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linux/drivers/i2c/busses/i2c-mv64xxx.c
Gregory CLEMENT 1534156e99 i2c: mv64xxx: Fix clock resource by adding an optional bus clock 
On Armada 7K/8K we need to explicitly enable the bus clock. The bus clock
is optional because not all the SoCs need them but at least for Armada
7K/8K it is actually mandatory.

The binding documentation is updating accordingly.

Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-01-26 18:51:03 +01:00

1015 lines
28 KiB
C
Raw Blame History

/*
* Driver for the i2c controller on the Marvell line of host bridges
* (e.g, gt642[46]0, mv643[46]0, mv644[46]0, and Orion SoC family).
*
* Author: Mark A. Greer <mgreer@mvista.com>
*
* 2005 (c) MontaVista, Software, Inc. This file is licensed under
* the terms of the GNU General Public License version 2. This program
* is licensed "as is" without any warranty of any kind, whether express
* or implied.
*/
#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/spinlock.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
#include <linux/mv643xx_i2c.h>
#include <linux/platform_device.h>
#include <linux/reset.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/of_irq.h>
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/delay.h>
#define MV64XXX_I2C_ADDR_ADDR(val) ((val & 0x7f) << 1)
#define MV64XXX_I2C_BAUD_DIV_N(val) (val & 0x7)
#define MV64XXX_I2C_BAUD_DIV_M(val) ((val & 0xf) << 3)
#define MV64XXX_I2C_REG_CONTROL_ACK BIT(2)
#define MV64XXX_I2C_REG_CONTROL_IFLG BIT(3)
#define MV64XXX_I2C_REG_CONTROL_STOP BIT(4)
#define MV64XXX_I2C_REG_CONTROL_START BIT(5)
#define MV64XXX_I2C_REG_CONTROL_TWSIEN BIT(6)
#define MV64XXX_I2C_REG_CONTROL_INTEN BIT(7)
/* Ctlr status values */
#define MV64XXX_I2C_STATUS_BUS_ERR 0x00
#define MV64XXX_I2C_STATUS_MAST_START 0x08
#define MV64XXX_I2C_STATUS_MAST_REPEAT_START 0x10
#define MV64XXX_I2C_STATUS_MAST_WR_ADDR_ACK 0x18
#define MV64XXX_I2C_STATUS_MAST_WR_ADDR_NO_ACK 0x20
#define MV64XXX_I2C_STATUS_MAST_WR_ACK 0x28
#define MV64XXX_I2C_STATUS_MAST_WR_NO_ACK 0x30
#define MV64XXX_I2C_STATUS_MAST_LOST_ARB 0x38
#define MV64XXX_I2C_STATUS_MAST_RD_ADDR_ACK 0x40
#define MV64XXX_I2C_STATUS_MAST_RD_ADDR_NO_ACK 0x48
#define MV64XXX_I2C_STATUS_MAST_RD_DATA_ACK 0x50
#define MV64XXX_I2C_STATUS_MAST_RD_DATA_NO_ACK 0x58
#define MV64XXX_I2C_STATUS_MAST_WR_ADDR_2_ACK 0xd0
#define MV64XXX_I2C_STATUS_MAST_WR_ADDR_2_NO_ACK 0xd8
#define MV64XXX_I2C_STATUS_MAST_RD_ADDR_2_ACK 0xe0
#define MV64XXX_I2C_STATUS_MAST_RD_ADDR_2_NO_ACK 0xe8
#define MV64XXX_I2C_STATUS_NO_STATUS 0xf8
/* Register defines (I2C bridge) */
#define MV64XXX_I2C_REG_TX_DATA_LO 0xc0
#define MV64XXX_I2C_REG_TX_DATA_HI 0xc4
#define MV64XXX_I2C_REG_RX_DATA_LO 0xc8
#define MV64XXX_I2C_REG_RX_DATA_HI 0xcc
#define MV64XXX_I2C_REG_BRIDGE_CONTROL 0xd0
#define MV64XXX_I2C_REG_BRIDGE_STATUS 0xd4
#define MV64XXX_I2C_REG_BRIDGE_INTR_CAUSE 0xd8
#define MV64XXX_I2C_REG_BRIDGE_INTR_MASK 0xdC
#define MV64XXX_I2C_REG_BRIDGE_TIMING 0xe0
/* Bridge Control values */
#define MV64XXX_I2C_BRIDGE_CONTROL_WR BIT(0)
#define MV64XXX_I2C_BRIDGE_CONTROL_RD BIT(1)
#define MV64XXX_I2C_BRIDGE_CONTROL_ADDR_SHIFT 2
#define MV64XXX_I2C_BRIDGE_CONTROL_ADDR_EXT BIT(12)
#define MV64XXX_I2C_BRIDGE_CONTROL_TX_SIZE_SHIFT 13
#define MV64XXX_I2C_BRIDGE_CONTROL_RX_SIZE_SHIFT 16
#define MV64XXX_I2C_BRIDGE_CONTROL_ENABLE BIT(19)
#define MV64XXX_I2C_BRIDGE_CONTROL_REPEATED_START BIT(20)
/* Bridge Status values */
#define MV64XXX_I2C_BRIDGE_STATUS_ERROR BIT(0)
/* Driver states */
enum {
MV64XXX_I2C_STATE_INVALID,
MV64XXX_I2C_STATE_IDLE,
