/* Copyright (c) 2014 The Chromium OS Authors. All rights reserved. * Use of this source code is governed by a BSD-style license that can be * found in the LICENSE file. */ /* I2C port module for Chrome EC */ #include "clock.h" #include "clock_chip.h" #include "common.h" #include "console.h" #include "gpio.h" #include "hooks.h" #include "i2c.h" #include "registers.h" #include "task.h" #include "timer.h" #include "util.h" #if !(DEBUG_I2C) #define CPUTS(...) #define CPRINTS(...) #else #define CPUTS(outstr) cputs(CC_I2C, outstr) #define CPRINTS(format, args...) cprints(CC_I2C, format, ## args) #endif /* Pull-up bit for I2C */ #define NPCX_I2C_PUBIT(controller, port) \ ((controller*2) + port) /* Data abort timeout unit:ms*/ #define I2C_ABORT_TIMEOUT 35 /* Marco functions of I2C */ #define I2C_START(ctrl) SET_BIT(NPCX_SMBCTL1(ctrl), NPCX_SMBCTL1_START) #define I2C_STOP(ctrl) SET_BIT(NPCX_SMBCTL1(ctrl), NPCX_SMBCTL1_STOP) #define I2C_NACK(ctrl) SET_BIT(NPCX_SMBCTL1(ctrl), NPCX_SMBCTL1_ACK) #define I2C_WRITE_BYTE(ctrl, data) (NPCX_SMBSDA(ctrl) = data) #define I2C_READ_BYTE(ctrl, data) (data = NPCX_SMBSDA(ctrl)) /* Error values that functions can return */ enum smb_error { SMB_OK = 0, /* No error */ SMB_CH_OCCUPIED, /* Channel is already occupied */ SMB_MEM_POOL_INIT_ERROR, /* Memory pool initialization error */ SMB_BUS_FREQ_ERROR, /* SMbus freq was not valid */ SMB_INVLAID_REGVALUE, /* Invalid SMbus register value */ SMB_UNEXIST_CH_ERROR, /* Channel does not exist */ SMB_NO_SUPPORT_PTL, /* Not support SMBus Protocol */ SMB_BUS_ERROR, /* Encounter bus error */ SMB_MASTER_NO_ADDRESS_MATCH,/* No slave address match (Master Mode)*/ SMB_READ_DATA_ERROR, /* Read data for SDA error */ SMB_READ_OVERFLOW_ERROR, /* Read data over than we predict */ SMB_TIMEOUT_ERROR, /* Timeout expired */ SMB_MODULE_ISBUSY, /* Module is occupied by other device */ SMB_BUS_BUSY, /* SMBus is occupied by other device */ }; /* * Internal SMBus Interface driver states values, which reflect events * which occured on the bus */ enum smb_oper_state_t { SMB_IDLE, SMB_MASTER_START, SMB_WRITE_OPER, SMB_READ_OPER, SMB_REPEAT_START, SMB_WAIT_REPEAT_START, }; /* IRQ for each port */ static const uint32_t i2c_irqs[I2C_CONTROLLER_COUNT] = { NPCX_IRQ_SMB1, NPCX_IRQ_SMB2, NPCX_IRQ_SMB3, NPCX_IRQ_SMB4}; BUILD_ASSERT(ARRAY_SIZE(i2c_irqs) == I2C_CONTROLLER_COUNT); /* I2C controller state data */ struct i2c_status { int flags; /* Flags (I2C_XFER_*) */ const uint8_t *tx_buf; /* Entry pointer of transmit buffer */ uint8_t *rx_buf; /* Entry pointer of receive buffer */ uint16_t sz_txbuf; /* Size of Tx buffer in bytes */ uint16_t sz_rxbuf; /* Size of rx buffer in bytes */ uint16_t idx_buf; /* Current index of Tx/Rx buffer */ uint8_t slave_addr;/* Target slave address */ enum smb_oper_state_t oper_state;/* Smbus operation state */ enum smb_error err_code; /* Error code */ int task_waiting; /* Task waiting on controller */ uint32_t timeout_us;/* Transaction timeout */ }; /* I2C controller state data array */ static struct i2c_status i2c_stsobjs[I2C_CONTROLLER_COUNT]; int i2c_port_to_controller(int port) { if (port < 0 || port >= I2C_PORT_COUNT) return -1; return (port == NPCX_I2C_PORT0_0) ? 