// SPDX-License-Identifier: GPL-2.0+ /* * Copyright 2013 Broadcom Corporation. * * NOTE: This driver should be converted to driver model before June 2017. * Please see doc/driver-model/i2c-howto.rst for instructions. */ #include #include #include #include #include #include #include #include /* Hardware register offsets and field defintions */ #define CS_OFFSET 0x00000020 #define CS_ACK_SHIFT 3 #define CS_ACK_MASK 0x00000008 #define CS_ACK_CMD_GEN_START 0x00000000 #define CS_ACK_CMD_GEN_RESTART 0x00000001 #define CS_CMD_SHIFT 1 #define CS_CMD_CMD_NO_ACTION 0x00000000 #define CS_CMD_CMD_START_RESTART 0x00000001 #define CS_CMD_CMD_STOP 0x00000002 #define CS_EN_SHIFT 0 #define CS_EN_CMD_ENABLE_BSC 0x00000001 #define TIM_OFFSET 0x00000024 #define TIM_PRESCALE_SHIFT 6 #define TIM_P_SHIFT 3 #define TIM_NO_DIV_SHIFT 2 #define TIM_DIV_SHIFT 0 #define DAT_OFFSET 0x00000028 #define TOUT_OFFSET 0x0000002c #define TXFCR_OFFSET 0x0000003c #define TXFCR_FIFO_FLUSH_MASK 0x00000080 #define TXFCR_FIFO_EN_MASK 0x00000040 #define IER_OFFSET 0x00000044 #define IER_READ_COMPLETE_INT_MASK 0x00000010 #define IER_I2C_INT_EN_MASK 0x00000008 #define IER_FIFO_INT_EN_MASK 0x00000002 #define IER_NOACK_EN_MASK 0x00000001 #define ISR_OFFSET 0x00000048 #define ISR_RESERVED_MASK 0xffffff60 #define ISR_CMDBUSY_MASK 0x00000080 #define ISR_READ_COMPLETE_MASK 0x00000010 #define ISR_SES_DONE_MASK 0x00000008 #define ISR_ERR_MASK 0x00000004 #define ISR_TXFIFOEMPTY_MASK 0x00000002 #define ISR_NOACK_MASK 0x00000001 #define CLKEN_OFFSET 0x0000004c #define CLKEN_AUTOSENSE_OFF_MASK 0x00000080 #define CLKEN_M_SHIFT 4 #define CLKEN_N_SHIFT 1 #define CLKEN_CLKEN_MASK 0x00000001 #define FIFO_STATUS_OFFSET 0x00000054 #define FIFO_STATUS_RXFIFO_EMPTY_MASK 0x00000004 #define FIFO_STATUS_TXFIFO_EMPTY_MASK 0x00000010 #define HSTIM_OFFSET 0x00000058 #define HSTIM_HS_MODE_MASK 0x00008000 #define HSTIM_HS_HOLD_SHIFT 10 #define HSTIM_HS_HIGH_PHASE_SHIFT 5 #define HSTIM_HS_SETUP_SHIFT 0 #define PADCTL_OFFSET 0x0000005c #define PADCTL_PAD_OUT_EN_MASK 0x00000004 #define RXFCR_OFFSET 0x00000068 #define RXFCR_NACK_EN_SHIFT 7 #define RXFCR_READ_COUNT_SHIFT 0 #define RXFIFORDOUT_OFFSET 0x0000006c /* Locally used constants */ #define MAX_RX_FIFO_SIZE 64U /* bytes */ #define MAX_TX_FIFO_SIZE 64U /* bytes */ #define I2C_TIMEOUT 100000 /* usecs */ #define WAIT_INT_CHK 100 /* usecs */ #if I2C_TIMEOUT % WAIT_INT_CHK #error I2C_TIMEOUT must be a multiple of WAIT_INT_CHK #endif /* Operations that can be commanded to the controller */ enum bcm_kona_cmd_t { BCM_CMD_NOACTION = 0, BCM_CMD_START, BCM_CMD_RESTART, BCM_CMD_STOP, }; /* Internal divider settings for standard mode, fast mode and fast mode plus */ struct bus_speed_cfg { uint8_t time_m; /* Number of cycles for setup time */ uint8_t time_n; /* Number of cycles for hold time */ uint8_t prescale; /* Prescale