->msg_err |= I2C_ERR_NO_ACK;
if (status & I2C_INT_ARBITRATION_LOST)
i2c_dev->msg_err |= I2C_ERR_ARBITRATION_LOST;
complete(&i2c_dev->msg_complete);
goto err;
}
if (i2c_dev->msg_read && (status & I2C_INT_RX_FIFO_DATA_REQ)) {
if (i2c_dev->msg_buf_remaining)
tegra_i2c_empty_rx_fifo(i2c_dev);
else
BUG();
}
if (!i2c_dev->msg_read && (status & I2C_INT_TX_FIFO_DATA_REQ)) {
if (i2c_dev->msg_buf_remaining)
tegra_i2c_fill_tx_fifo(i2c_dev);
else
tegra_i2c_mask_irq(i2c_dev, I2C_INT_TX_FIFO_DATA_REQ);
}
if ((status & I2C_INT_PACKET_XFER_COMPLETE) &&
!i2c_dev->msg_buf_remaining)
complete(&i2c_dev->msg_complete);
i2c_writel(i2c_dev, status, I2C_INT_STATUS);
if (i2c_dev->is_dvc)
dvc_writel(i2c_dev, DVC_STATUS_I2C_DONE_INTR, DVC_STATUS);
return IRQ_HANDLED;
err:
/* An error occured, mask all interrupts */
tegra_i2c_mask_irq(i2c_dev, I2C_INT_NO_ACK | I2C_INT_ARBITRATION_LOST |
I2C_INT_PACKET_XFER_COMPLETE | I2C_INT_TX_FIFO_DATA_REQ |
I2C_INT_RX_FIFO_DATA_REQ);
i2c_writel(i2c_dev, status, I2C_INT_STATUS);
return IRQ_HANDLED;
}
static int tegra_i2c_xfer_msg(struct tegra_i2c_dev *i2c_dev,
struct i2c_msg *msg, int stop)
{
u32 packet_header;
u32 int_mask;
int ret;
tegra_i2c_flush_fifos(i2c_dev);
i2c_writel(i2c_dev, 0xFF, I2C_INT_STATUS);
if (msg->len == 0)
return -EINVAL;
i2c_dev->msg_buf = msg->buf;
i2c_dev->msg_buf_remaining = msg->len;
i2c_dev->msg_err = I2C_ERR_NONE;
i2c_dev->msg_read = (msg->flags & I2C_M_RD);
INIT_COMPLETION(i2c_dev->msg_complete);
packet_header = (0 << PACKET_HEADER0_HEADER_SIZE_SHIFT) |
PACKET_HEADER0_PROTOCOL_I2C |
(i2c_dev->cont_id << PACKET_HEADER0_CONT_ID_SHIFT) |
(1 << PACKET_HEADER0_PACKET_ID_SHIFT);
i2c_writel(i2c_dev, packet_header, I2C_TX_FIFO);
packet_header = msg->len - 1;
i2c_writel(i2c_dev, packet_header, I2C_TX_FIFO);
packet_header = msg->addr << I2C_HEADER_SLAVE_ADDR_SHIFT;
packet_header |= I2C_HEADER_IE_ENABLE;
if (msg->flags & I2C_M_TEN)
packet_header |= I2C_HEADER_10BIT_ADDR;
if (msg->flags & I2C_M_IGNORE_NAK)
packet_header |= I2C_HEADER_CONT_ON_NAK;
if (msg->flags & I2C_M_NOSTART)
packet_header |= I2C_HEADER_REPEAT_START;
if (msg->flags & I2C_M_RD)
packet_header |= I2C_HEADER_READ;
i2c_writel(i2c_dev, packet_header, I2C_TX_FIFO);
if (!(msg->flags & I2C_M_RD))
tegra_i2c_fill_tx_fifo(i2c_dev);
int_mask = I2C_INT_NO_ACK | I2C_INT_ARBITRATION_LOST;
if (msg->flags & I2C_M_RD)
int_mask |= I2C_INT_RX_FIFO_DATA_REQ;
else if (i2c_dev->msg_buf_remaining)
int_mask |= I2C_INT_TX_FIFO_DATA_REQ;
tegra_i2c_unmask_irq(i2c_dev, int_mask);
dev_dbg(i2c_dev->dev, "unmasked irq: %02x\n",
i2c_readl(i2c_dev, I2C_INT_MASK));
ret = wait_for_completion_timeout(&i2c_dev->msg_complete, TEGRA_I2C_TIMEOUT);
tegra_i2c_mask_irq(i2c_dev, int_mask);
if (WARN_ON(ret == 0)) {
dev_err(i2c_dev->dev, "i2c transfer timed out\n");
tegra_i2c_init(i2c_dev);
return -ETIMEDOUT;
}
dev_dbg(i2c_dev->dev, "transfer complete: %d %d %d\n",
ret, completion_done(&i2c_dev->msg_complete), i2c_dev->msg_err);
