| // SPDX-License-Identifier: GPL-2.0+ |
| /* |
| * Copyright (c) 2016, Google Inc |
| * |
| * (C) Copyright 2002 |
| * David Mueller, ELSOFT AG, d.mueller@elsoft.ch |
| */ |
| |
| #include <dm.h> |
| #include <i2c.h> |
| #include <log.h> |
| #include <asm/arch/clk.h> |
| #include <asm/arch/cpu.h> |
| #include <asm/arch/pinmux.h> |
| #include <asm/global_data.h> |
| #include <linux/delay.h> |
| #include "s3c24x0_i2c.h" |
| |
| DECLARE_GLOBAL_DATA_PTR; |
| |
| /* HSI2C-specific register description */ |
| |
| /* I2C_CTL Register bits */ |
| #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_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_TX_UNDERRUN_EN (1u << 2) |
| #define HSI2C_TX_OVERRUN_EN (1u << 3) |
| #define HSI2C_RX_UNDERRUN_EN (1u << 4) |
| #define HSI2C_RX_OVERRUN_EN (1u << 5) |
| #define HSI2C_INT_TRAILING_EN (1u << 6) |
| #define HSI2C_INT_I2C_EN (1u << 9) |
| |
| #define HSI2C_INT_ERROR_MASK (HSI2C_TX_UNDERRUN_EN |\ |
| HSI2C_TX_OVERRUN_EN |\ |
| HSI2C_RX_UNDERRUN_EN |\ |
| HSI2C_RX_OVERRUN_EN |\ |
| HSI2C_INT_TRAILING_EN) |
| |
| /* 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_SUCCESS (1u << 0) |
| #define HSI2C_TRANS_ERROR_MASK (HSI2C_TIMEOUT_AUTO |\ |
| HSI2C_NO_DEV | HSI2C_NO_DEV_ACK |\ |
| HSI2C_TRANS_ABORT) |
| #define HSI2C_TRANS_FINISHED_MASK (HSI2C_TRANS_ERROR_MASK | HSI2C_TRANS_SUCCESS) |
| |
| /* I2C_FIFO_STAT Register bits */ |
| #define HSI2C_RX_FIFO_EMPTY (1u << 24) |
| #define HSI2C_RX_FIFO_FULL (1u << 23) |
| #define HSI2C_TX_FIFO_EMPTY (1u << 8) |
| #define HSI2C_TX_FIFO_FULL (1u << 7) |
| #define HSI2C_RX_FIFO_LEVEL(x) (((x) >> 16) & 0x7f) |
| #define HSI2C_TX_FIFO_LEVEL(x) ((x) & 0x7f) |
| |
| #define HSI2C_SLV_ADDR_MAS(x) ((x & 0x3ff) << 10) |
| |
| #define HSI2C_TIMEOUT_US 10000 /* 10 ms, finer granularity */ |
| |
| /* |
| * Wait for transfer completion. |
| * |
| * This function reads the interrupt status register waiting for the INT_I2C |
| * bit to be set, which indicates copletion of a transaction. |
| * |
| * @param i2c: pointer to the appropriate register bank |
| * |
| * @return: I2C_OK in case of successful completion, I2C_NOK_TIMEOUT in case |
| * the status bits do not get set in time, or an approrpiate error |
| * value in case of transfer errors. |
| */ |
| static int hsi2c_wait_for_trx(struct exynos5_hsi2c *i2c) |
| { |
| int i = HSI2C_TIMEOUT_US; |
| |
| while (i-- > 0) { |
| u32 int_status = readl(&i2c->usi_int_stat); |
| |
| if (int_status & HSI2C_INT_I2C_EN) { |
| u32 trans_status = readl(&i2c->usi_trans_status); |
| |
| /* Deassert pending interrupt. */ |
| writel(int_status, &i2c->usi_int_stat); |
| |
| if (trans_status & HSI2C_NO_DEV_ACK) { |
| debug("%s: no ACK from device\n", __func__); |
| return I2C_NACK; |
| } |
| if (trans_status & HSI2C_NO_DEV) { |
| debug("%s: no device\n", __func__); |
| return I2C_NOK; |
| } |
| if (trans_status & HSI2C_TRANS_ABORT) { |
| debug("%s: arbitration lost\n", __func__); |
| return I2C_NOK_LA; |
| } |
| if (trans_status & HSI2C_TIMEOUT_AUTO) { |
| debug("%s: device timed out\n", __func__); |
| return I2C_NOK_TOUT; |
| } |
| return I2C_OK; |
| } |
| udelay(1); |
| } |
| debug("%s: transaction timeout!\n", __func__); |
| return I2C_NOK_TOUT; |
| } |
| |
| static int hsi2c_get_clk_details(struct s3c24x0_i2c_bus *i2c_bus) |
| { |
| struct exynos5_hsi2c *hsregs = i2c_bus->hsregs; |
| ulong clkin; |
| unsigned int op_clk = i2c_bus->clock_frequency; |
| unsigned int i = 0, utemp0 = 0, utemp1 = 0; |
| unsigned int t_ftl_cycle; |
