// SPDX-License-Identifier: GPL-2.0-or-later /* * Synopsys DesignWare I2C adapter driver (master only). * * Based on the TI DAVINCI I2C adapter driver. * * Copyright (C) 2006 Texas Instruments. * Copyright (C) 2007 MontaVista Software Inc. * Copyright (C) 2009 Provigent Ltd. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include "i2c-designware-core.h" #define AMD_TIMEOUT_MIN_US 25 #define AMD_TIMEOUT_MAX_US 250 #define AMD_MASTERCFG_MASK GENMASK(15, 0) static void i2c_dw_configure_fifo_master(struct dw_i2c_dev *dev) { /* Configure Tx/Rx FIFO threshold levels */ regmap_write(dev->map, DW_IC_TX_TL, dev->tx_fifo_depth / 2); regmap_write(dev->map, DW_IC_RX_TL, 0); /* Configure the I2C master */ regmap_write(dev->map, DW_IC_CON, dev->master_cfg); } static int i2c_dw_set_timings_master(struct dw_i2c_dev *dev) { unsigned int comp_param1; u32 sda_falling_time, scl_falling_time; struct i2c_timings *t = &dev->timings; const char *fp_str = ""; u32 ic_clk; int ret; ret = i2c_dw_acquire_lock(dev); if (ret) return ret; ret = regmap_read(dev->map, DW_IC_COMP_PARAM_1, &comp_param1); i2c_dw_release_lock(dev); if (ret) return ret; /* Set standard and fast speed dividers for high/low periods */ sda_falling_time = t->sda_fall_ns ?: 300; /* ns */ scl_falling_time = t->scl_fall_ns ?: 300; /* ns */ /* Calculate SCL timing parameters for standard mode if not set */ if (!dev->ss_hcnt || !dev->ss_lcnt) { ic_clk = i2c_dw_clk_rate(dev); dev->ss_hcnt = i2c_dw_scl_hcnt(ic_clk, 4000, /* tHD;STA = tHIGH = 4.0 us */ sda_falling_time, 0, /* 0: DW default, 1: Ideal */ 0); /* No offset */ dev->ss_lcnt = i2c_dw_scl_lcnt(ic_clk, 4700, /* tLOW = 4.7 us */ scl_falling_time, 0); /* No offset */ } dev_dbg(dev->dev, "Standard Mode HCNT:LCNT = %d:%d\n", dev->ss_hcnt, dev->ss_lcnt); /* * Set SCL timing parameters for fast mode or fast mode plus. Only * difference is the timing parameter values since the registers are * the same. */ if (t->bus_freq_hz == I2C_MAX_FAST_MODE_PLUS_FREQ) { /* * Check are Fast Mode Plus parameters available. Calculate * SCL timing parameters for Fast Mode Plus if not set. */ if (dev->fp_hcnt && dev->fp_lcnt) { dev->fs_hcnt = dev->fp_hcnt; dev->fs_lcnt = dev->fp_lcnt; } else { ic_clk = i2c_dw_clk_rate(dev); dev->fs_hcnt = i2c_dw_scl_hcnt(ic_clk, 260, /* tHIGH = 260 ns */ sda_falling_time, 0, /* DW default */ 0); /* No offset */ dev->fs_lcnt = i2c_dw_scl_lcnt(ic_clk, 500, /* tLOW = 500 ns */ scl_falling_time, 0); /* No offset */ } fp_str = " Plus"; } /* * Calculate SCL timing parameters for fast mode if not set. They are * needed also in high speed mode. */ if (!dev->fs_hcnt || !dev->fs_lcnt) { ic_clk = i2c_dw_clk_rate(dev); dev->fs_hcnt = i2c_dw_scl_hcnt(ic_clk, 600, /* tHD;STA = tHIGH = 0.6 us */ sda_falling_time, 0, /* 0: DW default, 1: Ideal */ 0); /* No offset */ dev->fs_lcnt = i2c_dw_scl_lcnt(ic_clk, 1300, /* tLOW = 1.3 us */ scl_falling_time, 0); /* No offset */ } dev_dbg(dev->dev, "Fast Mode%s HCNT:LCNT = %d:%d\n", fp_str, dev->fs_hcnt, dev->fs_lcnt); /* Check is high speed possible and fall back to fast mode if not */ if ((dev->master_cfg & DW_IC_CON_SPEED_MASK) == DW_IC_CON_SPEED_HIGH) { if ((comp_param1 & DW_IC_COMP_PARAM_1_SPEED_MODE_MASK) != DW_IC_COMP_PARAM_1_SPEED_MODE_HIGH) { dev_err(dev->dev, "High Speed not supported!