diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-mt65xx.c')
| -rw-r--r-- | drivers/i2c/busses/i2c-mt65xx.c | 943 |
1 files changed, 943 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-mt65xx.c b/drivers/i2c/busses/i2c-mt65xx.c new file mode 100644 index 000000000..e09b065a6 --- /dev/null +++ b/drivers/i2c/busses/i2c-mt65xx.c @@ -0,0 +1,943 @@ +/* + * Copyright (c) 2014 MediaTek Inc. + * Author: Xudong Chen <xudong.chen@mediatek.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License 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/completion.h> +#include <linux/delay.h> +#include <linux/device.h> +#include <linux/dma-mapping.h> +#include <linux/err.h> +#include <linux/errno.h> +#include <linux/i2c.h> +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/mm.h> +#include <linux/module.h> +#include <linux/of_address.h> +#include <linux/of_device.h> +#include <linux/of_irq.h> +#include <linux/platform_device.h> +#include <linux/scatterlist.h> +#include <linux/sched.h> +#include <linux/slab.h> + +#define I2C_RS_TRANSFER (1 << 4) +#define I2C_HS_NACKERR (1 << 2) +#define I2C_ACKERR (1 << 1) +#define I2C_TRANSAC_COMP (1 << 0) +#define I2C_TRANSAC_START (1 << 0) +#define I2C_RS_MUL_CNFG (1 << 15) +#define I2C_RS_MUL_TRIG (1 << 14) +#define I2C_DCM_DISABLE 0x0000 +#define I2C_IO_CONFIG_OPEN_DRAIN 0x0003 +#define I2C_IO_CONFIG_PUSH_PULL 0x0000 +#define I2C_SOFT_RST 0x0001 +#define I2C_FIFO_ADDR_CLR 0x0001 +#define I2C_DELAY_LEN 0x0002 +#define I2C_ST_START_CON 0x8001 +#define I2C_FS_START_CON 0x1800 +#define I2C_TIME_CLR_VALUE 0x0000 +#define I2C_TIME_DEFAULT_VALUE 0x0003 +#define I2C_WRRD_TRANAC_VALUE 0x0002 +#define I2C_RD_TRANAC_VALUE 0x0001 + +#define I2C_DMA_CON_TX 0x0000 +#define I2C_DMA_CON_RX 0x0001 +#define I2C_DMA_START_EN 0x0001 +#define I2C_DMA_INT_FLAG_NONE 0x0000 +#define I2C_DMA_CLR_FLAG 0x0000 +#define I2C_DMA_HARD_RST 0x0002 +#define I2C_DMA_4G_MODE 0x0001 + +#define I2C_DEFAULT_CLK_DIV 5 +#define I2C_DEFAULT_SPEED 100000 /* hz */ +#define MAX_FS_MODE_SPEED 400000 +#define MAX_HS_MODE_SPEED 3400000 +#define MAX_SAMPLE_CNT_DIV 8 +#define MAX_STEP_CNT_DIV 64 +#define MAX_HS_STEP_CNT_DIV 8 + +#define I2C_CONTROL_RS (0x1 << 1) +#define I2C_CONTROL_DMA_EN (0x1 << 2) +#define I2C_CONTROL_CLK_EXT_EN (0x1 << 3) +#define I2C_CONTROL_DIR_CHANGE (0x1 << 4) +#define I2C_CONTROL_ACKERR_DET_EN (0x1 << 5) +#define I2C_CONTROL_TRANSFER_LEN_CHANGE (0x1 << 6) +#define I2C_CONTROL_WRAPPER (0x1 << 0) + +#define I2C_DRV_NAME "i2c-mt65xx" + +enum DMA_REGS_OFFSET { + OFFSET_INT_FLAG = 0x0, + OFFSET_INT_EN = 0x04, + OFFSET_EN = 0x08, + OFFSET_RST = 0x0c, + OFFSET_CON = 0x18, + OFFSET_TX_MEM_ADDR = 0x1c, + OFFSET_RX_MEM_ADDR = 0x20, + OFFSET_TX_LEN = 0x24, + OFFSET_RX_LEN = 0x28, + OFFSET_TX_4G_MODE = 0x54, + OFFSET_RX_4G_MODE = 0x58, +}; + +enum i2c_trans_st_rs { + I2C_TRANS_STOP = 0, + I2C_TRANS_REPEATED_START, +}; + +enum mtk_trans_op { + I2C_MASTER_WR = 1, + I2C_MASTER_RD, + I2C_MASTER_WRRD, +}; + +enum I2C_REGS_OFFSET { + OFFSET_DATA_PORT = 0x0, + OFFSET_SLAVE_ADDR = 0x04, + OFFSET_INTR_MASK = 0x08, + OFFSET_INTR_STAT = 0x0c, + OFFSET_CONTROL = 0x10, + OFFSET_TRANSFER_LEN = 0x14, + OFFSET_TRANSAC_LEN = 0x18, + OFFSET_DELAY_LEN = 0x1c, + OFFSET_TIMING = 0x20, + OFFSET_START = 0x24, + OFFSET_EXT_CONF = 0x28, + OFFSET_FIFO_STAT = 0x30, + OFFSET_FIFO_THRESH = 0x34, + OFFSET_FIFO_ADDR_CLR = 0x38, + OFFSET_IO_CONFIG = 0x40, + OFFSET_RSV_DEBUG = 0x44, + OFFSET_HS = 0x48, + OFFSET_SOFTRESET = 0x50, + OFFSET_DCM_EN = 0x54, + OFFSET_PATH_DIR = 0x60, + OFFSET_DEBUGSTAT = 0x64, + OFFSET_DEBUGCTRL = 0x68, + OFFSET_TRANSFER_LEN_AUX = 0x6c, + OFFSET_CLOCK_DIV = 0x70, +}; + +struct mtk_i2c_compatible { + const struct i2c_adapter_quirks *quirks; + unsigned char pmic_i2c: 1; + unsigned char dcm: 1; + unsigned char auto_restart: 1; + unsigned char aux_len_reg: 1; + unsigned char support_33bits: 1; + unsigned char timing_adjust: 1; +}; + +struct mtk_i2c { + struct i2c_adapter adap; /* i2c host adapter */ + struct device *dev; + struct completion msg_complete; + + /* set in i2c probe */ + void __iomem *base; /* i2c base addr */ + void __iomem *pdmabase; /* dma base address*/ + struct clk *clk_main; /* main clock for i2c bus */ + struct clk *clk_dma; /* DMA clock for i2c via DMA */ + struct clk *clk_pmic; /* PMIC clock for i2c from PMIC */ + bool have_pmic; /* can use i2c pins from PMIC */ + bool use_push_pull; /* IO config push-pull mode */ + + u16 irq_stat; /* interrupt status */ + unsigned int clk_src_div; + unsigned int speed_hz; /* The speed in transfer */ + enum mtk_trans_op op; + u16 timing_reg; + u16 high_speed_reg; + unsigned char auto_restart; + bool ignore_restart_irq; + const struct mtk_i2c_compatible *dev_comp; +}; + +static const struct i2c_adapter_quirks mt6577_i2c_quirks = { + .flags = I2C_AQ_COMB_WRITE_THEN_READ, + .max_num_msgs = 1, + .max_write_len = 255, + .max_read_len = 255, + .max_comb_1st_msg_len = 255, + .max_comb_2nd_msg_len = 31, +}; + +static const struct i2c_adapter_quirks mt7622_i2c_quirks = { + .max_num_msgs = 255, +}; + +static const struct mtk_i2c_compatible mt2712_compat = { + .pmic_i2c = 0, + .dcm = 1, + .auto_restart = 1, + .aux_len_reg = 1, + .support_33bits = 1, + .timing_adjust = 1, +}; + +static const struct mtk_i2c_compatible mt6577_compat = { + .quirks = &mt6577_i2c_quirks, + .pmic_i2c = 0, + .dcm = 1, + .auto_restart = 0, + .aux_len_reg = 0, + .support_33bits = 0, + .timing_adjust = 0, +}; + +static const struct mtk_i2c_compatible mt6589_compat = { + .quirks = &mt6577_i2c_quirks, + .pmic_i2c = 1, + .dcm = 0, + .auto_restart = 0, + .aux_len_reg = 0, + .support_33bits = 0, + .timing_adjust = 0, +}; + +static const struct mtk_i2c_compatible mt7622_compat = { + .quirks = &mt7622_i2c_quirks, + .pmic_i2c = 0, + .dcm = 1, + .auto_restart = 1, + .aux_len_reg = 1, + .support_33bits = 0, + .timing_adjust = 0, +}; + +static const struct mtk_i2c_compatible mt8173_compat = { + .pmic_i2c = 0, + .dcm = 1, + .auto_restart = 1, + .aux_len_reg = 1, + .support_33bits = 1, + .timing_adjust = 0, +}; + +static const struct of_device_id mtk_i2c_of_match[] = { + { .compatible = "mediatek,mt2712-i2c", .data = &mt2712_compat }, + { .compatible = "mediatek,mt6577-i2c", .data = &mt6577_compat }, + { .compatible = "mediatek,mt6589-i2c", .data = &mt6589_compat }, + { .compatible = "mediatek,mt7622-i2c", .data = &mt7622_compat }, + { .compatible = "mediatek,mt8173-i2c", .data = &mt8173_compat }, + {} +}; +MODULE_DEVICE_TABLE(of, mtk_i2c_of_match); + +static int mtk_i2c_clock_enable(struct mtk_i2c *i2c) +{ + int ret; + + ret = clk_prepare_enable(i2c->clk_dma); + if (ret) + return ret; + + ret = clk_prepare_enable(i2c->clk_main); + if (ret) + goto err_main; + + if (i2c->have_pmic) { + ret = clk_prepare_enable(i2c->clk_pmic); + if (ret) + goto err_pmic; + } + return 0; + +err_pmic: + clk_disable_unprepare(i2c->clk_main); +err_main: + clk_disable_unprepare(i2c->clk_dma); + + return ret; +} + +static void mtk_i2c_clock_disable(struct mtk_i2c *i2c) +{ + if (i2c->have_pmic) + clk_disable_unprepare(i2c->clk_pmic); + + clk_disable_unprepare(i2c->clk_main); + clk_disable_unprepare(i2c->clk_dma); +} + +static void mtk_i2c_init_hw(struct mtk_i2c *i2c) +{ + u16 control_reg; + + writew(I2C_SOFT_RST, i2c->base + OFFSET_SOFTRESET); + + /* Set ioconfig */ + if (i2c->use_push_pull) + writew(I2C_IO_CONFIG_PUSH_PULL, i2c->base + OFFSET_IO_CONFIG); + else + writew(I2C_IO_CONFIG_OPEN_DRAIN, i2c->base + OFFSET_IO_CONFIG); + + if (i2c->dev_comp->dcm) + writew(I2C_DCM_DISABLE, i2c->base + OFFSET_DCM_EN); + + if (i2c->dev_comp->timing_adjust) + writew(I2C_DEFAULT_CLK_DIV - 1, i2c->base + OFFSET_CLOCK_DIV); + + writew(i2c->timing_reg, i2c->base + OFFSET_TIMING); + writew(i2c->high_speed_reg, i2c->base + OFFSET_HS); + + /* If use i2c pin from PMIC mt6397 side, need set PATH_DIR first */ + if (i2c->have_pmic) + writew(I2C_CONTROL_WRAPPER, i2c->base + OFFSET_PATH_DIR); + + control_reg = I2C_CONTROL_ACKERR_DET_EN | + I2C_CONTROL_CLK_EXT_EN | I2C_CONTROL_DMA_EN; + writew(control_reg, i2c->base + OFFSET_CONTROL); + writew(I2C_DELAY_LEN, i2c->base + OFFSET_DELAY_LEN); + + writel(I2C_DMA_HARD_RST, i2c->pdmabase + OFFSET_RST); + udelay(50); + writel(I2C_DMA_CLR_FLAG, i2c->pdmabase + OFFSET_RST); +} + +/* + * Calculate i2c port speed + * + * Hardware design: + * i2c_bus_freq = parent_clk / (clock_div * 2 * sample_cnt * step_cnt) + * clock_div: fixed in hardware, but may be various in different SoCs + * + * The calculation want to pick the highest bus frequency that is still + * less than or equal to i2c->speed_hz. The calculation try to get + * sample_cnt and step_cn + */ +static int mtk_i2c_calculate_speed(struct mtk_i2c *i2c, unsigned int clk_src, + unsigned int target_speed, + unsigned int *timing_step_cnt, + unsigned int *timing_sample_cnt) +{ + unsigned int step_cnt; + unsigned int sample_cnt; + unsigned int max_step_cnt; + unsigned int base_sample_cnt = MAX_SAMPLE_CNT_DIV; + unsigned int base_step_cnt; + unsigned int opt_div; + unsigned int best_mul; + unsigned int cnt_mul; + + if (target_speed > MAX_HS_MODE_SPEED) + target_speed = MAX_HS_MODE_SPEED; + + if (target_speed > MAX_FS_MODE_SPEED) + max_step_cnt = MAX_HS_STEP_CNT_DIV; + else + max_step_cnt = MAX_STEP_CNT_DIV; + + base_step_cnt = max_step_cnt; + /* Find