| |
| clkin = get_i2c_clk(); |
| /* 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 = (readl(&hsregs->usi_conf) >> 16) & 0x7; |
| utemp0 = (clkin / op_clk) - 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; |
| } |
| } |
| return -EINVAL; |
| } |
| |
| static void hsi2c_ch_init(struct s3c24x0_i2c_bus *i2c_bus) |
| { |
| 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; |
| |
| 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; |
| |
| writel(HSI2C_TRAILING_COUNT, &hsregs->usi_trailing_ctl); |
| |
| /* Clear to enable Timeout */ |
| clrsetbits_le32(&hsregs->usi_timeout, HSI2C_TIMEOUT_EN, 0); |
| |
| /* set AUTO mode */ |
| writel(readl(&hsregs->usi_conf) | HSI2C_AUTO_MODE, &hsregs->usi_conf); |
| |
| /* Enable completion conditions' reporting. */ |
| writel(HSI2C_INT_I2C_EN, &hsregs->usi_int_en); |
| |
| /* Enable FIFOs */ |
| writel(HSI2C_RXFIFO_EN | HSI2C_TXFIFO_EN, &hsregs->usi_fifo_ctl); |
| |
| /* Currently operating in Fast speed mode. */ |
| writel(i2c_timing_s1, &hsregs->usi_timing_fs1); |
| writel(i2c_timing_s2, &hsregs->usi_timing_fs2); |
| writel(i2c_timing_s3, &hsregs->usi_timing_fs3); |
| writel(i2c_timing_sla, &hsregs->usi_timing_sla); |
| } |
| |
| /* SW reset for the high speed bus */ |
| static void exynos5_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 = readl(&i2c->usi_ctl); |
| i2c_ctl |= HSI2C_SW_RST; |
| writel(i2c_ctl, &i2c->usi_ctl); |
| |
| i2c_ctl = readl(&i2c->usi_ctl); |
| i2c_ctl &= ~HSI2C_SW_RST; |
| writel(i2c_ctl, &i2c->usi_ctl); |
| |
| /* Initialize the configure registers */ |
| hsi2c_ch_init(i2c_bus); |
| } |
| |
| /* |
| * Poll the appropriate bit of the fifo status register until the interface is |
| * ready to process the next byte or timeout expires. |
| * |
| * In addition to the FIFO status register this function also polls the |
| * interrupt status register to be able to detect unexpected transaction |
| * completion. |
| * |
| * When FIFO is ready to process the next byte, this function returns I2C_OK. |
| * If in course of polling the INT_I2C assertion is detected, the function |
| * returns I2C_NOK. If timeout happens before any of the above conditions is |
| * met - the function returns I2C_NOK_TOUT; |
| |
| * @param i2c: pointer to the appropriate i2c register bank. |
| * @param rx_transfer: set to True if the receive transaction is in progress. |
| * @return: as described above. |
| */ |
| static unsigned hsi2c_poll_fifo(struct exynos5_hsi2c *i2c, bool rx_transfer) |
| { |
| u32 fifo_bit = rx_transfer ? HSI2C_RX_FIFO_EMPTY : HSI2C_TX_FIFO_FULL; |
| int i = HSI2C_TIMEOUT_US; |
| |
| while (readl(&i2c->usi_fifo_stat) & fifo_bit) { |
| if (readl(&i2c->usi_int_stat) & HSI2C_INT_I2C_EN) { |
| /* |
| * There is a chance that assertion of |
| * HSI2C_INT_I2C_EN and deassertion of |
| * HSI2C_RX_FIFO_EMPTY happen simultaneously. Let's |
| * give FIFO status priority and check it one more |
| * time before reporting interrupt. The interrupt will |
| * be reported next time this function is called. |
| */ |
| if (rx_transfer && |
| !(readl(&i2c->usi_fifo_stat) & fifo_bit)) |
| break; |
| return I2C_NOK; |
| } |
| if (!i--) { |
| debug("%s: FIFO polling timeout!\n", __func__); |
| return I2C_NOK_TOUT; |
| } |
| udelay(1); |
| } |
| return I2C_OK; |
| } |
| |
| /* |
| * Preapre hsi2c transaction, either read or write. |
| * |
| * Set up transfer as described in section 27.5.1.2 'I2C Channel Auto Mode' of |
| * the 5420 UM. |
| * |
