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i2c-imx.c
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// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright (C) 2002 Motorola GSG-China
*
* 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>
*
* Copyright 2013 Freescale Semiconductor, Inc.
* Copyright 2020 NXP
*
*/
#include <linux/acpi.h>
#include <linux/clk.h>
#include <linux/completion.h>
#include <linux/delay.h>
#include <linux/dma-mapping.h>
#include <linux/dmaengine.h>
#include <linux/dmapool.h>
#include <linux/err.h>
#include <linux/errno.h>
#include <linux/gpio/consumer.h>
#include <linux/i2c.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/iopoll.h>
#include <linux/kernel.h>
#include <linux/spinlock.h>
#include <linux/hrtimer.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_dma.h>
#include <linux/pinctrl/consumer.h>
#include <linux/platform_data/i2c-imx.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
#include <linux/sched.h>
#include <linux/slab.h>
/* This will be the driver name the kernel reports */
#define DRIVER_NAME "imx-i2c"
#define I2C_IMX_CHECK_DELAY 30000 /* Time to check for bus idle, in NS */
/*
* Enable DMA if transfer byte size is bigger than this threshold.
* As the hardware request, it must bigger than 4 bytes.\
* I have set '16' here, maybe it's not the best but I think it's
* the appropriate.
*/
#define DMA_THRESHOLD 16
#define DMA_TIMEOUT 1000
/* IMX I2C registers:
* the I2C register offset is different between SoCs,
* to provide support for all these chips, split the
* register offset into a fixed base address and a
* variable shift value, then the full register offset
* will be calculated by
* reg_off = ( reg_base_addr << reg_shift)
*/
#define IMX_I2C_IADR 0x00 /* i2c slave address */
#define IMX_I2C_IFDR 0x01 /* i2c frequency divider */
#define IMX_I2C_I2CR 0x02 /* i2c control */
#define IMX_I2C_I2SR 0x03 /* i2c status */
#define IMX_I2C_I2DR 0x04 /* i2c transfer data */
/*
* All of the layerscape series SoCs support IBIC register.
*/
#define IMX_I2C_IBIC 0x05 /* i2c bus interrupt config */
#define IMX_I2C_REGSHIFT 2
#define VF610_I2C_REGSHIFT 0
/* 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_DMAEN 0x02
#define I2CR_RSTA 0x04
#define I2CR_TXAK 0x08
#define I2CR_MTX 0x10
#define I2CR_MSTA 0x20
#define I2CR_IIEN 0x40
#define I2CR_IEN 0x80
#define IBIC_BIIE 0x80 /* Bus idle interrupt enable */
/* register bits different operating codes definition:
* 1) I2SR: Interrupt flags clear operation differ between SoCs:
* - write zero to clear(w0c) INT flag on i.MX,
* - but write one to clear(w1c) INT flag on Vybrid.
* 2) I2CR: I2C module enable operation also differ between SoCs:
* - set I2CR_IEN bit enable the module on i.MX,
* - but clear I2CR_IEN bit enable the module on Vybrid.
*/
#define I2SR_CLR_OPCODE_W0C 0x0
#define I2SR_CLR_OPCODE_W1C (I2SR_IAL | I2SR_IIF)
#define I2CR_IEN_OPCODE_0 0x0