divider */ uint8_t time_p; /* Timing coefficient */ uint8_t no_div; /* Disable clock divider */ uint8_t time_div; /* Post-prescale divider */ }; static const struct bus_speed_cfg std_cfg_table[] = { [IC_SPEED_MODE_STANDARD] = {0x01, 0x01, 0x03, 0x06, 0x00, 0x02}, [IC_SPEED_MODE_FAST] = {0x05, 0x01, 0x03, 0x05, 0x01, 0x02}, [IC_SPEED_MODE_FAST_PLUS] = {0x01, 0x01, 0x03, 0x01, 0x01, 0x03}, }; struct bcm_kona_i2c_dev { void *base; uint speed; const struct bus_speed_cfg *std_cfg; }; /* Keep these two defines in sync */ #define DEF_SPD I2C_SPEED_STANDARD_RATE #define DEF_SPD_ENUM IC_SPEED_MODE_STANDARD #define DEF_DEVICE(num) \ {(void *)CONFIG_SYS_I2C_BASE##num, DEF_SPD, &std_cfg_table[DEF_SPD_ENUM]} static struct bcm_kona_i2c_dev g_i2c_devs[CFG_SYS_MAX_I2C_BUS] = { #ifdef CONFIG_SYS_I2C_BASE0 DEF_DEVICE(0), #endif #ifdef CONFIG_SYS_I2C_BASE1 DEF_DEVICE(1), #endif #ifdef CONFIG_SYS_I2C_BASE2 DEF_DEVICE(2), #endif #ifdef CONFIG_SYS_I2C_BASE3 DEF_DEVICE(3), #endif #ifdef CONFIG_SYS_I2C_BASE4 DEF_DEVICE(4), #endif #ifdef CONFIG_SYS_I2C_BASE5 DEF_DEVICE(5), #endif }; #define I2C_M_TEN 0x0010 /* ten bit address */ #define I2C_M_RD 0x0001 /* read data */ #define I2C_M_NOSTART 0x4000 /* no restart between msgs */ struct kona_i2c_msg { uint16_t addr; uint16_t flags; uint16_t len; uint8_t *buf; }; static void bcm_kona_i2c_send_cmd_to_ctrl(struct bcm_kona_i2c_dev *dev, enum bcm_kona_cmd_t cmd) { debug("%s, %d\n", __func__, cmd); switch (cmd) { case BCM_CMD_NOACTION: writel((CS_CMD_CMD_NO_ACTION << CS_CMD_SHIFT) | (CS_EN_CMD_ENABLE_BSC << CS_EN_SHIFT), dev->base + CS_OFFSET); break; case BCM_CMD_START: writel((CS_ACK_CMD_GEN_START << CS_ACK_SHIFT) | (CS_CMD_CMD_START_RESTART << CS_CMD_SHIFT) | (CS_EN_CMD_ENABLE_BSC << CS_EN_SHIFT), dev->base + CS_OFFSET); break; case BCM_CMD_RESTART: writel((CS_ACK_CMD_GEN_RESTART << CS_ACK_SHIFT) | (CS_CMD_CMD_START_RESTART << CS_CMD_SHIFT) | (CS_EN_CMD_ENABLE_BSC << CS_EN_SHIFT), dev->base + CS_OFFSET); break; case BCM_CMD_STOP: writel((CS_CMD_CMD_STOP << CS_CMD_SHIFT) | (CS_EN_CMD_ENABLE_BSC << CS_EN_SHIFT), dev->base + CS_OFFSET); break; default: printf("Unknown command %d\n", cmd); } } static void bcm_kona_i2c_enable_clock(struct bcm_kona_i2c_dev *dev) { writel(readl(dev->base + CLKEN_OFFSET) | CLKEN_CLKEN_MASK, dev->base + CLKEN_OFFSET); } static void bcm_kona_i2c_disable_clock(struct bcm_kona_i2c_dev *dev) { writel(readl(dev->base + CLKEN_OFFSET) & ~CLKEN_CLKEN_MASK, dev->base + CLKEN_OFFSET); } /* Wait until at least one of the mask bit(s) are set */ static unsigned long wait_for_int_timeout(struct bcm_kona_i2c_dev *dev, unsigned long time_left, uint32_t mask) { uint32_t status; while (time_left) { status = readl(dev->base + ISR_OFFSET); if ((status & ~ISR_RESERVED_MASK) == 0) { debug("Bogus I2C interrupt 0x%x\n", status); continue; } /* Must flush