MV64XXX_I2C_STATE_WAITING_FOR_START_COND,
MV64XXX_I2C_STATE_WAITING_FOR_RESTART,
MV64XXX_I2C_STATE_WAITING_FOR_ADDR_1_ACK,
MV64XXX_I2C_STATE_WAITING_FOR_ADDR_2_ACK,
MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_ACK,
MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_DATA,
};
/* Driver actions */
enum {
MV64XXX_I2C_ACTION_INVALID,
MV64XXX_I2C_ACTION_CONTINUE,
MV64XXX_I2C_ACTION_SEND_RESTART,
MV64XXX_I2C_ACTION_SEND_ADDR_1,
MV64XXX_I2C_ACTION_SEND_ADDR_2,
MV64XXX_I2C_ACTION_SEND_DATA,
MV64XXX_I2C_ACTION_RCV_DATA,
MV64XXX_I2C_ACTION_RCV_DATA_STOP,
MV64XXX_I2C_ACTION_SEND_STOP,
};
struct mv64xxx_i2c_regs {
u8 addr;
u8 ext_addr;
u8 data;
u8 control;
u8 status;
u8 clock;
u8 soft_reset;
};
struct mv64xxx_i2c_data {
struct i2c_msg *msgs;
int num_msgs;
int irq;
u32 state;
u32 action;
u32 aborting;
u32 cntl_bits;
void __iomem *reg_base;
struct mv64xxx_i2c_regs reg_offsets;
u32 addr1;
u32 addr2;
u32 bytes_left;
u32 byte_posn;
u32 send_stop;
u32 block;
int rc;
u32 freq_m;
u32 freq_n;
struct clk *clk;
struct clk *reg_clk;
wait_queue_head_t waitq;
spinlock_t lock;
struct i2c_msg *msg;
struct i2c_adapter adapter;
bool offload_enabled;
/* 5us delay in order to avoid repeated start timing violation */
bool errata_delay;
struct reset_control *rstc;
bool irq_clear_inverted;
/* Clk div is 2 to the power n, not 2 to the power n + 1 */
bool clk_n_base_0;
};
static struct mv64xxx_i2c_regs mv64xxx_i2c_regs_mv64xxx = {
.addr = 0x00,
.ext_addr = 0x10,
.data = 0x04,
.control = 0x08,
.status = 0x0c,
.clock = 0x0c,
.soft_reset = 0x1c,
};
static struct mv64xxx_i2c_regs mv64xxx_i2c_regs_sun4i = {
.addr = 0x00,
.ext_addr = 0x04,
.data = 0x08,
.control = 0x0c,
.status = 0x10,
.clock = 0x14,
.soft_reset = 0x18,
};
static void
mv64xxx_i2c_prepare_for_io(struct mv64xxx_i2c_data *drv_data,
struct i2c_msg *msg)
{
u32 dir = 0;
drv_data->cntl_bits = MV64XXX_I2C_REG_CONTROL_ACK |
MV64XXX_I2C_REG_CONTROL_INTEN | MV64XXX_I2C_REG_CONTROL_TWSIEN;
if (msg->flags & I2C_M_RD)
dir = 1;
if (msg->flags & I2C_M_TEN) {
drv_data->addr1 = 0xf0 | (((u32)msg->addr & 0x300) >> 7) | dir;
drv_data->addr2 = (u32)msg->addr & 0xff;
} else {
drv_data->addr1 = MV64XXX_I2C_ADDR_ADDR((u32)msg->addr) | dir;
drv_data->addr2 = 0;
}
}
/*
*****************************************************************************
*
* Finite State Machine & Interrupt Routines
*
*****************************************************************************
*/
/* Reset hardware and initialize FSM */
static void
mv64xxx_i2c_hw_init(struct mv64xxx_i2c_data *drv_data)
{
if (drv_data->offload_enabled) {
writel(0, drv_data->reg_base + MV64XXX_I2C_REG_BRIDGE_CONTROL);
writel(0, drv_data->reg_base + MV64XXX_I2C_REG_BRIDGE_TIMING);
writel(0, drv_data->reg_base +
MV64XXX_I2C_REG_BRIDGE_INTR_CAUSE);
writel(0, drv_data->reg_base +
MV64XXX_I2C_REG_BRIDGE_INTR_MASK);
}
writel(0, drv_data->reg_base + drv_data->reg_offsets.soft_reset);
writel(MV64XXX_I2C_BAUD_DIV_M(drv_data->freq_m) | MV64XXX_I2C_BAUD_DIV_N(drv_data->freq_n),
drv_data->reg_base + drv_data->reg_offsets.clock);
writel(0, drv_data->reg_base + drv_data->reg_offsets.addr);
writel(0, drv_data->reg_base + drv_data->reg_offsets.ext_addr);
writel(MV64XXX_I2C_REG_CONTROL_TWSIEN | MV64XXX_I2C_REG_CONTROL_STOP,
drv_data->reg_base + drv_data->reg_offsets.control);
drv_data->state = MV64XXX_I2C_STATE_IDLE;
}
static void
mv64xxx_i2c_fsm(struct mv64xxx_i2c_data *drv_data, u32 status)
{
/*
* If state is idle, then this is likely the remnants of an old
* operation that driver has given up on or the user has killed.