#define I2CR_IEN_OPCODE_1 I2CR_IEN
#define I2C_PM_TIMEOUT 10 /* ms */
/*
* 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
*/
struct imx_i2c_clk_pair {
u16 div;
u16 val;
};
static struct imx_i2c_clk_pair imx_i2c_clk_div[] = {
{ 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 }
};
/* Vybrid VF610 clock divider, register value pairs */
static struct imx_i2c_clk_pair vf610_i2c_clk_div[] = {
{ 20, 0x00 }, { 22, 0x01 }, { 24, 0x02 }, { 26, 0x03 },
{ 28, 0x04 }, { 30, 0x05 }, { 32, 0x09 }, { 34, 0x06 },
{ 36, 0x0A }, { 40, 0x07 }, { 44, 0x0C }, { 48, 0x0D },
{ 52, 0x43 }, { 56, 0x0E }, { 60, 0x45 }, { 64, 0x12 },
{ 68, 0x0F }, { 72, 0x13 }, { 80, 0x14 }, { 88, 0x15 },
{ 96, 0x19 }, { 104, 0x16 }, { 112, 0x1A }, { 128, 0x17 },
{ 136, 0x4F }, { 144, 0x1C }, { 160, 0x1D }, { 176, 0x55 },
{ 192, 0x1E }, { 208, 0x56 }, { 224, 0x22 }, { 228, 0x24 },
{ 240, 0x1F }, { 256, 0x23 }, { 288, 0x5C }, { 320, 0x25 },
{ 384, 0x26 }, { 448, 0x2A }, { 480, 0x27 }, { 512, 0x2B },
{ 576, 0x2C }, { 640, 0x2D }, { 768, 0x31 }, { 896, 0x32 },
{ 960, 0x2F }, { 1024, 0x33 }, { 1152, 0x34 }, { 1280, 0x35 },
{ 1536, 0x36 }, { 1792, 0x3A }, { 1920, 0x37 }, { 2048, 0x3B },
{ 2304, 0x3C }, { 2560, 0x3D }, { 3072, 0x3E }, { 3584, 0x7A },
{ 3840, 0x3F }, { 4096, 0x7B }, { 5120, 0x7D }, { 6144, 0x7E },
};
enum imx_i2c_type {
IMX1_I2C,
IMX21_I2C,
VF610_I2C,
};
struct imx_i2c_hwdata {
enum imx_i2c_type devtype;
unsigned int regshift;
struct imx_i2c_clk_pair *clk_div;
unsigned int ndivs;
unsigned int i2sr_clr_opcode;
unsigned int i2cr_ien_opcode;
/*
* Errata ERR007805 or e7805:
* I2C: When the I2C clock speed is configured for 400 kHz,
* the SCL low period violates the I2C spec of 1.3 uS min.
*/
bool has_err007805;
};
struct imx_i2c_dma {
struct dma_chan *chan_tx;
struct dma_chan *chan_rx;
struct dma_chan *chan_using;
struct completion cmd_complete;
dma_addr_t dma_buf;
unsigned int dma_len;
enum dma_transfer_direction dma_transfer_dir;
enum dma_data_direction dma_data_dir;
};
struct imx_i2c_struct {
struct i2c_adapter adapter;
struct clk *clk;
struct notifier_block clk_change_nb;
void __iomem *base;
wait_queue_head_t queue;
unsigned long i2csr;
unsigned int disable_delay;
int stopped;
unsigned int ifdr; /* IMX_I2C_IFDR */
unsigned int cur_clk;
unsigned int bitrate;
const struct imx_i2c_hwdata *hwdata;
struct i2c_bus_recovery_info rinfo;
struct imx_i2c_dma *dma;
struct i2c_client *slave;
enum i2c_slave_event last_slave_event;
/* For checking slave events. */
spinlock_t slave_lock;
struct hrtimer slave_timer;
};
static const struct imx_i2c_hwdata imx1_i2c_hwdata = {
.devtype = IMX1_I2C,
.regshift = IMX_I2C_REGSHIFT,
.clk_div = imx_i2c_clk_div,
.ndivs = ARRAY_SIZE(imx_i2c_clk_div),
.i2sr_clr_opcode = I2SR_CLR_OPCODE_W0C,
.i2cr_ien_opcode = I2CR_IEN_OPCODE_1,
};
static const struct imx_i2c_hwdata imx21_i2c_hwdata = {
.devtype = IMX21_I2C,
.regshift = IMX_I2C_REGSHIFT,
.clk_div = imx_i2c_clk_div,