| * @param i2c: pointer to the appropriate i2c register bank. |
| * @param chip: slave address on the i2c bus (with read/write bit exlcuded) |
| * @param len: number of bytes expected to be sent or received |
| * @param rx_transfer: set to true for receive transactions |
| * @param: issue_stop: set to true if i2c stop condition should be generated |
| * after this transaction. |
| * @return: I2C_NOK_TOUT in case the bus remained busy for HSI2C_TIMEOUT_US, |
| * I2C_OK otherwise. |
| */ |
| static int hsi2c_prepare_transaction(struct exynos5_hsi2c *i2c, |
| u8 chip, |
| u16 len, |
| bool rx_transfer, |
| bool issue_stop) |
| { |
| u32 conf; |
| |
| conf = len | HSI2C_MASTER_RUN; |
| |
| if (issue_stop) |
| conf |= HSI2C_STOP_AFTER_TRANS; |
| |
| /* Clear to enable Timeout */ |
| writel(readl(&i2c->usi_timeout) & ~HSI2C_TIMEOUT_EN, &i2c->usi_timeout); |
| |
| /* Set slave address */ |
| writel(HSI2C_SLV_ADDR_MAS(chip), &i2c->i2c_addr); |
| |
| if (rx_transfer) { |
| /* i2c master, read transaction */ |
| writel((HSI2C_RXCHON | HSI2C_FUNC_MODE_I2C | HSI2C_MASTER), |
| &i2c->usi_ctl); |
| |
| /* read up to len bytes, stop after transaction is finished */ |
| writel(conf | HSI2C_READ_WRITE, &i2c->usi_auto_conf); |
| } else { |
| /* i2c master, write transaction */ |
| writel((HSI2C_TXCHON | HSI2C_FUNC_MODE_I2C | HSI2C_MASTER), |
| &i2c->usi_ctl); |
| |
| /* write up to len bytes, stop after transaction is finished */ |
| writel(conf, &i2c->usi_auto_conf); |
| } |
| |
| /* Reset all pending interrupt status bits we care about, if any */ |
| writel(HSI2C_INT_I2C_EN, &i2c->usi_int_stat); |
| |
| return I2C_OK; |
| } |
| |
| /* |
| * Wait while i2c bus is settling down (mostly stop gets completed). |
| */ |
| static int hsi2c_wait_while_busy(struct exynos5_hsi2c *i2c) |
| { |
| int i = HSI2C_TIMEOUT_US; |
| |
| while (readl(&i2c->usi_trans_status) & HSI2C_MASTER_BUSY) { |
| if (!i--) { |
| debug("%s: bus busy\n", __func__); |
| return I2C_NOK_TOUT; |
| } |
| udelay(1); |
| } |
| return I2C_OK; |
| } |
| |
| static int hsi2c_write(struct exynos5_hsi2c *i2c, |
| unsigned char chip, |
| unsigned char addr[], |
| unsigned char alen, |
| unsigned char data[], |
| unsigned short len, |
| bool issue_stop) |
| { |
| int i, rv = 0; |
| |
| if (!(len + alen)) { |
| /* Writes of zero length not supported in auto mode. */ |
| debug("%s: zero length writes not supported\n", __func__); |
| return I2C_NOK; |
| } |
| |
| rv = hsi2c_prepare_transaction |
| (i2c, chip, len + alen, false, issue_stop); |
| if (rv != I2C_OK) |
| return rv; |
| |
| /* Move address, if any, and the data, if any, into the FIFO. */ |
| for (i = 0; i < alen; i++) { |
| rv = hsi2c_poll_fifo(i2c, false); |
| if (rv != I2C_OK) { |
| debug("%s: address write failed\n", __func__); |
| goto write_error; |
| } |
| writel(addr[i], &i2c->usi_txdata); |
| } |
| |
| for (i = 0; i < len; i++) { |
| rv = hsi2c_poll_fifo(i2c, false); |
| if (rv != I2C_OK) { |
| debug("%s: data write failed\n", __func__); |
| goto write_error; |
| } |
| writel(data[i], &i2c->usi_txdata); |
| } |
| |
| rv = hsi2c_wait_for_trx(i2c); |
| |
| write_error: |
| if (issue_stop) { |
| int tmp_ret = hsi2c_wait_while_busy(i2c); |
| if (rv == I2C_OK) |
| rv = tmp_ret; |
| } |
| |
| writel(HSI2C_FUNC_MODE_I2C, &i2c->usi_ctl); /* done */ |
| return rv; |
| } |
| |
| static int hsi2c_read(struct exynos5_hsi2c *i2c, |
| unsigned char chip, |
| unsigned char addr[], |
| unsigned char alen, |
| unsigned char data[], |
| unsigned short len) |