if (likely(i2c_dev->msg_err == I2C_ERR_NONE))
return 0;
tegra_i2c_init(i2c_dev);
if (i2c_dev->msg_err == I2C_ERR_NO_ACK) {
if (msg->flags & I2C_M_IGNORE_NAK)
return 0;
return -EREMOTEIO;
}
return -EIO;
}
static int tegra_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[],
int num)
{
struct tegra_i2c_dev *i2c_dev = i2c_get_adapdata(adap);
int i;
int ret = 0;
if (i2c_dev->is_suspended)
return -EBUSY;
clk_enable(i2c_dev->clk);
for (i = 0; i < num; i++) {
int stop = (i == (num - 1)) ? 1 : 0;
ret = tegra_i2c_xfer_msg(i2c_dev, &msgs[i], stop);
if (ret)
break;
}
clk_disable(i2c_dev->clk);
return ret ?: i;
}
static u32 tegra_i2c_func(struct i2c_adapter *adap)
{
return I2C_FUNC_I2C;
}
static const struct i2c_algorithm tegra_i2c_algo = {
.master_xfer = tegra_i2c_xfer,
.functionality = tegra_i2c_func,
};
static int tegra_i2c_probe(struct platform_device *pdev)
{
struct tegra_i2c_dev *i2c_dev;
struct tegra_i2c_platform_data *pdata = pdev->dev.platform_data;
struct resource *res;
struct resource *iomem;
struct clk *clk;
struct clk *i2c_clk;
void *base;
int irq;
int ret = 0;
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res) {
dev_err(&pdev->dev, "no mem resource\n");
return -EINVAL;
}
iomem = request_mem_region(res->start, resource_size(res), pdev->name);
if (!iomem) {
dev_err(&pdev->dev, "I2C region already claimed\n");
return -EBUSY;
}
base = ioremap(iomem->start, resource_size(iomem));
if (!base) {
dev_err(&pdev->dev, "Cannot ioremap I2C region\n");
return -ENOMEM;
}
res = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
if (!res) {
dev_err(&pdev->dev, "no irq resource\n");
ret = -EINVAL;
goto err_iounmap;
}
irq = res->start;
clk = clk_get(&pdev->dev, NULL);
if (IS_ERR(clk)) {
dev_err(&pdev->dev, "missing controller clock");
ret = PTR_ERR(clk);
goto err_release_region;
}
i2c_clk = clk_get(&pdev->dev, "i2c");
if (IS_ERR(i2c_clk)) {
dev_err(&pdev->dev, "missing bus clock");
ret = PTR_ERR(i2c_clk);
goto err_clk_put;
}
i2c_dev = kzalloc(sizeof(struct tegra_i2c_dev), GFP_KERNEL);
if (!i2c_dev) {
ret = -ENOMEM;
goto err_i2c_clk_put;
}
i2c_dev->base = base;
i2c_dev->clk = clk;
i2c_dev->i2c_clk = i2c_clk;
i2c_dev->iomem = iomem;
i2c_dev->adapter.algo = &tegra_i2c_algo;
i2c_dev->irq = irq;
i2c_dev->cont_id = pdev->id;
i2c_dev->dev = &pdev->dev;
i2c_dev->bus_clk_rate = pdata ? pdata->bus_clk_rate : 100000;
if (pdev->id == 3)
i2c_dev->is_dvc = 1;
init_completion(&i2c_dev->msg_complete);
platform_set_drvdata(pdev, i2c_dev);
ret = tegra_i2c_init(i2c_dev);
if (ret) {
dev_err(&pdev->dev, "Failed to initialize i2c controller");
goto err_free;
}
ret = request_irq(i2c_dev->irq, tegra_i2c_isr, 0, pdev->name, i2c_dev);
if (ret) {
dev_err(&pdev->dev, "Failed to request irq %i\n", i2c_dev->irq);
goto err_free;
}
clk_enable(i2c_dev->i2c_clk);
i2c_set_adapdata(&i2c_dev->adapter, i2c_dev);
i2c_dev->adapter.owner = THIS_MODULE;