.ndivs = ARRAY_SIZE(imx_i2c_clk_div),
.i2sr_clr_opcode = I2SR_CLR_OPCODE_W0C,
.i2cr_ien_opcode = I2CR_IEN_OPCODE_1,
};
static const struct imx_i2c_hwdata imx6_i2c_hwdata = {
.devtype = IMX21_I2C,
.regshift = IMX_I2C_REGSHIFT,
.clk_div = imx_i2c_clk_div,
.ndivs = ARRAY_SIZE(imx_i2c_clk_div),
.i2sr_clr_opcode = I2SR_CLR_OPCODE_W0C,
.i2cr_ien_opcode = I2CR_IEN_OPCODE_1,
.has_err007805 = true,
};
static struct imx_i2c_hwdata vf610_i2c_hwdata = {
.devtype = VF610_I2C,
.regshift = VF610_I2C_REGSHIFT,
.clk_div = vf610_i2c_clk_div,
.ndivs = ARRAY_SIZE(vf610_i2c_clk_div),
.i2sr_clr_opcode = I2SR_CLR_OPCODE_W1C,
.i2cr_ien_opcode = I2CR_IEN_OPCODE_0,
};
static const struct platform_device_id imx_i2c_devtype[] = {
{
.name = "imx1-i2c",
.driver_data = (kernel_ulong_t)&imx1_i2c_hwdata,
}, {
.name = "imx21-i2c",
.driver_data = (kernel_ulong_t)&imx21_i2c_hwdata,
}, {
/* sentinel */
}
};
MODULE_DEVICE_TABLE(platform, imx_i2c_devtype);
static const struct of_device_id i2c_imx_dt_ids[] = {
{ .compatible = "fsl,imx1-i2c", .data = &imx1_i2c_hwdata, },
{ .compatible = "fsl,imx21-i2c", .data = &imx21_i2c_hwdata, },
{ .compatible = "fsl,imx6q-i2c", .data = &imx6_i2c_hwdata, },
{ .compatible = "fsl,imx6sl-i2c", .data = &imx6_i2c_hwdata, },
{ .compatible = "fsl,imx6sll-i2c", .data = &imx6_i2c_hwdata, },
{ .compatible = "fsl,imx6sx-i2c", .data = &imx6_i2c_hwdata, },
{ .compatible = "fsl,imx6ul-i2c", .data = &imx6_i2c_hwdata, },
{ .compatible = "fsl,imx7s-i2c", .data = &imx6_i2c_hwdata, },
{ .compatible = "fsl,imx8mm-i2c", .data = &imx6_i2c_hwdata, },
{ .compatible = "fsl,imx8mn-i2c", .data = &imx6_i2c_hwdata, },
{ .compatible = "fsl,imx8mp-i2c", .data = &imx6_i2c_hwdata, },
{ .compatible = "fsl,imx8mq-i2c", .data = &imx6_i2c_hwdata, },
{ .compatible = "fsl,vf610-i2c", .data = &vf610_i2c_hwdata, },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, i2c_imx_dt_ids);
static const struct acpi_device_id i2c_imx_acpi_ids[] = {
{"NXP0001", .driver_data = (kernel_ulong_t)&vf610_i2c_hwdata},
{ }
};
MODULE_DEVICE_TABLE(acpi, i2c_imx_acpi_ids);
static inline int is_imx1_i2c(struct imx_i2c_struct *i2c_imx)
{
return i2c_imx->hwdata->devtype == IMX1_I2C;
}
static inline int is_vf610_i2c(struct imx_i2c_struct *i2c_imx)
{
return i2c_imx->hwdata->devtype == VF610_I2C;
}
static inline void imx_i2c_write_reg(unsigned int val,
struct imx_i2c_struct *i2c_imx, unsigned int reg)
{
writeb(val, i2c_imx->base + (reg << i2c_imx->hwdata->regshift));
}
static inline unsigned char imx_i2c_read_reg(struct imx_i2c_struct *i2c_imx,
unsigned int reg)
{
return readb(i2c_imx->base + (reg << i2c_imx->hwdata->regshift));
}
static void i2c_imx_clear_irq(struct imx_i2c_struct *i2c_imx, unsigned int bits)
{
unsigned int temp;
/*
* i2sr_clr_opcode is the value to clear all interrupts. Here we want to
* clear only <bits>, so we write ~i2sr_clr_opcode with just <bits>
* toggled. This is required because i.MX needs W0C and Vybrid uses W1C.