| { |
| int i, rv, tmp_ret; |
| bool drop_data = false; |
| |
| if (!len) { |
| /* Reads of zero length not supported in auto mode. */ |
| debug("%s: zero length read adjusted\n", __func__); |
| drop_data = true; |
| len = 1; |
| } |
| |
| if (alen) { |
| /* Internal register adress needs to be written first. */ |
| rv = hsi2c_write(i2c, chip, addr, alen, NULL, 0, false); |
| if (rv != I2C_OK) |
| return rv; |
| } |
| |
| rv = hsi2c_prepare_transaction(i2c, chip, len, true, true); |
| |
| if (rv != I2C_OK) |
| return rv; |
| |
| for (i = 0; i < len; i++) { |
| rv = hsi2c_poll_fifo(i2c, true); |
| if (rv != I2C_OK) |
| goto read_err; |
| if (drop_data) |
| continue; |
| data[i] = readl(&i2c->usi_rxdata); |
| } |
| |
| rv = hsi2c_wait_for_trx(i2c); |
| |
| read_err: |
| tmp_ret = hsi2c_wait_while_busy(i2c); |
| if (rv == I2C_OK) |
| rv = tmp_ret; |
| |
| writel(HSI2C_FUNC_MODE_I2C, &i2c->usi_ctl); /* done */ |
| return rv; |
| } |
| |
| static int exynos_hs_i2c_xfer(struct udevice *dev, struct i2c_msg *msg, |
| int nmsgs) |
| { |
| struct s3c24x0_i2c_bus *i2c_bus = dev_get_priv(dev); |
| struct exynos5_hsi2c *hsregs = i2c_bus->hsregs; |
| int ret; |
| |
| for (; nmsgs > 0; nmsgs--, msg++) { |
| if (msg->flags & I2C_M_RD) { |
| ret = hsi2c_read(hsregs, msg->addr, 0, 0, msg->buf, |
| msg->len); |
| } else { |
| ret = hsi2c_write(hsregs, msg->addr, 0, 0, msg->buf, |
| msg->len, true); |
| } |
| if (ret) { |
| exynos5_i2c_reset(i2c_bus); |
| return -EREMOTEIO; |
| } |
| } |
| |
| return 0; |
| } |
| |
| static int s3c24x0_i2c_set_bus_speed(struct udevice *dev, unsigned int speed) |
| { |
| struct s3c24x0_i2c_bus *i2c_bus = dev_get_priv(dev); |
| |
| i2c_bus->clock_frequency = speed; |
| |
| if (hsi2c_get_clk_details(i2c_bus)) |
| return -EFAULT; |
| hsi2c_ch_init(i2c_bus); |
| |
| return 0; |
| } |
| |
| static int s3c24x0_i2c_probe(struct udevice *dev, uint chip, uint chip_flags) |
| { |
| struct s3c24x0_i2c_bus *i2c_bus = dev_get_priv(dev); |
| uchar buf[1]; |
| int ret; |
| |
| buf[0] = 0; |
| |
| /* |
| * What is needed is to send the chip address and verify that the |
| * address was <ACK>ed (i.e. there was a chip at that address which |
| * drove the data line low). |
| */ |
| ret = hsi2c_read(i2c_bus->hsregs, chip, 0, 0, buf, 1); |
| |
| return ret != I2C_OK; |
| } |
| |
| static int s3c_i2c_of_to_plat(struct udevice *dev) |
| { |
| const void *blob = gd->fdt_blob; |
| struct s3c24x0_i2c_bus *i2c_bus = dev_get_priv(dev); |
| int node; |
| |
| node = dev_of_offset(dev); |
| |
| i2c_bus->hsregs = dev_read_addr_ptr(dev); |
| |
| i2c_bus->id = pinmux_decode_periph_id(blob, node); |
| |
| i2c_bus->clock_frequency = |
| dev_read_u32_default(dev, "clock-frequency", |
| I2C_SPEED_STANDARD_RATE); |
| i2c_bus->node = node; |
| i2c_bus->bus_num = dev_seq(dev); |
| |
| exynos_pinmux_config(i2c_bus->id, PINMUX_FLAG_HS_MODE); |
| |
| i2c_bus->active = true; |
| |
| return 0; |
| } |
| |
| static const struct dm_i2c_ops exynos_hs_i2c_ops = { |
| .xfer = exynos_hs_i2c_xfer, |
| .probe_chip = s3c24x0_i2c_probe, |
| .set_bus_speed = s3c24x0_i2c_set_bus_speed, |
| }; |
| |
| static const struct udevice_id exynos_hs_i2c_ids[] = { |
| { .compatible = "samsung,exynos5-hsi2c" }, |
| { } |
| }; |
| |
| U_BOOT_DRIVER(hs_i2c) = { |
| .name = "i2c_s3c_hs", |
| .id = UCLASS_I2C, |
| .of_match = exynos_hs_i2c_ids, |
| .of_to_plat = s3c_i2c_of_to_plat, |
| .priv_auto = sizeof(struct s3c24x0_i2c_bus), |
| .ops = &exynos_hs_i2c_ops, |
| }; |