* If so, issue the stop condition and go to idle.
*/
if (drv_data->state == MV64XXX_I2C_STATE_IDLE) {
drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP;
return;
}
/* The status from the ctlr [mostly] tells us what to do next */
switch (status) {
/* Start condition interrupt */
case MV64XXX_I2C_STATUS_MAST_START: /* 0x08 */
case MV64XXX_I2C_STATUS_MAST_REPEAT_START: /* 0x10 */
drv_data->action = MV64XXX_I2C_ACTION_SEND_ADDR_1;
drv_data->state = MV64XXX_I2C_STATE_WAITING_FOR_ADDR_1_ACK;
break;
/* Performing a write */
case MV64XXX_I2C_STATUS_MAST_WR_ADDR_ACK: /* 0x18 */
if (drv_data->msg->flags & I2C_M_TEN) {
drv_data->action = MV64XXX_I2C_ACTION_SEND_ADDR_2;
drv_data->state =
MV64XXX_I2C_STATE_WAITING_FOR_ADDR_2_ACK;
break;
}
/* FALLTHRU */
case MV64XXX_I2C_STATUS_MAST_WR_ADDR_2_ACK: /* 0xd0 */
case MV64XXX_I2C_STATUS_MAST_WR_ACK: /* 0x28 */
if ((drv_data->bytes_left == 0)
|| (drv_data->aborting
&& (drv_data->byte_posn != 0))) {
if (drv_data->send_stop || drv_data->aborting) {
drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP;
drv_data->state = MV64XXX_I2C_STATE_IDLE;
} else {
drv_data->action =
MV64XXX_I2C_ACTION_SEND_RESTART;
drv_data->state =
MV64XXX_I2C_STATE_WAITING_FOR_RESTART;
}
} else {
drv_data->action = MV64XXX_I2C_ACTION_SEND_DATA;
drv_data->state =
MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_ACK;
drv_data->bytes_left--;
}
break;
/* Performing a read */
case MV64XXX_I2C_STATUS_MAST_RD_ADDR_ACK: /* 40 */
if (drv_data->msg->flags & I2C_M_TEN) {
drv_data->action = MV64XXX_I2C_ACTION_SEND_ADDR_2;
drv_data->state =
MV64XXX_I2C_STATE_WAITING_FOR_ADDR_2_ACK;
break;
}
/* FALLTHRU */
case MV64XXX_I2C_STATUS_MAST_RD_ADDR_2_ACK: /* 0xe0 */
if (drv_data->bytes_left == 0) {
drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP;
drv_data->state = MV64XXX_I2C_STATE_IDLE;
break;
}
/* FALLTHRU */
case MV64XXX_I2C_STATUS_MAST_RD_DATA_ACK: /* 0x50 */
if (status != MV64XXX_I2C_STATUS_MAST_RD_DATA_ACK)
drv_data->action = MV64XXX_I2C_ACTION_CONTINUE;
else {
drv_data->action = MV64XXX_I2C_ACTION_RCV_DATA;
drv_data->bytes_left--;
}
drv_data->state = MV64XXX_I2C_STATE_WAITING_FOR_SLAVE_DATA;
if ((drv_data->bytes_left == 1) || drv_data->aborting)
drv_data->cntl_bits &= ~MV64XXX_I2C_REG_CONTROL_ACK;
break;
case MV64XXX_I2C_STATUS_MAST_RD_DATA_NO_ACK: /* 0x58 */
drv_data->action = MV64XXX_I2C_ACTION_RCV_DATA_STOP;
drv_data->state = MV64XXX_I2C_STATE_IDLE;
break;
case MV64XXX_I2C_STATUS_MAST_WR_ADDR_NO_ACK: /* 0x20 */
case MV64XXX_I2C_STATUS_MAST_WR_NO_ACK: /* 30 */
case MV64XXX_I2C_STATUS_MAST_RD_ADDR_NO_ACK: /* 48 */
/* Doesn't seem to be a device at other end */
drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP;
drv_data->state = MV64XXX_I2C_STATE_IDLE;
drv_data->rc = -ENXIO;
break;
default:
dev_err(&drv_data->adapter.dev,
"mv64xxx_i2c_fsm: Ctlr Error -- state: 0x%x, "
"status: 0x%x, addr: 0x%x, flags: 0x%x\n",
drv_data->state, status, drv_data->msg->addr,
drv_data->msg->flags);
drv_data->action = MV64XXX_I2C_ACTION_SEND_STOP;
mv64xxx_i2c_hw_init(drv_data);
drv_data->rc = -EIO;
}
}
static void mv64xxx_i2c_send_start(struct mv64xxx_i2c_data *drv_data)
{
drv_data->msg = drv_data->msgs;
drv_data->byte_posn = 0;
drv_data->bytes_left = drv_data->msg->len;
drv_data->aborting = 0;
drv_data->rc = 0;