*/
temp = ~i2c_imx->hwdata->i2sr_clr_opcode ^ bits;
imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2SR);
}
/* Set up i2c controller register and i2c status register to default value. */
static void i2c_imx_reset_regs(struct imx_i2c_struct *i2c_imx)
{
imx_i2c_write_reg(i2c_imx->hwdata->i2cr_ien_opcode ^ I2CR_IEN,
i2c_imx, IMX_I2C_I2CR);
i2c_imx_clear_irq(i2c_imx, I2SR_IIF | I2SR_IAL);
}
/* Functions for DMA support */
static void i2c_imx_dma_request(struct imx_i2c_struct *i2c_imx,
dma_addr_t phy_addr)
{
struct imx_i2c_dma *dma;
struct dma_slave_config dma_sconfig;
struct device *dev = &i2c_imx->adapter.dev;
int ret;
dma = devm_kzalloc(dev, sizeof(*dma), GFP_KERNEL);
if (!dma)
return;
dma->chan_tx = dma_request_chan(dev, "tx");
if (IS_ERR(dma->chan_tx)) {
ret = PTR_ERR(dma->chan_tx);
if (ret != -ENODEV && ret != -EPROBE_DEFER)
dev_err(dev, "can't request DMA tx channel (%d)\n", ret);
goto fail_al;
}
dma_sconfig.dst_addr = phy_addr +
(IMX_I2C_I2DR << i2c_imx->hwdata->regshift);
dma_sconfig.dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
dma_sconfig.dst_maxburst = 1;
dma_sconfig.direction = DMA_MEM_TO_DEV;
ret = dmaengine_slave_config(dma->chan_tx, &dma_sconfig);
if (ret < 0) {
dev_err(dev, "can't configure tx channel (%d)\n", ret);
goto fail_tx;
}
dma->chan_rx = dma_request_chan(dev, "rx");
if (IS_ERR(dma->chan_rx)) {
ret = PTR_ERR(dma->chan_rx);
if (ret != -ENODEV && ret != -EPROBE_DEFER)
dev_err(dev, "can't request DMA rx channel (%d)\n", ret);
goto fail_tx;
}
dma_sconfig.src_addr = phy_addr +
(IMX_I2C_I2DR << i2c_imx->hwdata->regshift);
dma_sconfig.src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
dma_sconfig.src_maxburst = 1;
dma_sconfig.direction = DMA_DEV_TO_MEM;
ret = dmaengine_slave_config(dma->chan_rx, &dma_sconfig);
if (ret < 0) {
dev_err(dev, "can't configure rx channel (%d)\n", ret);
goto fail_rx;
}
i2c_imx->dma = dma;
init_completion(&dma->cmd_complete);
dev_info(dev, "using %s (tx) and %s (rx) for DMA transfers\n",
dma_chan_name(dma->chan_tx), dma_chan_name(dma->chan_rx));
return;
fail_rx:
dma_release_channel(dma->chan_rx);
fail_tx:
dma_release_channel(dma->chan_tx);
fail_al:
devm_kfree(dev, dma);
}
static void i2c_imx_dma_callback(void *arg)
{
struct imx_i2c_struct *i2c_imx = (struct imx_i2c_struct *)arg;
struct imx_i2c_dma *dma = i2c_imx->dma;
dma_unmap_single(dma->chan_using->device->dev, dma->dma_buf,
dma->dma_len, dma->dma_data_dir);
complete(&dma->cmd_complete);
}
static int i2c_imx_dma_xfer(struct imx_i2c_struct *i2c_imx,
struct i2c_msg *msgs)
{
struct imx_i2c_dma *dma = i2c_imx->dma;
struct dma_async_tx_descriptor *txdesc;
struct device *dev = &i2c_imx->adapter.dev;
struct device *chan_dev = dma->chan_using->device->dev;
dma->dma_buf = dma_map_single(chan_dev, msgs->buf,
dma->dma_len, dma->dma_data_dir);
if (dma_mapping_error(chan_dev, dma->dma_buf)) {
dev_err(dev, "DMA mapping failed\n");
goto err_map;
}
txdesc = dmaengine_prep_slave_single(dma->chan_using, dma->dma_buf,
dma->dma_len, dma->dma_transfer_dir,
DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
if (!txdesc) {
dev_err(dev, "Not able to get desc for DMA xfer\n");
goto err_desc;
}
reinit_completion(&dma->cmd_complete);
txdesc->callback = i2c_imx_dma_callback;
txdesc->callback_param = i2c_imx;
if (dma_submit_error(dmaengine_submit(txdesc))) {
dev_err(dev, "DMA submit failed\n");
goto err_submit;
}
