// SPDX-License-Identifier: GPL-2.0-only /* * Copyright (c) 2014 MediaTek Inc. * Author: Xudong Chen */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define I2C_RS_TRANSFER (1 << 4) #define I2C_ARB_LOST (1 << 3) #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_TIME_CLR_VALUE 0x0000 #define I2C_TIME_DEFAULT_VALUE 0x0003 #define I2C_WRRD_TRANAC_VALUE 0x0002 #define I2C_RD_TRANAC_VALUE 0x0001 #define I2C_SCL_MIS_COMP_VALUE 0x0000 #define I2C_DMA_CON_TX 0x0000 #define I2C_DMA_CON_RX 0x0001 #define I2C_DMA_ASYNC_MODE 0x0004 #define I2C_DMA_SKIP_CONFIG 0x0010 #define I2C_DMA_DIR_CHANGE 0x0200 #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 MAX_SAMPLE_CNT_DIV 8 #define MAX_STEP_CNT_DIV 64 #define MAX_CLOCK_DIV 256 #define MAX_HS_STEP_CNT_DIV 8 #define I2C_STANDARD_MODE_BUFFER (1000 / 2) #define I2C_FAST_MODE_BUFFER (300 / 2) #define I2C_FAST_MODE_PLUS_BUFFER (20 / 2) #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_DMAACK_EN (0x1 << 8) #define I2C_CONTROL_ASYNC_MODE (0x1 << 9) #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, OFFSET_SLAVE_ADDR, OFFSET_INTR_MASK, OFFSET_INTR_STAT, OFFSET_CONTROL, OFFSET_TRANSFER_LEN, OFFSET_TRANSAC_LEN, OFFSET_DELAY_LEN, OFFSET_TIMING, OFFSET_START, OFFSET_EXT_CONF, OFFSET_FIFO_STAT, OFFSET_FIFO_THRESH, OFFSET_FIFO_ADDR_CLR, OFFSET_IO_CONFIG, OFFSET_RSV_DEBUG, OFFSET_HS, OFFSET_SOFTRESET, OFFSET_DCM_EN, OFFSET_PATH_DIR, OFFSET_DEBUGSTAT, OFFSET_DEBUGCTRL, OFFSET_TRANSFER_LEN_AUX, OFFSET_CLOCK_DIV, OFFSET_LTIMING, OFFSET_SCL_HIGH_LOW_RATIO, OFFSET_HS_SCL_HIGH_LOW_RATIO, OFFSET_SCL_MIS_COMP_POINT, OFFSET_STA_STO_AC_TIMING, OFFSET_HS_STA_STO_AC_TIMING, OFFSET_SDA_TIMING, }; static const u16 mt_i2c_regs_v1[] = { [OFFSET_DATA_PORT] = 0x0, [OFFSET_SLAVE_ADDR] = 0x4, [OFFSET_INTR_MASK] = 0x8, [OFFSET_INTR_STAT] = 0xc, [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, [OFFSET_SCL_HIGH_LOW_RATIO] = 0x74, [OFFSET_HS_SCL_HIGH_LOW_RATIO] = 0x78, [OFFSET_SCL_MIS_COMP_POINT] = 0x7C, [OFFSET_STA_STO_AC_TIMING] = 0x80, [OFFSET_HS_STA_STO_AC_TIMING] = 0x84, [OFFSET_SDA_TIMING] = 0x88, }; static const u16 mt_i2c_regs_v2[] = { [OFFSET_DATA_PORT] = 0x0, [OFFSET_SLAVE_ADDR] = 0x4, [OFFSET_INTR_MASK] = 0x8, [OFFSET_INTR_STAT] = 0xc, [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_LTIMING] = 0x2c, [OFFSET_HS] = 0x30, [OFFSET_IO_CONFIG] = 0x34, [OFFSET_FIFO_ADDR_CLR] = 0x38, [OFFSET_SDA_TIMING] = 0x3c, [OFFSET_TRANSFER_LEN_AUX] = 0x44, [OFFSET_CLOCK_DIV] = 0x48, [OFFSET_SOFTRESET] = 0x50, [OFFSET_SCL_MIS_COMP_POINT] = 0x90, [OFFSET_DEBUGSTAT] = 0xe0, [OFFSET_DEBUGCTRL] = 0xe8, [OFFSET_FIFO_STAT] = 0xf4, [OFFSET_FIFO_THRESH] = 0xf8, [OFFSET_DCM_EN] = 0xf88, }; struct mtk_i2c_compatible { const struct i2c_adapter_quirks *quirks; const u16 *regs; unsigned char pmic_i2c: 1; unsigned char dcm: 1; unsigned char auto_restart: 1; unsigned char aux_len_reg: 1; unsigned char timing_adjust: 1; unsigned char dma_sync: 1; unsigned char ltiming_adjust: 1; unsigned char