mv64xxx_i2c_prepare_for_io(drv_data, drv_data->msgs);
writel(drv_data->cntl_bits | MV64XXX_I2C_REG_CONTROL_START,
drv_data->reg_base + drv_data->reg_offsets.control);
}
static void
mv64xxx_i2c_do_action(struct mv64xxx_i2c_data *drv_data)
{
switch(drv_data->action) {
case MV64XXX_I2C_ACTION_SEND_RESTART:
/* We should only get here if we have further messages */
BUG_ON(drv_data->num_msgs == 0);
drv_data->msgs++;
drv_data->num_msgs--;
mv64xxx_i2c_send_start(drv_data);
if (drv_data->errata_delay)
udelay(5);
/*
* We're never at the start of the message here, and by this
* time it's already too late to do any protocol mangling.
* Thankfully, do not advertise support for that feature.
*/
drv_data->send_stop = drv_data->num_msgs == 1;
break;
case MV64XXX_I2C_ACTION_CONTINUE:
writel(drv_data->cntl_bits,
drv_data->reg_base + drv_data->reg_offsets.control);
break;
case MV64XXX_I2C_ACTION_SEND_ADDR_1:
writel(drv_data->addr1,
drv_data->reg_base + drv_data->reg_offsets.data);
writel(drv_data->cntl_bits,
drv_data->reg_base + drv_data->reg_offsets.control);
break;
case MV64XXX_I2C_ACTION_SEND_ADDR_2:
writel(drv_data->addr2,
drv_data->reg_base + drv_data->reg_offsets.data);
writel(drv_data->cntl_bits,
drv_data->reg_base + drv_data->reg_offsets.control);
break;
case MV64XXX_I2C_ACTION_SEND_DATA:
writel(drv_data->msg->buf[drv_data->byte_posn++],
drv_data->reg_base + drv_data->reg_offsets.data);
writel(drv_data->cntl_bits,
drv_data->reg_base + drv_data->reg_offsets.control);
break;
case MV64XXX_I2C_ACTION_RCV_DATA:
drv_data->msg->buf[drv_data->byte_posn++] =
readl(drv_data->reg_base + drv_data->reg_offsets.data);
writel(drv_data->cntl_bits,
drv_data->reg_base + drv_data->reg_offsets.control);
break;
case MV64XXX_I2C_ACTION_RCV_DATA_STOP:
drv_data->msg->buf[drv_data->byte_posn++] =
readl(drv_data->reg_base + drv_data->reg_offsets.data);
drv_data->cntl_bits &= ~MV64XXX_I2C_REG_CONTROL_INTEN;
writel(drv_data->cntl_bits | MV64XXX_I2C_REG_CONTROL_STOP,
drv_data->reg_base + drv_data->reg_offsets.control);
drv_data->block = 0;
if (drv_data->errata_delay)
udelay(5);
wake_up(&drv_data->waitq);
break;
case MV64XXX_I2C_ACTION_INVALID:
default:
dev_err(&drv_data->adapter.dev,
"mv64xxx_i2c_do_action: Invalid action: %d\n",
drv_data->action);
drv_data->rc = -EIO;
/* FALLTHRU */
case MV64XXX_I2C_ACTION_SEND_STOP:
drv_data->cntl_bits &= ~MV64XXX_I2C_REG_CONTROL_INTEN;
writel(drv_data->cntl_bits | MV64XXX_I2C_REG_CONTROL_STOP,
drv_data->reg_base + drv_data->reg_offsets.control);
drv_data->block = 0;
wake_up(&drv_data->waitq);
break;
}
}
static void
mv64xxx_i2c_read_offload_rx_data(struct mv64xxx_i2c_data *drv_data,
struct i2c_msg *msg)
{
u32 buf[2];
buf[0] = readl(drv_data->reg_base + MV64XXX_I2C_REG_RX_DATA_LO);
buf[1] = readl(drv_data->reg_base + MV64XXX_I2C_REG_RX_DATA_HI);
memcpy(msg->buf, buf, msg->len);
}
static int
mv64xxx_i2c_intr_offload(struct mv64xxx_i2c_data *drv_data)
{
u32 cause, status;
cause = readl(drv_data->reg_base +
MV64XXX_I2C_REG_BRIDGE_INTR_CAUSE);
if (!cause)
return IRQ_NONE;
status = readl(drv_data->reg_base +
MV64XXX_I2C_REG_BRIDGE_STATUS);
if (status & MV64XXX_I2C_BRIDGE_STATUS_ERROR) {
drv_data->rc = -EIO;
goto out;
}
drv_data->rc = 0;
/*
* Transaction is a one message read transaction, read data
* for this message.
