u-boot/drivers/i2c/qup_i2c.c
Sumit Garg 9bdec960b2 i2c: Add support for Qualcomm I2C driver
Add support for Qualcomm I2C QUP driver which is inspired from
corresponding driver in Linux: drivers/i2c/busses/i2c-qup.c.

Currently this driver only support FIFO polling mode which is sufficient
to support devices like eeprom, rtc etc.

Co-developed-by: Mike Worsfold <mworsfold@impinj.com>
Signed-off-by: Mike Worsfold <mworsfold@impinj.com>
Signed-off-by: Sumit Garg <sumit.garg@linaro.org>
2023-02-10 12:50:00 -05:00

579 lines
14 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2009-2013, 2016-2018, The Linux Foundation. All rights reserved.
* Copyright (c) 2014, Sony Mobile Communications AB.
* Copyright (c) 2022-2023, Sumit Garg <sumit.garg@linaro.org>
*
* Inspired by corresponding driver in Linux: drivers/i2c/busses/i2c-qup.c
*/
#include <init.h>
#include <env.h>
#include <common.h>
#include <log.h>
#include <dm/device_compat.h>
#include <linux/delay.h>
#include <linux/errno.h>
#include <linux/err.h>
#include <linux/compat.h>
#include <linux/bitops.h>
#include <asm/io.h>
#include <i2c.h>
#include <watchdog.h>
#include <fdtdec.h>
#include <clk.h>
#include <reset.h>
#include <asm/arch/gpio.h>
#include <cpu_func.h>
#include <asm/system.h>
#include <asm/gpio.h>
#include <dm.h>
#include <dm/pinctrl.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 /* NOT USED */
#define QUP_ERROR_FLAGS_EN 0x020 /* NOT USED */
#define QUP_TEST_CTRL 0x024 /* NOT USED */
#define QUP_OPERATIONAL_MASK 0x028 /* NOT USED */
#define QUP_HW_VERSION 0x030
#define QUP_MX_OUTPUT_CNT 0x100
#define QUP_OUT_DEBUG 0x108 /* NOT USED */
#define QUP_OUT_FIFO_CNT 0x10C /* NOT USED */
#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_READ_CUR 0x20C /* NOT USED */
#define QUP_IN_DEBUG 0x210 /* NOT USED */
#define QUP_IN_FIFO_CNT 0x214 /* NOT USED */
#define QUP_IN_FIFO_BASE 0x218
#define QUP_I2C_CLK_CTL 0x400
#define QUP_I2C_STATUS 0x404 /* NOT USED */
#define QUP_I2C_MASTER_GEN 0x408
#define QUP_I2C_MASTER_BUS_CLR 0x40C /* NOT USED */
/* 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_I2C_FLUSH BIT(6)
#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)
#define OUT_BLOCK_WRITE_REQ BIT(12)
#define IN_BLOCK_READ_REQ BIT(13)
/*
* QUP engine acting as I2C controller is referred to as
* I2C mini core, following are related macros.
*/
#define QUP_NO_OUTPUT BIT(6)
#define QUP_NO_INPUT BIT(7)
#define QUP_CLOCK_AUTO_GATE BIT(13)
#define QUP_I2C_MINI_CORE (2 << 8)
#define QUP_I2C_N_VAL_V2 7
/* Packing/Unpacking words in FIFOs, and IO modes */
#define QUP_OUTPUT_BLK_MODE BIT(10)
#define QUP_OUTPUT_BAM_MODE (BIT(10) | BIT(11))
#define QUP_INPUT_BLK_MODE BIT(12)
#define QUP_INPUT_BAM_MODE (BIT(12) | BIT(13))
#define QUP_BAM_MODE (QUP_OUTPUT_BAM_MODE | QUP_INPUT_BAM_MODE)
#define QUP_BLK_MODE (QUP_OUTPUT_BLK_MODE | QUP_INPUT_BLK_MODE)
#define QUP_UNPACK_EN BIT(14)
#define QUP_PACK_EN BIT(15)
#define QUP_REPACK_EN (QUP_UNPACK_EN | QUP_PACK_EN)
#define QUP_V2_TAGS_EN 1
#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 v2 tags */
#define QUP_TAG_V2_START 0x81
#define QUP_TAG_V2_DATAWR 0x82
#define QUP_TAG_V2_DATAWR_STOP 0x83
#define QUP_TAG_V2_DATARD 0x85
#define QUP_TAG_V2_DATARD_NACK 0x86
#define QUP_TAG_V2_DATARD_STOP 0x87