dma_async_issue_pending(dma->chan_using);
return 0;
err_submit:
dmaengine_terminate_sync(dma->chan_using);
err_desc:
dma_unmap_single(chan_dev, dma->dma_buf,
dma->dma_len, dma->dma_data_dir);
err_map:
return -EINVAL;
}
static void i2c_imx_dma_free(struct imx_i2c_struct *i2c_imx)
{
struct imx_i2c_dma *dma = i2c_imx->dma;
dma->dma_buf = 0;
dma->dma_len = 0;
dma_release_channel(dma->chan_tx);
dma->chan_tx = NULL;
dma_release_channel(dma->chan_rx);
dma->chan_rx = NULL;
dma->chan_using = NULL;
}
static int i2c_imx_bus_busy(struct imx_i2c_struct *i2c_imx, int for_busy, bool atomic)
{
unsigned long orig_jiffies = jiffies;
unsigned int temp;
while (1) {
temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR);
/* check for arbitration lost */
if (temp & I2SR_IAL) {
i2c_imx_clear_irq(i2c_imx, I2SR_IAL);
return -EAGAIN;
}
if (for_busy && (temp & I2SR_IBB)) {
i2c_imx->stopped = 0;
break;
}
if (!for_busy && !(temp & I2SR_IBB)) {
i2c_imx->stopped = 1;
break;
}
if (time_after(jiffies, orig_jiffies + msecs_to_jiffies(500))) {
dev_dbg(&i2c_imx->adapter.dev,
"<%s> I2C bus is busy\n", __func__);
return -ETIMEDOUT;
}
if (atomic)
udelay(100);
else
schedule();
}
return 0;
}
static int i2c_imx_trx_complete(struct imx_i2c_struct *i2c_imx, bool atomic)
{
if (atomic) {
void __iomem *addr = i2c_imx->base + (IMX_I2C_I2SR << i2c_imx->hwdata->regshift);
unsigned int regval;
/*
* The formula for the poll timeout is documented in the RM
* Rev.5 on page 1878:
* T_min = 10/F_scl
* Set the value hard as it is done for the non-atomic use-case.
* Use 10 kHz for the calculation since this is the minimum
* allowed SMBus frequency. Also add an offset of 100us since it
* turned out that the I2SR_IIF bit isn't set correctly within
* the minimum timeout in polling mode.
*/
readb_poll_timeout_atomic(addr, regval, regval & I2SR_IIF, 5, 1000 + 100);
i2c_imx->i2csr = regval;
i2c_imx_clear_irq(i2c_imx, I2SR_IIF | I2SR_IAL);
} else {
wait_event_timeout(i2c_imx->queue, i2c_imx->i2csr & I2SR_IIF, HZ / 10);
}
if (unlikely(!(i2c_imx->i2csr & I2SR_IIF))) {
dev_dbg(&i2c_imx->adapter.dev, "<%s> Timeout\n", __func__);
return -ETIMEDOUT;
}
/* check for arbitration lost */
if (i2c_imx->i2csr & I2SR_IAL) {
dev_dbg(&i2c_imx->adapter.dev, "<%s> Arbitration lost\n", __func__);
i2c_imx_clear_irq(i2c_imx, I2SR_IAL);
i2c_imx->i2csr = 0;
return -EAGAIN;
}
dev_dbg(&i2c_imx->adapter.dev, "<%s> TRX complete\n", __func__);
i2c_imx->i2csr = 0;
return 0;
}
static int i2c_imx_acked(struct imx_i2c_struct *i2c_imx)
{
if (imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR) & I2SR_RXAK) {
dev_dbg(&i2c_imx->adapter.dev, "<%s> No ACK\n", __func__);
return -ENXIO; /* No ACK */
}
dev_dbg(&i2c_imx->adapter.dev, "<%s> ACK received\n", __func__);
return 0;
}
static void i2c_imx_set_clk(struct imx_i2c_struct *i2c_imx,
unsigned int i2c_clk_rate)
{
struct imx_i2c_clk_pair *i2c_clk_div = i2c_imx->hwdata->clk_div;
unsigned int div;
int i;
if (i2c_imx->hwdata->has_err007805 && i2c_imx->bitrate > 384000) {
dev_dbg(&i2c_imx->adapter.dev,
"SoC errata ERR007805 or e7805 applies, bus frequency limited from %d Hz to 384000 Hz.\n",
i2c_imx->bitrate);
i2c_imx->bitrate = 384000;
}
/* Divider value calculation */
if (i2c_imx->cur_clk == i2c_clk_rate)
return;
i2c_imx->cur_clk = i2c_clk_rate;
div = DIV_ROUND_UP(i2c_clk_rate, i2c_imx->bitrate);
if (div < i2c_clk_div[0].div)
i = 0;
else if (div > i2c_clk_div[i2c_imx->hwdata->ndivs - 1].div)