the TX FIFO when NAK detected */ if (status & ISR_NOACK_MASK) writel(TXFCR_FIFO_FLUSH_MASK | TXFCR_FIFO_EN_MASK, dev->base + TXFCR_OFFSET); writel(status & ~ISR_RESERVED_MASK, dev->base + ISR_OFFSET); if (status & mask) { /* We are done since one of the mask bits are set */ return time_left; } udelay(WAIT_INT_CHK); time_left -= WAIT_INT_CHK; } return 0; } /* Send command to I2C bus */ static int bcm_kona_send_i2c_cmd(struct bcm_kona_i2c_dev *dev, enum bcm_kona_cmd_t cmd) { int rc = 0; unsigned long time_left = I2C_TIMEOUT; /* Send the command */ bcm_kona_i2c_send_cmd_to_ctrl(dev, cmd); /* Wait for transaction to finish or timeout */ time_left = wait_for_int_timeout(dev, time_left, IER_I2C_INT_EN_MASK); if (!time_left) { printf("controller timed out\n"); rc = -ETIMEDOUT; } /* Clear command */ bcm_kona_i2c_send_cmd_to_ctrl(dev, BCM_CMD_NOACTION); return rc; } /* Read a single RX FIFO worth of data from the i2c bus */ static int bcm_kona_i2c_read_fifo_single(struct bcm_kona_i2c_dev *dev, uint8_t *buf, unsigned int len, unsigned int last_byte_nak) { unsigned long time_left = I2C_TIMEOUT; /* Start the RX FIFO */ writel((last_byte_nak << RXFCR_NACK_EN_SHIFT) | (len << RXFCR_READ_COUNT_SHIFT), dev->base + RXFCR_OFFSET); /* Wait for FIFO read to complete */ time_left = wait_for_int_timeout(dev, time_left, IER_READ_COMPLETE_INT_MASK); if (!time_left) { printf("RX FIFO time out\n"); return -EREMOTEIO; } /* Read data from FIFO */ for (; len > 0; len--, buf++) *buf = readl(dev->base + RXFIFORDOUT_OFFSET); return 0; } /* Read any amount of data using the RX FIFO from the i2c bus */ static int bcm_kona_i2c_read_fifo(struct bcm_kona_i2c_dev *dev, struct kona_i2c_msg *msg) { unsigned int bytes_to_read = MAX_RX_FIFO_SIZE; unsigned int last_byte_nak = 0; unsigned int bytes_read = 0; int rc; uint8_t *tmp_buf = msg->buf; while (bytes_read < msg->len) { if (msg->len - bytes_read <= MAX_RX_FIFO_SIZE) { last_byte_nak = 1; /* NAK last byte of transfer */ bytes_to_read = msg->len - bytes_read; } rc = bcm_kona_i2c_read_fifo_single(dev, tmp_buf, bytes_to_read, last_byte_nak); if (rc < 0) return -EREMOTEIO; bytes_read += bytes_to_read; tmp_buf += bytes_to_read; } return 0; } /* Write a single byte of data to the i2c bus */ static int bcm_kona_i2c_write_byte(struct bcm_kona_i2c_dev *dev, uint8_t data, unsigned int nak_expected) { unsigned long time_left = I2C_TIMEOUT; unsigned int nak_received; /* Clear pending session done interrupt */ writel(ISR_SES_DONE_MASK, dev->base + ISR_OFFSET); /* Send one byte of data */ writel(data, dev->base + DAT_OFFSET); time_left = wait_for_int_timeout(dev, time_left, IER_I2C_INT_EN_MASK); if (!time_left) { debug("controller timed out\n"); return -ETIMEDOUT; } nak_received = readl(dev->base + CS_OFFSET) & CS_ACK_MASK ? 