0 : port - 1; } static void i2c_select_port(int port) { /* * I2C0_1 uses port 1 of controller 0. All other I2C pin sets * use port 0. */ if (port > NPCX_I2C_PORT0_1) return; /* Select IO pins for multi-ports I2C controllers */ UPDATE_BIT(NPCX_GLUE_SMBSEL, NPCX_SMBSEL_SMB0SEL, (port == NPCX_I2C_PORT0_1)); } int i2c_bus_busy(int controller) { return IS_BIT_SET(NPCX_SMBCST(controller), NPCX_SMBCST_BB) ? 1 : 0; } int i2c_abort_data(int controller) { uint16_t timeout = I2C_ABORT_TIMEOUT; /* Clear NEGACK, STASTR and BER bits */ SET_BIT(NPCX_SMBST(controller), NPCX_SMBST_BER); SET_BIT(NPCX_SMBST(controller), NPCX_SMBST_STASTR); SET_BIT(NPCX_SMBST(controller), NPCX_SMBST_NEGACK); /* Wait till STOP condition is generated */ while (--timeout) { if (!IS_BIT_SET(NPCX_SMBCTL1(controller), NPCX_SMBCTL1_STOP)) break; msleep(1); } /* Clear BB (BUS BUSY) bit */ SET_BIT(NPCX_SMBCST(controller), NPCX_SMBCST_BB); if (timeout == 0) { cprints(CC_I2C, "Abort i2c %02x fail!", controller); return 0; } else return 1; } void i2c_reset(int controller) { uint16_t timeout = I2C_ABORT_TIMEOUT; /* Disable the SMB module */ CLEAR_BIT(NPCX_SMBCTL2(controller), NPCX_SMBCTL2_ENABLE); while (--timeout) { /* WAIT FOR SCL & SDA IS HIGH */ if (IS_BIT_SET(NPCX_SMBCTL3(controller), NPCX_SMBCTL3_SCL_LVL) && IS_BIT_SET(NPCX_SMBCTL3(controller), NPCX_SMBCTL3_SDA_LVL)) break; msleep(1); } if (timeout == 0) cprints(CC_I2C, "Reset i2c %02x fail!", controller); /* Enable the SMB module */ SET_BIT(NPCX_SMBCTL2(controller), NPCX_SMBCTL2_ENABLE); } void i2c_recovery(int controller) { CPUTS("RECOVERY\r\n"); /* Abort data, generating STOP condition */ if (i2c_abort_data(controller) == 1 && i2c_stsobjs[controller].err_code == SMB_MASTER_NO_ADDRESS_MATCH) return; /* Reset i2c controller by re-enable i2c controller*/ i2c_reset(controller); } enum smb_error i2c_master_transaction(int controller) { /* Set i2c mode to object */ int events = 0; volatile struct i2c_status *p_status = i2c_stsobjs + controller; if (p_status->oper_state == SMB_IDLE) { p_status->oper_state = SMB_MASTER_START; } else if (p_status->oper_state == SMB_WAIT_REPEAT_START) { p_status->oper_state = SMB_REPEAT_START; CPUTS("R"); } /* Generate a START condition */ I2C_START(controller); CPUTS("ST"); /* Wait for transfer complete or timeout */ events = task_wait_event_mask(TASK_EVENT_I2C_IDLE, p_status->timeout_us); /* Handle timeout */ if ((events & TASK_EVENT_I2C_IDLE) == 0) { /* Recovery I2C controller */ i2c_recovery(controller); p_status->err_code = SMB_TIMEOUT_ERROR; } /* * In slave write operation, NACK is OK, otherwise it is a problem */ else if (p_status->err_code == SMB_BUS_ERROR || p_status->err_code == SMB_MASTER_NO_ADDRESS_MATCH){ i2c_recovery(controller); } return p_status->err_code; } inline void i2c_handle_sda_irq(int controller) { volatile struct i2c_status *p_status = i2c_stsobjs + controller; /* 1 Issue Start is successful ie. write address byte */ if (p_status->oper_state == SMB_MASTER_START || p_status->oper_state == SMB_REPEAT_START) { uint8_t addr = p_status->slave_addr; /* Prepare address byte */ if (p_status->sz_txbuf == 0) {/* Receive mode */ p_status->oper_state = SMB_READ_OPER; /* * Receiving one byte only - set nack just * before writing address byte */ if (p_status->sz_rxbuf == 1) I2C_NACK(controller); /* Write the address to the bus R bit*/ I2C_WRITE_BYTE(controller, (addr | 0x1)); CPRINTS("-ARR-0x%02x", addr); } else {/* Transmit mode */ p_status->oper_state = SMB_WRITE_OPER; /* Write the address to the bus W bit*/ I2C_WRITE_BYTE(controller, addr); CPRINTS("-ARW-0x%02x", addr); } /* Completed handling START condition */ return; } /* 2 Handle master write operation */ else if (p_status->oper_state == SMB_WRITE_OPER) { /* all bytes have been written, in a pure write operation */ if (p_status->idx_buf == p_status->sz_txbuf) { /* no more message */ if (p_status->sz_rxbuf == 0) { /* need to STOP or not */ if (p_status->flags & I2C_XFER_STOP) { /* Issue a STOP condition on the bus */ I2C_STOP(controller); CPUTS("-SP"); } /* Clear SDA Status bit by writing dummy byte */ I2C_WRITE_BYTE(controller, 0xFF); /* Set error code */ p_status->err_code = SMB_OK; /* Notify upper layer */ p_status->oper_state = (p_status->flags & I2C_XFER_STOP) ? SMB_IDLE : SMB_WAIT_REPEAT_START; task_set_event(p_status->task_waiting, TASK_EVENT_I2C_IDLE, 0); CPUTS("-END"); } /* need to restart & send slave address immediately */ else { uint8_t addr_byte = p_status->slave_addr; /* * Prepare address byte * and start to receive bytes */ p_status->oper_state = SMB_READ_OPER; /* Reset index of buffer */ p_status->idx_buf = 0; /* * Generate (Repeated) Start * upon next write to SDA */ I2C_START(controller); CPUTS("-RST"); /* * Receiving one byte only - set nack just * before writing address byte */ if (p_status->sz_rxbuf == 1) { I2C_NACK(controller); CPUTS("-GNA"); } /* Write the address to the bus R bit*/ I2C_WRITE_BYTE(controller, (addr_byte | 0x1)); CPUTS("-ARR"); } } /* write next byte (not last byte and not slave address */ else { I2C_WRITE_BYTE(controller, p_status->tx_buf[p_status->idx_buf++]); CPRINTS("-W(%02x)", p_status->tx_buf[p_status->idx_buf-1]); } } /* 3 Handle master read operation (read or after a write operation) */ else if (p_status->oper_state == SMB_READ_OPER) { uint8_t data; /* last byte is about to be read - end of transaction */ if (p_status->idx_buf == (p_status->sz_rxbuf - 1)) { /* need to STOP or not */ if (p_status->flags & I2C_XFER_STOP) { /* Stop should set before reading last byte */ I2C_STOP(controller); CPUTS("-SP"); } } /* Check if byte-before-last is about to be read */ else if (p_status->idx_buf == (p_status->sz_rxbuf - 2)) { /* * Set nack before reading byte-before-last, * so that nack will be generated after receive * of last byte */ I2C_NACK(controller); CPUTS("-GNA"); } /* Read data for SMBSDA */ I2C_READ_BYTE(controller, data); CPRINTS("-R(%02x)", data); /* Read