diff options
Diffstat (limited to 'drivers/i2c/busses/i2c-designware-master.c')
| -rw-r--r-- | drivers/i2c/busses/i2c-designware-master.c | 133 |
1 files changed, 133 insertions, 0 deletions
diff --git a/drivers/i2c/busses/i2c-designware-master.c b/drivers/i2c/busses/i2c-designware-master.c index dd27b9dbe931..e288b654cb47 100644 --- a/drivers/i2c/busses/i2c-designware-master.c +++ b/drivers/i2c/busses/i2c-designware-master.c @@ -23,6 +23,10 @@ #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 */ @@ -259,6 +263,108 @@ static void i2c_dw_xfer_init(struct dw_i2c_dev *dev) regmap_write(dev->map, DW_IC_INTR_MASK, DW_IC_INTR_MASTER_MASK); } +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; + u32 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); + i2c_dw_disable_int(dev); + + /* 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; +} + /* * Initiate (and continue) low level master read/write transaction. * This function is only called from i2c_dw_isr, and pumping i2c_msg @@ -462,6 +568,16 @@ i2c_dw_xfer(struct i2c_adapter *adap, struct i2c_msg msgs[], int num) pm_runtime_get_sync(dev->dev); + /* + * Initiate I2C message transfer when AMD NAVI GPU card is enabled, + * As it is polling based transfer mechanism, which does not support + * interrupt based functionalities of existing DesignWare driver. + */ + if ((dev->flags & MODEL_MASK) == MODEL_AMD_NAVI_GPU) { + ret = amd_i2c_dw_xfer_quirk(adap, msgs, num); + goto done_nolock; + } + if (dev_WARN_ONCE(dev->dev, dev->suspended, "Transfer while suspended\n")) { ret = -ESHUTDOWN; goto done_nolock; @@ -738,6 +854,20 @@ static int i2c_dw_init_recovery_info(struct dw_i2c_dev *dev) return 0; } +static int amd_i2c_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; +} + int i2c_dw_probe_master(struct dw_i2c_dev *dev) { struct i2c_adapter *adap = &dev->adapter; @@ -774,6 +904,9 @@ int i2c_dw_probe_master(struct dw_i2c_dev *dev) adap->dev.parent = dev->dev; i2c_set_adapdata(adap, dev); + if ((dev->flags & MODEL_MASK) == MODEL_AMD_NAVI_GPU) + return amd_i2c_adap_quirk(dev); + if (dev->flags & ACCESS_NO_IRQ_SUSPEND) { irq_flags = IRQF_NO_SUSPEND; } else { |