\n"); t->bus_freq_hz = I2C_MAX_FAST_MODE_FREQ; dev->master_cfg &= ~DW_IC_CON_SPEED_MASK; dev->master_cfg |= DW_IC_CON_SPEED_FAST; dev->hs_hcnt = 0; dev->hs_lcnt = 0; } else if (!dev->hs_hcnt || !dev->hs_lcnt) { ic_clk = i2c_dw_clk_rate(dev); dev->hs_hcnt = i2c_dw_scl_hcnt(ic_clk, 160, /* tHIGH = 160 ns */ sda_falling_time, 0, /* DW default */ 0); /* No offset */ dev->hs_lcnt = i2c_dw_scl_lcnt(ic_clk, 320, /* tLOW = 320 ns */ scl_falling_time, 0); /* No offset */ } dev_dbg(dev->dev, "High Speed Mode HCNT:LCNT = %d:%d\n", dev->hs_hcnt, dev->hs_lcnt); } ret = i2c_dw_set_sda_hold(dev); if (ret) return ret; dev_dbg(dev->dev, "Bus speed: %s\n", i2c_freq_mode_string(t->bus_freq_hz)); return 0; } /** * i2c_dw_init_master() - Initialize the designware I2C master hardware * @dev: device private data * * This functions configures and enables the I2C master. * This function is called during I2C init function, and in case of timeout at * run time. */ static int i2c_dw_init_master(struct dw_i2c_dev *dev) { int ret; ret = i2c_dw_acquire_lock(dev); if (ret) return ret; /* Disable the adapter */ __i2c_dw_disable(dev); /* Write standard speed timing parameters */ regmap_write(dev->map, DW_IC_SS_SCL_HCNT, dev->ss_hcnt); regmap_write(dev->map, DW_IC_SS_SCL_LCNT, dev->ss_lcnt); /* Write fast mode/fast mode plus timing parameters */ regmap_write(dev->map, DW_IC_FS_SCL_HCNT, dev->fs_hcnt); regmap_write(dev->map, DW_IC_FS_SCL_LCNT, dev->fs_lcnt); /* Write high speed timing parameters if supported */ if (dev->hs_hcnt && dev->hs_lcnt) { regmap_write(dev->map, DW_IC_HS_SCL_HCNT, dev->hs_hcnt); regmap_write(dev->map, DW_IC_HS_SCL_LCNT, dev->hs_lcnt); } /* Write SDA hold time if supported */ if (dev->sda_hold_time) regmap_write(dev->map, DW_IC_SDA_HOLD, dev->sda_hold_time); i2c_dw_configure_fifo_master(dev); i2c_dw_release_lock(dev); return 0; } static void i2c_dw_xfer_init(struct dw_i2c_dev *dev) { struct i2c_msg *msgs = dev->msgs; u32 ic_con = 0, ic_tar = 0; unsigned int dummy; /* Disable the adapter */ __i2c_dw_disable(dev); /* If the slave address is ten bit address, enable 10BITADDR */ if (msgs[dev->msg_write_idx].flags & I2C_M_TEN) { ic_con = DW_IC_CON_10BITADDR_MASTER; /* * If I2C_DYNAMIC_TAR_UPDATE is set, the 10-bit addressing * mode has to be enabled via bit 12 of IC_TAR register. * We set it always as I2C_DYNAMIC_TAR_UPDATE can't be * detected from registers. */ ic_tar = DW_IC_TAR_10BITADDR_MASTER; } regmap_update_bits(dev->map, DW_IC_CON, DW_IC_CON_10BITADDR_MASTER, ic_con); /* * Set the slave (target) address and enable 10-bit addressing mode * if applicable. */ regmap_write(dev->map, DW_IC_TAR, msgs[dev->msg_write_idx].addr | ic_tar); /* Enforce disabled interrupts (due to HW issues) */ regmap_write(dev->map, DW_IC_INTR_MASK, 0); /* Enable the adapter */ __i2c_dw_enable(dev); /* Dummy read to avoid the register getting stuck on Bay Trail */ regmap_read(dev->map, DW_IC_ENABLE_STATUS, &dummy); /* Clear and enable interrupts */ regmap_read(dev->map, DW_IC_CLR_INTR, &dummy); regmap_write(dev->map, DW_IC_INTR_MASK, DW_IC_INTR_MASTER_MASK); } /* * This function waits for the controller to be idle before disabling I2C * When the controller is not in the IDLE state, the MST_ACTIVITY bit * (IC_STATUS[5]) is set. * * Values: * 0x1 (ACTIVE): Controller not idle * 0x0 (IDLE): Controller is idle * * The function is called after completing the current transfer. * * Returns: * False when the controller is in the IDLE state. * True when the controller is in the ACTIVE state. */ static bool i2c_dw_is_controller_active(struct dw_i2c_dev *dev) { u32 status; regmap_read(dev->map, DW_IC_STATUS, &status); if (!