/*
* Copyright (c) 2009-2013, The Linux Foundation. All rights reserved.
* Copyright (c) 2014, Sony Mobile Communications AB.
*
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 and
* only version 2 as published by the Free Software Foundation.
*
* 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/clk.h>
#include <linux/delay.h>
#include <linux/err.h>
#include <linux/i2c.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/platform_device.h>
#include <linux/pm_runtime.h>
/* QUP Registers */
#define QUP_CONFIG 0x000
#define QUP_STATE 0x004
#define QUP_IO_MODE 0x008
#define QUP_SW_RESET 0x00c
#define QUP_OPERATIONAL 0x018
#define QUP_ERROR_FLAGS 0x01c
#define QUP_ERROR_FLAGS_EN 0x020
#define QUP_HW_VERSION 0x030
#define QUP_MX_OUTPUT_CNT 0x100
#define QUP_OUT_FIFO_BASE 0x110
#define QUP_MX_WRITE_CNT 0x150
#define QUP_MX_INPUT_CNT 0x200
#define QUP_MX_READ_CNT 0x208
#define QUP_IN_FIFO_BASE 0x218
#define QUP_I2C_CLK_CTL 0x400
#define QUP_I2C_STATUS 0x404
/* QUP States and reset values */
#define QUP_RESET_STATE 0
#define QUP_RUN_STATE 1
#define QUP_PAUSE_STATE 3
#define QUP_STATE_MASK 3
#define QUP_STATE_VALID BIT(2)
#define QUP_I2C_MAST_GEN BIT(4)
#define QUP_OPERATIONAL_RESET 0x000ff0
#define QUP_I2C_STATUS_RESET 0xfffffc
/* QUP OPERATIONAL FLAGS */
#define QUP_I2C_NACK_FLAG BIT(3)
#define QUP_OUT_NOT_EMPTY BIT(4)
#define QUP_IN_NOT_EMPTY BIT(5)
#define QUP_OUT_FULL BIT(6)
#define QUP_OUT_SVC_FLAG BIT(8)
#define QUP_IN_SVC_FLAG BIT(9)
#define QUP_MX_OUTPUT_DONE BIT(10)
#define QUP_MX_INPUT_DONE BIT(11)
/* I2C mini core related values */
#define QUP_CLOCK_AUTO_GATE BIT(13)
#define I2C_MINI_CORE (2 << 8)
#define I2C_N_VAL 15
/* Most significant word offset in FIFO port */
#define QUP_MSW_SHIFT (I2C_N_VAL + 1)
/* Packing/Unpacking words in FIFOs, and IO modes */
#define QUP_OUTPUT_BLK_MODE (1 << 10)
#define QUP_INPUT_BLK_MODE (1 << 12)
#define QUP_UNPACK_EN BIT(14)
#define QUP_PACK_EN BIT(15)
#define QUP_REPACK_EN (QUP_UNPACK_EN | QUP_PACK_EN)
#define QUP_OUTPUT_BLOCK_SIZE(x)(((x) >> 0) & 0x03)
#define QUP_OUTPUT_FIFO_SIZE(x) (((x) >> 2) & 0x07)
#define QUP_INPUT_BLOCK_SIZE(x) (((x) >> 5) & 0x03)
#define QUP_INPUT_FIFO_SIZE(x) (((x) >> 7) & 0x07)
/* QUP tags */
#define QUP_TAG_START (1 << 8)
#define QUP_TAG_DATA (2 << 8)
#define QUP_TAG_STOP (3 << 8)
#define QUP_TAG_REC (4 << 8)
/* Status, Error flags */
#define I2C_STATUS_WR_BUFFER_FULL BIT(0)
#define I2C_STATUS_BUS_ACTIVE BIT(8)
#define I2C_STATUS_ERROR_MASK 0x38000fc
#define QUP_STATUS_ERROR_FLAGS 0x7c
#define QUP_READ_LIMIT 256
struct qup_i2c_dev {
struct device *dev;
void __iomem *base;
int irq;
struct clk *clk;
struct clk *pclk;
struct i2c_adapter adap;
int clk_ctl;
int out_fifo_sz;
int in_fifo_sz;
int out_blk_sz;
int in_blk_sz;
unsigned long one_byte_t;
struct i2c_msg *msg;
/* Current posion in user message buffer */
int pos;
/* I2C protocol errors */
u32 bus_err;
/* QUP core errors */
u32 qup_err;
struct completion xfer;
};
static irqreturn_t qup_i2c_interrupt(int irq, void *dev)
{
struct qup_i2c_dev *qup = dev;
u32 bus_err;
u32 qup_err;
u32 opflags;
bus_err = readl(qup->base + QUP_I2C_STATUS);
qup_err = readl(qup->base + QUP_ERROR_FLAGS);
opflags = readl(qup->base + QUP_OPERATIONAL);
if (!qup->msg) {
/* Clear Error interrupt */
writel(QUP_RESET_STATE, qup->base + QUP_STATE);
return IRQ_HANDLED;
}
bus_err &= I2C_STATUS_ERROR_MASK;
qup_err &= QUP_STATUS_ERROR_FLAGS;
if (qup_err) {
/* Clear Error interrupt */
writel(qup_err, qup->base + QUP_ERROR_FLAGS);
goto done;
}
if (bus_err) {
/* Clear Error interrupt */
writel(QUP_RESET_STATE, qup->base + QUP_STATE);
goto done;
}
if (opflags & QUP_IN_SVC_FLAG)
writel(QUP_IN_SVC_FLAG, qup->base + QUP_OPERATIONAL);
if (opflags & QUP_OUT_SVC_FLAG)
writel(QUP_OUT_SVC_FLAG, qup->base + QUP_OPERATIONAL);
done:
qup->qup_err = qup_err;
qup->bus_err = bus_err;
complete(&qup->xfer);
return IRQ_HANDLED;
}
static int qup_i2c_poll_state_mask(struct qup_i2c_dev *qup,
u32 req_state, u32 req_mask)
{
int retries = 1;
u32 state;
/*
* State transition takes 3 AHB clocks cycles + 3 I2C master clock
* cycles. So retry once after a 1uS delay.