the best combination */ + opt_div = DIV_ROUND_UP(clk_src >> 1, target_speed); + best_mul = MAX_SAMPLE_CNT_DIV * max_step_cnt; + + /* Search for the best pair (sample_cnt, step_cnt) with + * 0 < sample_cnt < MAX_SAMPLE_CNT_DIV + * 0 < step_cnt < max_step_cnt + * sample_cnt * step_cnt >= opt_div + * optimizing for sample_cnt * step_cnt being minimal + */ + for (sample_cnt = 1; sample_cnt <= MAX_SAMPLE_CNT_DIV; sample_cnt++) { + step_cnt = DIV_ROUND_UP(opt_div, sample_cnt); + cnt_mul = step_cnt * sample_cnt; + if (step_cnt > max_step_cnt) + continue; + + if (cnt_mul < best_mul) { + best_mul = cnt_mul; + base_sample_cnt = sample_cnt; + base_step_cnt = step_cnt; + if (best_mul == opt_div) + break; + } + } + + sample_cnt = base_sample_cnt; + step_cnt = base_step_cnt; + + if ((clk_src / (2 * sample_cnt * step_cnt)) > target_speed) { + /* In this case, hardware can't support such + * low i2c_bus_freq + */ + dev_dbg(i2c->dev, "Unsupported speed (%uhz)\n", target_speed); + return -EINVAL; + } + + *timing_step_cnt = step_cnt - 1; + *timing_sample_cnt = sample_cnt - 1; + + return 0; +} + +static int mtk_i2c_set_speed(struct mtk_i2c *i2c, unsigned int parent_clk) +{ + unsigned int clk_src; + unsigned int step_cnt; + unsigned int sample_cnt; + unsigned int target_speed; + int ret; + + clk_src = parent_clk / i2c->clk_src_div; + target_speed = i2c->speed_hz; + + if (target_speed > MAX_FS_MODE_SPEED) { + /* Set master code speed register */ + ret = mtk_i2c_calculate_speed(i2c, clk_src, MAX_FS_MODE_SPEED, + &step_cnt, &sample_cnt); + if (ret < 0) + return ret; + + i2c->timing_reg = (sample_cnt << 8) | step_cnt; + + /* Set the high speed mode register */ + ret = mtk_i2c_calculate_speed(i2c, clk_src, target_speed, + &step_cnt, &sample_cnt); + if (ret < 0) + return ret; + + i2c->high_speed_reg = I2C_TIME_DEFAULT_VALUE | + (sample_cnt << 12) | (step_cnt << 8); + } else { + ret = mtk_i2c_calculate_speed(i2c, clk_src, target_speed, + &step_cnt, &sample_cnt); + if (ret < 0) + return ret; + + i2c->timing_reg = (sample_cnt << 8) | step_cnt; + + /* Disable the high speed transaction */ + i2c->high_speed_reg = I2C_TIME_CLR_VALUE; + } + + return 0; +} + +static inline u32 mtk_i2c_set_4g_mode(dma_addr_t addr) +{ + return (addr & BIT_ULL(32)) ? I2C_DMA_4G_MODE : I2C_DMA_CLR_FLAG; +} + +static int mtk_i2c_do_transfer(struct mtk_i2c *i2c, struct i2c_msg *msgs, + int num, int left_num) +{ + u16 addr_reg; + u16 start_reg; + u16 control_reg; + u16 restart_flag = 0; + u32 reg_4g_mode; + u8 *dma_rd_buf = NULL; + u8 *dma_wr_buf = NULL; + dma_addr_t rpaddr = 0; + dma_addr_t wpaddr = 0; + int ret; + + i2c->irq_stat = 0; + + if (i2c->auto_restart) + restart_flag = I2C_RS_TRANSFER; + + reinit_completion(&i2c->msg_complete); + + control_reg = readw(i2c->base + OFFSET_CONTROL) & + ~(I2C_CONTROL_DIR_CHANGE | I2C_CONTROL_RS); + if ((i2c->speed_hz > 400000) || (left_num >= 1)) + control_reg |= I2C_CONTROL_RS; + + if (i2c->op == I2C_MASTER_WRRD) + control_reg |= I2C_CONTROL_DIR_CHANGE | I2C_CONTROL_RS; + + writew(control_reg, i2c->base + OFFSET_CONTROL); + + /* set start