/* * This file is part of the coreboot project. * * (C) Copyright 2002 * David Mueller, ELSOFT AG, d.mueller@elsoft.ch * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; version 2 of the License. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */ #include #include #include #include #include #include "clk.h" #include "i2c.h" #include "pinmux.h" #define I2C_WRITE 0 #define I2C_READ 1 #define I2C_OK 0 #define I2C_NOK 1 #define I2C_NACK 2 #define I2C_NOK_LA 3 /* Lost arbitration */ #define I2C_NOK_TOUT 4 /* time out */ /* HSI2C specific register description */ /* I2C_CTL Register bits */ /* FIXME(dhendrix): do we really need to cast these as unsigned? */ #define HSI2C_FUNC_MODE_I2C (1u << 0) #define HSI2C_MASTER (1u << 3) #define HSI2C_RXCHON (1u << 6) /* Write/Send */ #define HSI2C_TXCHON (1u << 7) /* Read/Receive */ #define HSI2C_SW_RST (1u << 31) /* I2C_FIFO_STAT Register bits */ #define HSI2C_TX_FIFO_LEVEL (0x7f << 0) #define HSI2C_TX_FIFO_FULL (1u << 7) #define HSI2C_TX_FIFO_EMPTY (1u << 8) #define HSI2C_RX_FIFO_LEVEL (0x7f << 16) #define HSI2C_RX_FIFO_FULL (1u << 23) #define HSI2C_RX_FIFO_EMPTY (1u << 24) /* I2C_FIFO_CTL Register bits */ #define HSI2C_RXFIFO_EN (1u << 0) #define HSI2C_TXFIFO_EN (1u << 1) #define HSI2C_TXFIFO_TRIGGER_LEVEL (0x20 << 16) #define HSI2C_RXFIFO_TRIGGER_LEVEL (0x20 << 4) /* I2C_TRAILING_CTL Register bits */ #define HSI2C_TRAILING_COUNT (0xff) /* I2C_INT_EN Register bits */ #define HSI2C_INT_TX_ALMOSTEMPTY_EN (1u << 0) #define HSI2C_INT_RX_ALMOSTFULL_EN (1u << 1) #define HSI2C_INT_TRAILING_EN (1u << 6) #define HSI2C_INT_I2C_EN (1u << 9) /* I2C_CONF Register bits */ #define HSI2C_AUTO_MODE (1u << 31) #define HSI2C_10BIT_ADDR_MODE (1u << 30) #define HSI2C_HS_MODE (1u << 29) /* I2C_AUTO_CONF Register bits */ #define HSI2C_READ_WRITE (1u << 16) #define HSI2C_STOP_AFTER_TRANS (1u << 17) #define HSI2C_MASTER_RUN (1u << 31) /* I2C_TIMEOUT Register bits */ #define HSI2C_TIMEOUT_EN (1u << 31) /* I2C_TRANS_STATUS register bits */ #define HSI2C_MASTER_BUSY (1u << 17) #define HSI2C_SLAVE_BUSY (1u << 16) #define HSI2C_TIMEOUT_AUTO (1u << 4) #define HSI2C_NO_DEV (1u << 3) #define HSI2C_NO_DEV_ACK (1u << 2) #define HSI2C_TRANS_ABORT (1u << 1) #define HSI2C_TRANS_DONE (1u << 0) #define HSI2C_SLV_ADDR_MAS(x) ((x & 0x3ff) << 10) /* S3C I2C Controller bits */ #define I2CSTAT_BSY 0x20 /* Busy bit */ #define I2CSTAT_NACK 0x01 /* Nack bit */ #define I2CCON_ACKGEN 0x80 /* Acknowledge generation */ #define I2CCON_IRPND 0x10 /* Interrupt pending bit */ #define I2C_MODE_MT 0xC0 /* Master Transmit Mode */ #define I2C_MODE_MR 0x80 /* Master Receive Mode */ #define I2C_START_STOP 0x20 /* START / STOP */ #define I2C_TXRX_ENA 0x10 /* I2C Tx/Rx enable */ #define I2C_TIMEOUT_MS 