*/
if (drv_data->num_msgs == 1 && drv_data->msgs[0].flags & I2C_M_RD) {
mv64xxx_i2c_read_offload_rx_data(drv_data, drv_data->msgs);
drv_data->msgs++;
drv_data->num_msgs--;
}
/*
* Transaction is a two messages write/read transaction, read
* data for the second (read) message.
*/
else if (drv_data->num_msgs == 2 &&
!(drv_data->msgs[0].flags & I2C_M_RD) &&
drv_data->msgs[1].flags & I2C_M_RD) {
mv64xxx_i2c_read_offload_rx_data(drv_data, drv_data->msgs + 1);
drv_data->msgs += 2;
drv_data->num_msgs -= 2;
}
out:
writel(0, drv_data->reg_base + MV64XXX_I2C_REG_BRIDGE_CONTROL);
writel(0, drv_data->reg_base +
MV64XXX_I2C_REG_BRIDGE_INTR_CAUSE);
drv_data->block = 0;
wake_up(&drv_data->waitq);
return IRQ_HANDLED;
}
static irqreturn_t
mv64xxx_i2c_intr(int irq, void *dev_id)
{
struct mv64xxx_i2c_data *drv_data = dev_id;
unsigned long flags;
u32 status;
irqreturn_t rc = IRQ_NONE;
spin_lock_irqsave(&drv_data->lock, flags);
if (drv_data->offload_enabled)
rc = mv64xxx_i2c_intr_offload(drv_data);
while (readl(drv_data->reg_base + drv_data->reg_offsets.control) &
MV64XXX_I2C_REG_CONTROL_IFLG) {
status = readl(drv_data->reg_base + drv_data->reg_offsets.status);
mv64xxx_i2c_fsm(drv_data, status);
mv64xxx_i2c_do_action(drv_data);
if (drv_data->irq_clear_inverted)
writel(drv_data->cntl_bits | MV64XXX_I2C_REG_CONTROL_IFLG,
drv_data->reg_base + drv_data->reg_offsets.control);
rc = IRQ_HANDLED;
}
spin_unlock_irqrestore(&drv_data->lock, flags);
return rc;
}
/*
*****************************************************************************
*
* I2C Msg Execution Routines
*
*****************************************************************************
*/
static void
mv64xxx_i2c_wait_for_completion(struct mv64xxx_i2c_data *drv_data)
{
long time_left;
unsigned long flags;
char abort = 0;
time_left = wait_event_timeout(drv_data->waitq,
!drv_data->block, drv_data->adapter.timeout);
spin_lock_irqsave(&drv_data->lock, flags);
if (!time_left) { /* Timed out */
drv_data->rc = -ETIMEDOUT;
abort = 1;
} else if (time_left < 0) { /* Interrupted/Error */
drv_data->rc = time_left; /* errno value */
abort = 1;
}
if (abort && drv_data->block) {
drv_data->aborting = 1;
spin_unlock_irqrestore(&drv_data->lock, flags);
time_left = wait_event_timeout(drv_data->waitq,
!drv_data->block, drv_data->adapter.timeout);
if ((time_left <= 0) && drv_data->block) {
drv_data->state = MV64XXX_I2C_STATE_IDLE;
dev_err(&drv_data->adapter.dev,
"mv64xxx: I2C bus locked, block: %d, "
"time_left: %d\n", drv_data->block,
(int)time_left);
mv64xxx_i2c_hw_init(drv_data);
}
} else
spin_unlock_irqrestore(&drv_data->lock, flags);
}
static int
mv64xxx_i2c_execute_msg(struct mv64xxx_i2c_data *drv_data, struct i2c_msg *msg,
int is_last)
{
unsigned long flags;
spin_lock_irqsave(&drv_data->lock, flags);