#define QUP_I2C_MX_CONFIG_DURING_RUN BIT(31)
/* Minimum transfer timeout for i2c transfers in micro seconds */
#define TOUT_CNT (2 * 1000 * 1000)
/* Default values. Use these if FW query fails */
#define DEFAULT_CLK_FREQ I2C_SPEED_STANDARD_RATE
#define DEFAULT_SRC_CLK 19200000
/*
* Max tags length (start, stop and maximum 2 bytes address) for each QUP
* data transfer
*/
#define QUP_MAX_TAGS_LEN 4
/* Max data length for each DATARD tags */
#define RECV_MAX_DATA_LEN 254
/* TAG length for DATA READ in RX FIFO */
#define READ_RX_TAGS_LEN 2
struct qup_i2c_priv {
phys_addr_t base;
struct clk core;
struct clk iface;
u32 in_fifo_sz;
u32 out_fifo_sz;
u32 clk_ctl;
u32 config_run;
};
static inline u8 i2c_8bit_addr_from_msg(const struct i2c_msg *msg)
{
return (msg->addr << 1) | (msg->flags & I2C_M_RD ? 1 : 0);
}
static int qup_i2c_poll_state_mask(struct qup_i2c_priv *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_priv *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_priv *qup)
{
return qup_i2c_poll_state_mask(qup, 0, 0);
}
static int qup_i2c_poll_state_i2c_master(struct qup_i2c_priv *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_priv *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;
}
/*
* Function to check wheather Input or Output FIFO
* has data to be serviced
*/
static int qup_i2c_check_fifo_status(struct qup_i2c_priv *qup, u32 reg_addr,
u32 flags)
{
unsigned long count = TOUT_CNT;
u32 val, status_flag;
int ret = 0;
do {
val = readl(qup->base + reg_addr);
status_flag = val & flags;
if (!count) {
printf("%s, timeout\n", __func__);
ret = -ETIMEDOUT;
break;
}
count--;
udelay(1);
} while (!status_flag);
return ret;
}
/*
* Function to configure Input and Output enable/disable
*/
static void qup_i2c_enable_io_config(struct qup_i2c_priv *qup, u32 write_cnt,
u32 read_cnt)
{
u32 qup_config = QUP_I2C_MINI_CORE | QUP_I2C_N_VAL_V2;
writel(qup->config_run | write_cnt, qup->base + QUP_MX_WRITE_CNT);
if (read_cnt)
writel(qup->config_run | read_cnt, qup->base + QUP_MX_READ_CNT);
else
qup_config |= QUP_NO_INPUT;
writel(qup_config, qup->base + QUP_CONFIG);
}
static unsigned int qup_i2c_read_word(struct qup_i2c_priv *qup)
{
return readl(qup->base + QUP_IN_FIFO_BASE);
}
static void qup_i2c_write_word(struct qup_i2c_priv *qup, u32 word)
{
writel(word, qup->base + QUP_OUT_FIFO_BASE);
}
static int qup_i2c_blsp_read(struct qup_i2c_priv *qup, unsigned int addr,
bool last, u8 *buffer, unsigned int bytes)
{
unsigned int i, j, word;
int ret = 0;
/* FIFO mode size limitation, for larger size implement block mode */
if (bytes > (qup->in_fifo_sz - READ_RX_TAGS_LEN))
return -EINVAL;
qup_i2c_enable_io_config(qup, QUP_MAX_TAGS_LEN,
bytes + READ_RX_TAGS_LEN);
if (last)
qup_i2c_write_word(qup, QUP_TAG_V2_START | addr << 8 |
QUP_TAG_V2_DATARD_STOP << 16 |
bytes << 24);
else
qup_i2c_write_word(qup, QUP_TAG_V2_START | addr << 8 |
QUP_TAG_V2_DATARD << 16 | bytes << 24);
ret = qup_i2c_change_state(qup, QUP_RUN_STATE);
if (ret)
return ret;
ret = qup_i2c_check_fifo_status(qup, QUP_OPERATIONAL, QUP_OUT_SVC_FLAG);
if (ret)
return ret;
writel(QUP_OUT_SVC_FLAG, qup->base + QUP_OPERATIONAL);
ret = qup_i2c_check_fifo_status(qup, QUP_OPERATIONAL, QUP_IN_SVC_FLAG);
if (ret)
return ret;
writel(QUP_IN_SVC_FLAG, qup->base + QUP_OPERATIONAL);