(status & DW_IC_STATUS_MASTER_ACTIVITY)) return false; return regmap_read_poll_timeout(dev->map, DW_IC_STATUS, status, !(status & DW_IC_STATUS_MASTER_ACTIVITY), 1100, 20000) != 0; } static int i2c_dw_check_stopbit(struct dw_i2c_dev *dev) { u32 val; int ret; ret = regmap_read_poll_timeout(dev->map, DW_IC_INTR_STAT, val, !(val & DW_IC_INTR_STOP_DET), 1100, 20000); if (ret) dev_err(dev->dev, "i2c timeout error %d\n", ret); return ret; } static int i2c_dw_status(struct dw_i2c_dev *dev) { int status; status = i2c_dw_wait_bus_not_busy(dev); if (status) return status; return i2c_dw_check_stopbit(dev); } /* * Initiate and continue master read/write transaction with polling * based transfer routine afterward write messages into the Tx buffer. */ static int amd_i2c_dw_xfer_quirk(struct i2c_adapter *adap, struct i2c_msg *msgs, int num_msgs) { struct dw_i2c_dev *dev = i2c_get_adapdata(adap); int msg_wrt_idx, msg_itr_lmt, buf_len, data_idx; int cmd = 0, status; u8 *tx_buf; unsigned int val; /* * In order to enable the interrupt for UCSI i.e. AMD NAVI GPU card, * it is mandatory to set the right value in specific register * (offset:0x474) as per the hardware IP specification. */ regmap_write(dev->map, AMD_UCSI_INTR_REG, AMD_UCSI_INTR_EN); dev->msgs = msgs; dev->msgs_num = num_msgs; i2c_dw_xfer_init(dev); regmap_write(dev->map, DW_IC_INTR_MASK, 0); /* Initiate messages read/write transaction */ for (msg_wrt_idx = 0; msg_wrt_idx < num_msgs; msg_wrt_idx++) { tx_buf = msgs[msg_wrt_idx].buf; buf_len = msgs[msg_wrt_idx].len; if (!(msgs[msg_wrt_idx].flags & I2C_M_RD)) regmap_write(dev->map, DW_IC_TX_TL, buf_len - 1); /* * Initiate the i2c read/write transaction of buffer length, * and poll for bus busy status. For the last message transfer, * update the command with stopbit enable. */ for (msg_itr_lmt = buf_len; msg_itr_lmt > 0; msg_itr_lmt--) { if (msg_wrt_idx == num_msgs - 1 && msg_itr_lmt == 1) cmd |= BIT(9); if (msgs[msg_wrt_idx].flags & I2C_M_RD) { /* Due to hardware bug, need to write the same command twice. */ regmap_write(dev->map, DW_IC_DATA_CMD, 0x100); regmap_write(dev->map, DW_IC_DATA_CMD, 0x100 | cmd); if (cmd) { regmap_write(dev->map, DW_IC_TX_TL, 2 * (buf_len - 1)); regmap_write(dev->map, DW_IC_RX_TL, 2 * (buf_len - 1)); /* * Need to check the stop bit. However, it cannot be * detected from the registers so we check it always * when read/write the last byte. */ status = i2c_dw_status(dev); if (status) return status; for (data_idx = 0; data_idx < buf_len; data_idx++) { regmap_read(dev->map, DW_IC_DATA_CMD, &val); tx_buf[data_idx] = val; } status = i2c_dw_check_stopbit(dev); if (status) return status; } } else { regmap_write(dev->map, DW_IC_DATA_CMD, *tx_buf++ | cmd); usleep_range(AMD_TIMEOUT_MIN_US, AMD_TIMEOUT_MAX_US); } } status = i2c_dw_check_stopbit(dev); if (status) return status; } return 0; } static int i2c_dw_poll_tx_empty(struct dw_i2c_dev *dev) { u32 val; return regmap_read_poll_timeout(dev->map, DW_IC_RAW_INTR_STAT, val, val & DW_IC_INTR_TX_EMPTY, 100, 1000); } static int i2c_dw_poll_rx_full(struct dw_i2c_dev *dev) { u32 val; return regmap_read_poll_timeout(dev->map, DW_IC_RAW_INTR_STAT, val, val & DW_IC_INTR_RX_FULL, 100, 1000); } static int txgbe_i2c_dw_xfer_quirk(struct i2c_adapter *adap, struct i2c_msg *msgs, int num_msgs) { struct dw_i2c_dev *dev = i2c_get_adapdata(adap); int msg_idx, buf_len, data_idx, ret; unsigned int val, stop = 0; u8 *buf; dev->msgs = msgs; dev->msgs_num = num_msgs; i2c_dw_xfer_init(dev); regmap_write(dev->map, DW_IC_INTR_MASK, 0); for (msg_idx = 0; msg_idx < num_msgs; msg_idx++) { buf = msgs[msg_idx].buf; buf_len = msgs[msg_idx].len; for (data_idx = 0; data_idx < buf_len; data_idx++) { if (msg_idx == num_msgs - 1 && data_idx == buf_len - 1) stop |= BIT(9); if (msgs[msg_idx].flags & I2C_M_RD) { regmap_write(dev->map, DW_IC_DATA_CMD, 0x100 | stop); ret = i2c_dw_poll_rx_full(dev); if (ret) return ret; regmap_read(dev->map, DW_IC_DATA_CMD, &val); buf[data_idx] = val; } else { ret = i2c_dw_poll_tx_empty(dev); if (ret) return ret; regmap_write(dev->map, DW_IC_DATA_CMD, buf[data_idx] | stop); } } } return num_msgs; } /* * Initiate (and continue) low level master read/write transaction. * This function is only called from i2c_dw_isr, and pumping i2c_msg * messages into the tx buffer. Even if the size of i2c_msg data is * longer than the size of the tx buffer, it handles everything. */ static void i2c_dw_xfer_msg(struct dw_i2c_dev *dev) { struct i2c_msg *msgs = dev->msgs; u32 intr_mask; int tx_limit, rx_limit; u32 addr = msgs[dev->msg_write_idx].addr; u32 buf_len = dev->tx_buf_len; u8 *buf = dev->tx_buf; bool need_restart = false; unsigned int flr; intr_mask = DW_IC_INTR_MASTER_MASK; for (; dev->msg_write_idx < dev->msgs_num; dev->msg_write_idx++) { u32 flags = msgs[dev->msg_write_idx].flags; /* * If target address has changed, we need to * reprogram the target address in the I2C * adapter when we are done with this transfer. */ if (msgs[dev->msg_write_idx].addr != addr) { dev_err(dev->dev, "%s: invalid target address\n", __func__); dev->msg_err = -EINVAL; break; } if (!(dev->status & STATUS_WRITE_IN_PROGRESS)) { /* new i2c_msg */ buf = msgs[dev->msg_write_idx].buf; buf_len = msgs[dev->msg_write_idx].len; /* If both IC_EMPTYFIFO_HOLD_MASTER_EN and * IC_RESTART_EN are set, we must manually * set restart bit between messages. */ if ((dev->master_cfg & DW_IC_CON_RESTART_EN) && (dev->msg_write_idx > 0)) need_restart = true; } regmap_read(dev->map, DW_IC_TXFLR, &flr); tx_limit = dev->tx_fifo_depth - flr; regmap_read(dev->map, DW_IC_RXFLR, &flr); rx_limit = dev->rx_fifo_depth - flr; while (buf_len > 0 && tx_limit > 0 && rx_limit > 0) { u32 cmd = 0; /* * If IC_EMPTYFIFO_HOLD_MASTER_EN is set we must * manually set the stop bit. However, it cannot be * detected from the registers so we set it always * when writing/reading the last byte. */ /* * i2c-core always sets the buffer length of * I2C_FUNC_SMBUS_BLOCK_DATA to 1. The length will * be adjusted when receiving the first byte. * Thus we can't stop the transaction here. */ if (dev->msg_write_idx == dev->msgs_num - 1 && buf_len == 1 && !(flags & I2C_M_RECV_LEN)) cmd |= BIT(9); if (need_restart) { cmd |= BIT(10); need_restart = false; } if (msgs[dev->msg_write_idx].flags & I2C_M_RD) { /* Avoid rx buffer overrun */ if (dev->rx_outstanding >= dev->rx_fifo_depth) break; regmap_write(dev->map, DW_IC_DATA_CMD, cmd | 0x100); rx_limit--; dev->rx_outstanding++; } else { regmap_write(dev->map, DW_IC_DATA_CMD, cmd | *buf++); } tx_limit--; buf_len--; } dev->tx_buf = buf; dev->tx_buf_len = buf_len; /* * Because we don't know the buffer length in the * I2C_FUNC_SMBUS_BLOCK_DATA case, we can't stop the * transaction here. Also disable the TX_EMPTY IRQ * while waiting for the data length byte to avoid the * bogus interrupts flood. */ if (flags & I2C_M_RECV_LEN) { dev->status |= STATUS_WRITE_IN_PROGRESS; intr_mask &= ~DW_IC_INTR_TX_EMPTY; break; } else if (buf_len > 0) { /* more bytes to be written */ dev->status |= STATUS_WRITE_IN_PROGRESS; break; } else dev->status &= ~STATUS_WRITE_IN_PROGRESS; } /* * If i2c_msg index search is completed, we don't need TX_EMPTY * interrupt any more. */ if (dev->msg_write_idx == dev->msgs_num) intr_mask &= ~DW_IC_INTR_TX_EMPTY; if (dev->msg_err) intr_mask = 0; regmap_write(dev->map, DW_IC_INTR_MASK, intr_mask); } static u8 i2c_dw_recv_len(struct dw_i2c_dev *dev, u8 len) { struct i2c_msg *msgs = dev->msgs; u32 flags = msgs[dev->msg_read_idx].flags; /* * Adjust the buffer length and mask the flag * after receiving the first byte. */ len += (flags & I2C_CLIENT_PEC) ? 2 : 1; dev->tx_buf_len = len - min_t(u8, len, dev->rx_outstanding); msgs[dev->msg_read_idx].len = len; msgs[dev->msg_read_idx].flags &= ~I2C_M_RECV_LEN; /* * Received buffer length, re-enable TX_EMPTY interrupt * to resume the SMBUS transaction. */ regmap_update_bits(dev->map, DW_IC_INTR_MASK, DW_IC_INTR_TX_EMPTY, DW_IC_INTR_TX_EMPTY); return len; } static void i2c_dw_read(struct dw_i2c_dev *dev) { struct i2c_msg *msgs = dev->msgs; unsigned int rx_valid; for (; dev->msg_read_idx < dev->msgs_num; dev->msg_read_idx++) { unsigned int tmp; u32 len; u8 *buf; if (!(msgs[dev->msg_read_idx].flags & I2C_M_RD)) continue; if (!(dev->status & STATUS_READ_IN_PROGRESS)) { len = msgs[dev->msg_read_idx].len; buf = msgs[dev->msg_read_idx].buf; } else { len = dev->rx_buf_len; buf = dev->rx_buf; } regmap_read(dev->map, DW_IC_RXFLR, &rx_valid); for (; len > 0 && rx_valid > 0; len--, rx_valid--) { u32 flags = msgs[dev->msg_read_idx].flags; regmap_read(dev->map, DW_IC_DATA_CMD, &tmp); tmp &= DW_IC_DATA_CMD_DAT; /* Ensure length byte is a valid value */ if (flags & I2C_M_RECV_LEN) { /* * if IC_EMPTYFIFO_HOLD_MASTER_EN is set, which cannot be * detected from the registers, the controller can be * disabled if the STOP bit is set. But it is only set * after receiving block data response length in * I2C_FUNC_SMBUS_BLOCK_DATA case. That needs to read * another byte with STOP bit set when the block data * response length is invalid to complete the transaction. */ if (!tmp || tmp > I2C_SMBUS_BLOCK_MAX) tmp = 1; len = i2c_dw_recv_len(dev, tmp); } *buf++ = tmp; dev->rx_outstanding--; } if (len > 0) { dev->status |= STATUS_READ_IN_PROGRESS; dev->rx_buf_len = len; dev->rx_buf = buf; return; } else dev->status &= ~STATUS_READ_IN_PROGRESS; } } /* * Prepare controller for a transaction and call i2c_dw_xfer_msg. */ static int i2c_dw_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) { struct dw_i2c_dev *dev = i2c_get_adapdata(adap); int ret; dev_dbg(dev->dev, "%s: msgs: %d\n", __func__, num); pm_runtime_get_sync(dev->dev); /* * Initiate I2C message transfer when polling mode is enabled, * As it is polling based transfer mechanism, which does not support * interrupt based functionalities of existing DesignWare driver. */ switch (dev->flags & MODEL_MASK) { case MODEL_AMD_NAVI_GPU: ret = amd_i2c_dw_xfer_quirk(adap, msgs, num); goto done_nolock; case MODEL_WANGXUN_SP: ret = txgbe_i2c_dw_xfer_quirk(adap, msgs, num); goto done_nolock; default: break; } reinit_completion(&dev->cmd_complete); dev->msgs = msgs; dev->msgs_num = num; dev->cmd_err = 0; dev->msg_write_idx = 0; dev->msg_read_idx = 0; dev->msg_err = 0; dev->status = 0; dev->abort_source = 0; dev->rx_outstanding = 0; ret = i2c_dw_acquire_lock(dev); if (ret) goto done_nolock; ret = i2c_dw_wait_bus_not_busy(dev); if (ret < 0) goto done; /* Start the transfers */ i2c_dw_xfer_init(dev); /* Wait for tx to complete */ if (!wait_for_completion_timeout(&dev->cmd_complete, adap->timeout)) { dev_err(dev->dev, "controller timed out\n"); /* i2c_dw_init implicitly disables the adapter */ i2c_recover_bus(&dev->adapter); i2c_dw_init_master(dev); ret = -ETIMEDOUT; goto done; } /* * This happens rarely (~1:500) and is hard to reproduce. Debug trace * showed that IC_STATUS had value of 0x23 when STOP_DET occurred, * if disable IC_ENABLE.ENABLE immediately that can result in * IC_RAW_INTR_STAT.MASTER_ON_HOLD holding SCL low. Check if * controller is still ACTIVE before disabling I2C. */ if (i2c_dw_is_controller_active(dev)) dev_err(dev->dev, "controller active\n"); /* * We must disable the adapter before returning and signaling the end * of the current transfer. Otherwise the hardware might continue * generating interrupts which in turn causes a race condition with * the following transfer. Needs some more investigation if the * additional interrupts are a hardware bug or this driver doesn't * handle them correctly yet. */ __i2c_dw_disable_nowait(dev); if (dev->msg_err) { ret = dev->msg_err; goto done; } /* No error */ if (likely(!dev->cmd_err && !dev->status)) { ret = num; goto done; } /* We have an error */ if (dev->cmd_err == DW_IC_ERR_TX_ABRT) { ret = i2c_dw_handle_tx_abort(dev); goto done; } if (dev->status) dev_err(dev->dev, "transfer terminated early - interrupt latency too high?\n"); ret = -EIO; done: i2c_dw_release_lock(dev); done_nolock: pm_runtime_mark_last_busy(dev->dev); pm_runtime_put_autosuspend(dev->dev); return ret; } static const struct i2c_algorithm i2c_dw_algo = { .master_xfer = i2c_dw_xfer, .functionality = i2c_dw_func, }; static const struct i2c_adapter_quirks i2c_dw_quirks = { .flags = I2C_AQ_NO_ZERO_LEN, }; static u32 i2c_dw_read_clear_intrbits(struct dw_i2c_dev *dev) { unsigned int stat, dummy; /* * The IC_INTR_STAT register just indicates "enabled" interrupts. * The unmasked raw version of interrupt status bits is available * in the IC_RAW_INTR_STAT register. * * That is, * stat = readl(IC_INTR_STAT); * equals to, * stat = readl(IC_RAW_INTR_STAT) & readl(IC_INTR_MASK); * * The raw version might be useful for debugging purposes. */ regmap_read(dev->map, DW_IC_INTR_STAT, &stat); /* * Do not use the IC_CLR_INTR register to clear interrupts, or * you'll miss some interrupts, triggered during the period from * readl(IC_INTR_STAT) to readl(IC_CLR_INTR). * * Instead, use the separately-prepared IC_CLR_* registers. */ if (stat & DW_IC_INTR_RX_UNDER) regmap_read(dev->map, DW_IC_CLR_RX_UNDER, &dummy); if (stat & DW_IC_INTR_RX_OVER) regmap_read(dev->map, DW_IC_CLR_RX_OVER, &dummy); if (stat & DW_IC_INTR_TX_OVER) regmap_read(dev->map, DW_IC_CLR_TX_OVER, &dummy); if (stat & DW_IC_INTR_RD_REQ) regmap_read(dev->map, DW_IC_CLR_RD_REQ, &dummy); if (stat & DW_IC_INTR_TX_ABRT) { /* * The IC_TX_ABRT_SOURCE register is cleared whenever * the IC_CLR_TX_ABRT is read. Preserve it beforehand. */ regmap_read(dev->map, DW_IC_TX_ABRT_SOURCE, &dev->abort_source); regmap_read(dev->map, DW_IC_CLR_TX_ABRT, &dummy); } if (stat & DW_IC_INTR_RX_DONE) regmap_read(dev->map, DW_IC_CLR_RX_DONE, &dummy); if (stat & DW_IC_INTR_ACTIVITY) regmap_read(dev->map, DW_IC_CLR_ACTIVITY, &dummy); if ((stat & DW_IC_INTR_STOP_DET) && ((dev->rx_outstanding == 0) || (stat & DW_IC_INTR_RX_FULL))) regmap_read(dev->map, DW_IC_CLR_STOP_DET, &dummy); if (stat & DW_IC_INTR_START_DET) regmap_read(dev->map, DW_IC_CLR_START_DET, &dummy); if (stat & DW_IC_INTR_GEN_CALL) regmap_read(dev->map, DW_IC_CLR_GEN_CALL, &dummy); return stat; } /* * Interrupt service routine. This gets called whenever an I2C master interrupt * occurs. */ static irqreturn_t i2c_dw_isr(int this_irq, void *dev_id) { struct dw_i2c_dev *dev = dev_id; unsigned int stat, enabled; regmap_read(dev->map, DW_IC_ENABLE, &enabled); regmap_read(dev->map, DW_IC_RAW_INTR_STAT, &stat); if (!enabled || !(stat & ~DW_IC_INTR_ACTIVITY)) return IRQ_NONE; if (pm_runtime_suspended(dev->dev) || stat == GENMASK(31, 0)) return IRQ_NONE; dev_dbg(dev->dev, "enabled=%#x stat=%#x\n", enabled, stat); stat = i2c_dw_read_clear_intrbits(dev); if (!(dev->status & STATUS_ACTIVE)) { /* * Unexpected interrupt in driver point of view. State * variables are either unset or stale so acknowledge and * disable interrupts for suppressing further interrupts if * interrupt really came from this HW (E.g. firmware has left * the HW active). */ regmap_write(dev->map, DW_IC_INTR_MASK, 0); return IRQ_HANDLED; } if (stat & DW_IC_INTR_TX_ABRT) { dev->cmd_err |= DW_IC_ERR_TX_ABRT; dev->status &= ~STATUS_MASK; dev->rx_outstanding = 0; /* * Anytime TX_ABRT is set, the contents of the tx/rx * buffers are flushed. Make sure to skip them. */ regmap_write(dev->map, DW_IC_INTR_MASK, 0); goto tx_aborted; } if (stat & DW_IC_INTR_RX_FULL) i2c_dw_read(dev); if (stat & DW_IC_INTR_TX_EMPTY) i2c_dw_xfer_msg(dev); /* * No need to modify or disable the interrupt mask here. * i2c_dw_xfer_msg() will take care of it according to * the current transmit status. */ tx_aborted: if (((stat & (DW_IC_INTR_TX_ABRT | DW_IC_INTR_STOP_DET)) || dev->msg_err) && (dev->rx_outstanding == 0)) complete(&dev->cmd_complete); else if (unlikely(dev->flags & ACCESS_INTR_MASK)) { /* Workaround to trigger pending interrupt */ regmap_read(dev->map, DW_IC_INTR_MASK, &stat); regmap_write(dev->map, DW_IC_INTR_MASK, 0); regmap_write(dev->map, DW_IC_INTR_MASK, stat); } return IRQ_HANDLED; } void i2c_dw_configure_master(struct dw_i2c_dev *dev) { struct i2c_timings *t = &dev->timings; dev->functionality = I2C_FUNC_10BIT_ADDR | DW_IC_DEFAULT_FUNCTIONALITY; dev->master_cfg = DW_IC_CON_MASTER | DW_IC_CON_SLAVE_DISABLE | DW_IC_CON_RESTART_EN; dev->mode = DW_IC_MASTER; switch (t->bus_freq_hz) { case I2C_MAX_STANDARD_MODE_FREQ: dev->master_cfg |= DW_IC_CON_SPEED_STD; break; case I2C_MAX_HIGH_SPEED_MODE_FREQ: dev->master_cfg |= DW_IC_CON_SPEED_HIGH; break; default: dev->master_cfg |= DW_IC_CON_SPEED_FAST; } } EXPORT_SYMBOL_GPL(i2c_dw_configure_master); static void i2c_dw_prepare_recovery(struct i2c_adapter *adap) { struct dw_i2c_dev *dev = i2c_get_adapdata(adap); i2c_dw_disable(dev); reset_control_assert(dev->rst); i2c_dw_prepare_clk(dev, false); } static void i2c_dw_unprepare_recovery(struct i2c_adapter *adap) { struct dw_i2c_dev *dev = i2c_get_adapdata(adap); i2c_dw_prepare_clk(dev, true); reset_control_deassert(dev->rst); i2c_dw_init_master(dev); } static int i2c_dw_init_recovery_info(struct dw_i2c_dev *dev) { struct i2c_bus_recovery_info *rinfo = &dev->rinfo; struct i2c_adapter *adap = &dev->adapter; struct gpio_desc *gpio; gpio = devm_gpiod_get_optional(dev->dev, "scl", GPIOD_OUT_HIGH); if (IS_ERR_OR_NULL(gpio)) return PTR_ERR_OR_ZERO(gpio); rinfo->scl_gpiod = gpio; gpio = devm_gpiod_get_optional(dev->dev, "sda", GPIOD_IN); if (IS_ERR(gpio)) return