1000 /* 1 second */ #define HSI2C_TIMEOUT 100 /* The timeouts we live by */ enum { I2C_XFER_TIMEOUT_MS = 35, /* xfer to complete */ I2C_INIT_TIMEOUT_MS = 1000, /* bus free on init */ I2C_IDLE_TIMEOUT_MS = 100, /* waiting for bus idle */ I2C_STOP_TIMEOUT_US = 200, /* waiting for stop events */ }; static struct s3c24x0_i2c_bus i2c_buses[] = { { .bus_num = 0, .regs = (struct s3c24x0_i2c *)0x12c60000, .periph_id = PERIPH_ID_I2C0, }, { .bus_num = 1, .regs = (struct s3c24x0_i2c *)0x12c70000, .periph_id = PERIPH_ID_I2C1, }, { .bus_num = 2, .regs = (struct s3c24x0_i2c *)0x12c80000, .periph_id = PERIPH_ID_I2C2, }, { .bus_num = 3, .regs = (struct s3c24x0_i2c *)0x12c90000, .periph_id = PERIPH_ID_I2C3, }, /* I2C4-I2C10 are part of the USI block */ { .bus_num = 4, .hsregs = (struct exynos5_hsi2c *)0x12ca0000, .periph_id = PERIPH_ID_I2C4, .is_highspeed = 1, }, { .bus_num = 5, .hsregs = (struct exynos5_hsi2c *)0x12cb0000, .periph_id = PERIPH_ID_I2C5, .is_highspeed = 1, }, { .bus_num = 6, .hsregs = (struct exynos5_hsi2c *)0x12cc0000, .periph_id = PERIPH_ID_I2C6, .is_highspeed = 1, }, { .bus_num = 7, .hsregs = (struct exynos5_hsi2c *)0x12cd0000, .periph_id = PERIPH_ID_I2C7, .is_highspeed = 1, }, { .bus_num = 8, .hsregs = (struct exynos5_hsi2c *)0x12e00000, .periph_id = PERIPH_ID_I2C8, .is_highspeed = 1, }, { .bus_num = 9, .hsregs = (struct exynos5_hsi2c *)0x12e10000, .periph_id = PERIPH_ID_I2C9, .is_highspeed = 1, }, { .bus_num = 10, .hsregs = (struct exynos5_hsi2c *)0x12e20000, .periph_id = PERIPH_ID_I2C10, .is_highspeed = 1, }, }; /* * Wait til the byte transfer is completed. * * @param i2c- pointer to the appropriate i2c register bank. * @return I2C_OK, if transmission was ACKED * I2C_NACK, if transmission was NACKED * I2C_NOK_TIMEOUT, if transaction did not complete in I2C_TIMEOUT_MS */ static int WaitForXfer(struct s3c24x0_i2c *i2c) { struct mono_time current, end; timer_monotonic_get(¤t); end = current; mono_time_add_usecs(&end, I2C_TIMEOUT_MS * 1000); do { if (read32(&i2c->iiccon) & I2CCON_IRPND) return (read32(&i2c->iicstat) & I2CSTAT_NACK) ? I2C_NACK : I2C_OK; timer_monotonic_get(¤t); } while (mono_time_before(¤t, &end)); printk(BIOS_ERR, "%s timed out\n", __func__); return I2C_NOK_TOUT; } static void ReadWriteByte(struct s3c24x0_i2c *i2c) { writel(read32(&i2c->iiccon) & ~I2CCON_IRPND, &i2c->iiccon); } static void i2c_ch_init(struct s3c24x0_i2c_bus *bus, int speed, int slaveadd) { unsigned long freq, pres = 16, div; unsigned long val; freq = clock_get_periph_rate(bus->periph_id); /* calculate prescaler and divisor values */ if ((freq / pres / (16 + 1)) > speed) /* set prescaler to 512 */ pres = 512; div = 0; while ((freq / pres / (div + 1)) > speed) div++; /* set prescaler, divisor according to freq, also set ACKGEN, IRQ */ val = (div & 0x0F) | 0xA0 | ((pres == 512) ? 