diff options
Diffstat (limited to 'src/soc/rockchip/common')
| -rw-r--r-- | src/soc/rockchip/common/i2c.c | 288 |
1 files changed, 288 insertions, 0 deletions
diff --git a/src/soc/rockchip/common/i2c.c b/src/soc/rockchip/common/i2c.c new file mode 100644 index 0000000000..1bd88bbe9d --- /dev/null +++ b/src/soc/rockchip/common/i2c.c @@ -0,0 +1,288 @@ +/* + * This file is part of the coreboot project. + * + * Copyright 2014 Rockchip Inc. + * + * 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. + */ + +#include <arch/io.h> +#include <assert.h> +#include <cbfs.h> +#include <console/console.h> +#include <delay.h> +#include <device/i2c.h> +#include <soc/addressmap.h> +#include <soc/grf.h> +#include <soc/soc.h> +#include <soc/i2c.h> +#include <soc/clock.h> +#include <stdlib.h> +#include <string.h> + +#define RETRY_COUNT 3 +/* 100000us = 100ms */ +#define I2C_TIMEOUT_US 100000 +#define I2C_BUS_MAX 6 +#define I2C_NOACK 2 +#define I2C_TIMEOUT 3 + +#define i2c_info(x...) do {if (0) printk(BIOS_DEBUG, x); } while (0) + +struct rk_i2c_regs { + u32 i2c_con; + u32 i2c_clkdiv; + u32 i2c_mrxaddr; + u32 i2c_mrxraddr; + u32 i2c_mtxcnt; + u32 i2c_mrxcnt; + u32 i2c_ien; + u32 i2c_ipd; + u32 i2c_fcnt; + u32 reserved0[(0x100 - 0x24) / 4]; + u32 txdata[8]; + u32 reserved1[(0x200 - 0x120) / 4]; + u32 rxdata[8]; +}; + +static const uintptr_t i2c_bus[] = IC_BASES; + +/* Con register bits. */ +#define I2C_ACT2NAK (1<<6) +#define I2C_NAK (1<<5) +#define I2C_STOP (1<<4) +#define I2C_START (1<<3) +#define I2C_MODE_TX (0<<1) +#define I2C_MODE_TRX (1<<1) +#define I2C_MODE_RX (2<<1) +#define I2C_EN (1<<0) + +#define I2C_8BIT (1<<24) +#define I2C_16BIT (3<<24) +#define I2C_24BIT (7<<24) + +/* Mtxcnt register bits. */ +#define I2C_CNT(cnt) ((cnt) & 0x3F) + +#define I2C_NAKRCVI (1<<6) +#define I2C_STOPI (1<<5) +#define I2C_STARTI (1<<4) +#define I2C_MBRFI (1<<3) +#define I2C_MBTFI (1<<2) +#define I2C_BRFI (1<<1) +#define I2C_BTFI (1<<0) +#define I2C_CLEANI 0x7F + +static int i2c_send_start(struct rk_i2c_regs *reg_addr) +{ + int res = 0; + int timeout = I2C_TIMEOUT_US; + + i2c_info("I2c Start::Send Start bit\n"); + write32(®_addr->i2c_ipd, I2C_CLEANI); + write32(®_addr->i2c_con, I2C_EN | I2C_START); + while (timeout--) { + if (read32(®_addr->i2c_ipd) & I2C_STARTI) + break; + udelay(1); + } + + if (timeout <= 0) { + printk(BIOS_ERR, "I2C Start::Send Start Bit Timeout\n"); + res = I2C_TIMEOUT; + } + + return res; +} + +static int i2c_send_stop(struct rk_i2c_regs *reg_addr) +{ + int res = 0; + int timeout = I2C_TIMEOUT_US; + + i2c_info("I2c Stop::Send Stop bit\n"); + write32(®_addr->i2c_ipd, I2C_CLEANI); + write32(®_addr->i2c_con, I2C_EN | I2C_STOP); + while (timeout--) { + if (read32(®_addr->i2c_ipd) & I2C_STOPI) + break; + udelay(1); + } + write32(®_addr->i2c_con, 0); + if (timeout <= 0) { + printk(BIOS_ERR, "I2C Stop::Send Stop Bit Timeout\n"); + res = I2C_TIMEOUT; + } + + return res; +} + +static int i2c_read(struct rk_i2c_regs *reg_addr, struct i2c_seg segment) +{ + int res = 0; + uint8_t *data = segment.buf; + int timeout = I2C_TIMEOUT_US; + unsigned int bytes_remaining = segment.len; + unsigned int bytes_transferred = 0; + unsigned int words_transferred = 0; + unsigned int rxdata = 0; + unsigned int con = 0; + unsigned int i, j; + + write32(®_addr->i2c_mrxaddr, I2C_8BIT | segment.chip << 1 | 1); + write32(®_addr->i2c_mrxraddr, 0); + con = I2C_MODE_TRX | I2C_EN | I2C_ACT2NAK; + while (bytes_remaining) { + bytes_transferred = MIN(bytes_remaining, 32); + bytes_remaining -= bytes_transferred; + if (!bytes_remaining) + con |= I2C_EN | I2C_NAK; + words_transferred = ALIGN_UP(bytes_transferred, 4) / 4; + + write32(®_addr->i2c_ipd, I2C_CLEANI); + write32(®_addr->i2c_con, con); + write32(®_addr->i2c_mrxcnt, bytes_transferred); + + timeout = I2C_TIMEOUT_US; + while (timeout--) { + if (read32(®_addr->i2c_ipd) & I2C_NAKRCVI) { + write32(®_addr->i2c_mrxcnt, 0); + write32(®_addr->i2c_con, 0); + return I2C_NOACK; + } + if (read32(®_addr->i2c_ipd) & I2C_MBRFI) + break; + udelay(1); + } + if (timeout <= 0) { + printk(BIOS_ERR, "I2C Read::Recv Data Timeout\n"); + write32(®_addr->i2c_mrxcnt, 0); + write32(®_addr->i2c_con, 0); + return I2C_TIMEOUT; + } + + for (i = 0; i < words_transferred; i++) { + rxdata = read32(®_addr->rxdata[i]); + i2c_info("I2c Read::RXDATA[%d] = 0x%x\n", i, rxdata); + for (j = 0; j < 4; j++) { + if ((i * 4 + j) == bytes_transferred) + break; + *data++ = (rxdata >> (j * 8)) & 0xff; + } + } + con = I2C_MODE_RX | I2C_EN | I2C_ACT2NAK; + } + return res; +} + +static int i2c_write(struct rk_i2c_regs *reg_addr, struct i2c_seg segment) +{ + int res = 0; + uint8_t *data = segment.buf; + int timeout = I2C_TIMEOUT_US; + int bytes_remaining = segment.len + 1; + int bytes_transferred = 0; + int words_transferred = 0; + unsigned int i; + unsigned int j = 1; + u32 txdata = 0; + + txdata |= (segment.chip << 1); + while (bytes_remaining) { + bytes_transferred = MIN(bytes_remaining, 32); + words_transferred = ALIGN_UP(bytes_transferred, 4) / 4; + for (i = 0; i < words_transferred; i++) { + do { + if ((i * 4 + j) == bytes_transferred) + break; + txdata |= (*data++) << (j * 8); + } while (++j < 4); + write32(®_addr->txdata[i], txdata); + j = 0; + i2c_info("I2c Write::TXDATA[%d] = 0x%x\n", i, txdata); + txdata = 0; + } + + write32(®_addr->i2c_ipd, I2C_CLEANI); + write32(®_addr->i2c_con, + I2C_EN | I2C_MODE_TX | I2C_ACT2NAK); + write32(®_addr->i2c_mtxcnt, bytes_transferred); + + timeout = I2C_TIMEOUT_US; + while (timeout--) { + if (read32(®_addr->i2c_ipd) & I2C_NAKRCVI) { + write32(®_addr->i2c_mtxcnt, 0); + write32(®_addr->i2c_con, 0); + return I2C_NOACK; + } + if (read32(®_addr->i2c_ipd) & I2C_MBTFI) + break; + udelay(1); + } + + if (timeout <= 0) { + printk(BIOS_ERR, "I2C Write::Send Data Timeout\n"); + write32(®_addr->i2c_mtxcnt, 0); + write32(®_addr->i2c_con, 0); + return I2C_TIMEOUT; + } + + bytes_remaining -= bytes_transferred; + } + return res; +} + +static int i2c_do_xfer(void *reg_addr, struct i2c_seg segment) +{ + int res = 0; + + if (i2c_send_start(reg_addr)) + return I2C_TIMEOUT; + if (segment.read) + res = i2c_read(reg_addr, segment); + else + res = i2c_write(reg_addr, segment); + return i2c_send_stop(reg_addr) || res; +} + +int platform_i2c_transfer(unsigned bus, struct i2c_seg *segments, int seg_count) +{ + int i; + int res = 0; + struct rk_i2c_regs *regs = (struct rk_i2c_regs *)(i2c_bus[bus]); + struct i2c_seg *seg = segments; + + for (i = 0; i < seg_count; i++, seg++) { + res = i2c_do_xfer(regs, *seg); + if (res) + break; + } + return res; +} + +void i2c_init(unsigned int bus, unsigned int hz) +{ + unsigned int clk_div; + unsigned int divl; + unsigned int divh; + unsigned int i2c_src_clk; + struct rk_i2c_regs *regs = (struct rk_i2c_regs *)(i2c_bus[bus]); + + i2c_src_clk = rkclk_i2c_clock_for_bus(bus); + + /*SCL Divisor = 8*(CLKDIVL + 1 + CLKDIVH + 1) + SCL = PCLK/ SCLK Divisor + */ + clk_div = div_round_up(i2c_src_clk, hz * 8); + divh = clk_div * 3 / 7 - 1; + divl = clk_div - divh - 2; + assert((divh < 65536) && (divl < 65536)); + write32(®s->i2c_clkdiv, (divh << 16) | (divl << 0)); +} |