1 : 0; if (nak_received ^ nak_expected) { debug("unexpected NAK/ACK\n"); return -EREMOTEIO; } return 0; } /* Write a single TX FIFO worth of data to the i2c bus */ static int bcm_kona_i2c_write_fifo_single(struct bcm_kona_i2c_dev *dev, uint8_t *buf, unsigned int len) { int k; unsigned long time_left = I2C_TIMEOUT; unsigned int fifo_status; /* Write data into FIFO */ for (k = 0; k < len; k++) writel(buf[k], (dev->base + DAT_OFFSET)); /* Wait for FIFO to empty */ do { time_left = wait_for_int_timeout(dev, time_left, (IER_FIFO_INT_EN_MASK | IER_NOACK_EN_MASK)); fifo_status = readl(dev->base + FIFO_STATUS_OFFSET); } while (time_left && !(fifo_status & FIFO_STATUS_TXFIFO_EMPTY_MASK)); /* Check if there was a NAK */ if (readl(dev->base + CS_OFFSET) & CS_ACK_MASK) { printf("unexpected NAK\n"); return -EREMOTEIO; } /* Check if a timeout occurred */ if (!time_left) { printf("completion timed out\n"); return -EREMOTEIO; } return 0; } /* Write any amount of data using TX FIFO to the i2c bus */ static int bcm_kona_i2c_write_fifo(struct bcm_kona_i2c_dev *dev, struct kona_i2c_msg *msg) { unsigned int bytes_to_write = MAX_TX_FIFO_SIZE; unsigned int bytes_written = 0; int rc; uint8_t *tmp_buf = msg->buf; while (bytes_written < msg->len) { if (msg->len - bytes_written <= MAX_TX_FIFO_SIZE) bytes_to_write = msg->len - bytes_written; rc = bcm_kona_i2c_write_fifo_single(dev, tmp_buf, bytes_to_write); if (rc < 0) return -EREMOTEIO; bytes_written += bytes_to_write; tmp_buf += bytes_to_write; } return 0; } /* Send i2c address */ static int bcm_kona_i2c_do_addr(struct bcm_kona_i2c_dev *dev, struct kona_i2c_msg *msg) { unsigned char addr; if (msg->flags & I2C_M_TEN) { /* First byte is 11110XX0 where XX is upper 2 bits */ addr = 0xf0 | ((msg->addr & 0x300) >> 7); if (bcm_kona_i2c_write_byte(dev, addr, 0) < 0) return -EREMOTEIO; /* Second byte is the remaining 8 bits */ addr = msg->addr & 0xff; if (bcm_kona_i2c_write_byte(dev, addr, 0) < 0) return -EREMOTEIO; if (msg->flags & I2C_M_RD) { /* For read, send restart command */ if (bcm_kona_send_i2c_cmd(dev, BCM_CMD_RESTART) < 0) return -EREMOTEIO; /* Then re-send the first byte with the read bit set */ addr = 0xf0 | ((msg->addr & 0x300) >> 7) | 0x01; if (bcm_kona_i2c_write_byte(dev, addr, 0) < 0) return -EREMOTEIO; } } else { addr = msg->addr << 1; if (msg->flags & I2C_M_RD) addr |= 1; if (bcm_kona_i2c_write_byte(dev, addr, 0) < 0) return -EREMOTEIO; } return 0; } static void bcm_kona_i2c_enable_autosense(struct bcm_kona_i2c_dev *dev) { writel(readl(dev->base + CLKEN_OFFSET) & ~CLKEN_AUTOSENSE_OFF_MASK, dev->base + CLKEN_OFFSET); } static void bcm_kona_i2c_config_timing(struct bcm_kona_i2c_dev *dev) { writel(readl(dev->base + HSTIM_OFFSET) & ~HSTIM_HS_MODE_MASK, dev->base + HSTIM_OFFSET); writel((dev->std_cfg->prescale << TIM_PRESCALE_SHIFT) | (dev->std_cfg->time_p << TIM_P_SHIFT) | (dev->std_cfg->no_div << TIM_NO_DIV_SHIFT) | (dev->std_cfg->time_div << TIM_DIV_SHIFT), dev->base + TIM_OFFSET); writel((dev->std_cfg->time_m << CLKEN_M_SHIFT) | (dev->std_cfg->time_n << CLKEN_N_SHIFT) | CLKEN_CLKEN_MASK, dev->base + CLKEN_OFFSET); } /* Master transfer function */ static int bcm_kona_i2c_xfer(struct bcm_kona_i2c_dev *dev, struct kona_i2c_msg msgs[], int num) { struct kona_i2c_msg *pmsg; int rc = 0; int i; /* Enable pad output */ writel(0, dev->base + PADCTL_OFFSET); /* Enable internal clocks */ bcm_kona_i2c_enable_clock(dev); /* Send start command */ rc = bcm_kona_send_i2c_cmd(dev, BCM_CMD_START); if (rc < 0) { printf("Start command failed rc = %d\n", rc); goto xfer_disable_pad; } /* Loop through all messages */ for (i = 0; i < num; i++) { pmsg = &msgs[i]; /* Send restart for subsequent messages */ if ((i != 0) && ((pmsg->flags & I2C_M_NOSTART) == 0)) { rc = bcm_kona_send_i2c_cmd(dev, BCM_CMD_RESTART); if (rc < 0) { printf("restart cmd failed rc = %d\n", rc); goto xfer_send_stop; } } /* Send slave address */ if (!(pmsg->flags & I2C_M_NOSTART)) { rc = bcm_kona_i2c_do_addr(dev, pmsg); if (rc < 0) { debug("NAK from addr %2.2x msg#%d rc = %d\n", pmsg->addr, i, rc); goto xfer_send_stop; } } /* Perform data transfer */ if (pmsg->flags & I2C_M_RD) { rc = bcm_kona_i2c_read_fifo(dev, pmsg); if (rc < 0) { printf("read failure\n"); goto xfer_send_stop; } } else { rc = bcm_kona_i2c_write_fifo(dev, pmsg); if (rc < 0) { printf("write failure"); goto xfer_send_stop; } } } rc = num; xfer_send_stop: /* Send a STOP command */ bcm_kona_send_i2c_cmd(dev, BCM_CMD_STOP); xfer_disable_pad: /* Disable pad output */ writel(PADCTL_PAD_OUT_EN_MASK, dev->base + PADCTL_OFFSET); /* Stop internal clock */ bcm_kona_i2c_disable_clock(dev); return rc; } static uint bcm_kona_i2c_assign_bus_speed(struct bcm_kona_i2c_dev *dev, uint speed) { switch (speed) { case I2C_SPEED_STANDARD_RATE: dev->std_cfg = &std_cfg_table[IC_SPEED_MODE_STANDARD]; break; case I2C_SPEED_FAST_RATE: dev->std_cfg = &std_cfg_table[IC_SPEED_MODE_FAST]; break; case I2C_SPEED_FAST_PLUS_RATE: dev->std_cfg = &std_cfg_table[IC_SPEED_MODE_FAST_PLUS]; break; default: printf("%d hz bus speed not supported\n", speed); return -EINVAL; } dev->speed = speed; return 0; } static void bcm_kona_i2c_init(struct bcm_kona_i2c_dev *dev) { /* Parse bus speed */ bcm_kona_i2c_assign_bus_speed(dev, dev->speed); /* Enable internal clocks */ bcm_kona_i2c_enable_clock(dev); /* Configure internal dividers */ bcm_kona_i2c_config_timing(dev); /* Disable timeout */ writel(0, dev->base + TOUT_OFFSET); /* Enable autosense */ bcm_kona_i2c_enable_autosense(dev); /* Enable TX FIFO */ writel(TXFCR_FIFO_FLUSH_MASK | TXFCR_FIFO_EN_MASK, dev->base + TXFCR_OFFSET); /* Mask all interrupts */ writel(0, dev->base + IER_OFFSET); /* Clear all pending interrupts */ writel(ISR_CMDBUSY_MASK | ISR_READ_COMPLETE_MASK | ISR_SES_DONE_MASK | ISR_ERR_MASK | ISR_TXFIFOEMPTY_MASK | ISR_NOACK_MASK, dev->base + ISR_OFFSET); /* Enable the controller but leave it idle */ bcm_kona_i2c_send_cmd_to_ctrl(dev, BCM_CMD_NOACTION); /* Disable pad output */ writel(PADCTL_PAD_OUT_EN_MASK, dev->base + PADCTL_OFFSET); } /* * uboot layer */ struct bcm_kona_i2c_dev *kona_get_dev(struct i2c_adapter *adap) { return &g_i2c_devs[adap->hwadapnr]; } static void kona_i2c_init(struct i2c_adapter *adap, int speed, int slaveaddr) { struct bcm_kona_i2c_dev *dev = kona_get_dev(adap); if (clk_bsc_enable(dev->base)) return; bcm_kona_i2c_init(dev); } static int kona_i2c_read(struct i2c_adapter *adap, uchar chip, uint addr, int alen, uchar *buffer, int len) { /* msg[0] writes the addr, msg[1] reads the data */ struct kona_i2c_msg msg[2]; unsigned char msgbuf0[64]; struct bcm_kona_i2c_dev *dev = kona_get_dev(adap); msg[0].addr = chip; msg[0].flags = 0; msg[0].len = 1; msg[0].buf = msgbuf0; /* msgbuf0 contains incrementing reg addr */ msg[1].addr = chip; msg[1].flags = I2C_M_RD; /* msg[1].buf dest ptr increments each read */ msgbuf0[0] = (unsigned char)addr; msg[1].buf = buffer; msg[1].len = len; if (bcm_kona_i2c_xfer(dev, msg, 2) < 0) { /* Sending 2 i2c messages */ kona_i2c_init(adap, adap->speed, adap->slaveaddr); debug("I2C read: I/O error\n"); return -EIO; } return 0; } static int kona_i2c_write(struct i2c_adapter *adap, uchar chip, uint addr, int alen, uchar *buffer, int len) { struct kona_i2c_msg msg[1]; unsigned char msgbuf0[64]; unsigned int i; struct bcm_kona_i2c_dev *dev = kona_get_dev(adap); msg[0].addr = chip; msg[0].flags = 0; msg[0].len = 2; /* addr byte plus data */ msg[0].buf = msgbuf0; for (i = 0; i < len; i++) { msgbuf0[0] = addr++; msgbuf0[1] = buffer[i]; if (bcm_kona_i2c_xfer(dev, msg, 1) < 0) { kona_i2c_init(adap, adap->speed, adap->slaveaddr); debug("I2C write: I/O error\n"); return -EIO; } } return 0; } static int kona_i2c_probe(struct i2c_adapter *adap, uchar chip) { uchar tmp; /* * read addr 0x0 of the given chip. */ return kona_i2c_read(adap, chip, 0x0, 1, &tmp, 1); } static uint kona_i2c_set_bus_speed(struct i2c_adapter *adap, uint speed) { struct bcm_kona_i2c_dev *dev = kona_get_dev(adap); return bcm_kona_i2c_assign_bus_speed(dev, speed); } /* * Register kona i2c adapters. Keep the order below so * that the bus number matches the adapter number. */ #define DEF_ADAPTER(num) \ U_BOOT_I2C_ADAP_COMPLETE(kona##num, kona_i2c_init, kona_i2c_probe, \ kona_i2c_read, kona_i2c_write, \ kona_i2c_set_bus_speed, DEF_SPD, 0x00, num) #ifdef CONFIG_SYS_I2C_BASE0 DEF_ADAPTER(0) #endif #ifdef CONFIG_SYS_I2C_BASE1 DEF_ADAPTER(1) #endif #ifdef CONFIG_SYS_I2C_BASE2 DEF_ADAPTER(2) #endif #ifdef CONFIG_SYS_I2C_BASE3 DEF_ADAPTER(3) #endif #ifdef CONFIG_SYS_I2C_BASE4 DEF_ADAPTER(4) #endif #ifdef CONFIG_SYS_I2C_BASE5 DEF_ADAPTER(5) #endif