0x40 : 0); write32(val, &bus->regs->iiccon); /* init to SLAVE RECEIVE mode and clear I2CADDn */ write32(0, &bus->regs->iicstat); write32(slaveadd, &bus->regs->iicadd); /* program Master Transmit (and implicit STOP) */ write32(I2C_MODE_MT | I2C_TXRX_ENA, &bus->regs->iicstat); } static int hsi2c_get_clk_details(struct s3c24x0_i2c_bus *i2c_bus, unsigned int bus_freq_hz) { struct exynos5_hsi2c *hsregs = i2c_bus->hsregs; unsigned long clkin = clock_get_periph_rate(i2c_bus->periph_id); unsigned int i = 0, utemp0 = 0, utemp1 = 0; unsigned int t_ftl_cycle; /* FPCLK / FI2C = * (CLK_DIV + 1) * (TSCLK_L + TSCLK_H + 2) + 8 + 2 * FLT_CYCLE * uTemp0 = (CLK_DIV + 1) * (TSCLK_L + TSCLK_H + 2) * uTemp1 = (TSCLK_L + TSCLK_H + 2) * uTemp2 = TSCLK_L + TSCLK_H */ t_ftl_cycle = (read32(&hsregs->usi_conf) >> 16) & 0x7; utemp0 = (clkin / bus_freq_hz) - 8 - 2 * t_ftl_cycle; /* CLK_DIV max is 256 */ for (i = 0; i < 256; i++) { utemp1 = utemp0 / (i + 1); if ((utemp1 < 512) && (utemp1 > 4)) { i2c_bus->clk_cycle = utemp1 - 2; i2c_bus->clk_div = i; return 0; } } printk(BIOS_ERR, "%s: failed?\n", __func__); return -1; } static void hsi2c_ch_init(struct s3c24x0_i2c_bus *i2c_bus, unsigned int bus_freq_hz) { struct exynos5_hsi2c *hsregs = i2c_bus->hsregs; unsigned int t_sr_release; unsigned int n_clkdiv; unsigned int t_start_su, t_start_hd; unsigned int t_stop_su; unsigned int t_data_su, t_data_hd; unsigned int t_scl_l, t_scl_h; u32 i2c_timing_s1; u32 i2c_timing_s2; u32 i2c_timing_s3; u32 i2c_timing_sla; hsi2c_get_clk_details(i2c_bus, bus_freq_hz); n_clkdiv = i2c_bus->clk_div; t_scl_l = i2c_bus->clk_cycle / 2; t_scl_h = i2c_bus->clk_cycle / 2; t_start_su = t_scl_l; t_start_hd = t_scl_l; t_stop_su = t_scl_l; t_data_su = t_scl_l / 2; t_data_hd = t_scl_l / 2; t_sr_release = i2c_bus->clk_cycle; i2c_timing_s1 = t_start_su << 24 | t_start_hd << 16 | t_stop_su << 8; i2c_timing_s2 = t_data_su << 24 | t_scl_l << 8 | t_scl_h << 0; i2c_timing_s3 = n_clkdiv << 16 | t_sr_release << 0; i2c_timing_sla = t_data_hd << 0; write32(HSI2C_TRAILING_COUNT, &hsregs->usi_trailing_ctl); /* Clear to enable Timeout */ clrsetbits_le32(&hsregs->usi_timeout, HSI2C_TIMEOUT_EN, 0); write32(read32(&hsregs->usi_conf) | HSI2C_AUTO_MODE, &hsregs->usi_conf); /* Currently operating in Fast speed mode. */ write32(i2c_timing_s1, &hsregs->usi_timing_fs1); write32(i2c_timing_s2, &hsregs->usi_timing_fs2); write32(i2c_timing_s3, &hsregs->usi_timing_fs3); write32(i2c_timing_sla, &hsregs->usi_timing_sla); /* Enable TXFIFO and RXFIFO */ write32(HSI2C_RXFIFO_EN | HSI2C_TXFIFO_EN, &hsregs->usi_fifo_ctl); /* i2c_conf configure */ write32(readl(&hsregs->usi_conf) | HSI2C_AUTO_MODE, &hsregs->usi_conf); } /* SW