condition */ + if (i2c->speed_hz <= 100000) + writew(I2C_ST_START_CON, i2c->base + OFFSET_EXT_CONF); + else + writew(I2C_FS_START_CON, i2c->base + OFFSET_EXT_CONF); + + addr_reg = i2c_8bit_addr_from_msg(msgs); + writew(addr_reg, i2c->base + OFFSET_SLAVE_ADDR); + + /* Clear interrupt status */ + writew(restart_flag | I2C_HS_NACKERR | I2C_ACKERR | + I2C_TRANSAC_COMP, i2c->base + OFFSET_INTR_STAT); + writew(I2C_FIFO_ADDR_CLR, i2c->base + OFFSET_FIFO_ADDR_CLR); + + /* Enable interrupt */ + writew(restart_flag | I2C_HS_NACKERR | I2C_ACKERR | + I2C_TRANSAC_COMP, i2c->base + OFFSET_INTR_MASK); + + /* Set transfer and transaction len */ + if (i2c->op == I2C_MASTER_WRRD) { + if (i2c->dev_comp->aux_len_reg) { + writew(msgs->len, i2c->base + OFFSET_TRANSFER_LEN); + writew((msgs + 1)->len, i2c->base + + OFFSET_TRANSFER_LEN_AUX); + } else { + writew(msgs->len | ((msgs + 1)->len) << 8, + i2c->base + OFFSET_TRANSFER_LEN); + } + writew(I2C_WRRD_TRANAC_VALUE, i2c->base + OFFSET_TRANSAC_LEN); + } else { + writew(msgs->len, i2c->base + OFFSET_TRANSFER_LEN); + writew(num, i2c->base + OFFSET_TRANSAC_LEN); + } + + /* Prepare buffer data to start transfer */ + if (i2c->op == I2C_MASTER_RD) { + writel(I2C_DMA_INT_FLAG_NONE, i2c->pdmabase + OFFSET_INT_FLAG); + writel(I2C_DMA_CON_RX, i2c->pdmabase + OFFSET_CON); + + dma_rd_buf = i2c_get_dma_safe_msg_buf(msgs, 1); + if (!dma_rd_buf) + return -ENOMEM; + + rpaddr = dma_map_single(i2c->dev, dma_rd_buf, + msgs->len, DMA_FROM_DEVICE); + if (dma_mapping_error(i2c->dev, rpaddr)) { + i2c_put_dma_safe_msg_buf(dma_rd_buf, msgs, false); + + return -ENOMEM; + } + + if (i2c->dev_comp->support_33bits) { + reg_4g_mode = mtk_i2c_set_4g_mode(rpaddr); + writel(reg_4g_mode, i2c->pdmabase + OFFSET_RX_4G_MODE); + } + + writel((u32)rpaddr, i2c->pdmabase + OFFSET_RX_MEM_ADDR); + writel(msgs->len, i2c->pdmabase + OFFSET_RX_LEN); + } else if (i2c->op == I2C_MASTER_WR) { + writel(I2C_DMA_INT_FLAG_NONE, i2c->pdmabase + OFFSET_INT_FLAG); + writel(I2C_DMA_CON_TX, i2c->pdmabase + OFFSET_CON); + + dma_wr_buf = i2c_get_dma_safe_msg_buf(msgs, 1); + if (!dma_wr_buf) + return -ENOMEM; + + wpaddr = dma_map_single(i2c->dev, dma_wr_buf, + msgs->len, DMA_TO_DEVICE); + if (dma_mapping_error(i2c->dev, wpaddr)) { + i2c_put_dma_safe_msg_buf(dma_wr_buf, msgs, false); + + return -ENOMEM; + } + + if (i2c->dev_comp->support_33bits) { + reg_4g_mode = mtk_i2c_set_4g_mode(wpaddr); + writel(reg_4g_mode, i2c->pdmabase + OFFSET_TX_4G_MODE); + } + + writel((u32)wpaddr, i2c->pdmabase + OFFSET_TX_MEM_ADDR); + writel(msgs->len, i2c->pdmabase + OFFSET_TX_LEN); + } else { + writel(I2C_DMA_CLR_FLAG, i2c->pdmabase + OFFSET_INT_FLAG); + writel(I2C_DMA_CLR_FLAG, i2c->pdmabase + OFFSET_CON); + + dma_wr_buf = i2c_get_dma_safe_msg_buf(msgs, 1); + if (!dma_wr_buf) + return -ENOMEM; + + wpaddr = dma_map_single(i2c->dev, dma_wr_buf, + msgs->len, DMA_TO_DEVICE); + if (dma_mapping_error(i2c->dev, wpaddr)) { + i2c_put_dma_safe_msg_buf(dma_wr_buf, msgs, false); + + return -ENOMEM; + } + + dma_rd_buf = i2c_get_dma_safe_msg_buf((msgs + 1), 1); + if (!dma_rd_buf) { + dma_unmap_single(i2c->dev, wpaddr, + msgs->len, DMA_TO_DEVICE); + + i2c_put_dma_safe_msg_buf(dma_wr_buf, msgs, false); + + return -ENOMEM; + } + + rpaddr = dma_map_single(i2c->dev, dma_rd_buf, + (msgs + 1)->len, + DMA_FROM_DEVICE); + if (dma_mapping_error(i2c->dev, rpaddr)) { + dma_unmap_single(i2c->dev, wpaddr, + msgs->len, DMA_TO_DEVICE); + + i2c_put_dma_safe_msg_buf(dma_wr_buf, msgs, false); + i2c_put_dma_safe_msg_buf(dma_rd_buf, (msgs + 1), false); + + return -ENOMEM; + } + + if (i2c->dev_comp->support_33bits) { + reg_4g_mode = mtk_i2c_set_4g_mode(wpaddr); + writel(reg_4g_mode, i2c->pdmabase + OFFSET_TX_4G_MODE); + + reg_4g_mode = mtk_i2c_set_4g_mode(rpaddr); + writel(reg_4g_mode, i2c->pdmabase + OFFSET_RX_4G_MODE); + } + + writel((u32)wpaddr, i2c->pdmabase + OFFSET_TX_MEM_ADDR); + writel((u32)rpaddr, i2c->pdmabase + OFFSET_RX_MEM_ADDR); + writel(msgs->len, i2c->pdmabase + OFFSET_TX_LEN); + writel((msgs + 1)->len, i2c->pdmabase + OFFSET_RX_LEN); + } + + writel(I2C_DMA_START_EN, i2c->pdmabase + OFFSET_EN); + + if (!i2c->auto_restart) { + start_reg = I2C_TRANSAC_START; + } else { + start_reg = I2C_TRANSAC_START | I2C_RS_MUL_TRIG; + if (left_num >= 1) + start_reg |= I2C_RS_MUL_CNFG; + } + writew(start_reg, i2c->base + OFFSET_START); + + ret = wait_for_completion_timeout(&i2c->msg_complete, + i2c->adap.timeout); + + /* Clear interrupt mask */ + writew(~(restart_flag | I2C_HS_NACKERR | I2C_ACKERR | + I2C_TRANSAC_COMP), i2c->base + OFFSET_INTR_MASK); + + if (i2c->op == I2C_MASTER_WR) { + dma_unmap_single(i2c->dev, wpaddr, + msgs->len, DMA_TO_DEVICE); + + i2c_put_dma_safe_msg_buf(dma_wr_buf, msgs, true); + } else if (i2c->op == I2C_MASTER_RD) { + dma_unmap_single(i2c->dev, rpaddr, + msgs->len, DMA_FROM_DEVICE); + + i2c_put_dma_safe_msg_buf(dma_rd_buf, msgs, true); + } else { + dma_unmap_single(i2c->dev, wpaddr, msgs->len, + DMA_TO_DEVICE); + dma_unmap_single(i2c->dev, rpaddr, (msgs + 1)->len, + DMA_FROM_DEVICE); + + i2c_put_dma_safe_msg_buf(dma_wr_buf, msgs, true); + i2c_put_dma_safe_msg_buf(dma_rd_buf, (msgs + 1), true); + } + + if (ret == 0) { + dev_dbg(i2c->dev, "addr: %x, transfer timeout\n", msgs->addr); + mtk_i2c_init_hw(i2c); + return -ETIMEDOUT; + } + + completion_done(&i2c->msg_complete); + + if (i2c->irq_stat & (I2C_HS_NACKERR | I2C_ACKERR)) { + dev_dbg(i2c->dev, "addr: %x, transfer ACK error\n", msgs->addr); + mtk_i2c_init_hw(i2c); + return -ENXIO; + } + + return 0; +} + +static int mtk_i2c_transfer(struct i2c_adapter *adap, + struct i2c_msg msgs[], int num) +{ + int ret; + int left_num = num; + struct mtk_i2c *i2c = i2c_get_adapdata(adap); + + ret = mtk_i2c_clock_enable(i2c); + if (ret) + return ret; + + i2c->auto_restart = i2c->dev_comp->auto_restart; + + /* checking if we can skip restart and optimize using WRRD mode */ + if (i2c->auto_restart && num == 2) { + if (!(msgs[0].flags & I2C_M_RD) && (msgs[1].flags & I2C_M_RD) && + msgs[0].addr == msgs[1].addr) { + i2c->auto_restart = 0; + } + } + + if (i2c->auto_restart && num >= 2 && i2c->speed_hz > MAX_FS_MODE_SPEED) + /* ignore the first restart irq after the master code, + * otherwise the first transfer will be discarded. + */ + i2c->ignore_restart_irq = true; + else + i2c->ignore_restart_irq = false; + + while (left_num--) { + if (!msgs->buf) { + dev_dbg(i2c->dev, "data buffer is NULL.