i = i2c_imx->hwdata->ndivs - 1;
else
for (i = 0; i2c_clk_div[i].div < div; i++)
;
/* Store divider value */
i2c_imx->ifdr = i2c_clk_div[i].val;
/*
* 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 = DIV_ROUND_UP(500000U * i2c_clk_div[i].div,
i2c_clk_rate / 2);
#ifdef CONFIG_I2C_DEBUG_BUS
dev_dbg(&i2c_imx->adapter.dev, "I2C_CLK=%d, REQ DIV=%d\n",
i2c_clk_rate, div);
dev_dbg(&i2c_imx->adapter.dev, "IFDR[IC]=0x%x, REAL DIV=%d\n",
i2c_clk_div[i].val, i2c_clk_div[i].div);
#endif
}
static int i2c_imx_clk_notifier_call(struct notifier_block *nb,
unsigned long action, void *data)
{
struct clk_notifier_data *ndata = data;
struct imx_i2c_struct *i2c_imx = container_of(nb,
struct imx_i2c_struct,
clk_change_nb);
if (action & POST_RATE_CHANGE)
i2c_imx_set_clk(i2c_imx, ndata->new_rate);
return NOTIFY_OK;
}
static int i2c_imx_start(struct imx_i2c_struct *i2c_imx, bool atomic)
{
unsigned int temp = 0;
int result;
imx_i2c_write_reg(i2c_imx->ifdr, i2c_imx, IMX_I2C_IFDR);
/* Enable I2C controller */
imx_i2c_write_reg(i2c_imx->hwdata->i2sr_clr_opcode, i2c_imx, IMX_I2C_I2SR);
imx_i2c_write_reg(i2c_imx->hwdata->i2cr_ien_opcode, i2c_imx, IMX_I2C_I2CR);
/* Wait controller to be stable */
if (atomic)
udelay(50);
else
usleep_range(50, 150);
/* Start I2C transaction */
temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
temp |= I2CR_MSTA;
imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
result = i2c_imx_bus_busy(i2c_imx, 1, atomic);
if (result)
return result;
temp |= I2CR_IIEN | I2CR_MTX | I2CR_TXAK;
if (atomic)
temp &= ~I2CR_IIEN; /* Disable interrupt */
temp &= ~I2CR_DMAEN;
imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
return result;
}
static void i2c_imx_stop(struct imx_i2c_struct *i2c_imx, bool atomic)
{
unsigned int temp = 0;
if (!i2c_imx->stopped) {
/* Stop I2C transaction */
temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
if (!(temp & I2CR_MSTA))
i2c_imx->stopped = 1;
temp &= ~(I2CR_MSTA | I2CR_MTX);
if (i2c_imx->dma)
temp &= ~I2CR_DMAEN;
imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
}
if (is_imx1_i2c(i2c_imx)) {
/*
* 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(i2c_imx, 0, atomic);
/* Disable I2C controller */
temp = i2c_imx->hwdata->i2cr_ien_opcode ^ I2CR_IEN,
imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
}
/*
* Enable bus idle interrupts
* Note: IBIC register will be cleared after disabled i2c module.
* All of layerscape series SoCs support IBIC register.
*/
static void i2c_imx_enable_bus_idle(struct imx_i2c_struct *i2c_imx)
{
if (is_vf610_i2c(i2c_imx)) {
unsigned int temp;
temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_IBIC);
temp |= IBIC_BIIE;
imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_IBIC);
}
}
static void i2c_imx_slave_event(struct imx_i2c_struct *i2c_imx,
enum i2c_slave_event event, u8 *val)
{
i2c_slave_event(i2c_imx->slave, event, val);
i2c_imx->last_slave_event = event;
}
static void i2c_imx_slave_finish_op(struct imx_i2c_struct *i2c_imx)
{
u8 val = 0;
while (i2c_imx->last_slave_event != I2C_SLAVE_STOP) {
switch (i2c_imx->last_slave_event) {
case I2C_SLAVE_READ_REQUESTED:
i2c_imx_slave_event(i2c_imx, I2C_SLAVE_READ_PROCESSED,
&val);
break;
case I2C_SLAVE_WRITE_REQUESTED:
case I2C_SLAVE_READ_PROCESSED:
case I2C_SLAVE_WRITE_RECEIVED:
i2c_imx_slave_event(i2c_imx, I2C_SLAVE_STOP, &val);
break;
case I2C_SLAVE_STOP:
break;
}
}
}
