diff options
Diffstat (limited to 'src/soc/mediatek/mt8173/i2c.c')
| -rw-r--r-- | src/soc/mediatek/mt8173/i2c.c | 329 |
1 files changed, 329 insertions, 0 deletions
diff --git a/src/soc/mediatek/mt8173/i2c.c b/src/soc/mediatek/mt8173/i2c.c new file mode 100644 index 0000000000..52b1fb270f --- /dev/null +++ b/src/soc/mediatek/mt8173/i2c.c @@ -0,0 +1,329 @@ +/* + * This file is part of the coreboot project. + * + * Copyright 2015 MediaTek 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 <assert.h> +#include <delay.h> +#include <device/i2c.h> +#include <string.h> +#include <symbols.h> +#include <timer.h> +#include <arch/io.h> +#include <soc/addressmap.h> +#include <soc/i2c.h> +#include <soc/pll.h> + +#define I2C_CLK_HZ (AXI_HZ / 16) + +static struct mtk_i2c i2c[7] = { + /* i2c0 setting */ + { + .i2c_regs = (void *)I2C_BASE, + .i2c_dma_regs = (void *)(I2C_DMA_BASE + 0x80), + }, + + /* i2c1 setting */ + { + .i2c_regs = (void *)(I2C_BASE + 0x1000), + .i2c_dma_regs = (void *)(I2C_DMA_BASE + 0x100), + }, + + /* i2c2 setting */ + { + .i2c_regs = (void *)(I2C_BASE + 0x2000), + .i2c_dma_regs = (void *)(I2C_DMA_BASE + 0x180), + }, + + /* i2c3 setting */ + { + .i2c_regs = (void *)(I2C_BASE + 0x9000), + .i2c_dma_regs = (void *)(I2C_DMA_BASE + 0x200), + }, + + /* i2c4 setting */ + { + .i2c_regs = (void *)(I2C_BASE + 0xa000), + .i2c_dma_regs = (void *)(I2C_DMA_BASE + 0x280), + }, + + /* i2c5 is reserved for internal use. */ + { + }, + + /* i2c6 setting */ + { + .i2c_regs = (void *)(I2C_BASE + 0xc000), + .i2c_dma_regs = (void *)I2C_DMA_BASE, + } +}; + +#define I2CTAG "[I2C][PL] " + +#if CONFIG_DEBUG_I2C +#define I2CLOG(fmt, arg...) printk(BIOS_INFO, I2CTAG fmt, ##arg) +#else +#define I2CLOG(fmt, arg...) +#endif /* CONFIG_DEBUG_I2C */ + +#define I2CERR(fmt, arg...) printk(BIOS_ERR, I2CTAG fmt, ##arg) + +static inline void i2c_dma_reset(struct mt8173_i2c_dma_regs *dma_regs) +{ + write32(&dma_regs->dma_rst, 0x1); + udelay(50); + write32(&dma_regs->dma_rst, 0x2); + udelay(50); + write32(&dma_regs->dma_rst, 0x0); + udelay(50); +} + +static inline void mtk_i2c_dump_info(uint8_t bus) +{ + struct mt8173_i2c_regs *regs; + + regs = i2c[bus].i2c_regs; + + I2CLOG("I2C register:\nSLAVE_ADDR %x\nINTR_MASK %x\nINTR_STAT %x\n" + "CONTROL %x\nTRANSFER_LEN %x\nTRANSAC_LEN %x\nDELAY_LEN %x\n" + "TIMING %x\nSTART %x\nFIFO_STAT %x\nIO_CONFIG %x\nHS %x\n" + "DEBUGSTAT %x\nEXT_CONF %x\n", + (read32(®s->salve_addr)), + (read32(®s->intr_mask)), + (read32(®s->intr_stat)), + (read32(®s->control)), + (read32(®s->transfer_len)), + (read32(®s->transac_len)), + (read32(®s->delay_len)), + (read32(®s->timing)), + (read32(®s->start)), + (read32(®s->fifo_stat)), + (read32(®s->io_config)), + (read32(®s->hs)), + (read32(®s->debug_stat)), + (read32(®s->ext_conf))); + + I2CLOG("addr address %x\n", (uint32_t)regs); +} + +static uint32_t mtk_i2c_transfer(uint8_t bus, struct i2c_seg *seg, + enum i2c_modes read) +{ + uint32_t ret_code = I2C_OK; + uint16_t status; + uint32_t time_out_val = 0; + uint8_t addr; + uint32_t write_len = 0; + uint32_t read_len = 0; + uint8_t *write_buffer = NULL; + uint8_t *read_buffer = NULL; + uint8_t sample_div; + uint8_t step_div; + uint32_t i2c_freq; + struct mt8173_i2c_regs *regs; + struct mt8173_i2c_dma_regs *dma_regs; + struct stopwatch sw; + + regs = i2c[bus].i2c_regs; + dma_regs = i2c[bus].i2c_dma_regs; + + addr = seg[0].chip; + + switch (read) { + case I2C_WRITE_MODE: + assert(seg[0].len > 0 && seg[0].len <= 255); + write_len = seg[0].len; + write_buffer = seg[0].buf; + break; + + case I2C_READ_MODE: + assert(seg[0].len > 0 && seg[0].len <= 255); + read_len = seg[0].len; + read_buffer = seg[0].buf; + break; + + /* Must use special write-then-read mode for repeated starts. */ + case I2C_WRITE_READ_MODE: + assert(seg[0].len > 0 && seg[0].len <= 255); + assert(seg[1].len > 0 && seg[1].len <= 255); + write_len = seg[0].len; + read_len = seg[1].len; + write_buffer = seg[0].buf; + read_buffer = seg[1].buf; + break; + } + + /* Calculate i2c frequency */ + sample_div = 1; + step_div = div_round_up(I2C_CLK_HZ, (400 * KHz * sample_div * 2)); + i2c_freq = I2C_CLK_HZ / (step_div * sample_div * 2); + assert(sample_div < 8 && i2c_freq < 400 * KHz && i2c_freq >= 380 * KHz); + write32(®s->timing, (sample_div - 1) << 8 | (step_div - 1)); + + /* Clear interrupt status */ + write32(®s->intr_stat, I2C_TRANSAC_COMP | I2C_ACKERR | + I2C_HS_NACKERR); + + write32(®s->fifo_addr_clr, 0x1); + + /* Enable interrupt */ + write32(®s->intr_mask, I2C_HS_NACKERR | I2C_ACKERR | + I2C_TRANSAC_COMP); + + switch (read) { + case I2C_WRITE_MODE: + memcpy(_dma_coherent, write_buffer, write_len); + + /* control registers */ + write32(®s->control, ACK_ERR_DET_EN | DMA_EN | CLK_EXT | + REPEATED_START_FLAG); + + /* Set transfer and transaction len */ + write32(®s->transac_len, 1); + write32(®s->transfer_len, write_len); + + /* set i2c write slave address*/ + write32(®s->slave_addr, addr << 1); + + /* Prepare buffer data to start transfer */ + write32(&dma_regs->dma_con, I2C_DMA_CON_TX); + write32(&dma_regs->dma_tx_mem_addr, (uintptr_t)_dma_coherent); + write32(&dma_regs->dma_tx_len, write_len); + break; + + case I2C_READ_MODE: + /* control registers */ + write32(®s->control, ACK_ERR_DET_EN | DMA_EN | CLK_EXT | + REPEATED_START_FLAG); + + /* Set transfer and transaction len */ + write32(®s->transac_len, 1); + write32(®s->transfer_len, read_len); + + /* set i2c read slave address*/ + write32(®s->slave_addr, (addr << 1 | 0x1)); + + /* Prepare buffer data to start transfer */ + write32(&dma_regs->dma_con, I2C_DMA_CON_RX); + write32(&dma_regs->dma_rx_mem_addr, (uintptr_t)_dma_coherent); + write32(&dma_regs->dma_rx_len, read_len); + break; + + case I2C_WRITE_READ_MODE: + memcpy(_dma_coherent, write_buffer, write_len); + + /* control registers */ + write32(®s->control, DIR_CHG | ACK_ERR_DET_EN | DMA_EN | + CLK_EXT | REPEATED_START_FLAG); + + /* Set transfer and transaction len */ + write32(®s->transfer_len, write_len); + write32(®s->transfer_aux_len, read_len); + write32(®s->transac_len, 2); + + /* set i2c write slave address*/ + write32(®s->slave_addr, addr << 1); + + /* Prepare buffer data to start transfer */ + write32(&dma_regs->dma_con, I2C_DMA_CLR_FLAG); + write32(&dma_regs->dma_tx_mem_addr, (uintptr_t)_dma_coherent); + write32(&dma_regs->dma_tx_len, write_len); + write32(&dma_regs->dma_rx_mem_addr, (uintptr_t)_dma_coherent); + write32(&dma_regs->dma_rx_len, read_len); + break; + } + + write32(&dma_regs->dma_int_flag, I2C_DMA_CLR_FLAG); + write32(&dma_regs->dma_en, I2C_DMA_START_EN); + + /* start transfer transaction */ + write32(®s->start, 0x1); + + stopwatch_init_msecs_expire(&sw, 100); + + /* polling mode : see if transaction complete */ + while (1) { + status = read32(®s->intr_stat); + if (status & I2C_HS_NACKERR) { + ret_code = I2C_TRANSFER_FAIL_HS_NACKERR; + I2CERR("[i2c%d transfer] transaction NACK error\n", + bus); + mtk_i2c_dump_info(bus); + break; + } else if (status & I2C_ACKERR) { + ret_code = I2C_TRANSFER_FAIL_ACKERR; + I2CERR("[i2c%d transfer] transaction ACK error\n", bus); + mtk_i2c_dump_info(bus); + break; + } else if (status & I2C_TRANSAC_COMP) { + ret_code = I2C_OK; + memcpy(read_buffer, _dma_coherent, read_len); + break; + } + + if (stopwatch_expired(&sw)) { + ret_code = I2C_TRANSFER_FAIL_TIMEOUT; + I2CERR("[i2c%d transfer] transaction timeout:%d\n", bus, + time_out_val); + mtk_i2c_dump_info(bus); + break; + } + } + + write32(®s->intr_stat, I2C_TRANSAC_COMP | I2C_ACKERR | + I2C_HS_NACKERR); + + /* clear bit mask */ + write32(®s->intr_mask, I2C_HS_NACKERR | I2C_ACKERR | + I2C_TRANSAC_COMP); + + /* reset the i2c controller for next i2c transfer. */ + write32(®s->softreset, 0x1); + + i2c_dma_reset(dma_regs); + + return ret_code; +} + +static uint8_t mtk_i2c_should_combine(struct i2c_seg *seg, int left_count) +{ + if (left_count >= 2 && seg[0].read == 0 && seg[1].read == 1 && + seg[0].chip == seg[1].chip) + return 1; + else + return 0; +} + +int platform_i2c_transfer(unsigned bus, struct i2c_seg *segments, int seg_count) +{ + int ret = 0; + int i; + int read; + + for (i = 0; i < seg_count; i++) { + if (mtk_i2c_should_combine(&segments[i], seg_count - i)) + read = I2C_WRITE_READ_MODE; + else + read = segments[i].read; + + ret = mtk_i2c_transfer(bus, &segments[i], read); + + if (ret) + break; + + if (read == I2C_WRITE_READ_MODE) + i++; + } + + return ret; +} |