\n"); + ret = -EINVAL; + goto err_exit; + } + + if (msgs->flags & I2C_M_RD) + i2c->op = I2C_MASTER_RD; + else + i2c->op = I2C_MASTER_WR; + + if (!i2c->auto_restart) { + if (num > 1) { + /* combined two messages into one transaction */ + i2c->op = I2C_MASTER_WRRD; + left_num--; + } + } + + /* always use DMA mode. */ + ret = mtk_i2c_do_transfer(i2c, msgs, num, left_num); + if (ret < 0) + goto err_exit; + + msgs++; + } + /* the return value is number of executed messages */ + ret = num; + +err_exit: + mtk_i2c_clock_disable(i2c); + return ret; +} + +static irqreturn_t mtk_i2c_irq(int irqno, void *dev_id) +{ + struct mtk_i2c *i2c = dev_id; + u16 restart_flag = 0; + u16 intr_stat; + + if (i2c->auto_restart) + restart_flag = I2C_RS_TRANSFER; + + intr_stat = readw(i2c->base + OFFSET_INTR_STAT); + writew(intr_stat, i2c->base + OFFSET_INTR_STAT); + + /* + * when occurs ack error, i2c controller generate two interrupts + * first is the ack error interrupt, then the complete interrupt + * i2c->irq_stat need keep the two interrupt value. + */ + i2c->irq_stat |= intr_stat; + + if (i2c->ignore_restart_irq && (i2c->irq_stat & restart_flag)) { + i2c->ignore_restart_irq = false; + i2c->irq_stat = 0; + writew(I2C_RS_MUL_CNFG | I2C_RS_MUL_TRIG | I2C_TRANSAC_START, + i2c->base + OFFSET_START); + } else { + if (i2c->irq_stat & (I2C_TRANSAC_COMP | restart_flag)) + complete(&i2c->msg_complete); + } + + return IRQ_HANDLED; +} + +static u32 mtk_i2c_functionality(struct i2c_adapter *adap) +{ + return I2C_FUNC_I2C | I2C_FUNC_SMBUS_EMUL; +} + +static const struct i2c_algorithm mtk_i2c_algorithm = { + .master_xfer = mtk_i2c_transfer, + .functionality = mtk_i2c_functionality, +}; + +static int mtk_i2c_parse_dt(struct device_node *np, struct mtk_i2c *i2c) +{ + int ret; + + ret = of_property_read_u32(np, "clock-frequency", &i2c->speed_hz); + if (ret < 0) + i2c->speed_hz = I2C_DEFAULT_SPEED; + + ret = of_property_read_u32(np, "clock-div", &i2c->clk_src_div); + if (ret < 0) + return ret; + + if (i2c->clk_src_div == 0) + return -EINVAL; + + i2c->have_pmic = of_property_read_bool(np, "mediatek,have-pmic"); + i2c->use_push_pull = + of_property_read_bool(np, "mediatek,use-push-pull"); + + return 0; +} + +static int mtk_i2c_probe(struct platform_device *pdev) +{ + int ret = 0; + struct mtk_i2c *i2c; + struct clk *clk; + struct resource *res; + int irq; + + i2c = devm_kzalloc(&pdev->dev, sizeof(*i2c), GFP_KERNEL); + if (!i2c) + return -ENOMEM; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + i2c->base = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(i2c->base)) + return PTR_ERR(i2c->base); + + res = platform_get_resource(pdev, IORESOURCE_MEM, 1); + i2c->pdmabase = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(i2c->pdmabase)) + return PTR_ERR(i2c->pdmabase); + + irq = platform_get_irq(pdev, 0); + if (irq < 0) + return