apdma_sync: 1; unsigned char max_dma_support; }; struct mtk_i2c_ac_timing { u16 htiming; u16 ltiming; u16 hs; u16 ext; u16 inter_clk_div; u16 scl_hl_ratio; u16 hs_scl_hl_ratio; u16 sta_stop; u16 hs_sta_stop; u16 sda_timing; }; 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 */ struct clk *clk_arb; /* Arbitrator clock for i2c */ 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; u16 ltiming_reg; unsigned char auto_restart; bool ignore_restart_irq; struct mtk_i2c_ac_timing ac_timing; const struct mtk_i2c_compatible *dev_comp; }; /** * struct i2c_spec_values: * @min_low_ns: min LOW period of the SCL clock * @min_su_sta_ns: min set-up time for a repeated START condition * @max_hd_dat_ns: max data hold time * @min_su_dat_ns: min data set-up time */ struct i2c_spec_values { unsigned int min_low_ns; unsigned int min_su_sta_ns; unsigned int max_hd_dat_ns; unsigned int min_su_dat_ns; }; static const struct i2c_spec_values standard_mode_spec = { .min_low_ns = 4700 + I2C_STANDARD_MODE_BUFFER, .min_su_sta_ns = 4700 + I2C_STANDARD_MODE_BUFFER, .max_hd_dat_ns = 3450 - I2C_STANDARD_MODE_BUFFER, .min_su_dat_ns = 250 + I2C_STANDARD_MODE_BUFFER, }; static const struct i2c_spec_values fast_mode_spec = { .min_low_ns = 1300 + I2C_FAST_MODE_BUFFER, .min_su_sta_ns = 600 + I2C_FAST_MODE_BUFFER, .max_hd_dat_ns = 900 - I2C_FAST_MODE_BUFFER, .min_su_dat_ns = 100 + I2C_FAST_MODE_BUFFER, }; static const struct i2c_spec_values fast_mode_plus_spec = { .min_low_ns = 500 + I2C_FAST_MODE_PLUS_BUFFER, .min_su_sta_ns = 260 + I2C_FAST_MODE_PLUS_BUFFER, .max_hd_dat_ns = 400 - I2C_FAST_MODE_PLUS_BUFFER, .min_su_dat_ns = 50 + I2C_FAST_MODE_PLUS_BUFFER, }; 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 i2c_adapter_quirks mt8183_i2c_quirks = { .flags = I2C_AQ_NO_ZERO_LEN, }; static const struct mtk_i2c_compatible mt2712_compat = { .regs = mt_i2c_regs_v1, .pmic_i2c = 0, .dcm = 1, .auto_restart = 1, .aux_len_reg = 1, .timing_adjust = 1, .dma_sync = 0, .ltiming_adjust = 0, .apdma_sync = 0, .max_dma_support = 33, }; static const struct mtk_i2c_compatible mt6577_compat = { .quirks = &mt6577_i2c_quirks, .regs = mt_i2c_regs_v1, .pmic_i2c = 0, .dcm = 1, .auto_restart = 0, .aux_len_reg = 0, .timing_adjust = 0, .dma_sync = 0, .ltiming_adjust = 0, .apdma_sync = 0, .max_dma_support = 32, }; static const struct mtk_i2c_compatible mt6589_compat = { .quirks = &mt6577_i2c_quirks, .regs = mt_i2c_regs_v1, .pmic_i2c = 1, .dcm = 0, .auto_restart = 0, .aux_len_reg = 0, .timing_adjust = 0, .dma_sync = 0, .ltiming_adjust = 0, .apdma_sync = 0, .max_dma_support = 32, }; static const struct mtk_i2c_compatible mt7622_compat = { .quirks = &mt7622_i2c_quirks, .regs = mt_i2c_regs_v1, .pmic_i2c = 0, .dcm = 1, .auto_restart = 1, .aux_len_reg = 1, .timing_adjust = 0, .dma_sync = 0, .ltiming_adjust = 0, .apdma_sync = 0, .max_dma_support = 32, }; static const struct mtk_i2c_compatible mt8173_compat = { .regs = mt_i2c_regs_v1, .pmic_i2c = 0, .dcm = 1, .auto_restart = 1, .aux_len_reg = 1, .timing_adjust = 0, .dma_sync = 0, .ltiming_adjust = 0, .apdma_sync = 0, .max_dma_support = 33, }; static const struct mtk_i2c_compatible mt8183_compat = { .quirks = &mt8183_i2c_quirks, .regs = mt_i2c_regs_v2, .pmic_i2c = 0, .dcm = 0, .auto_restart = 1, .aux_len_reg = 1, .timing_adjust = 1, .dma_sync = 1, .ltiming_adjust = 1, .apdma_sync = 0, .max_dma_support = 33, }; static const struct mtk_i2c_compatible mt8192_compat = { .quirks = &mt8183_i2c_quirks, .regs = mt_i2c_regs_v2, .pmic_i2c = 0, .dcm = 0, .auto_restart = 1, .aux_len_reg = 1, .timing_adjust = 1, .dma_sync = 1, .ltiming_adjust = 1, .apdma_sync = 1, .max_dma_support = 36, }; 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 }, { .compatible = "mediatek,mt8183-i2c", .data = &mt8183_compat }, { .compatible = "mediatek,mt8192-i2c", .data = &mt8192_compat }, {} }; MODULE_DEVICE_TABLE(of, mtk_i2c_of_match); static u16 mtk_i2c_readw(struct mtk_i2c *i2c, enum I2C_REGS_OFFSET reg) { return readw(i2c->base + i2c->dev_comp->regs[reg]); } static void mtk_i2c_writew(struct mtk_i2c *i2c, u16 val, enum I2C_REGS_OFFSET reg) { writew(val, i2c->base + i2c->dev_comp->regs[reg]); } 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; } if (i2c->clk_arb) { ret = clk_prepare_enable(i2c->clk_arb); if (ret) goto err_arb; } return 0; err_arb: if (i2c->have_pmic) clk_disable_unprepare(i2c->clk_pmic); 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->clk_arb) clk_disable_unprepare(i2c->clk_arb); 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; mtk_i2c_writew(i2c, I2C_SOFT_RST, OFFSET_SOFTRESET); /* Set ioconfig */ if (i2c->use_push_pull) mtk_i2c_writew(i2c, I2C_IO_CONFIG_PUSH_PULL, OFFSET_IO_CONFIG); else mtk_i2c_writew(i2c, I2C_IO_CONFIG_OPEN_DRAIN, OFFSET_IO_CONFIG); if (i2c->dev_comp->dcm) mtk_i2c_writew(i2c, I2C_DCM_DISABLE, OFFSET_DCM_EN); mtk_i2c_writew(i2c, i2c->timing_reg, OFFSET_TIMING); mtk_i2c_writew(i2c, i2c->high_speed_reg, OFFSET_HS); if (i2c->dev_comp->ltiming_adjust) mtk_i2c_writew(i2c, i2c->ltiming_reg, OFFSET_LTIMING); if (i2c->dev_comp->timing_adjust) { mtk_i2c_writew(i2c, i2c->ac_timing.ext, OFFSET_EXT_CONF); mtk_i2c_writew(i2c, i2c->ac_timing.inter_clk_div, OFFSET_CLOCK_DIV); mtk_i2c_writew(i2c, I2C_SCL_MIS_COMP_VALUE, OFFSET_SCL_MIS_COMP_POINT); mtk_i2c_writew(i2c, i2c->ac_timing.sda_timing, OFFSET_SDA_TIMING); if (i2c->dev_comp->ltiming_adjust) { mtk_i2c_writew(i2c, i2c->ac_timing.htiming, OFFSET_TIMING); mtk_i2c_writew(i2c, i2c->ac_timing.hs, OFFSET_HS); mtk_i2c_writew(i2c, i2c->ac_timing.ltiming, OFFSET_LTIMING); } else { mtk_i2c_writew(i2c, i2c->ac_timing.scl_hl_ratio, OFFSET_SCL_HIGH_LOW_RATIO); mtk_i2c_writew(i2c, i2c->ac_timing.hs_scl_hl_ratio, OFFSET_HS_SCL_HIGH_LOW_RATIO); mtk_i2c_writew(i2c, i2c->ac_timing.sta_stop, OFFSET_STA_STO_AC_TIMING); mtk_i2c_writew(i2c, i2c->ac_timing.hs_sta_stop, OFFSET_HS_STA_STO_AC_TIMING); } } /* If use i2c pin from PMIC mt6397 side, need set PATH_DIR first */ if (i2c->have_pmic) mtk_i2c_writew(i2c, I2C_CONTROL_WRAPPER, OFFSET_PATH_DIR); control_reg = I2C_CONTROL_ACKERR_DET_EN | I2C_CONTROL_CLK_EXT_EN | I2C_CONTROL_DMA_EN; if (i2c->dev_comp->dma_sync) control_reg |= I2C_CONTROL_DMAACK_EN | I2C_CONTROL_ASYNC_MODE; mtk_i2c_writew(i2c, control_reg, OFFSET_CONTROL); mtk_i2c_writew(i2c, I2C_DELAY_LEN, OFFSET_DELAY_LEN); writel(I2C_DMA_HARD_RST, i2c->pdmabase + OFFSET_RST); udelay(50); writel(I2C_DMA_CLR_FLAG, i2c->pdmabase + OFFSET_RST); } static const struct i2c_spec_values *mtk_i2c_get_spec(unsigned int speed) { if (speed <= I2C_MAX_STANDARD_MODE_FREQ) return &standard_mode_spec; else if (speed <= I2C_MAX_FAST_MODE_FREQ) return &fast_mode_spec; else return &fast_mode_plus_spec; } static int mtk_i2c_max_step_cnt(unsigned int target_speed) { if (target_speed > I2C_MAX_FAST_MODE_FREQ) return MAX_HS_STEP_CNT_DIV; else return MAX_STEP_CNT_DIV; } /* * Check and Calculate i2c ac-timing * * Hardware design: * sample_ns = (1000000000 * (sample_cnt + 1)) / clk_src * xxx_cnt_div = spec->min_xxx_ns / sample_ns * * Sample_ns is rounded down for xxx_cnt_div would be greater * than the smallest spec. * The sda_timing is chosen as the middle value between * the largest and smallest. */ static int mtk_i2c_check_ac_timing(struct mtk_i2c *i2c, unsigned int clk_src, unsigned int check_speed, unsigned int step_cnt, unsigned int sample_cnt) { const struct i2c_spec_values *spec; unsigned int su_sta_cnt, low_cnt, high_cnt, max_step_cnt; unsigned int sda_max, sda_min, clk_ns, max_sta_cnt = 0x3f; unsigned int sample_ns = div_u64(1000000000ULL * (sample_cnt + 1), clk_src); if (!i2c->dev_comp->timing_adjust) return 0; if (i2c->dev_comp->ltiming_adjust) max_sta_cnt = 0x100; spec = mtk_i2c_get_spec(check_speed); if (i2c->dev_comp->ltiming_adjust) clk_ns = 1000000000 / clk_src; else clk_ns = sample_ns / 2; su_sta_cnt = DIV_ROUND_UP(spec->min_su_sta_ns, clk_ns); if (su_sta_cnt > max_sta_cnt) return -1; low_cnt = DIV_ROUND_UP(spec->min_low_ns, sample_ns); max_step_cnt = mtk_i2c_max_step_cnt(check_speed); if ((2 * step_cnt) > low_cnt && low_cnt < max_step_cnt) { if (low_cnt > step_cnt) { high_cnt = 2 * step_cnt - low_cnt; } else { high_cnt = step_cnt; low_cnt = step_cnt; } } else { return -2; } sda_max = spec->max_hd_dat_ns / sample_ns; if (sda_max > low_cnt) sda_max = 0; sda_min = DIV_ROUND_UP(spec->min_su_dat_ns, sample_ns); if (sda_min < low_cnt) sda_min = 0; if (sda_min > sda_max) return -3; if (check_speed > I2C_MAX_FAST_MODE_FREQ) { if (i2c->dev_comp->ltiming_adjust) { i2c->ac_timing.hs = I2C_TIME_DEFAULT_VALUE | (sample_cnt << 12) | (high_cnt << 8); i2c->ac_timing.ltiming &= ~GENMASK(15, 9); i2c->ac_timing.ltiming |= (sample_cnt << 12) | (low_cnt << 9); i2c->ac_timing.ext &= ~GENMASK(7, 1); i2c->ac_timing.ext |= (su_sta_cnt << 1) | (1 << 0); } else { i2c->ac_timing.hs_scl_hl_ratio = (1 << 12) | (high_cnt << 6) | low_cnt; i2c->ac_timing.hs_sta_stop = (su_sta_cnt << 8) | su_sta_cnt; } i2c->ac_timing.sda_timing &= ~GENMASK(11, 6); i2c->ac_timing.sda_timing |= (1 << 12) | ((sda_max + sda_min) / 2) << 6; } else { if (i2c->dev_comp->ltiming_adjust) { i2c->ac_timing.htiming = (sample_cnt << 8) | (high_cnt); i2c->ac_timing.ltiming = (sample_cnt << 6) | (low_cnt); i2c->ac_timing.ext = (su_sta_cnt << 8) | (1 << 0); } else { i2c->ac_timing.scl_hl_ratio = (1 << 12) | (high_cnt << 6) | low_cnt; i2c->ac_timing.sta_stop = (su_sta_cnt << 8) | su_sta_cnt; } i2c->ac_timing.sda_timing = (1 << 12) | (sda_max + sda_min) / 2; } return 0; } /* * 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; int ret = -EINVAL; if (target_speed > I2C_MAX_FAST_MODE_PLUS_FREQ) target_speed = I2C_MAX_FAST_MODE_PLUS_FREQ; max_step_cnt = mtk_i2c_max_step_cnt(target_speed); 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) { ret = mtk_i2c_check_ac_timing(i2c, clk_src, target_speed, step_cnt - 1, sample_cnt - 1); if (ret) continue; best_mul = cnt_mul; base_sample_cnt = sample_cnt; base_step_cnt = step_cnt; if (best_mul == opt_div) break; } } if (ret) return -EINVAL; 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 l_step_cnt; unsigned int l_sample_cnt; unsigned int target_speed; unsigned int clk_div; unsigned int max_clk_div; int ret; target_speed = i2c->speed_hz; parent_clk /= i2c->clk_src_div; if (i2c->dev_comp->timing_adjust) max_clk_div = MAX_CLOCK_DIV; else max_clk_div = 1; for (clk_div = 1; clk_div <= max_clk_div; clk_div++) { clk_src = parent_clk / clk_div; if (target_speed > I2C_MAX_FAST_MODE_FREQ) { /* Set master code speed register */ ret = mtk_i2c_calculate_speed(i2c, clk_src, I2C_MAX_FAST_MODE_FREQ, &l_step_cnt, &l_sample_cnt); if (ret < 0) continue; i2c->timing_reg = (l_sample_cnt << 8) | l_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) continue; i2c->high_speed_reg = I2C_TIME_DEFAULT_VALUE | (sample_cnt << 12) | (step_cnt << 8); if (i2c->dev_comp->ltiming_adjust) i2c->ltiming_reg = (l_sample_cnt << 6) | l_step_cnt | (sample_cnt << 12) | (step_cnt << 9); } else { ret = mtk_i2c_calculate_speed(i2c, clk_src, target_speed, &l_step_cnt, &l_sample_cnt); if (ret < 0) continue; i2c->timing_reg = (l_sample_cnt << 8) | l_step_cnt; /* Disable the high speed transaction */ i2c->high_speed_reg = I2C_TIME_CLR_VALUE; if (i2c->dev_comp->ltiming_adjust) i2c->ltiming_reg = (l_sample_cnt << 6) | l_step_cnt; } break; } i2c->ac_timing.inter_clk_div = clk_div - 1; return 0; } 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; u16 dma_sync = 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 = mtk_i2c_readw(i2c, OFFSET_CONTROL) & ~(I2C_CONTROL_DIR_CHANGE | I2C_CONTROL_RS); if ((i2c->speed_hz > I2C_MAX_FAST_MODE_FREQ) || (left_num >= 1)) control_reg |= I2C_CONTROL_RS; if (i2c->op == I2C_MASTER_WRRD) control_reg |= I2C_CONTROL_DIR_CHANGE | I2C_CONTROL_RS; mtk_i2c_writew(i2c, control_reg, OFFSET_CONTROL); addr_reg = i2c_8bit_addr_from_msg(msgs); mtk_i2c_writew(i2c, addr_reg, OFFSET_SLAVE_ADDR); /* Clear interrupt status */ mtk_i2c_writew(i2c, restart_flag | I2C_HS_NACKERR | I2C_ACKERR | I2C_ARB_LOST | I2C_TRANSAC_COMP, OFFSET_INTR_STAT); mtk_i2c_writew(i2c, I2C_FIFO_ADDR_CLR, OFFSET_FIFO_ADDR_CLR); /* Enable interrupt */ mtk_i2c_writew(i2c, restart_flag | I2C_HS_NACKERR | I2C_ACKERR | I2C_ARB_LOST | I2C_TRANSAC_COMP, OFFSET_INTR_MASK); /* Set transfer and transaction len */ if (i2c->op == I2C_MASTER_WRRD) { if (i2c->dev_comp->aux_len_reg) { mtk_i2c_writew(i2c, msgs->len, OFFSET_TRANSFER_LEN); mtk_i2c_writew(i2c, (msgs + 1)->len, OFFSET_TRANSFER_LEN_AUX); } else { mtk_i2c_writew(i2c, msgs->len | ((msgs + 1)->len) << 8, OFFSET_TRANSFER_LEN); } mtk_i2c_writew(i2c, I2C_WRRD_TRANAC_VALUE, OFFSET_TRANSAC_LEN); } else { mtk_i2c_writew(i2c, msgs->len, OFFSET_TRANSFER_LEN); mtk_i2c_writew(i2c, num, OFFSET_TRANSAC_LEN); } if (i2c->dev_comp->apdma_sync) { dma_sync = I2C_DMA_SKIP_CONFIG | I2C_DMA_ASYNC_MODE; if (i2c->op == I2C_MASTER_WRRD) dma_sync |= I2C_DMA_DIR_CHANGE; } /* 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 | dma_sync, 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->max_dma_support > 32) { reg_4g_mode = upper_32_bits(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 | dma_sync, 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->max_dma_support > 32) { reg_4g_mode = upper_32_bits(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 | dma_sync, 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->max_dma_support > 32) { reg_4g_mode = upper_32_bits(wpaddr); writel(reg_4g_mode, i2c->pdmabase + OFFSET_TX_4G_MODE); reg_4g_mode = upper_32_bits(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; } mtk_i2c_writew(i2c, start_reg, OFFSET_START); ret = wait_for_completion_timeout(&i2c->msg_complete, i2c->adap.timeout); /* Clear interrupt mask */ mtk_i2c_writew(i2c, ~(restart_flag | I2C_HS_NACKERR | I2C_ACKERR | I2C_ARB_LOST | I2C_TRANSAC_COMP), 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; } 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 > I2C_MAX_FAST_MODE_FREQ) /* 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 = mtk_i2c_readw(i2c, OFFSET_INTR_STAT); mtk_i2c_writew(i2c, intr_stat, 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; mtk_i2c_writew(i2c, I2C_RS_MUL_CNFG | I2C_RS_MUL_TRIG | I2C_TRANSAC_START, 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) { if (i2c_check_quirks(adap, I2C_AQ_NO_ZERO_LEN)) return I2C_FUNC_I2C | (I2C_FUNC_SMBUS_EMUL & ~I2C_FUNC_SMBUS_QUICK); else 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_MAX_STANDARD_MODE_FREQ; 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->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); } i2c->clk_arb = devm_clk_get(&pdev->dev, "arb"); if (IS_ERR(i2c->clk_arb)) i2c->clk_arb = NULL; 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->max_dma_support > 32) { ret = dma_set_mask(&pdev->dev, DMA_BIT_MASK(i2c->dev_comp->max_dma_support)); 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 ");