/* 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 #ifdef CONFIG_SHARED_IRQ #include #endif #ifdef CONFIG_IOAPIC #include #endif #include "i2c_dw.h" #include "i2c_dw_registers.h" #define SYS_LOG_LEVEL CONFIG_SYS_LOG_I2C_LEVEL #include static inline void _i2c_dw_data_ask(struct device *dev) { struct i2c_dw_dev_config * const dw = dev->driver_data; uint32_t data; uint8_t tx_empty; int8_t rx_empty; uint8_t cnt; volatile struct i2c_dw_registers * const regs = (struct i2c_dw_registers *)dw->base_address; /* No more bytes to request, so command queue is no longer needed */ if (dw->request_bytes == 0) { regs->ic_intr_mask.bits.tx_empty = 0; return; } /* How many bytes we can actually ask */ rx_empty = (I2C_DW_FIFO_DEPTH - regs->ic_rxflr) - 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 = I2C_DW_FIFO_DEPTH - regs->ic_txflr; /* Figure out how many bytes we can request */ cnt = min(I2C_DW_FIFO_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 == 1)) { data |= IC_DATA_CMD_STOP; } regs->ic_data_cmd.raw = data; dw->rx_pending++; dw->request_bytes--; cnt--; } } static void _i2c_dw_data_read(struct device *dev) { struct i2c_dw_dev_config * const dw = dev->driver_data; volatile struct i2c_dw_registers * const regs = (struct i2c_dw_registers *)dw->base_address; while (regs->ic_status.bits.rfne && (dw->xfr_len > 0)) { dw->xfr_buf[0] = regs->ic_data_cmd.raw; dw->xfr_buf++; dw->xfr_len--; dw->rx_pending--; if (dw->xfr_len == 0) { break; } } /* Nothing to receive anymore */ if (dw->xfr_len == 0) { dw->state &= ~I2C_DW_CMD_RECV; return; } } static int _i2c_dw_data_send(struct device *dev) { struct i2c_dw_dev_config * const dw = dev->driver_data; uint32_t data = 0; volatile struct i2c_dw_registers * const regs = (struct i2c_dw_registers *)dw->base_address; /* Nothing to send anymore, mask the interrupt */ if (dw->xfr_len == 0) { regs->ic_intr_mask.bits.tx_empty = 0; dw->state &= ~I2C_DW_CMD_SEND; return 0; } while (regs->ic_status.bits.tfnf && (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 == 1) && (dw->xfr_flags & I2C_MSG_STOP)) { data |= IC_DATA_CMD_STOP; } regs->ic_data_cmd.raw = data; dw->xfr_len--; dw->xfr_buf++; if (regs->ic_intr_stat.bits.tx_abrt) { return -EIO; } } return 0; } static inline void _i2c_dw_transfer_complete(struct device *dev) { struct i2c_dw_dev_config * const dw = dev->driver_data; uint32_t value; volatile struct i2c_dw_registers * const regs = (struct i2c_dw_registers *)dw->base_address; regs->ic_intr_mask.raw = DW_DISABLE_ALL_I2C_INT; value = regs->ic_clr_intr; k_sem_give(&dw->device_sync_sem); } static void i2c_dw_isr(void *arg) { struct device *port = (struct device *)arg; struct i2c_dw_dev_config * const dw = port->driver_data; union ic_interrupt_register intr_stat; uint32_t value; int ret = 0; volatile struct i2c_dw_registers * const regs = (struct i2c_dw_registers *)dw->base_address; /* Cache ic_intr_stat for processing, so there is no need to read * the register multiple times. */ intr_stat.raw = regs->ic_intr_stat.raw; #if CONFIG_SHARED_IRQ /* If using with shared IRQ, this function will be called * by the shared IRQ driver. So check here if the interrupt * is coming from the I2C controller (or somewhere else). */ if (!intr_stat.raw) { return; } #endif /* * 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) */ SYS_LOG_DBG("I2C: interrupt received"); /* Check if we are configured as a master device */ if (regs->ic_con.bits.master_mode) { /* 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 == 0) && !