word = qup_i2c_read_word(qup);
*(buffer++) = (word >> (8 * READ_RX_TAGS_LEN)) & 0xff;
if (bytes > 1)
*(buffer++) = (word >> (8 * (READ_RX_TAGS_LEN + 1))) & 0xff;
for (i = 2; i < bytes; i += 4) {
word = qup_i2c_read_word(qup);
for (j = 0; j < 4; j++) {
if ((i + j) == bytes)
break;
*buffer = (word >> (j * 8)) & 0xff;
buffer++;
}
}
ret = qup_i2c_change_state(qup, QUP_PAUSE_STATE);
return ret;
}
static int qup_i2c_blsp_write(struct qup_i2c_priv *qup, unsigned int addr,
bool first, bool last, const u8 *buffer,
unsigned int bytes)
{
unsigned int i;
u32 word = 0;
int ret = 0;
/* FIFO mode size limitation, for larger size implement block mode */
if (bytes > (qup->out_fifo_sz - QUP_MAX_TAGS_LEN))
return -EINVAL;
qup_i2c_enable_io_config(qup, bytes + QUP_MAX_TAGS_LEN, 0);
if (first) {
ret = qup_i2c_change_state(qup, QUP_RUN_STATE);
if (ret)
return ret;
writel(qup->clk_ctl, qup->base + QUP_I2C_CLK_CTL);
ret = qup_i2c_change_state(qup, QUP_PAUSE_STATE);
if (ret)
return ret;
}
if (last)
qup_i2c_write_word(qup, QUP_TAG_V2_START | addr << 8 |
QUP_TAG_V2_DATAWR_STOP << 16 |
bytes << 24);
else
qup_i2c_write_word(qup, QUP_TAG_V2_START | addr << 8 |
QUP_TAG_V2_DATAWR << 16 | bytes << 24);
for (i = 0; i < bytes; i++) {
/* Write the byte of data */
word |= *buffer << ((i % 4) * 8);
if ((i % 4) == 3) {
qup_i2c_write_word(qup, word);
word = 0;
}
buffer++;
}
if ((i % 4) != 0)
qup_i2c_write_word(qup, word);
ret = qup_i2c_change_state(qup, QUP_RUN_STATE);
if (ret)
return ret;
ret = qup_i2c_check_fifo_status(qup, QUP_OPERATIONAL, QUP_OUT_SVC_FLAG);
if (ret)
return ret;
writel(QUP_OUT_SVC_FLAG, qup->base + QUP_OPERATIONAL);
ret = qup_i2c_change_state(qup, QUP_PAUSE_STATE);
return ret;
}
static void qup_i2c_conf_mode_v2(struct qup_i2c_priv *qup)
{
u32 io_mode = QUP_REPACK_EN;
writel(0, qup->base + QUP_MX_OUTPUT_CNT);
writel(0, qup->base + QUP_MX_INPUT_CNT);
writel(io_mode, qup->base + QUP_IO_MODE);
}
static int qup_i2c_xfer_v2(struct udevice *bus, struct i2c_msg msgs[], int num)
{
struct qup_i2c_priv *qup = dev_get_priv(bus);
int ret, idx = 0;
u32 i2c_addr;
writel(1, qup->base + QUP_SW_RESET);
ret = qup_i2c_poll_state(qup, QUP_RESET_STATE);
if (ret)
goto out;
/* Configure QUP as I2C mini core */
writel(QUP_I2C_MINI_CORE | QUP_I2C_N_VAL_V2 | QUP_NO_INPUT,
qup->base + QUP_CONFIG);
writel(QUP_V2_TAGS_EN, qup->base + QUP_I2C_MASTER_GEN);
if (qup_i2c_poll_state_i2c_master(qup)) {
ret = -EIO;
goto out;
}
qup_i2c_conf_mode_v2(qup);
for (idx = 0; idx < num; idx++) {
struct i2c_msg *m = &msgs[idx];
qup->config_run = !idx ? 0 : QUP_I2C_MX_CONFIG_DURING_RUN;
i2c_addr = i2c_8bit_addr_from_msg(m);
if (m->flags & I2C_M_RD)
ret = qup_i2c_blsp_read(qup, i2c_addr, idx == (num - 1),
m->buf, m->len);
else
ret = qup_i2c_blsp_write(qup, i2c_addr, idx == 0,
idx == (num - 1), m->buf,
m->len);
if (ret)
break;
}
out:
qup_i2c_change_state(qup, QUP_RESET_STATE);
return ret;
}
static int qup_i2c_enable_clocks(struct udevice *dev, struct qup_i2c_priv *qup)
{
int ret;
ret = clk_enable(&qup->core);
if (ret) {
dev_err(dev, "clk_enable failed %d\n", ret);
return ret;
}
ret = clk_enable(&qup->iface);
if (ret) {
dev_err(dev, "clk_enable failed %d\n", ret);
return ret;
}
return 0;
}
static int qup_i2c_probe(struct udevice *dev)
{
static const int blk_sizes[] = {4, 16, 32};
