| /* SPDX-License-Identifier: GPL-2.0-only */ |
| |
| #include <device/mmio.h> |
| #include <assert.h> |
| #include <console/console.h> |
| #include <delay.h> |
| #include <device/i2c_simple.h> |
| #include <soc/addressmap.h> |
| #include <soc/grf.h> |
| #include <soc/soc.h> |
| #include <soc/i2c.h> |
| #include <soc/clock.h> |
| #include <stddef.h> |
| #include <stdint.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_msg segment) |
| { |
| int res = 0; |
| uint8_t *data = segment.buf; |
| int timeout = I2C_TIMEOUT_US; |
| unsigned int bytes_remaining = segment.len; |
| unsigned int con = 0; |
| |
| write32(®_addr->i2c_mrxaddr, I2C_8BIT | segment.slave << 1 | 1); |
| write32(®_addr->i2c_mrxraddr, 0); |
| con = I2C_MODE_TRX | I2C_EN | I2C_ACT2NAK; |
| while (bytes_remaining) { |
| size_t size = MIN(bytes_remaining, 32); |
| bytes_remaining -= size; |
| if (!bytes_remaining) |
| con |= I2C_EN | I2C_NAK; |
| |
| i2c_info("I2C Read::%zu bytes\n", size); |
| write32(®_addr->i2c_ipd, I2C_CLEANI); |
| write32(®_addr->i2c_con, con); |
| write32(®_addr->i2c_mrxcnt, size); |
| |
| 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; |
| } |
| |
| buffer_from_fifo32(data, size, ®_addr->rxdata, 4, 4); |
| data += size; |
| con = I2C_MODE_RX | I2C_EN | I2C_ACT2NAK; |
| } |
| return res; |
| } |
| |
| static int i2c_write(struct rk_i2c_regs *reg_addr, struct i2c_msg segment) |
| { |
| int res = 0; |
| uint8_t *data = segment.buf; |
| int timeout = I2C_TIMEOUT_US; |
| int bytes_remaining = segment.len + 1; |
| |
| /* Prepend one byte for the slave address to the transfer. */ |
| u32 prefix = segment.slave << 1; |
| int prefsz = 1; |
| |
| while (bytes_remaining) { |
| size_t size = MIN(bytes_remaining, 32); |
| buffer_to_fifo32_prefix(data, prefix, prefsz, size, |
| ®_addr->txdata, 4, 4); |
| data += size - prefsz; |
| |
| i2c_info("I2C Write::%zu bytes\n", size); |
| write32(®_addr->i2c_ipd, I2C_CLEANI); |
| write32(®_addr->i2c_con, |
| I2C_EN | I2C_MODE_TX | I2C_ACT2NAK); |
| write32(®_addr->i2c_mtxcnt, size); |
| |
| 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 -= size; |
| prefsz = 0; |
| prefix = 0; |
| } |
| return res; |
| } |
| |
| static int i2c_do_xfer(void *reg_addr, struct i2c_msg segment) |
| { |
| int res = 0; |
| |
| if (i2c_send_start(reg_addr)) |
| return I2C_TIMEOUT; |
| if (segment.flags & I2C_M_RD) |
| 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 int bus, struct i2c_msg *segments, |
| int seg_count) |
| { |
| int i; |
| int res = 0; |
| struct rk_i2c_regs *regs = (struct rk_i2c_regs *)(i2c_bus[bus]); |
| struct i2c_msg *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; |
| unsigned int i2c_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; |
| i2c_clk = i2c_src_clk / (8 * (divl + 1 + divh + 1)); |
| printk(BIOS_DEBUG, "I2C bus %u: %uHz (divh = %u, divl = %u)\n", |
| bus, i2c_clk, divh, divl); |
| assert((divh < 65536) && (divl < 65536) && hz - i2c_clk < 15*KHz); |
| write32(®s->i2c_clkdiv, (divh << 16) | (divl << 0)); |
| } |