(dw->xfr_flags & I2C_MSG_STOP)) || (ret != 0)) { goto done; } } } else { /* we must be configured as a slave device */ /* We have a read requested by the master device */ if (intr_stat.bits.rd_req && (!dw->app_config.bits.is_slave_read)) { /* data is not ready to send */ if (intr_stat.bits.tx_abrt) { /* clear the TX_ABRT interrupt */ value = regs->ic_clr_tx_abrt; } _i2c_dw_data_send(port); value = regs->ic_clr_rd_req; } /* The slave device is ready to receive */ if (intr_stat.bits.rx_full && dw->app_config.bits.is_slave_read) { _i2c_dw_data_read(port); } } /* STOP detected: finish processing this message */ if (intr_stat.bits.stop_det) { value = regs->ic_clr_stop_det; goto done; } return; done: _i2c_dw_transfer_complete(port); } static int _i2c_dw_setup(struct device *dev, uint16_t slave_address) { struct i2c_dw_dev_config * const dw = dev->driver_data; uint32_t value; union ic_con_register ic_con; volatile struct i2c_dw_registers * const regs = (struct i2c_dw_registers *)dw->base_address; ic_con.raw = 0; /* Disable the device controller to be able set TAR */ regs->ic_enable.bits.enable = 0; /* Disable interrupts */ regs->ic_intr_mask.raw = 0; /* Clear interrupts */ value = regs->ic_clr_intr; /* Set master or slave mode - (initialization = slave) */ if (dw->app_config.bits.is_master_device) { /* * Make sure to set both the master_mode and slave_disable_bit * to both 0 or both 1 */ SYS_LOG_DBG("I2C: host configured as Master Device"); ic_con.bits.master_mode = 1; ic_con.bits.slave_disable = 1; } ic_con.bits.restart_en = 1; /* Set addressing mode - (initialization = 7 bit) */ if (dw->app_config.bits.use_10_bit_addr) { SYS_LOG_DBG("I2C: using 10-bit address"); ic_con.bits.addr_master_10bit = 1; ic_con.bits.addr_slave_10bit = 1; } /* Setup the clock frequency and speed mode */ switch (dw->app_config.bits.speed) { case I2C_SPEED_STANDARD: SYS_LOG_DBG("I2C: speed set to STANDARD"); regs->ic_ss_scl_lcnt = dw->lcnt; regs->ic_ss_scl_hcnt = dw->hcnt; ic_con.bits.speed = I2C_DW_SPEED_STANDARD; break; case I2C_SPEED_FAST: /* fall through */ case I2C_SPEED_FAST_PLUS: SYS_LOG_DBG("I2C: speed set to FAST or FAST_PLUS"); regs->ic_fs_scl_lcnt = dw->lcnt; regs->ic_fs_scl_hcnt = dw->hcnt; ic_con.bits.speed = I2C_DW_SPEED_FAST; break; case I2C_SPEED_HIGH: if (!dw->support_hs_mode) { return -EINVAL; } SYS_LOG_DBG("I2C: speed set to HIGH"); regs->ic_hs_scl_lcnt = dw->lcnt; regs->ic_hs_scl_hcnt = dw->hcnt; ic_con.bits.speed = I2C_DW_SPEED_HIGH; break; default: SYS_LOG_DBG("I2C: invalid speed requested"); return -EINVAL; } SYS_LOG_DBG("I2C: lcnt = %d", dw->lcnt); SYS_LOG_DBG("I2C: hcnt = %d", dw->hcnt); /* Set the IC_CON register */ regs->ic_con = ic_con; /* 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. */ regs->ic_rx_tl = 0; /* 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. */ regs->ic_tx_tl = 0; if (regs->ic_con.bits.master_mode) { /* Set address of target slave */ regs->ic_tar.bits.ic_tar = slave_address; } else { /* Set slave address for device */ regs->ic_sar.bits.ic_sar = slave_address; } return 0; } static int i2c_dw_transfer(struct device *dev, struct i2c_msg *msgs, uint8_t num_msgs, uint16_t slave_address) { struct i2c_dw_dev_config * const dw = dev->driver_data; struct i2c_msg *cur_msg = msgs; uint8_t msg_left = num_msgs; uint8_t pflags; int ret; volatile struct i2c_dw_registers * const regs = (struct i2c_dw_registers *)dw->base_address; /* Why bother processing no messages */ if (!msgs || !num_msgs) { return -ENOTSUP; } /* First step, check if there is current activity */ if ((regs->ic_status.bits.activity) || (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 */ regs->ic_enable.bits.enable = 1; /* * While waiting at device_sync_sem, kernel can switch to idle * task which in turn can call _sys_soc_suspend() hook of Power * Management App (PMA). * 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 */ 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 = 0; /* 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 == 1) { 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 = 0; } else { dw->state |= I2C_DW_CMD_RECV; dw->request_bytes = dw->xfr_len; } /* Enable interrupts to trigger ISR */ if (regs->ic_con.bits.master_mode) { /* Enable necessary interrupts */ regs->ic_intr_mask.raw = (DW_ENABLE_TX_INT_I2C_MASTER | DW_ENABLE_RX_INT_I2C_MASTER); } else { /* Enable necessary interrupts */ regs->ic_intr_mask.raw = DW_ENABLE_TX_INT_I2C_SLAVE; } /* 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--; } device_busy_clear(dev); dw->state = I2C_DW_STATE_READY; return ret; } static int i2c_dw_runtime_configure(struct device *dev, uint32_t config) { struct i2c_dw_dev_config * const dw = dev->driver_data; uint32_t value = 0; uint32_t rc = 0; volatile struct i2c_dw_registers * const regs = (struct i2c_dw_registers *)dw->base_address; dw->app_config.raw = config; /* Make sure we have a supported speed for the DesignWare model */ /* and have setup the clock frequency and speed mode */ switch (dw->app_config.bits.speed) { 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 <= (regs->ic_fs_spklen + 7)) { value = regs->ic_fs_spklen + 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 <= (regs->ic_fs_spklen + 5)) { value = regs->ic_fs_spklen + 6; } else { value = I2C_STD_HCNT; } dw->hcnt = value; break; case I2C_SPEED_FAST: /* fall through */ 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 <= (regs->ic_fs_spklen + 7)) { value = regs->ic_fs_spklen + 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 <= (regs->ic_fs_spklen + 5)) { value = regs->ic_fs_spklen + 6; } else { value = I2C_FS_HCNT; } dw->hcnt = value; break; case I2C_SPEED_HIGH: if (dw->support_hs_mode) { if (I2C_HS_LCNT <= (regs->ic_hs_spklen + 7)) { value = regs->ic_hs_spklen + 8; } else { value = I2C_HS_LCNT; } dw->lcnt = value; if (I2C_HS_HCNT <= (regs->ic_hs_spklen + 5)) { value = regs->ic_hs_spklen + 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 = regs->ic_clr_intr; /* * 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.bits.is_master_device = 1; return rc; } static const struct i2c_driver_api funcs = { .configure = i2c_dw_runtime_configure, .transfer = i2c_dw_transfer, }; #ifdef CONFIG_PCI static inline int i2c_dw_pci_setup(struct device *dev) { struct i2c_dw_dev_config * const dw = dev->driver_data; pci_bus_scan_init(); if (!pci_bus_scan(&dw->pci_dev)) { SYS_LOG_DBG("Could not find device"); return 0; } #ifdef CONFIG_PCI_ENUMERATION dw->base_address = dw->pci_dev.addr; #endif pci_enable_regs(&dw->pci_dev); pci_show(&dw->pci_dev); return 1; } #else #define i2c_dw_pci_setup(_unused_) (1) #endif /* CONFIG_PCI */ static int i2c_dw_initialize(struct device *port) { const struct i2c_dw_rom_config * const rom = port->config->config_info; struct i2c_dw_dev_config * const dev = port->driver_data; volatile struct i2c_dw_registers *regs; if (!i2c_dw_pci_setup(port)) { port->driver_api = NULL; return -EPERM; } k_sem_init(&dev->device_sync_sem, 0, UINT_MAX); regs = (struct i2c_dw_registers *) dev->base_address; /* verify that we have a valid DesignWare register first */ if (regs->ic_comp_type != I2C_DW_MAGIC_KEY) { port->driver_api = NULL; SYS_LOG_DBG("I2C: DesignWare magic key not found, check base " "address. Stopping initialization"); return -EPERM; } /* * 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 */ if (regs->ic_con.bits.speed == I2C_DW_SPEED_HIGH) { SYS_LOG_DBG("I2C: high speed supported"); dev->support_hs_mode = true; } else { SYS_LOG_DBG("I2C: high speed NOT supported"); dev->support_hs_mode = false; } rom->config_func(port); if (i2c_dw_runtime_configure(port, dev->app_config.raw) != 0) { SYS_LOG_DBG("I2C: Cannot set default configuration 0x%x", dev->app_config.raw); return -EPERM; } dev->state = I2C_DW_STATE_READY; return 0; } /* system bindings */ #if CONFIG_I2C_0 static void i2c_config_0(struct device *port); static const struct i2c_dw_rom_config i2c_config_dw_0 = { #ifdef CONFIG_I2C_0_IRQ_DIRECT .irq_num = I2C_DW_0_IRQ, #endif .config_func = i2c_config_0, #ifdef CONFIG_GPIO_DW_0_IRQ_SHARED .shared_irq_dev_name = CONFIG_I2C_0_IRQ_SHARED_NAME, #endif }; static struct i2c_dw_dev_config i2c_0_runtime = { .base_address = I2C_DW_0_BASE_ADDR, .app_config.raw = CONFIG_I2C_0_DEFAULT_CFG, #if CONFIG_PCI .pci_dev.class_type = I2C_DW_PCI_CLASS, .pci_dev.bus = I2C_DW_0_PCI_BUS, .pci_dev.dev = I2C_DW_0_PCI_DEV, .pci_dev.vendor_id = I2C_DW_PCI_VENDOR_ID, .pci_dev.device_id = I2C_DW_PCI_DEVICE_ID, .pci_dev.function = I2C_DW_0_PCI_FUNCTION, .pci_dev.bar = I2C_DW_0_PCI_BAR, #endif }; DEVICE_AND_API_INIT(i2c_0, CONFIG_I2C_0_NAME, &i2c_dw_initialize, &i2c_0_runtime, &i2c_config_dw_0, POST_KERNEL, CONFIG_I2C_INIT_PRIORITY, &funcs); static void i2c_config_0(struct device *port) { #if defined(CONFIG_I2C_0_IRQ_DIRECT) IRQ_CONNECT(I2C_DW_0_IRQ, CONFIG_I2C_0_IRQ_PRI, i2c_dw_isr, DEVICE_GET(i2c_0), I2C_DW_IRQ_FLAGS); irq_enable(I2C_DW_0_IRQ); #elif defined(CONFIG_I2C_0_IRQ_SHARED) const struct i2c_dw_rom_config * const config = port->config->config_info; struct device *shared_irq_dev; shared_irq_dev = device_get_binding(config->shared_irq_dev_name); shared_irq_isr_register(shared_irq_dev, (isr_t)i2c_dw_isr, port); shared_irq_enable(shared_irq_dev, port); #endif } #endif /* CONFIG_I2C_0 */ /* * Adding in I2C1 */ #if CONFIG_I2C_1 static void i2c_config_1(struct device *port); static const struct i2c_dw_rom_config i2c_config_dw_1 = { .irq_num = I2C_DW_1_IRQ, .config_func = i2c_config_1, }; static struct i2c_dw_dev_config i2c_1_runtime = { .base_address = I2C_DW_1_BASE_ADDR, .app_config.raw = CONFIG_I2C_1_DEFAULT_CFG, #if CONFIG_PCI .pci_dev.class_type = I2C_DW_PCI_CLASS, .pci_dev.bus = I2C_DW_1_PCI_BUS, .pci_dev.dev = I2C_DW_1_PCI_DEV, .pci_dev.vendor_id = I2C_DW_PCI_VENDOR_ID, .pci_dev.device_id = I2C_DW_PCI_DEVICE_ID, .pci_dev.function = I2C_DW_1_PCI_FUNCTION, .pci_dev.bar = I2C_DW_1_PCI_BAR, #endif }; DEVICE_AND_API_INIT(i2c_1, CONFIG_I2C_1_NAME, &i2c_dw_initialize, &i2c_1_runtime, &i2c_config_dw_1, POST_KERNEL, CONFIG_KERNEL_INIT_PRIORITY_DEFAULT, &funcs); static void i2c_config_1(struct device *port) { IRQ_CONNECT(I2C_DW_1_IRQ, CONFIG_I2C_1_IRQ_PRI, i2c_dw_isr, DEVICE_GET(i2c_1), I2C_DW_IRQ_FLAGS); irq_enable(I2C_DW_1_IRQ); } #endif /* CONFIG_I2C_1 */