reset for the high speed bus */ static void i2c_reset(struct s3c24x0_i2c_bus *i2c_bus) { struct exynos5_hsi2c *i2c = i2c_bus->hsregs; u32 i2c_ctl; /* Set and clear the bit for reset */ i2c_ctl = read32(&i2c->usi_ctl); i2c_ctl |= HSI2C_SW_RST; write32(i2c_ctl, &i2c->usi_ctl); i2c_ctl = read32(&i2c->usi_ctl); i2c_ctl &= ~HSI2C_SW_RST; write32(i2c_ctl, &i2c->usi_ctl); /* Initialize the configure registers */ /* FIXME: This just assumes 100KHz as a default bus freq */ hsi2c_ch_init(i2c_bus, 100000); } void i2c_init(unsigned bus_num, int speed, int slaveadd) { struct s3c24x0_i2c_bus *i2c; i2c = &i2c_buses[bus_num]; i2c_reset(i2c); if (i2c->is_highspeed) hsi2c_ch_init(i2c, speed); else i2c_ch_init(i2c, speed, slaveadd); } /* * Check whether the transfer is complete. */ static int hsi2c_check_transfer(struct exynos5_hsi2c *i2c) { uint32_t status = read32(&i2c->usi_trans_status); if (status & HSI2C_TRANS_ABORT) printk(BIOS_ERR, "%s: Transaction aborted.\n", __func__); if (status & HSI2C_NO_DEV_ACK) printk(BIOS_ERR, "%s: No ack from device.\n", __func__); if (status & HSI2C_NO_DEV) printk(BIOS_ERR, "%s: No response from device.\n", __func__); if (status & HSI2C_TIMEOUT_AUTO) printk(BIOS_ERR, "%s: Transaction time out.\n", __func__); return !!(status & HSI2C_MASTER_BUSY); } /* * Wait for the transfer to finish. */ static int hsi2c_wait_for_transfer(struct exynos5_hsi2c *i2c) { struct mono_time current, end; timer_monotonic_get(¤t); end = current; mono_time_add_usecs(&end, HSI2C_TIMEOUT * 1000); while (mono_time_before(¤t, &end)) { if (!hsi2c_check_transfer(i2c)) return 0; udelay(5); timer_monotonic_get(¤t); } return 1; } static int hsi2c_senddata(struct exynos5_hsi2c *i2c, uint8_t *data, int len) { while (hsi2c_check_transfer(i2c) && len) { if (!(read32(&i2c->usi_fifo_stat) & HSI2C_TX_FIFO_FULL)) { write32(*data++, &i2c->usi_txdata); len--; } } return len ? -1 : 0; } static int hsi2c_recvdata(struct exynos5_hsi2c *i2c, uint8_t *data, int len) { while (hsi2c_check_transfer(i2c) && len) { if (!(read32(&i2c->usi_fifo_stat) & HSI2C_RX_FIFO_EMPTY)) { *data++ = read32(&i2c->usi_rxdata); len--; } } return len ? -1 : 0; } static int hsi2c_write(struct exynos5_hsi2c *i2c, unsigned char chip, unsigned char addr[], unsigned char alen, unsigned char data[], unsigned short len) { uint32_t i2c_auto_conf; if (hsi2c_wait_for_transfer(i2c)) return -1; /* chip address */ write32(HSI2C_SLV_ADDR_MAS(chip), &i2c->i2c_addr); /* usi_ctl enable i2c func, master write configure */ write32((HSI2C_TXCHON | HSI2C_FUNC_MODE_I2C | HSI2C_MASTER), &i2c->usi_ctl); /* auto_conf for write length and stop configure */ i2c_auto_conf = ((len + alen) | HSI2C_STOP_AFTER_TRANS); i2c_auto_conf &= ~HSI2C_READ_WRITE; /* Master