/* dw_i2c.c - I2C file for Design Ware */ /* * Copyright (c) 2015 Intel Corporation * * SPDX-License-Identifier: Apache-2.0 */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #ifdef CONFIG_IOAPIC #include #endif #include "i2c_dw.h" #include "i2c_dw_registers.h" #define LOG_LEVEL CONFIG_I2C_LOG_LEVEL #include LOG_MODULE_REGISTER(i2c_dw); #include "i2c-priv.h" static inline uint32_t get_regs(const struct device *dev) { return (uint32_t)DEVICE_MMIO_GET(dev); } static inline void i2c_dw_data_ask(const struct device *dev) { struct i2c_dw_dev_config * const dw = dev->data; uint32_t data; uint8_t tx_empty; int8_t rx_empty; uint8_t cnt; uint8_t rx_buffer_depth, tx_buffer_depth; union ic_comp_param_1_register ic_comp_param_1; uint32_t reg_base = get_regs(dev); /* No more bytes to request, so command queue is no longer needed */ if (dw->request_bytes == 0U) { clear_bit_intr_mask_tx_empty(reg_base); return; } /* Get the FIFO depth that could be from 2 to 256 from HW spec */ ic_comp_param_1.raw = read_comp_param_1(reg_base); rx_buffer_depth = ic_comp_param_1.bits.rx_buffer_depth + 1; tx_buffer_depth = ic_comp_param_1.bits.tx_buffer_depth + 1; /* How many bytes we can actually ask */ rx_empty = (rx_buffer_depth - read_rxflr(reg_base)) - dw->rx_pending; if (rx_empty < 0) { /* RX FIFO expected to be full. * So don't request any bytes, yet. */ return; } /* How many empty slots in TX FIFO (as command queue) */ tx_empty = tx_buffer_depth - read_txflr(reg_base); /* Figure out how many bytes we can request */ cnt = MIN(rx_buffer_depth, dw->request_bytes); cnt = MIN(MIN(tx_empty, rx_empty), cnt); while (cnt > 0) { /* Tell controller to get another byte */ data = IC_DATA_CMD_CMD; /* Send RESTART if needed */ if (dw->xfr_flags & I2C_MSG_RESTART) { data |= IC_DATA_CMD_RESTART; dw->xfr_flags &= ~(I2C_MSG_RESTART); } /* After receiving the last byte, send STOP if needed */ if ((dw->xfr_flags & I2C_MSG_STOP) && (dw->request_bytes == 1U)) { data |= IC_DATA_CMD_STOP; } write_cmd_data(data, reg_base); dw->rx_pending++; dw->request_bytes--; cnt--; } } static void i2c_dw_data_read(const struct device *dev) { struct i2c_dw_dev_config * const dw = dev->data; uint32_t reg_base = get_regs(dev); while (test_bit_status_rfne(reg_base) && (dw->xfr_len > 0)) { dw->xfr_buf[0] = (uint8_t)read_cmd_data(reg_base); dw->xfr_buf++; dw->xfr_len--; dw->rx_pending--; if (dw->xfr_len == 0U) { break; } } /* Nothing to receive anymore */ if (dw->xfr_len == 0U) { dw->state &= ~I2C_DW_CMD_RECV; return; } } static int i2c_dw_data_send(const struct device *dev) { struct i2c_dw_dev_config * const dw = dev->data; uint32_t data = 0U; uint32_t reg_base = get_regs(dev); /* Nothing to send anymore, mask the interrupt */ if (dw->xfr_len == 0U) { clear_bit_intr_mask_tx_empty(reg_base); dw->state &= ~I2C_DW_CMD_SEND; return 0; } while (test_bit_status_tfnt(reg_base) && (dw->xfr_len > 0)) { /* We have something to transmit to a specific host */ data = dw->xfr_buf[0]; /* Send RESTART if needed */ if (dw->xfr_flags & I2C_MSG_RESTART) { data |= IC_DATA_CMD_RESTART; dw->xfr_flags &= ~(I2C_MSG_RESTART); } /* Send STOP if needed */ if ((dw->xfr_len == 1U) && (dw->xfr_flags & I2C_MSG_STOP)) { data |= IC_DATA_CMD_STOP; } write_cmd_data(data, reg_base); dw->xfr_len--; dw->xfr_buf++; if (test_bit_intr_stat_tx_abrt(reg_base)) { return -EIO; } } return 0; } static inline void i2c_dw_transfer_complete(const struct device *dev) { struct i2c_dw_dev_config * const dw = dev->data; uint32_t value; uint32_t reg_base = get_regs(dev); write_intr_mask(DW_DISABLE_ALL_I2C_INT, reg_base); value = read_clr_intr(reg_base); k_sem_give(&dw->device_sync_sem); } static void i2c_dw_isr(void *arg) { const struct device *port = (const struct device *)arg; struct i2c_dw_dev_config * const dw = port->data; union ic_interrupt_register intr_stat; uint32_t value; int ret = 0; uint32_t reg_base = get_regs(port); /* Cache ic_intr_stat for processing, so there is no need to read * the register multiple times. */ intr_stat.raw = read_intr_stat(reg_base); /* * Causes of an interrupt: * - STOP condition is detected * - Transfer is aborted * - Transmit FIFO is empty * - Transmit FIFO has overflowed * - Receive FIFO is full * - Receive FIFO has overflowed * - Received FIFO has underrun * - Transmit data is required (tx_req) * - Receive data is available (rx_avail) */ LOG_DBG("I2C: interrupt received"); /* Check if we are configured as a master device */ if (test_bit_con_master_mode(reg_base)) { /* Bail early if there is any error. */ if ((DW_INTR_STAT_TX_ABRT | DW_INTR_STAT_TX_OVER | DW_INTR_STAT_RX_OVER | DW_INTR_STAT_RX_UNDER) & intr_stat.raw) { dw->state = I2C_DW_CMD_ERROR; goto done; } /* Check if the RX FIFO reached threshold */ if (intr_stat.bits.rx_full) { i2c_dw_data_read(port); } /* Check if the TX FIFO is ready for commands. * TX FIFO also serves as command queue where read requests * are written to TX FIFO. */ if (intr_stat.bits.tx_empty) { if ((dw->xfr_flags & I2C_MSG_RW_MASK) == I2C_MSG_WRITE) { ret = i2c_dw_data_send(port); } else { i2c_dw_data_ask(port); } /* If STOP is not expected, finish processing this * message if there is nothing left to do anymore. */ if (((dw->xfr_len == 0U) && !(dw->xfr_flags & I2C_MSG_STOP)) || (ret != 0)) { goto done; } } } /* STOP detected: finish processing this message */ if (intr_stat.bits.stop_det) { value = read_clr_stop_det(reg_base); goto done; } return; done: i2c_dw_transfer_complete(port); } static int i2c_dw_setup(const struct device *dev, uint16_t slave_address) { struct i2c_dw_dev_config * const dw = dev->data; uint32_t value; union ic_con_register ic_con; union ic_tar_register ic_tar; uint32_t reg_base = get_regs(dev); ic_con.raw = 0U; /* Disable the device controller to be able set TAR */ clear_bit_enable_en(reg_base); /* Disable interrupts */ write_intr_mask(0, reg_base); /* Clear interrupts */ value = read_clr_intr(reg_base); /* Set master or slave mode - (initialization = slave) */ if (I2C_MODE_MASTER & dw->app_config) { /* * Make sure to set both the master_mode and slave_disable_bit * to both 0 or both 1 */ LOG_DBG("I2C: host configured as Master Device"); ic_con.bits.master_mode = 1U; ic_con.bits.slave_disable = 1U; } else { return -EINVAL; } ic_con.bits.restart_en = 1U; /* Set addressing mode - (initialization = 7 bit) */ if (I2C_ADDR_10_BITS & dw->app_config) { LOG_DBG("I2C: using 10-bit address"); ic_con.bits.addr_master_10bit = 1U; ic_con.bits.addr_slave_10bit = 1U; } /* Setup the clock frequency and speed mode */ switch (I2C_SPEED_GET(dw->app_config)) { case I2C_SPEED_STANDARD: LOG_DBG("I2C: speed set to STANDARD"); write_ss_scl_lcnt(dw->lcnt, reg_base); write_ss_scl_hcnt(dw->hcnt, reg_base); ic_con.bits.speed = I2C_DW_SPEED_STANDARD; break; case I2C_SPEED_FAST: __fallthrough; case I2C_SPEED_FAST_PLUS: LOG_DBG("I2C: speed set to FAST or FAST_PLUS"); write_fs_scl_lcnt(dw->lcnt, reg_base); write_fs_scl_hcnt(dw->hcnt, reg_base); ic_con.bits.speed = I2C_DW_SPEED_FAST; break; case I2C_SPEED_HIGH: if (!dw->support_hs_mode) { return -EINVAL; } LOG_DBG("I2C: speed set to HIGH"); write_hs_scl_lcnt(dw->lcnt, reg_base); write_hs_scl_hcnt(dw->hcnt, reg_base); ic_con.bits.speed = I2C_DW_SPEED_HIGH; break; default: LOG_DBG("I2C: invalid speed requested"); return -EINVAL; } LOG_DBG("I2C: lcnt = %d", dw->lcnt); LOG_DBG("I2C: hcnt = %d", dw->hcnt); /* Set the IC_CON register */ write_con(ic_con.raw, reg_base); /* Set RX fifo threshold level. * Setting it to zero automatically triggers interrupt * RX_FULL whenever there is data received. * * TODO: extend the threshold for multi-byte RX. */ write_rx_tl(0, reg_base); /* Set TX fifo threshold level. * TX_EMPTY interrupt is triggered only when the * TX FIFO is truly empty. So that we can let * the controller do the transfers for longer period * before we need to fill the FIFO again. This may * cause some pauses during transfers, but this keeps * the device from interrupting often. */ write_tx_tl(0, reg_base); ic_tar.raw = read_tar(reg_base); if (test_bit_con_master_mode(reg_base)) { /* Set address of target slave */ ic_tar.bits.ic_tar = slave_address; } else { /* Set slave address for device */ write_sar(slave_address, reg_base); } /* If I2C is being operated in master mode and I2C_DYNAMIC_TAR_UPDATE * configuration parameter is set to Yes (1), the ic_10bitaddr_master * bit in ic_tar register would control whether the DW_apb_i2c starts * its transfers in 7-bit or 10-bit addressing mode. */ if (I2C_MODE_MASTER & dw->app_config) { if (I2C_ADDR_10_BITS & dw->app_config) { ic_tar.bits.ic_10bitaddr_master = 1U; } else { ic_tar.bits.ic_10bitaddr_master = 0U; } } write_tar(ic_tar.raw, reg_base); return 0; } static int i2c_dw_transfer(const struct device *dev, struct i2c_msg *msgs, uint8_t num_msgs, uint16_t slave_address) { struct i2c_dw_dev_config * const dw = dev->data; struct i2c_msg *cur_msg = msgs; uint8_t msg_left = num_msgs; uint8_t pflags; int ret; uint32_t reg_base = get_regs(dev); __ASSERT_NO_MSG(msgs); if (!num_msgs) { return 0; } /* First step, check if there is current activity */ if (test_bit_status_activity(reg_base) || (dw->state & I2C_DW_BUSY)) { return -EIO; } dw->state |= I2C_DW_BUSY; ret = i2c_dw_setup(dev, slave_address); if (ret) { dw->state = I2C_DW_STATE_READY; return ret; } /* Enable controller */ set_bit_enable_en(reg_base); /* * While waiting at device_sync_sem, kernel can switch to idle * task which in turn can call pm_system_suspend() hook of Power * Management App (PMA). * pm_device_busy_set() call here, would indicate to PMA that it should * not execute PM policies that would turn off this ip block, causing an * ongoing hw transaction to be left in an inconsistent state. * Note : This is just a sample to show a possible use of the API, it is * upto the driver expert to see, if he actually needs it here, or * somewhere else, or not needed as the driver's suspend()/resume() * can handle everything */ pm_device_busy_set(dev); /* Process all the messages */ while (msg_left > 0) { pflags = dw->xfr_flags; dw->xfr_buf = cur_msg->buf; dw->xfr_len = cur_msg->len; dw->xfr_flags = cur_msg->flags; dw->rx_pending = 0U; /* Need to RESTART if changing transfer direction */ if ((pflags & I2C_MSG_RW_MASK) != (dw->xfr_flags & I2C_MSG_RW_MASK)) { dw->xfr_flags |= I2C_MSG_RESTART; } /* Send STOP if this is the last message */ if (msg_left == 1U) { dw->xfr_flags |= I2C_MSG_STOP; } dw->state &= ~(I2C_DW_CMD_SEND | I2C_DW_CMD_RECV); if ((dw->xfr_flags & I2C_MSG_RW_MASK) == I2C_MSG_WRITE) { dw->state |= I2C_DW_CMD_SEND; dw->request_bytes = 0U; } else { dw->state |= I2C_DW_CMD_RECV; dw->request_bytes = dw->xfr_len; } /* Enable interrupts to trigger ISR */ if (test_bit_con_master_mode(reg_base)) { /* Enable necessary interrupts */ write_intr_mask((DW_ENABLE_TX_INT_I2C_MASTER | DW_ENABLE_RX_INT_I2C_MASTER), reg_base); } else { /* Enable necessary interrupts */ write_intr_mask(DW_ENABLE_TX_INT_I2C_SLAVE, reg_base); } /* Wait for transfer to be done */ k_sem_take(&dw->device_sync_sem, K_FOREVER); if (dw->state & I2C_DW_CMD_ERROR) { ret = -EIO; break; } /* Something wrong if there is something left to do */ if (dw->xfr_len > 0) { ret = -EIO; break; } cur_msg++; msg_left--; } pm_device_busy_clear(dev); dw->state = I2C_DW_STATE_READY; return ret; } static int i2c_dw_runtime_configure(const struct device *dev, uint32_t config) { struct i2c_dw_dev_config * const dw = dev->data; uint32_t value = 0U; uint32_t rc = 0U; uint32_t reg_base = get_regs(dev); dw->app_config = config; /* Make sure we have a supported speed for the DesignWare model */ /* and have setup the clock frequency and speed mode */ switch (I2C_SPEED_GET(dw->app_config)) { case I2C_SPEED_STANDARD: /* Following the directions on DW spec page 59, IC_SS_SCL_LCNT * must have register values larger than IC_FS_SPKLEN + 7 */ if (I2C_STD_LCNT <= (read_fs_spklen(reg_base) + 7)) { value = read_fs_spklen(reg_base) + 8; } else { value = I2C_STD_LCNT; } dw->lcnt = value; /* Following the directions on DW spec page 59, IC_SS_SCL_HCNT * must have register values larger than IC_FS_SPKLEN + 5 */ if (I2C_STD_HCNT <= (read_fs_spklen(reg_base) + 5)) { value = read_fs_spklen(reg_base) + 6; } else { value = I2C_STD_HCNT; } dw->hcnt = value; break; case I2C_SPEED_FAST: __fallthrough; case I2C_SPEED_FAST_PLUS: /* * Following the directions on DW spec page 59, IC_FS_SCL_LCNT * must have register values larger than IC_FS_SPKLEN + 7 */ if (I2C_FS_LCNT <= (read_fs_spklen(reg_base) + 7)) { value = read_fs_spklen(reg_base) + 8; } else { value = I2C_FS_LCNT; } dw->lcnt = value; /* * Following the directions on DW spec page 59, IC_FS_SCL_HCNT * must have register values larger than IC_FS_SPKLEN + 5 */ if (I2C_FS_HCNT <= (read_fs_spklen(reg_base) + 5)) { value = read_fs_spklen(reg_base) + 6; } else { value = I2C_FS_HCNT; } dw->hcnt = value; break; case I2C_SPEED_HIGH: if (dw->support_hs_mode) { if (I2C_HS_LCNT <= (read_hs_spklen(reg_base) + 7)) { value = read_hs_spklen(reg_base) + 8; } else { value = I2C_HS_LCNT; } dw->lcnt = value; if (I2C_HS_HCNT <= (read_hs_spklen(reg_base) + 5)) { value = read_hs_spklen(reg_base) + 6; } else { value = I2C_HS_HCNT; } dw->hcnt = value; } else { rc = -EINVAL; } break; default: /* TODO change */ rc = -EINVAL; } /* * Clear any interrupts currently waiting in the controller */ value = read_clr_intr(reg_base); /* * TEMPORARY HACK - The I2C does not work in any mode other than Master * currently. This "hack" forces us to always be configured for master * mode, until we can verify that Slave mode works correctly. */ dw->app_config |= I2C_MODE_MASTER; return rc; } static const struct i2c_driver_api funcs = { .configure = i2c_dw_runtime_configure, .transfer = i2c_dw_transfer, }; static int i2c_dw_initialize(const struct device *dev) { const struct i2c_dw_rom_config * const rom = dev->config; struct i2c_dw_dev_config * const dw = dev->data; union ic_con_register ic_con; uint32_t reg_base = get_regs(dev); #if DT_ANY_INST_ON_BUS_STATUS_OKAY(pcie) if (rom->pcie) { struct pcie_mbar mbar; if (!pcie_probe(rom->pcie_bdf, rom->pcie_id)) { return -EINVAL; } pcie_probe_mbar(rom->pcie_bdf, 0, &mbar); pcie_set_cmd(rom->pcie_bdf, PCIE_CONF_CMDSTAT_MEM, true); device_map(DEVICE_MMIO_RAM_PTR(dev), mbar.phys_addr, mbar.size, K_MEM_CACHE_NONE); } else #endif { DEVICE_MMIO_MAP(dev, K_MEM_CACHE_NONE); } k_sem_init(&dw->device_sync_sem, 0, K_SEM_MAX_LIMIT); /* verify that we have a valid DesignWare register first */ if (read_comp_type(reg_base) != I2C_DW_MAGIC_KEY) { LOG_DBG("I2C: DesignWare magic key not found, check base " "address. Stopping initialization"); return -EIO; } /* * grab the default value on initialization. This should be set to the * IC_MAX_SPEED_MODE in the hardware. If it does support high speed we * can move provide support for it */ ic_con.raw = read_con(reg_base); if (ic_con.bits.speed == I2C_DW_SPEED_HIGH) { LOG_DBG("I2C: high speed supported"); dw->support_hs_mode = true; } else { LOG_DBG("I2C: high speed NOT supported"); dw->support_hs_mode = false; } rom->config_func(dev); dw->app_config = I2C_MODE_MASTER | i2c_map_dt_bitrate(rom->bitrate); if (i2c_dw_runtime_configure(dev, dw->app_config) != 0) { LOG_DBG("I2C: Cannot set default configuration"); return -EIO; } dw->state = I2C_DW_STATE_READY; return 0; } #define I2C_DW_INIT_PCIE0(n) #define I2C_DW_INIT_PCIE1(n) \ .pcie = true, \ .pcie_bdf = DT_INST_REG_ADDR(n), \ .pcie_id = DT_INST_REG_SIZE(n), #define I2C_DW_INIT_PCIE(n) \ _CONCAT(I2C_DW_INIT_PCIE, DT_INST_ON_BUS(n, pcie))(n) #define I2C_DW_IRQ_FLAGS_SENSE0(n) 0 #define I2C_DW_IRQ_FLAGS_SENSE1(n) DT_INST_IRQ(n, sense) #define I2C_DW_IRQ_FLAGS(n) \ _CONCAT(I2C_DW_IRQ_FLAGS_SENSE, DT_INST_IRQ_HAS_CELL(n, sense))(n) /* not PCI(e) */ #define I2C_DW_IRQ_CONFIG_PCIE0(n) \ static void i2c_config_##n(const struct device *port) \ { \ ARG_UNUSED(port); \ IRQ_CONNECT(DT_INST_IRQN(n), DT_INST_IRQ(n, priority), \ i2c_dw_isr, DEVICE_DT_INST_GET(n), \ I2C_DW_IRQ_FLAGS(n)); \ irq_enable(DT_INST_IRQN(n)); \ } /* PCI(e) with auto IRQ detection */ #define I2C_DW_IRQ_CONFIG_PCIE1(n) \ static void i2c_config_##n(const struct device *port) \ { \ ARG_UNUSED(port); \ BUILD_ASSERT(DT_INST_IRQN(n) == PCIE_IRQ_DETECT, \ "Only runtime IRQ configuration is supported"); \ BUILD_ASSERT(IS_ENABLED(CONFIG_DYNAMIC_INTERRUPTS), \ "DW I2C PCI needs CONFIG_DYNAMIC_INTERRUPTS"); \ unsigned int irq = pcie_alloc_irq(DT_INST_REG_ADDR(n)); \ if (irq == PCIE_CONF_INTR_IRQ_NONE) { \ return; \ } \ pcie_connect_dynamic_irq(DT_INST_REG_ADDR(n), irq, \ DT_INST_IRQ(n, priority), \ (void (*)(const void *))i2c_dw_isr, \ DEVICE_DT_INST_GET(n), \ I2C_DW_IRQ_FLAGS(n)); \ pcie_irq_enable(DT_INST_REG_ADDR(n), irq); \ } #define I2C_DW_IRQ_CONFIG(n) \ _CONCAT(I2C_DW_IRQ_CONFIG_PCIE, DT_INST_ON_BUS(n, pcie))(n) #define I2C_DEVICE_INIT_DW(n) \ static void i2c_config_##n(const struct device *port); \ static const struct i2c_dw_rom_config i2c_config_dw_##n = { \ DEVICE_MMIO_ROM_INIT(DT_DRV_INST(n)), \ .config_func = i2c_config_##n, \ .bitrate = DT_INST_PROP(n, clock_frequency), \ I2C_DW_INIT_PCIE(n) \ }; \ static struct i2c_dw_dev_config i2c_##n##_runtime; \ I2C_DEVICE_DT_INST_DEFINE(n, i2c_dw_initialize, NULL, \ &i2c_##n##_runtime, &i2c_config_dw_##n, \ POST_KERNEL, CONFIG_I2C_INIT_PRIORITY, \ &funcs); \ I2C_DW_IRQ_CONFIG(n) DT_INST_FOREACH_STATUS_OKAY(I2C_DEVICE_INIT_DW)