to buffer */ p_status->rx_buf[p_status->idx_buf++] = data; /* last byte is read - end of transaction */ if (p_status->idx_buf == p_status->sz_rxbuf) { /* Set error code */ p_status->err_code = SMB_OK; /* Notify upper layer of missing data */ p_status->oper_state = (p_status->flags & I2C_XFER_STOP) ? SMB_IDLE : SMB_WAIT_REPEAT_START; task_set_event(p_status->task_waiting, TASK_EVENT_I2C_IDLE, 0); CPUTS("-END"); } } } void i2c_master_int_handler (int controller) { volatile struct i2c_status *p_status = i2c_stsobjs + controller; /* Condition 1 : A Bus Error has been identified */ if (IS_BIT_SET(NPCX_SMBST(controller), NPCX_SMBST_BER)) { /* Generate a STOP condition */ I2C_STOP(controller); CPUTS("-SP"); /* Clear BER Bit */ SET_BIT(NPCX_SMBST(controller), NPCX_SMBST_BER); /* Set error code */ p_status->err_code = SMB_BUS_ERROR; /* Notify upper layer */ p_status->oper_state = SMB_IDLE; task_set_event(p_status->task_waiting, TASK_EVENT_I2C_IDLE, 0); CPUTS("-BER"); } /* Condition 2: A negative acknowledge has occurred */ if (IS_BIT_SET(NPCX_SMBST(controller), NPCX_SMBST_NEGACK)) { /* Generate a STOP condition */ I2C_STOP(controller); CPUTS("-SP"); /* Clear NEGACK Bit */ SET_BIT(NPCX_SMBST(controller), NPCX_SMBST_NEGACK); /* Set error code */ p_status->err_code = SMB_MASTER_NO_ADDRESS_MATCH; /* Notify upper layer */ p_status->oper_state = SMB_IDLE; task_set_event(p_status->task_waiting, TASK_EVENT_I2C_IDLE, 0); CPUTS("-NA"); } /* Condition 3: SDA status is set - transmit or receive */ if (IS_BIT_SET(NPCX_SMBST(controller), NPCX_SMBST_SDAST)) i2c_handle_sda_irq(controller); } /** * Handle an interrupt on the specified controller. * * @param controller I2C controller generating interrupt */ void handle_interrupt(int controller) { i2c_master_int_handler(controller); } void i2c0_interrupt(void) { handle_interrupt(0); } void i2c1_interrupt(void) { handle_interrupt(1); } void i2c2_interrupt(void) { handle_interrupt(2); } void i2c3_interrupt(void) { handle_interrupt(3); } DECLARE_IRQ(NPCX_IRQ_SMB1, i2c0_interrupt, 2); DECLARE_IRQ(NPCX_IRQ_SMB2, i2c1_interrupt, 2); DECLARE_IRQ(NPCX_IRQ_SMB3, i2c2_interrupt, 2); DECLARE_IRQ(NPCX_IRQ_SMB4, i2c3_interrupt, 2); /*****************************************************************************/ /* IC specific low-level driver */ void i2c_set_timeout(int port, uint32_t timeout) { int ctrl = i2c_port_to_controller(port); /* Param is port, but timeout is stored by-controller. */ i2c_stsobjs[ctrl].timeout_us = timeout ? timeout : I2C_TIMEOUT_DEFAULT_US; } int chip_i2c_xfer(int port, int slave_addr, const uint8_t *out, int out_size, uint8_t *in, int in_size, int flags) { int ctrl = i2c_port_to_controller(port); volatile struct i2c_status *p_status = i2c_stsobjs + ctrl; if (out_size == 0 && in_size == 0) return EC_SUCCESS; interrupt_disable(); /* make sure bus is not occupied by the other task */ if (p_status->task_waiting != TASK_ID_INVALID) { interrupt_enable(); return EC_ERROR_BUSY; } /* Assign current task ID */ p_status->task_waiting = task_get_current(); interrupt_enable(); /* Select port for multi-ports i2c controller */ i2c_select_port(port); /* Copy data to controller struct */ p_status->flags = flags; p_status->tx_buf = out; p_status->sz_txbuf = out_size; p_status->rx_buf = in; p_status->sz_rxbuf = in_size; #if I2C_7BITS_ADDR /* Set slave address from 7-bits to 8-bits */ p_status->slave_addr = (slave_addr<<1); #else /* Set slave address (8-bits) */ p_status->slave_addr = slave_addr; #endif /* Reset index & error */ p_status->idx_buf = 0; p_status->err_code = SMB_OK; /* Make sure we're in a good state to start */ if ((flags & I2C_XFER_START) && (i2c_bus_busy(ctrl) || (i2c_get_line_levels(port) != I2C_LINE_IDLE))) { /* Attempt to unwedge the controller. */ i2c_unwedge(ctrl); /* recovery i2c controller */ i2c_recovery(ctrl); /* Select port again for recovery */ i2c_select_port(port); } /* Enable SMB interrupt and New Address Match interrupt source */ SET_BIT(NPCX_SMBCTL1(ctrl), NPCX_SMBCTL1_NMINTE); SET_BIT(NPCX_SMBCTL1(ctrl), NPCX_SMBCTL1_INTEN); CPUTS("\n"); /* Start master transaction */ i2c_master_transaction(ctrl); /* Reset task ID */ p_status->task_waiting = TASK_ID_INVALID; /* Disable SMB interrupt and New Address Match interrupt source */ CLEAR_BIT(NPCX_SMBCTL1(ctrl), NPCX_SMBCTL1_NMINTE); CLEAR_BIT(NPCX_SMBCTL1(ctrl), NPCX_SMBCTL1_INTEN); CPRINTS("-Err:0x%02x\n", p_status->err_code); return (p_status->err_code == SMB_OK) ? EC_SUCCESS : EC_ERROR_UNKNOWN; } /** * Return raw I/O line levels (I2C_LINE_*) for a port when port is in alternate * function mode. * * @param port Port to check * @return State of SCL/SDA bit 0/1 */ int i2c_get_line_levels(int port) { return (i2c_raw_get_sda(port) ? I2C_LINE_SDA_HIGH : 0) | (i2c_raw_get_scl(port) ? I2C_LINE_SCL_HIGH : 0); } /* * Due to we couldn't support GPIO reading when IO is selected SMBus, we need * to distingulish which mode we used currently. */ int i2c_is_raw_mode(int port) { int bit = (port > NPCX_I2C_PORT0_1) ? port * 2 : port; if (IS_BIT_SET(NPCX_DEVALT(2), bit)) return 0; else return 1; } int i2c_raw_get_scl(int port) { enum gpio_signal g; /* * Check do we support this port of i2c and return gpio number of scl. * Please notice we cannot read voltage level from GPIO in M4 EC */ if (get_scl_from_i2c_port(port, &g) == EC_SUCCESS) { if (i2c_is_raw_mode(port)) return gpio_get_level(g); else return IS_BIT_SET(NPCX_SMBCTL3( i2c_port_to_controller(port)), NPCX_SMBCTL3_SCL_LVL); } /* If no SCL pin defined for this port, then return 1 to appear idle */ return 1; } int i2c_raw_get_sda(int port) { enum gpio_signal g; /* * Check do we support this port of i2c and return gpio number of scl. * Please notice we cannot read voltage level from GPIO in M4 EC */ if (get_sda_from_i2c_port(port, &g) == EC_SUCCESS) { if (i2c_is_raw_mode(port)) return gpio_get_level(g); else return IS_BIT_SET(NPCX_SMBCTL3( i2c_port_to_controller(port)), NPCX_SMBCTL3_SDA_LVL); } /* If no SDA pin defined for this port, then return 1 to appear idle */ return 