/* Returns true if the timer should be restarted, false if not. */
static irqreturn_t i2c_imx_slave_handle(struct imx_i2c_struct *i2c_imx,
unsigned int status, unsigned int ctl)
{
u8 value = 0;
if (status & I2SR_IAL) { /* Arbitration lost */
i2c_imx_clear_irq(i2c_imx, I2SR_IAL);
if (!(status & I2SR_IAAS))
return IRQ_HANDLED;
}
if (!(status & I2SR_IBB)) {
/* No master on the bus, that could mean a stop condition. */
i2c_imx_slave_finish_op(i2c_imx);
return IRQ_HANDLED;
}
if (!(status & I2SR_ICF))
/* Data transfer still in progress, ignore this. */
goto out;
if (status & I2SR_IAAS) { /* Addressed as a slave */
i2c_imx_slave_finish_op(i2c_imx);
if (status & I2SR_SRW) { /* Master wants to read from us*/
dev_dbg(&i2c_imx->adapter.dev, "read requested");
i2c_imx_slave_event(i2c_imx,
I2C_SLAVE_READ_REQUESTED, &value);
/* Slave transmit */
ctl |= I2CR_MTX;
imx_i2c_write_reg(ctl, i2c_imx, IMX_I2C_I2CR);
/* Send data */
imx_i2c_write_reg(value, i2c_imx, IMX_I2C_I2DR);
} else { /* Master wants to write to us */
dev_dbg(&i2c_imx->adapter.dev, "write requested");
i2c_imx_slave_event(i2c_imx,
I2C_SLAVE_WRITE_REQUESTED, &value);
/* Slave receive */
ctl &= ~I2CR_MTX;
imx_i2c_write_reg(ctl, i2c_imx, IMX_I2C_I2CR);
/* Dummy read */
imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR);
}
} else if (!(ctl & I2CR_MTX)) { /* Receive mode */
value = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR);
i2c_imx_slave_event(i2c_imx,
I2C_SLAVE_WRITE_RECEIVED, &value);
} else if (!(status & I2SR_RXAK)) { /* Transmit mode received ACK */
ctl |= I2CR_MTX;
imx_i2c_write_reg(ctl, i2c_imx, IMX_I2C_I2CR);
i2c_imx_slave_event(i2c_imx,
I2C_SLAVE_READ_PROCESSED, &value);
imx_i2c_write_reg(value, i2c_imx, IMX_I2C_I2DR);
} else { /* Transmit mode received NAK, operation is done */
ctl &= ~I2CR_MTX;
imx_i2c_write_reg(ctl, i2c_imx, IMX_I2C_I2CR);
imx_i2c_read_reg(i2c_imx, IMX_I2C_I2DR);
/* flag the last byte as processed */
i2c_imx_slave_event(i2c_imx,
I2C_SLAVE_READ_PROCESSED, &value);
i2c_imx_slave_finish_op(i2c_imx);
return IRQ_HANDLED;
}
out:
/*
* No need to check the return value here. If it returns 0 or
* 1, then everything is fine. If it returns -1, then the
* timer is running in the handler. This will still work,
* though it may be redone (or already have been done) by the
* timer function.
*/
hrtimer_try_to_cancel(&i2c_imx->slave_timer);
hrtimer_forward_now(&i2c_imx->slave_timer, I2C_IMX_CHECK_DELAY);
hrtimer_restart(&i2c_imx->slave_timer);
return IRQ_HANDLED;
}
static enum hrtimer_restart i2c_imx_slave_timeout(struct hrtimer *t)
{
struct imx_i2c_struct *i2c_imx = container_of(t, struct imx_i2c_struct,
slave_timer);
unsigned int ctl, status;
unsigned long flags;
spin_lock_irqsave(&i2c_imx->slave_lock, flags);
status = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR);
ctl = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
i2c_imx_slave_handle(i2c_imx, status, ctl);
spin_unlock_irqrestore(&i2c_imx->slave_lock, flags);
return HRTIMER_NORESTART;
}
static void i2c_imx_slave_init(struct imx_i2c_struct *i2c_imx)
{
int temp;
/* Set slave addr. */
imx_i2c_write_reg((i2c_imx->slave->addr << 1), i2c_imx, IMX_I2C_IADR);
i2c_imx_reset_regs(i2c_imx);
/* Enable module */
temp = i2c_imx->hwdata->i2cr_ien_opcode;
imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
/* Enable interrupt from i2c module */
temp |= I2CR_IIEN;
imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