run, start xfer */ i2c_auto_conf |= HSI2C_MASTER_RUN; write32(i2c_auto_conf, &i2c->usi_auto_conf); if (hsi2c_senddata(i2c, addr, alen) || hsi2c_senddata(i2c, data, len) || hsi2c_wait_for_transfer(i2c)) { return -1; } write32(HSI2C_FUNC_MODE_I2C, &i2c->usi_ctl); return 0; } static int hsi2c_read(struct exynos5_hsi2c *i2c, unsigned char chip, unsigned char addr[], unsigned char alen, unsigned char data[], unsigned short len, int check) { uint32_t i2c_auto_conf; /* start read */ if (hsi2c_wait_for_transfer(i2c)) return -1; /* chip address */ write32(HSI2C_SLV_ADDR_MAS(chip), &i2c->i2c_addr); /* usi_ctl enable i2c func, master write configure */ write32((HSI2C_TXCHON | HSI2C_FUNC_MODE_I2C | HSI2C_MASTER), &i2c->usi_ctl); /* auto_conf */ write32(alen | HSI2C_MASTER_RUN | HSI2C_STOP_AFTER_TRANS, &i2c->usi_auto_conf); if (hsi2c_senddata(i2c, addr, alen) || hsi2c_wait_for_transfer(i2c)) { return -1; } /* usi_ctl enable i2c func, master WRITE configure */ write32((HSI2C_RXCHON | HSI2C_FUNC_MODE_I2C | HSI2C_MASTER), &i2c->usi_ctl); /* auto_conf, length and stop configure */ i2c_auto_conf = (len | HSI2C_STOP_AFTER_TRANS | HSI2C_READ_WRITE); i2c_auto_conf |= HSI2C_MASTER_RUN; /* Master run, start xfer */ write32(i2c_auto_conf, &i2c->usi_auto_conf); if (hsi2c_recvdata(i2c, data, len) || hsi2c_wait_for_transfer(i2c)) { return -1; } write32(HSI2C_FUNC_MODE_I2C, &i2c->usi_ctl); return 0; } /* * cmd_type is 0 for write, 1 for read. * * addr_len can take any value from 0-255, it is only limited * by the char, we could make it larger if needed. If it is * 0 we skip the address write cycle. */ static int i2c_transfer(struct s3c24x0_i2c *i2c, unsigned char cmd_type, unsigned char chip, unsigned char addr[], unsigned char addr_len, unsigned char data[], unsigned short data_len) { int i = 0, result; struct mono_time current, end; if (data == 0 || data_len == 0) { printk(BIOS_ERR, "i2c_transfer: bad call\n"); return I2C_NOK; } timer_monotonic_get(¤t); end = current; mono_time_add_usecs(&end, I2C_TIMEOUT_MS * 1000); while (readl(&i2c->iicstat) & I2CSTAT_BSY) { if (!mono_time_before(¤t, &end)){ printk(BIOS_ERR, "%s timed out\n", __func__); return I2C_NOK_TOUT; } timer_monotonic_get(¤t); } write32(read32(&i2c->iiccon) | I2CCON_ACKGEN, &i2c->iiccon); /* Get the slave chip address going */ write32(chip, &i2c->iicds); if ((cmd_type == I2C_WRITE) || (addr && addr_len)) write32(I2C_MODE_MT | I2C_TXRX_ENA | I2C_START_STOP, &i2c->iicstat); else write32(I2C_MODE_MR | I2C_TXRX_ENA | I2C_START_STOP, &i2c->iicstat); /* Wait for chip address to transmit. */ result = WaitForXfer(i2c); if (result != I2C_OK) goto bailout; /* If register address needs to be transmitted - do it now. */ if (addr && addr_len) { while ((i < addr_len) && (result == I2C_OK)) { write32(addr[i++], &i2c->iicds); ReadWriteByte(i2c); result = WaitForXfer(i2c); } i = 0; if (result != I2C_OK) goto bailout; } switch (cmd_type) { case I2C_WRITE: while ((i < data_len) && (result == I2C_OK)) { write32(data[i++], &i2c->iicds); ReadWriteByte(i2c); result = WaitForXfer(i2c); } break; case I2C_READ: if (addr && addr_len) { /* * Register address has been sent, now send slave chip * address again to start the actual read transaction. */ write32(chip, &i2c->iicds); /* Generate a re-START. */ write32(I2C_MODE_MR | I2C_TXRX_ENA | I2C_START_STOP, &i2c->iicstat); ReadWriteByte(i2c); result = WaitForXfer(i2c); if (result != I2C_OK) goto bailout; } while ((i < data_len) && (result == I2C_OK)) { /* disable ACK for final READ */ if (i == data_len - 1) write32(readl(&i2c->iiccon) & ~I2CCON_ACKGEN, &i2c->iiccon); ReadWriteByte(i2c); result = WaitForXfer(i2c); data[i++] = read32(&i2c->iicds); } if (result == I2C_NACK) result = I2C_OK; /* Normal terminated read. */ break; default: printk(BIOS_ERR, "i2c_transfer: bad call\n"); result = I2C_NOK; break; } bailout: /* Send STOP. */ write32(I2C_MODE_MR | I2C_TXRX_ENA, &i2c->iicstat); ReadWriteByte(i2c); return result; } int i2c_read(unsigned bus, unsigned chip, unsigned addr, unsigned alen, unsigned char *buf, unsigned len) { struct s3c24x0_i2c_bus *i2c; unsigned char xaddr[4]; int ret; if (alen > 4) { printk(BIOS_ERR, "I2C read: addr len %d not supported\n", alen); return 1; } if (alen > 0) { xaddr[0] = (addr >> 24) & 0xFF; xaddr[1] = (addr >> 16) & 0xFF; xaddr[2] = (addr >> 8) & 0xFF; xaddr[3] = addr & 0xFF; } i2c = &i2c_buses[bus]; if (i2c->is_highspeed) ret = hsi2c_read(i2c->hsregs, chip, &xaddr[4 - alen], alen, buf, len, 0); else ret = i2c_transfer(i2c->regs, I2C_READ, chip << 1, &xaddr[4 - alen], alen, buf, len); if (ret) { i2c_reset(i2c); printk(BIOS_ERR, "I2C read (bus %02x, chip addr %02x) failed: " "%d\n", bus, chip, ret); return 1; } return 0; } int i2c_write(unsigned bus, unsigned chip, unsigned addr, unsigned alen, unsigned char *buf, unsigned len) { struct s3c24x0_i2c_bus *i2c; unsigned char xaddr[4]; int ret; if (alen > 4) { printk(BIOS_ERR, "I2C write: addr len %d not supported\n", alen); return 1; } if (alen > 0) { xaddr[0] = (addr >> 24) & 0xFF; xaddr[1] = (addr >> 16) & 0xFF; xaddr[2] = (addr >> 8) & 0xFF; xaddr[3] = addr & 0xFF; } i2c = &i2c_buses[bus]; if (i2c->is_highspeed) ret = hsi2c_write(i2c->hsregs, chip, &xaddr[4 - alen], alen, buf, len); else ret = i2c_transfer(i2c->regs, I2C_WRITE, chip << 1, &xaddr[4 - alen], alen, buf, len); if (ret != 0) { i2c_reset(i2c); printk(BIOS_ERR, "I2C write (bus %02x, chip addr %02x) failed: " "%d\n", bus, chip, ret); return 1; } return 0; }