PTR_ERR(gpio); rinfo->sda_gpiod = gpio; rinfo->pinctrl = devm_pinctrl_get(dev->dev); if (IS_ERR(rinfo->pinctrl)) { if (PTR_ERR(rinfo->pinctrl) == -EPROBE_DEFER) return PTR_ERR(rinfo->pinctrl); rinfo->pinctrl = NULL; dev_err(dev->dev, "getting pinctrl info failed: bus recovery might not work\n"); } else if (!rinfo->pinctrl) { dev_dbg(dev->dev, "pinctrl is disabled, bus recovery might not work\n"); } rinfo->recover_bus = i2c_generic_scl_recovery; rinfo->prepare_recovery = i2c_dw_prepare_recovery; rinfo->unprepare_recovery = i2c_dw_unprepare_recovery; adap->bus_recovery_info = rinfo; dev_info(dev->dev, "running with gpio recovery mode! scl%s", rinfo->sda_gpiod ? ",sda" : ""); return 0; } static int i2c_dw_poll_adap_quirk(struct dw_i2c_dev *dev) { struct i2c_adapter *adap = &dev->adapter; int ret; pm_runtime_get_noresume(dev->dev); ret = i2c_add_numbered_adapter(adap); if (ret) dev_err(dev->dev, "Failed to add adapter: %d\n", ret); pm_runtime_put_noidle(dev->dev); return ret; } static bool i2c_dw_is_model_poll(struct dw_i2c_dev *dev) { switch (dev->flags & MODEL_MASK) { case MODEL_AMD_NAVI_GPU: case MODEL_WANGXUN_SP: return true; default: return false; } } int i2c_dw_probe_master(struct dw_i2c_dev *dev) { struct i2c_adapter *adap = &dev->adapter; unsigned long irq_flags; unsigned int ic_con; int ret; init_completion(&dev->cmd_complete); dev->init = i2c_dw_init_master; dev->disable = i2c_dw_disable; ret = i2c_dw_init_regmap(dev); if (ret) return ret; ret = i2c_dw_set_timings_master(dev); if (ret) return ret; ret = i2c_dw_set_fifo_size(dev); if (ret) return ret; /* Lock the bus for accessing DW_IC_CON */ ret = i2c_dw_acquire_lock(dev); if (ret) return ret; /* * On AMD platforms BIOS advertises the bus clear feature * and enables the SCL/SDA stuck low. SMU FW does the * bus recovery process. Driver should not ignore this BIOS * advertisement of bus clear feature. */ ret = regmap_read(dev->map, DW_IC_CON, &ic_con); i2c_dw_release_lock(dev); if (ret) return ret; if (ic_con & DW_IC_CON_BUS_CLEAR_CTRL) dev->master_cfg |= DW_IC_CON_BUS_CLEAR_CTRL; ret = dev->init(dev); if (ret) return ret; snprintf(adap->name, sizeof(adap->name), "Synopsys DesignWare I2C adapter"); adap->retries = 3; adap->algo = &i2c_dw_algo; adap->quirks = &i2c_dw_quirks; adap->dev.parent = dev->dev; i2c_set_adapdata(adap, dev); if (i2c_dw_is_model_poll(dev)) return i2c_dw_poll_adap_quirk(dev); if (dev->flags & ACCESS_NO_IRQ_SUSPEND) { irq_flags = IRQF_NO_SUSPEND; } else { irq_flags = IRQF_SHARED | IRQF_COND_SUSPEND; } ret = i2c_dw_acquire_lock(dev); if (ret) return ret; regmap_write(dev->map, DW_IC_INTR_MASK, 0); i2c_dw_release_lock(dev); ret = devm_request_irq(dev->dev, dev->irq, i2c_dw_isr, irq_flags, dev_name(dev->dev), dev); if (ret) { dev_err(dev->dev, "failure requesting irq %i: %d\n", dev->irq, ret); return ret; } ret = i2c_dw_init_recovery_info(dev); if (ret) return ret; /* * Increment PM usage count during adapter registration in order to * avoid possible spurious runtime suspend when adapter device is * registered to the device core and immediate resume in case bus has * registered I2C slaves that do I2C transfers in their probe. */ pm_runtime_get_noresume(dev->dev); ret = i2c_add_numbered_adapter(adap); if (ret) dev_err(dev->dev, "failure adding adapter: %d\n", ret); pm_runtime_put_noidle(dev->dev); return ret; } EXPORT_SYMBOL_GPL(i2c_dw_probe_master); MODULE_DESCRIPTION("Synopsys DesignWare I2C bus master adapter"); MODULE_LICENSE("GPL");