drv_data->state = MV64XXX_I2C_STATE_WAITING_FOR_START_COND;
drv_data->send_stop = is_last;
drv_data->block = 1;
mv64xxx_i2c_send_start(drv_data);
spin_unlock_irqrestore(&drv_data->lock, flags);
mv64xxx_i2c_wait_for_completion(drv_data);
return drv_data->rc;
}
static void
mv64xxx_i2c_prepare_tx(struct mv64xxx_i2c_data *drv_data)
{
struct i2c_msg *msg = drv_data->msgs;
u32 buf[2];
memcpy(buf, msg->buf, msg->len);
writel(buf[0], drv_data->reg_base + MV64XXX_I2C_REG_TX_DATA_LO);
writel(buf[1], drv_data->reg_base + MV64XXX_I2C_REG_TX_DATA_HI);
}
static int
mv64xxx_i2c_offload_xfer(struct mv64xxx_i2c_data *drv_data)
{
struct i2c_msg *msgs = drv_data->msgs;
int num = drv_data->num_msgs;
unsigned long ctrl_reg;
unsigned long flags;
spin_lock_irqsave(&drv_data->lock, flags);
/* Build transaction */
ctrl_reg = MV64XXX_I2C_BRIDGE_CONTROL_ENABLE |
(msgs[0].addr << MV64XXX_I2C_BRIDGE_CONTROL_ADDR_SHIFT);
if (msgs[0].flags & I2C_M_TEN)
ctrl_reg |= MV64XXX_I2C_BRIDGE_CONTROL_ADDR_EXT;
/* Single write message transaction */
if (num == 1 && !(msgs[0].flags & I2C_M_RD)) {
size_t len = msgs[0].len - 1;
ctrl_reg |= MV64XXX_I2C_BRIDGE_CONTROL_WR |
(len << MV64XXX_I2C_BRIDGE_CONTROL_TX_SIZE_SHIFT);
mv64xxx_i2c_prepare_tx(drv_data);
}
/* Single read message transaction */
else if (num == 1 && msgs[0].flags & I2C_M_RD) {
size_t len = msgs[0].len - 1;
ctrl_reg |= MV64XXX_I2C_BRIDGE_CONTROL_RD |
(len << MV64XXX_I2C_BRIDGE_CONTROL_RX_SIZE_SHIFT);
}
/*
* Transaction with one write and one read message. This is
* guaranteed by the mv64xx_i2c_can_offload() checks.
*/
else if (num == 2) {
size_t lentx = msgs[0].len - 1;
size_t lenrx = msgs[1].len - 1;
ctrl_reg |=
MV64XXX_I2C_BRIDGE_CONTROL_RD |
MV64XXX_I2C_BRIDGE_CONTROL_WR |
(lentx << MV64XXX_I2C_BRIDGE_CONTROL_TX_SIZE_SHIFT) |
(lenrx << MV64XXX_I2C_BRIDGE_CONTROL_RX_SIZE_SHIFT) |
MV64XXX_I2C_BRIDGE_CONTROL_REPEATED_START;
mv64xxx_i2c_prepare_tx(drv_data);
}
/* Execute transaction */
drv_data->block = 1;
writel(ctrl_reg, drv_data->reg_base + MV64XXX_I2C_REG_BRIDGE_CONTROL);
spin_unlock_irqrestore(&drv_data->lock, flags);
mv64xxx_i2c_wait_for_completion(drv_data);
return drv_data->rc;
}
static bool
mv64xxx_i2c_valid_offload_sz(struct i2c_msg *msg)
{
return msg->len <= 8 && msg->len >= 1;
}
static bool
mv64xxx_i2c_can_offload(struct mv64xxx_i2c_data *drv_data)
{
struct i2c_msg *msgs = drv_data->msgs;
int num = drv_data->num_msgs;
if (!drv_data->offload_enabled)
return false;
/*
* We can offload a transaction consisting of a single
* message, as long as the message has a length between 1 and
* 8 bytes.
*/
if (num == 1 && mv64xxx_i2c_valid_offload_sz(msgs))
return true;
/*
* We can offload a transaction consisting of two messages, if
* the first is a write and a second is a read, and both have
* a length between 1 and 8 bytes.