i2c_dev->adapter.class = I2C_CLASS_HWMON;
strlcpy(i2c_dev->adapter.name, "Tegra I2C adapter",
sizeof(i2c_dev->adapter.name));
i2c_dev->adapter.algo = &tegra_i2c_algo;
i2c_dev->adapter.dev.parent = &pdev->dev;
i2c_dev->adapter.nr = pdev->id;
ret = i2c_add_numbered_adapter(&i2c_dev->adapter);
if (ret) {
dev_err(&pdev->dev, "Failed to add I2C adapter\n");
goto err_free_irq;
}
return 0;
err_free_irq:
free_irq(i2c_dev->irq, i2c_dev);
err_free:
kfree(i2c_dev);
err_i2c_clk_put:
clk_put(i2c_clk);
err_clk_put:
clk_put(clk);
err_release_region:
release_mem_region(iomem->start, resource_size(iomem));
err_iounmap:
iounmap(base);
return ret;
}
static int tegra_i2c_remove(struct platform_device *pdev)
{
struct tegra_i2c_dev *i2c_dev = platform_get_drvdata(pdev);
i2c_del_adapter(&i2c_dev->adapter);
free_irq(i2c_dev->irq, i2c_dev);
clk_put(i2c_dev->i2c_clk);
clk_put(i2c_dev->clk);
release_mem_region(i2c_dev->iomem->start,
resource_size(i2c_dev->iomem));
iounmap(i2c_dev->base);
kfree(i2c_dev);
return 0;
}
#ifdef CONFIG_PM
static int tegra_i2c_suspend(struct platform_device *pdev, pm_message_t state)
{
struct tegra_i2c_dev *i2c_dev = platform_get_drvdata(pdev);
i2c_lock_adapter(&i2c_dev->adapter);
i2c_dev->is_suspended = true;
i2c_unlock_adapter(&i2c_dev->adapter);
return 0;
}
static int tegra_i2c_resume(struct platform_device *pdev)
{
struct tegra_i2c_dev *i2c_dev = platform_get_drvdata(pdev);
int ret;
i2c_lock_adapter(&i2c_dev->adapter);
ret = tegra_i2c_init(i2c_dev);
if (ret) {
i2c_unlock_adapter(&i2c_dev->adapter);
return ret;
}
i2c_dev->is_suspended = false;
i2c_unlock_adapter(&i2c_dev->adapter);
return 0;
}
#endif
static struct platform_driver tegra_i2c_driver = {
.probe = tegra_i2c_probe,
.remove = tegra_i2c_remove,
#ifdef CONFIG_PM
.suspend = tegra_i2c_suspend,
.resume = tegra_i2c_resume,
#endif
.driver = {
.name = "tegra-i2c",
.owner = THIS_MODULE,
},
};
static int __init tegra_i2c_init_driver(void)
{
return platform_driver_register(&tegra_i2c_driver);
}
static void __exit tegra_i2c_exit_driver(void)
{
platform_driver_unregister(&tegra_i2c_driver);
}
subsys_initcall(tegra_i2c_init_driver);
module_exit(tegra_i2c_exit_driver);
MODULE_DESCRIPTION("nVidia Tegra2 I2C Bus Controller driver");
MODULE_AUTHOR("Colin Cross");
MODULE_LICENSE("GPL v2");

25
include/linux/i2c-tegra.h Normal file
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@ -0,0 +1,25 @@
/*
* drivers/i2c/busses/i2c-tegra.c
*
* Copyright (C) 2010 Google, Inc.
* Author: Colin Cross <ccross@android.com>
*
* This software is licensed under the terms of the GNU General Public
* License version 2, as published by the Free Software Foundation, and
* may be copied, distributed, and modified under those terms.
*
* 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.
*
*/
#ifndef _LINUX_I2C_TEGRA_H
#define _LINUX_I2C_TEGRA_H
struct tegra_i2c_platform_data {
unsigned long bus_clk_rate;
};
#endif /* _LINUX_I2C_TEGRA_H */