i2c_imx_enable_bus_idle(i2c_imx);
}
static int i2c_imx_reg_slave(struct i2c_client *client)
{
struct imx_i2c_struct *i2c_imx = i2c_get_adapdata(client->adapter);
int ret;
if (i2c_imx->slave)
return -EBUSY;
i2c_imx->slave = client;
i2c_imx->last_slave_event = I2C_SLAVE_STOP;
/* Resume */
ret = pm_runtime_resume_and_get(i2c_imx->adapter.dev.parent);
if (ret < 0) {
dev_err(&i2c_imx->adapter.dev, "failed to resume i2c controller");
return ret;
}
i2c_imx_slave_init(i2c_imx);
return 0;
}
static int i2c_imx_unreg_slave(struct i2c_client *client)
{
struct imx_i2c_struct *i2c_imx = i2c_get_adapdata(client->adapter);
int ret;
if (!i2c_imx->slave)
return -EINVAL;
/* Reset slave address. */
imx_i2c_write_reg(0, i2c_imx, IMX_I2C_IADR);
i2c_imx_reset_regs(i2c_imx);
i2c_imx->slave = NULL;
/* Suspend */
ret = pm_runtime_put_sync(i2c_imx->adapter.dev.parent);
if (ret < 0)
dev_err(&i2c_imx->adapter.dev, "failed to suspend i2c controller");
return ret;
}
static irqreturn_t i2c_imx_master_isr(struct imx_i2c_struct *i2c_imx, unsigned int status)
{
/* save status register */
i2c_imx->i2csr = status;
wake_up(&i2c_imx->queue);
return IRQ_HANDLED;
}
static irqreturn_t i2c_imx_isr(int irq, void *dev_id)
{
struct imx_i2c_struct *i2c_imx = dev_id;
unsigned int ctl, status;
unsigned long flags;
spin_lock_irqsave(&i2c_imx->slave_lock, flags);
status = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR);
ctl = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
if (status & I2SR_IIF) {
i2c_imx_clear_irq(i2c_imx, I2SR_IIF);
if (i2c_imx->slave) {
if (!(ctl & I2CR_MSTA)) {
irqreturn_t ret;
ret = i2c_imx_slave_handle(i2c_imx,
status, ctl);
spin_unlock_irqrestore(&i2c_imx->slave_lock,
flags);
return ret;
}
i2c_imx_slave_finish_op(i2c_imx);
}
spin_unlock_irqrestore(&i2c_imx->slave_lock, flags);
return i2c_imx_master_isr(i2c_imx, status);
}
spin_unlock_irqrestore(&i2c_imx->slave_lock, flags);
return IRQ_NONE;
}
static int i2c_imx_dma_write(struct imx_i2c_struct *i2c_imx,
struct i2c_msg *msgs)
{
int result;
unsigned long time_left;
unsigned int temp = 0;
unsigned long orig_jiffies = jiffies;
struct imx_i2c_dma *dma = i2c_imx->dma;
struct device *dev = &i2c_imx->adapter.dev;
dma->chan_using = dma->chan_tx;
dma->dma_transfer_dir = DMA_MEM_TO_DEV;
dma->dma_data_dir = DMA_TO_DEVICE;
dma->dma_len = msgs->len - 1;
result = i2c_imx_dma_xfer(i2c_imx, msgs);
if (result)
return result;
temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
temp |= I2CR_DMAEN;
imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
/*
* Write slave address.
* The first byte must be transmitted by the CPU.
*/
imx_i2c_write_reg(i2c_8bit_addr_from_msg(msgs), i2c_imx, IMX_I2C_I2DR);
time_left = wait_for_completion_timeout(
&i2c_imx->dma->cmd_complete,
msecs_to_jiffies(DMA_TIMEOUT));
if (time_left == 0) {
dmaengine_terminate_sync(dma->chan_using);
return -ETIMEDOUT;
}
/* Waiting for transfer complete. */
while (1) {
temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2SR);
if (temp & I2SR_ICF)
break;
if (time_after(jiffies, orig_jiffies +
msecs_to_jiffies(DMA_TIMEOUT))) {
dev_dbg(dev, "<%s> Timeout\n", __func__);
return -ETIMEDOUT;
}
schedule();
}
temp = imx_i2c_read_reg(i2c_imx, IMX_I2C_I2CR);
temp &= ~I2CR_DMAEN;
imx_i2c_write_reg(temp, i2c_imx, IMX_I2C_I2CR);
/* The last data byte must be transferred by the CPU. */
imx_i2c_write_reg(msgs->buf[msgs->len-1],