*/
if (num == 2 &&
mv64xxx_i2c_valid_offload_sz(msgs) &&
mv64xxx_i2c_valid_offload_sz(msgs + 1) &&
!(msgs[0].flags & I2C_M_RD) &&
msgs[1].flags & I2C_M_RD)
return true;
return false;
}
/*
*****************************************************************************
*
* I2C Core Support Routines (Interface to higher level I2C code)
*
*****************************************************************************
*/
static u32
mv64xxx_i2c_functionality(struct i2c_adapter *adap)
{
return I2C_FUNC_I2C | I2C_FUNC_10BIT_ADDR | I2C_FUNC_SMBUS_EMUL;
}
static int
mv64xxx_i2c_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num)
{
struct mv64xxx_i2c_data *drv_data = i2c_get_adapdata(adap);
int rc, ret = num;
BUG_ON(drv_data->msgs != NULL);
drv_data->msgs = msgs;
drv_data->num_msgs = num;
if (mv64xxx_i2c_can_offload(drv_data))
rc = mv64xxx_i2c_offload_xfer(drv_data);
else
rc = mv64xxx_i2c_execute_msg(drv_data, &msgs[0], num == 1);
if (rc < 0)
ret = rc;
drv_data->num_msgs = 0;
drv_data->msgs = NULL;
return ret;
}
static const struct i2c_algorithm mv64xxx_i2c_algo = {
.master_xfer = mv64xxx_i2c_xfer,
.functionality = mv64xxx_i2c_functionality,
};
/*
*****************************************************************************
*
* Driver Interface & Early Init Routines
*
*****************************************************************************
*/
static const struct of_device_id mv64xxx_i2c_of_match_table[] = {
{ .compatible = "allwinner,sun4i-a10-i2c", .data = &mv64xxx_i2c_regs_sun4i},
{ .compatible = "allwinner,sun6i-a31-i2c", .data = &mv64xxx_i2c_regs_sun4i},
{ .compatible = "marvell,mv64xxx-i2c", .data = &mv64xxx_i2c_regs_mv64xxx},
{ .compatible = "marvell,mv78230-i2c", .data = &mv64xxx_i2c_regs_mv64xxx},
{ .compatible = "marvell,mv78230-a0-i2c", .data = &mv64xxx_i2c_regs_mv64xxx},
{}
};
MODULE_DEVICE_TABLE(of, mv64xxx_i2c_of_match_table);
#ifdef CONFIG_OF
static int
mv64xxx_calc_freq(struct mv64xxx_i2c_data *drv_data,
const int tclk, const int n, const int m)
{
if (drv_data->clk_n_base_0)
return tclk / (10 * (m + 1) * (1 << n));
else
return tclk / (10 * (m + 1) * (2 << n));
}
static bool
mv64xxx_find_baud_factors(struct mv64xxx_i2c_data *drv_data,
const u32 req_freq, const u32 tclk)
{
int freq, delta, best_delta = INT_MAX;
int m, n;
for (n = 0; n <= 7; n++)
for (m = 0; m <= 15; m++) {
freq = mv64xxx_calc_freq(drv_data, tclk, n, m);
delta = req_freq - freq;
if (delta >= 0 && delta < best_delta) {
drv_data->freq_m = m;
drv_data->freq_n = n;
best_delta = delta;
}
if (best_delta == 0)
return true;
}
if (best_delta == INT_MAX)
return false;
return true;
}
static int
mv64xxx_of_config(struct mv64xxx_i2c_data *drv_data,
struct device *dev)
{
const struct of_device_id *device;
struct device_node *np = dev->of_node;
u32 bus_freq, tclk;
int rc = 0;
/* CLK is mandatory when using DT to describe the i2c bus. We
* need to know tclk in order to calculate bus clock
* factors.
*/
if (IS_ERR(drv_data->clk)) {
rc = -ENODEV;
goto out;
}
tclk = clk_get_rate(drv_data->clk);
if (of_property_read_u32(np, "clock-frequency", &bus_freq))
bus_freq = 100000; /* 100kHz by default */
if (of_device_is_compatible(np, "allwinner,sun4i-a10-i2c") ||
of_device_is_compatible(np, "allwinner,sun6i-a31-i2c"))
drv_data->clk_n_base_0 = true;
if (!mv64xxx_find_baud_factors(drv_data, bus_freq, tclk)) {
rc = -EINVAL;
goto out;
}
drv_data->rstc = devm_reset_control_get_optional_exclusive(dev, NULL);
if (IS_ERR(drv_data->rstc)) {
rc = PTR_ERR(drv_data->rstc);
goto out;
}
reset_control_deassert(drv_data->rstc);
/* Its not yet defined how timeouts will be specified in device tree.
* So hard code the value to 1 second.
*/
drv_data->adapter.timeout = HZ;
device = of_match_device(mv64xxx_i2c_of_match_table, dev);
if (!device)
return -ENODEV;
memcpy(&drv_data->reg_offsets, device->data, sizeof(drv_data->reg_offsets));
/*
* For controllers embedded in new SoCs activate the
* Transaction Generator support and the errata fix.