1; } /*****************************************************************************/ /* Hooks */ static void i2c_freq_changed(void) { int freq, i; for (i = 0; i < i2c_ports_used; i++) { int bus_freq = i2c_ports[i].kbps; int ctrl = i2c_port_to_controller(i2c_ports[i].port); int scl_time; /* SMB0/1 use core clock & SMB2/3 use apb2 clock */ if (ctrl < 2) freq = clock_get_freq(); else freq = clock_get_apb2_freq(); /* use Fast Mode */ SET_BIT(NPCX_SMBCTL3(ctrl) , NPCX_SMBCTL3_400K); /* * Set SCLLT/SCLHT: * tSCLL = 2 * SCLLT7-0 * tCLK * tSCLH = 2 * SCLHT7-0 * tCLK * (tSCLL+tSCLH) = 4 * SCLH(L)T * tCLK if tSCLL == tSCLH * SCLH(L)T = T(SCL)/4/T(CLK) = FREQ(CLK)/4/FREQ(SCL) */ scl_time = (freq/1000) / (bus_freq * 4); /* bus_freq is KHz */ /* set SCL High/Low time */ NPCX_SMBSCLLT(ctrl) = scl_time; NPCX_SMBSCLHT(ctrl) = scl_time; } } DECLARE_HOOK(HOOK_FREQ_CHANGE, i2c_freq_changed, HOOK_PRIO_DEFAULT); static void i2c_init(void) { int i; /* Configure pins from GPIOs to I2Cs */ gpio_config_module(MODULE_I2C, 1); /* Enable clock for I2C peripheral */ clock_enable_peripheral(CGC_OFFSET_I2C, CGC_I2C_MASK, CGC_MODE_RUN | CGC_MODE_SLEEP); /* Set I2C freq */ i2c_freq_changed(); /* * initialize smb status and register */ for (i = 0; i < i2c_ports_used; i++) { int port = i2c_ports[i].port; int ctrl = i2c_port_to_controller(port); volatile struct i2c_status *p_status = i2c_stsobjs + ctrl; /* Configure pull-up for SMB interface pins */ /* Enable 3.3V pull-up or turn to 1.8V support */ if (port == NPCX_I2C_PORT0_0) { #ifdef NPCX_I2C0_0_1P8V SET_BIT(NPCX_LV_GPIO_CTL0, NPCX_LV_GPIO_CTL0_SC0_0_LV); SET_BIT(NPCX_LV_GPIO_CTL0, NPCX_LV_GPIO_CTL0_SD0_0_LV); #else SET_BIT(NPCX_DEVPU0, NPCX_I2C_PUBIT(ctrl, 0)); #endif } else if (port == NPCX_I2C_PORT0_1) { #ifdef NPCX_I2C0_1_1P8V SET_BIT(NPCX_LV_GPIO_CTL1, NPCX_LV_GPIO_CTL0_SC0_1_LV); SET_BIT(NPCX_LV_GPIO_CTL1, NPCX_LV_GPIO_CTL0_SD0_1_LV); #else SET_BIT(NPCX_DEVPU0, NPCX_I2C_PUBIT(ctrl, 1)); #endif } else if (port == NPCX_I2C_PORT1) { #ifdef NPCX_I2C1_1P8V SET_BIT(NPCX_LV_GPIO_CTL0, NPCX_LV_GPIO_CTL0_SC1_0_LV); SET_BIT(NPCX_LV_GPIO_CTL0, NPCX_LV_GPIO_CTL0_SD1_0_LV); #else SET_BIT(NPCX_DEVPU0, NPCX_I2C_PUBIT(ctrl, 0)); #endif } else if (port == NPCX_I2C_PORT2) { #ifdef NPCX_I2C2_1P8V SET_BIT(NPCX_LV_GPIO_CTL1, NPCX_LV_GPIO_CTL1_SC2_0_LV); SET_BIT(NPCX_LV_GPIO_CTL1, NPCX_LV_GPIO_CTL1_SD2_0_LV); #else SET_BIT(NPCX_DEVPU0, NPCX_I2C_PUBIT(ctrl, 0)); #endif } else if (port == NPCX_I2C_PORT3) { #ifdef NPCX_I2C3_1P8V SET_BIT(NPCX_LV_GPIO_CTL1, NPCX_LV_GPIO_CTL1_SC3_0_LV); SET_BIT(NPCX_LV_GPIO_CTL1, NPCX_LV_GPIO_CTL1_SD3_0_LV); #else SET_BIT(NPCX_DEVPU0, NPCX_I2C_PUBIT(ctrl, 0)); #endif } /* Enable module - before configuring CTL1 */ SET_BIT(NPCX_SMBCTL2(ctrl), NPCX_SMBCTL2_ENABLE); /* status init */ p_status->oper_state = SMB_IDLE; /* Reset task ID */ p_status->task_waiting = TASK_ID_INVALID; /* Enable event and error interrupts */ task_enable_irq(i2c_irqs[ctrl]); /* Use default timeout. */ i2c_set_timeout(port, 0); } } DECLARE_HOOK(HOOK_INIT, i2c_init, HOOK_PRIO_INIT_I2C);