irq; + + init_completion(&i2c->msg_complete); + + i2c->dev_comp = of_device_get_match_data(&pdev->dev); + i2c->adap.dev.of_node = pdev->dev.of_node; + i2c->dev = &pdev->dev; + i2c->adap.dev.parent = &pdev->dev; + i2c->adap.owner = THIS_MODULE; + i2c->adap.algo = &mtk_i2c_algorithm; + i2c->adap.quirks = i2c->dev_comp->quirks; + i2c->adap.timeout = 2 * HZ; + i2c->adap.retries = 1; + + ret = mtk_i2c_parse_dt(pdev->dev.of_node, i2c); + if (ret) + return -EINVAL; + + if (i2c->dev_comp->timing_adjust) + i2c->clk_src_div *= I2C_DEFAULT_CLK_DIV; + + if (i2c->have_pmic && !i2c->dev_comp->pmic_i2c) + return -EINVAL; + + i2c->clk_main = devm_clk_get(&pdev->dev, "main"); + if (IS_ERR(i2c->clk_main)) { + dev_err(&pdev->dev, "cannot get main clock\n"); + return PTR_ERR(i2c->clk_main); + } + + i2c->clk_dma = devm_clk_get(&pdev->dev, "dma"); + if (IS_ERR(i2c->clk_dma)) { + dev_err(&pdev->dev, "cannot get dma clock\n"); + return PTR_ERR(i2c->clk_dma); + } + + clk = i2c->clk_main; + if (i2c->have_pmic) { + i2c->clk_pmic = devm_clk_get(&pdev->dev, "pmic"); + if (IS_ERR(i2c->clk_pmic)) { + dev_err(&pdev->dev, "cannot get pmic clock\n"); + return PTR_ERR(i2c->clk_pmic); + } + clk = i2c->clk_pmic; + } + + strlcpy(i2c->adap.name, I2C_DRV_NAME, sizeof(i2c->adap.name)); + + ret = mtk_i2c_set_speed(i2c, clk_get_rate(clk)); + if (ret) { + dev_err(&pdev->dev, "Failed to set the speed.\n"); + return -EINVAL; + } + + if (i2c->dev_comp->support_33bits) { + ret = dma_set_mask(&pdev->dev, DMA_BIT_MASK(33)); + if (ret) { + dev_err(&pdev->dev, "dma_set_mask return error.\n"); + return ret; + } + } + + ret = mtk_i2c_clock_enable(i2c); + if (ret) { + dev_err(&pdev->dev, "clock enable failed!\n"); + return ret; + } + mtk_i2c_init_hw(i2c); + mtk_i2c_clock_disable(i2c); + + ret = devm_request_irq(&pdev->dev, irq, mtk_i2c_irq, + IRQF_TRIGGER_NONE, I2C_DRV_NAME, i2c); + if (ret < 0) { + dev_err(&pdev->dev, + "Request I2C IRQ %d fail\n", irq); + return ret; + } + + i2c_set_adapdata(&i2c->adap, i2c); + ret = i2c_add_adapter(&i2c->adap); + if (ret) + return ret; + + platform_set_drvdata(pdev, i2c); + + return 0; +} + +static int mtk_i2c_remove(struct platform_device *pdev) +{ + struct mtk_i2c *i2c = platform_get_drvdata(pdev); + + i2c_del_adapter(&i2c->adap); + + return 0; +} + +#ifdef CONFIG_PM_SLEEP +static int mtk_i2c_resume(struct device *dev) +{ + int ret; + struct mtk_i2c *i2c = dev_get_drvdata(dev); + + ret = mtk_i2c_clock_enable(i2c); + if (ret) { + dev_err(dev, "clock enable failed!\n"); + return ret; + } + + mtk_i2c_init_hw(i2c); + + mtk_i2c_clock_disable(i2c); + + return 0; +} +#endif + +static const struct dev_pm_ops mtk_i2c_pm = { + SET_SYSTEM_SLEEP_PM_OPS(NULL, mtk_i2c_resume) +}; + +static struct platform_driver mtk_i2c_driver = { + .probe = mtk_i2c_probe, + .remove = mtk_i2c_remove, + .driver = { + .name = I2C_DRV_NAME, + .pm = &mtk_i2c_pm, + .of_match_table = of_match_ptr(mtk_i2c_of_match), + }, +}; + +module_platform_driver(mtk_i2c_driver); + +MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION("MediaTek I2C Bus Driver"); +MODULE_AUTHOR("Xudong Chen <xudong.chen@mediatek.com>"); |