*/
if (of_device_is_compatible(np, "marvell,mv78230-i2c")) {
drv_data->offload_enabled = true;
drv_data->errata_delay = true;
}
if (of_device_is_compatible(np, "marvell,mv78230-a0-i2c")) {
drv_data->offload_enabled = false;
drv_data->errata_delay = true;
}
if (of_device_is_compatible(np, "allwinner,sun6i-a31-i2c"))
drv_data->irq_clear_inverted = true;
out:
return rc;
}
#else /* CONFIG_OF */
static int
mv64xxx_of_config(struct mv64xxx_i2c_data *drv_data,
struct device *dev)
{
return -ENODEV;
}
#endif /* CONFIG_OF */
static int
mv64xxx_i2c_probe(struct platform_device *pd)
{
struct mv64xxx_i2c_data *drv_data;
struct mv64xxx_i2c_pdata *pdata = dev_get_platdata(&pd->dev);
struct resource *r;
int rc;
if ((!pdata && !pd->dev.of_node))
return -ENODEV;
drv_data = devm_kzalloc(&pd->dev, sizeof(struct mv64xxx_i2c_data),
GFP_KERNEL);
if (!drv_data)
return -ENOMEM;
r = platform_get_resource(pd, IORESOURCE_MEM, 0);
drv_data->reg_base = devm_ioremap_resource(&pd->dev, r);
if (IS_ERR(drv_data->reg_base))
return PTR_ERR(drv_data->reg_base);
strlcpy(drv_data->adapter.name, MV64XXX_I2C_CTLR_NAME " adapter",
sizeof(drv_data->adapter.name));
init_waitqueue_head(&drv_data->waitq);
spin_lock_init(&drv_data->lock);
/* Not all platforms have clocks */
drv_data->clk = devm_clk_get(&pd->dev, NULL);
if (IS_ERR(drv_data->clk) && PTR_ERR(drv_data->clk) == -EPROBE_DEFER)
return -EPROBE_DEFER;
if (!IS_ERR(drv_data->clk))
clk_prepare_enable(drv_data->clk);
drv_data->reg_clk = devm_clk_get(&pd->dev, "reg");
if (IS_ERR(drv_data->reg_clk) &&
PTR_ERR(drv_data->reg_clk) == -EPROBE_DEFER)
return -EPROBE_DEFER;
if (!IS_ERR(drv_data->reg_clk))
clk_prepare_enable(drv_data->reg_clk);
drv_data->irq = platform_get_irq(pd, 0);
if (pdata) {
drv_data->freq_m = pdata->freq_m;
drv_data->freq_n = pdata->freq_n;
drv_data->adapter.timeout = msecs_to_jiffies(pdata->timeout);
drv_data->offload_enabled = false;
memcpy(&drv_data->reg_offsets, &mv64xxx_i2c_regs_mv64xxx, sizeof(drv_data->reg_offsets));
} else if (pd->dev.of_node) {
rc = mv64xxx_of_config(drv_data, &pd->dev);
if (rc)
goto exit_clk;
}
if (drv_data->irq < 0) {
rc = drv_data->irq;
goto exit_reset;
}
drv_data->adapter.dev.parent = &pd->dev;
drv_data->adapter.algo = &mv64xxx_i2c_algo;
drv_data->adapter.owner = THIS_MODULE;
drv_data->adapter.class = I2C_CLASS_DEPRECATED;
drv_data->adapter.nr = pd->id;
drv_data->adapter.dev.of_node = pd->dev.of_node;
platform_set_drvdata(pd, drv_data);
i2c_set_adapdata(&drv_data->adapter, drv_data);
mv64xxx_i2c_hw_init(drv_data);
rc = request_irq(drv_data->irq, mv64xxx_i2c_intr, 0,
MV64XXX_I2C_CTLR_NAME, drv_data);
if (rc) {
dev_err(&drv_data->adapter.dev,
"mv64xxx: Can't register intr handler irq%d: %d\n",
drv_data->irq, rc);
goto exit_reset;
} else if ((rc = i2c_add_numbered_adapter(&drv_data->adapter)) != 0) {
dev_err(&drv_data->adapter.dev,
"mv64xxx: Can't add i2c adapter, rc: %d\n", -rc);
goto exit_free_irq;
}
return 0;
exit_free_irq:
free_irq(drv_data->irq, drv_data);
exit_reset:
reset_control_assert(drv_data->rstc);
exit_clk:
clk_disable_unprepare(drv_data->reg_clk);
clk_disable_unprepare(drv_data->clk);
return rc;
}
static int
mv64xxx_i2c_remove(struct platform_device *dev)
{
struct mv64xxx_i2c_data *drv_data = platform_get_drvdata(dev);
i2c_del_adapter(&drv_data->adapter);
free_irq(drv_data->irq, drv_data);
reset_control_assert(drv_data->rstc);
clk_disable_unprepare(drv_data->reg_clk);
clk_disable_unprepare(drv_data->clk);
return 0;
}
#ifdef CONFIG_PM
static int mv64xxx_i2c_resume(struct device *dev)
{
struct mv64xxx_i2c_data *drv_data = dev_get_drvdata(dev);
mv64xxx_i2c_hw_init(drv_data);
return 0;
}
static const struct dev_pm_ops mv64xxx_i2c_pm = {
.resume = mv64xxx_i2c_resume,
};
#define mv64xxx_i2c_pm_ops (&mv64xxx_i2c_pm)
#else
#define mv64xxx_i2c_pm_ops NULL
#endif
static struct platform_driver mv64xxx_i2c_driver = {
.probe = mv64xxx_i2c_probe,
.remove = mv64xxx_i2c_remove,
.driver = {
.name = MV64XXX_I2C_CTLR_NAME,
.pm = mv64xxx_i2c_pm_ops,
.of_match_table = mv64xxx_i2c_of_match_table,
},
};
module_platform_driver(mv64xxx_i2c_driver);
MODULE_AUTHOR("Mark A. Greer <mgreer@mvista.com>");
MODULE_DESCRIPTION("Marvell mv64xxx host bridge i2c ctlr driver");
MODULE_LICENSE("GPL");
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