struct qup_i2c_priv *qup = dev_get_priv(dev);
u32 io_mode, hw_ver, size, size_idx;
int ret;
qup->base = (phys_addr_t)dev_read_addr_ptr(dev);
if (!qup->base)
return -EINVAL;
ret = clk_get_by_name(dev, "core", &qup->core);
if (ret) {
pr_err("clk_get_by_name(core) failed: %d\n", ret);
return ret;
}
ret = clk_get_by_name(dev, "iface", &qup->iface);
if (ret) {
pr_err("clk_get_by_name(iface) failed: %d\n", ret);
return ret;
}
qup_i2c_enable_clocks(dev, qup);
writel(1, qup->base + QUP_SW_RESET);
ret = qup_i2c_poll_state_valid(qup);
if (ret)
return ret;
hw_ver = readl(qup->base + QUP_HW_VERSION);
dev_dbg(dev, "Revision %x\n", hw_ver);
io_mode = readl(qup->base + QUP_IO_MODE);
/*
* The block/fifo size w.r.t. 'actual data' is 1/2 due to 'tag'
* associated with each byte written/received
*/
size_idx = QUP_OUTPUT_BLOCK_SIZE(io_mode);
if (size_idx >= ARRAY_SIZE(blk_sizes)) {
ret = -EIO;
return ret;
}
size = QUP_OUTPUT_FIFO_SIZE(io_mode);
qup->out_fifo_sz = blk_sizes[size_idx] * (2 << size);
size_idx = QUP_INPUT_BLOCK_SIZE(io_mode);
if (size_idx >= ARRAY_SIZE(blk_sizes)) {
ret = -EIO;
return ret;
}
size = QUP_INPUT_FIFO_SIZE(io_mode);
qup->in_fifo_sz = blk_sizes[size_idx] * (2 << size);
dev_dbg(dev, "IN:fifo:%d, OUT:fifo:%d\n", qup->in_fifo_sz,
qup->out_fifo_sz);
return 0;
}
static int qup_i2c_set_bus_speed(struct udevice *dev, unsigned int clk_freq)
{
struct qup_i2c_priv *qup = dev_get_priv(dev);
unsigned int src_clk_freq;
int fs_div, hs_div;
/* We support frequencies up to FAST Mode Plus (1MHz) */
if (!clk_freq || clk_freq > I2C_SPEED_FAST_PLUS_RATE) {
dev_err(dev, "clock frequency not supported %d\n", clk_freq);
return -EINVAL;
}
src_clk_freq = clk_get_rate(&qup->iface);
if ((int)src_clk_freq < 0) {
src_clk_freq = DEFAULT_SRC_CLK;
dev_dbg(dev, "using default core freq %d\n", src_clk_freq);
}
dev_dbg(dev, "src_clk_freq %u\n", src_clk_freq);
dev_dbg(dev, "clk_freq %u\n", clk_freq);
hs_div = 3;
if (clk_freq <= I2C_SPEED_STANDARD_RATE) {
fs_div = ((src_clk_freq / clk_freq) / 2) - 3;
qup->clk_ctl = (hs_div << 8) | (fs_div & 0xff);
} else {
/* 33%/66% duty cycle */
fs_div = ((src_clk_freq / clk_freq) - 6) * 2 / 3;
qup->clk_ctl = ((fs_div / 2) << 16) | (hs_div << 8) | (fs_div & 0xff);
}
dev_dbg(dev, "clk_ctl %u\n", qup->clk_ctl);
return 0;
}
/* Probe to see if a chip is present. */
static int qup_i2c_probe_chip(struct udevice *dev, uint chip_addr,
uint chip_flags)
{
struct qup_i2c_priv *qup = dev_get_priv(dev);
u32 hw_ver = readl(qup->base + QUP_HW_VERSION);
return hw_ver ? 0 : -1;
}
static const struct dm_i2c_ops qup_i2c_ops = {
.xfer = qup_i2c_xfer_v2,
.probe_chip = qup_i2c_probe_chip,
.set_bus_speed = qup_i2c_set_bus_speed,
};
/*
* Currently this driver only supports v2.x of QUP I2C controller, hence
* functions above are named with a _v2 suffix. So when we have the
* v1.1.1 support added as per the Linux counterpart then it should be easy
* to add corresponding functions named with a _v1 suffix.
*/
static const struct udevice_id qup_i2c_ids[] = {
{ .compatible = "qcom,i2c-qup-v2.1.1" },
{ .compatible = "qcom,i2c-qup-v2.2.1" },
{}
};
U_BOOT_DRIVER(i2c_qup) = {
.name = "i2c_qup",
.id = UCLASS_I2C,
.of_match = qup_i2c_ids,
.probe = qup_i2c_probe,
.priv_auto = sizeof(struct qup_i2c_priv),
.ops = &qup_i2c_ops,
};