*/
do {
state = readl(qup->base + QUP_STATE);
if (state & QUP_STATE_VALID &&
(state & req_mask) == req_state)
return 0;
udelay(1);
} while (retries--);
return -ETIMEDOUT;
}
static int qup_i2c_poll_state(struct qup_i2c_dev *qup, u32 req_state)
{
return qup_i2c_poll_state_mask(qup, req_state, QUP_STATE_MASK);
}
static int qup_i2c_poll_state_valid(struct qup_i2c_dev *qup)
{
return qup_i2c_poll_state_mask(qup, 0, 0);
}
static int qup_i2c_poll_state_i2c_master(struct qup_i2c_dev *qup)
{
return qup_i2c_poll_state_mask(qup, QUP_I2C_MAST_GEN, QUP_I2C_MAST_GEN);
}
static int qup_i2c_change_state(struct qup_i2c_dev *qup, u32 state)
{
if (qup_i2c_poll_state_valid(qup) != 0)
return -EIO;
writel(state, qup->base + QUP_STATE);
if (qup_i2c_poll_state(qup, state) != 0)
return -EIO;
return 0;
}
static int qup_i2c_wait_writeready(struct qup_i2c_dev *qup)
{
unsigned long timeout;
u32 opflags;
u32 status;
timeout = jiffies + HZ;
for (;;) {
opflags = readl(qup->base + QUP_OPERATIONAL);
status = readl(qup->base + QUP_I2C_STATUS);
if (!(opflags & QUP_OUT_NOT_EMPTY) &&
!(status & I2C_STATUS_BUS_ACTIVE))
return 0;
if (time_after(jiffies, timeout))
return -ETIMEDOUT;
usleep_range(qup->one_byte_t, qup->one_byte_t * 2);
}
}
static void qup_i2c_set_write_mode(struct qup_i2c_dev *qup, struct i2c_msg *msg)
{
/* Number of entries to shift out, including the start */
int total = msg->len + 1;
if (total < qup->out_fifo_sz) {
/* FIFO mode */
writel(QUP_REPACK_EN, qup->base + QUP_IO_MODE);
writel(total, qup->base + QUP_MX_WRITE_CNT);
} else {
/* BLOCK mode (transfer data on chunks) */
writel(QUP_OUTPUT_BLK_MODE | QUP_REPACK_EN,
qup->base + QUP_IO_MODE);
writel(total, qup->base + QUP_MX_OUTPUT_CNT);
}
}
static void qup_i2c_issue_write(struct qup_i2c_dev *qup, struct i2c_msg *msg)
{
u32 addr = msg->addr << 1;
u32 qup_tag;
u32 opflags;
int idx;
u32 val;
if (qup->pos == 0) {
val = QUP_TAG_START | addr;
idx = 1;
} else {
val = 0;
idx = 0;
}
while (qup->pos < msg->len) {
/* Check that there's space in the FIFO for our pair */
opflags = readl(qup->base + QUP_OPERATIONAL);
if (opflags & QUP_OUT_FULL)
break;
if (qup->pos == msg->len - 1)
qup_tag = QUP_TAG_STOP;
else
qup_tag = QUP_TAG_DATA;
if (idx & 1)
val |= (qup_tag | msg->buf[qup->pos]) << QUP_MSW_SHIFT;
else
val = qup_tag | msg->buf[qup->pos];
/* Write out the pair and the last odd value */
if (idx & 1 || qup->pos == msg->len - 1)
writel(val, qup->base + QUP_OUT_FIFO_BASE);
qup->pos++;
idx++;
}
}
static int qup_i2c_write_one(struct qup_i2c_dev *qup, struct i2c_msg *msg)
{
unsigned long left;
int ret;
qup->msg = msg;
qup->pos = 0;
enable_irq(qup->irq);
qup_i2c_set_write_mode(qup, msg);
ret = qup_i2c_change_state(qup, QUP_RUN_STATE);
if (ret)
goto err;
writel(qup->clk_ctl, qup->base + QUP_I2C_CLK_CTL);
do {
ret = qup_i2c_change_state(qup, QUP_PAUSE_STATE);
if (ret)
goto err;
qup_i2c_issue_write(qup, msg);
ret = qup_i2c_change_state(qup, QUP_RUN_STATE);
if (ret)
goto err;
left = wait_for_completion_timeout(&qup->xfer, HZ);
if (!left) {
writel(1, qup->base + QUP_SW_RESET);
ret = -ETIMEDOUT;
goto err;
}
if (qup->bus_err || qup->qup_err) {
if (qup->bus_err & QUP_I2C_NACK_FLAG)
dev_e