--- /dev/null
+// 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,
+};
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