From 956d57a8ddf17dbd69f9120b399f621f15ea3f95 Mon Sep 17 00:00:00 2001 From: Rayagonda Kokatanur Date: Wed, 8 Apr 2020 11:12:27 +0530 Subject: drivers: i2c: add brcm iproc I2C driver support Add I2C driver support for Broadcom iproc-based socs. Signed-off-by: Arjun Jyothi Signed-off-by: Rayagonda Kokatanur Signed-off-by: Sheetal Tigadoli Signed-off-by: Vladimir Olovyannikov Reviewed-by: Heiko Schocher --- drivers/i2c/iproc_i2c.c | 713 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 713 insertions(+) create mode 100644 drivers/i2c/iproc_i2c.c (limited to 'drivers/i2c/iproc_i2c.c') diff --git a/drivers/i2c/iproc_i2c.c b/drivers/i2c/iproc_i2c.c new file mode 100644 index 0000000000..a846e0a1fe --- /dev/null +++ b/drivers/i2c/iproc_i2c.c @@ -0,0 +1,713 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Copyright (C) 2018 Broadcom + * + */ + +#include +#include +#include +#include +#include "errno.h" +#include +#include "iproc_i2c.h" + +DECLARE_GLOBAL_DATA_PTR; + +struct iproc_i2c_regs { + u32 cfg_reg; + u32 timg_cfg; + u32 addr_reg; + u32 mstr_fifo_ctrl; + u32 slv_fifo_ctrl; + u32 bitbng_ctrl; + u32 blnks[6]; /* Not to be used */ + u32 mstr_cmd; + u32 slv_cmd; + u32 evt_en; + u32 evt_sts; + u32 mstr_datawr; + u32 mstr_datard; + u32 slv_datawr; + u32 slv_datard; +}; + +struct iproc_i2c { + struct iproc_i2c_regs __iomem *base; /* register base */ + int bus_speed; + int i2c_init_done; +}; + +/* Function to read a value from specified register. */ +static unsigned int iproc_i2c_reg_read(u32 *reg_addr) +{ + unsigned int val; + + val = readl((void *)(reg_addr)); + return cpu_to_le32(val); +} + +/* Function to write a value ('val') in to a specified register. */ +static int iproc_i2c_reg_write(u32 *reg_addr, unsigned int val) +{ + val = cpu_to_le32(val); + writel(val, (void *)(reg_addr)); + return 0; +} + +#if defined(DEBUG) +static int iproc_dump_i2c_regs(struct iproc_i2c *bus_prvdata) +{ + struct iproc_i2c_regs *base = bus_prvdata->base; + unsigned int regval; + + debug("\n----------------------------------------------\n"); + debug("%s: Dumping SMBus registers...\n", __func__); + + regval = iproc_i2c_reg_read(&base->cfg_reg); + debug("CCB_SMB_CFG_REG=0x%08X\n", regval); + + regval = iproc_i2c_reg_read(&base->timg_cfg); + debug("CCB_SMB_TIMGCFG_REG=0x%08X\n", regval); + + regval = iproc_i2c_reg_read(&base->addr_reg); + debug("CCB_SMB_ADDR_REG=0x%08X\n", regval); + + regval = iproc_i2c_reg_read(&base->mstr_fifo_ctrl); + debug("CCB_SMB_MSTRFIFOCTL_REG=0x%08X\n", regval); + + regval = iproc_i2c_reg_read(&base->slv_fifo_ctrl); + debug("CCB_SMB_SLVFIFOCTL_REG=0x%08X\n", regval); + + regval = iproc_i2c_reg_read(&base->bitbng_ctrl); + debug("CCB_SMB_BITBANGCTL_REG=0x%08X\n", regval); + + regval = iproc_i2c_reg_read(&base->mstr_cmd); + debug("CCB_SMB_MSTRCMD_REG=0x%08X\n", regval); + + regval = iproc_i2c_reg_read(&base->slv_cmd); + debug("CCB_SMB_SLVCMD_REG=0x%08X\n", regval); + + regval = iproc_i2c_reg_read(&base->evt_en); + debug("CCB_SMB_EVTEN_REG=0x%08X\n", regval); + + regval = iproc_i2c_reg_read(&base->evt_sts); + debug("CCB_SMB_EVTSTS_REG=0x%08X\n", regval); + + regval = iproc_i2c_reg_read(&base->mstr_datawr); + debug("CCB_SMB_MSTRDATAWR_REG=0x%08X\n", regval); + + regval = iproc_i2c_reg_read(&base->mstr_datard); + debug("CCB_SMB_MSTRDATARD_REG=0x%08X\n", regval); + + regval = iproc_i2c_reg_read(&base->slv_datawr); + debug("CCB_SMB_SLVDATAWR_REG=0x%08X\n", regval); + + regval = iproc_i2c_reg_read(&base->slv_datard); + debug("CCB_SMB_SLVDATARD_REG=0x%08X\n", regval); + + debug("----------------------------------------------\n\n"); + return 0; +} +#else +static int iproc_dump_i2c_regs(struct iproc_i2c *bus_prvdata) +{ + return 0; +} +#endif + +/* + * Function to ensure that the previous transaction was completed before + * initiating a new transaction. It can also be used in polling mode to + * check status of completion of a command + */ +static int iproc_i2c_startbusy_wait(struct iproc_i2c *bus_prvdata) +{ + struct iproc_i2c_regs *base = bus_prvdata->base; + unsigned int regval; + + regval = iproc_i2c_reg_read(&base->mstr_cmd); + + /* Check if an operation is in progress. During probe it won't be. + * But when shutdown/remove was called we want to make sure that + * the transaction in progress completed + */ + if (regval & CCB_SMB_MSTRSTARTBUSYCMD_MASK) { + unsigned int i = 0; + + do { + mdelay(10); + i++; + regval = iproc_i2c_reg_read(&base->mstr_cmd); + + /* If start-busy bit cleared, exit the loop */ + } while ((regval & CCB_SMB_MSTRSTARTBUSYCMD_MASK) && + (i < IPROC_SMB_MAX_RETRIES)); + + if (i >= IPROC_SMB_MAX_RETRIES) { + pr_err("%s: START_BUSY bit didn't clear, exiting\n", + __func__); + return -ETIMEDOUT; + } + } + return 0; +} + +/* + * This function set clock frequency for SMBus block. As per hardware + * engineering, the clock frequency can be changed dynamically. + */ +static int iproc_i2c_set_clk_freq(struct iproc_i2c *bus_prvdata) +{ + struct iproc_i2c_regs *base = bus_prvdata->base; + unsigned int regval; + + regval = iproc_i2c_reg_read(&base->timg_cfg); + + switch (bus_prvdata->bus_speed) { + case I2C_SPEED_STANDARD_RATE: + regval &= ~CCB_SMB_TIMGCFG_MODE400_MASK; + break; + + case I2C_SPEED_FAST_RATE: + regval |= CCB_SMB_TIMGCFG_MODE400_MASK; + break; + + default: + return -EINVAL; + } + + iproc_i2c_reg_write(&base->timg_cfg, regval); + return 0; +} + +static int iproc_i2c_init(struct udevice *bus) +{ + struct iproc_i2c *bus_prvdata = dev_get_priv(bus); + struct iproc_i2c_regs *base = bus_prvdata->base; + unsigned int regval; + + debug("\nEntering %s\n", __func__); + + /* Put controller in reset */ + regval = iproc_i2c_reg_read(&base->cfg_reg); + regval |= CCB_SMB_CFG_RST_MASK; + regval &= ~CCB_SMB_CFG_SMBEN_MASK; + iproc_i2c_reg_write(&base->cfg_reg, regval); + + /* Wait 100 usec as per spec */ + udelay(100); + + /* bring controller out of reset */ + regval &= ~CCB_SMB_CFG_RST_MASK; + iproc_i2c_reg_write(&base->cfg_reg, regval); + + /* Flush Tx, Rx FIFOs. Note we are setting the Rx FIFO threshold to 0. + * May be OK since we are setting RX_EVENT and RX_FIFO_FULL interrupts + */ + regval = CCB_SMB_MSTRRXFIFOFLSH_MASK | CCB_SMB_MSTRTXFIFOFLSH_MASK; + iproc_i2c_reg_write(&base->mstr_fifo_ctrl, regval); + + /* Enable SMbus block. Note, we are setting MASTER_RETRY_COUNT to zero + * since there will be only one master + */ + regval = iproc_i2c_reg_read(&base->cfg_reg); + regval |= CCB_SMB_CFG_SMBEN_MASK; + iproc_i2c_reg_write(&base->cfg_reg, regval); + + /* Set default clock frequency */ + iproc_i2c_set_clk_freq(bus_prvdata); + + /* Disable intrs */ + iproc_i2c_reg_write(&base->evt_en, 0); + + /* Clear intrs (W1TC) */ + regval = iproc_i2c_reg_read(&base->evt_sts); + iproc_i2c_reg_write(&base->evt_sts, regval); + + bus_prvdata->i2c_init_done = 1; + + iproc_dump_i2c_regs(bus_prvdata); + debug("%s: Init successful\n", __func__); + + return 0; +} + +/* + * This function copies data to SMBus's Tx FIFO. Valid for write transactions + * only + * + * base_addr: Mapped address of this SMBus instance + * dev_addr: SMBus (I2C) device address. We are assuming 7-bit addresses + * initially + * info: Data to copy in to Tx FIFO. For read commands, the size should be + * set to zero by the caller + * + */ +static void iproc_i2c_write_trans_data(struct iproc_i2c *bus_prvdata, + unsigned short dev_addr, + struct iproc_xact_info *info) +{ + struct iproc_i2c_regs *base = bus_prvdata->base; + unsigned int regval; + unsigned int i; + unsigned int num_data_bytes = 0; + + debug("%s: dev_addr=0x%X cmd_valid=%d cmd=0x%02x size=%u proto=%d buf[] %x\n", + __func__, dev_addr, info->cmd_valid, + info->command, info->size, info->smb_proto, info->data[0]); + + /* Write SMBus device address first */ + /* Note, we are assuming 7-bit addresses for now. For 10-bit addresses, + * we may have one more write to send the upper 3 bits of 10-bit addr + */ + iproc_i2c_reg_write(&base->mstr_datawr, dev_addr); + + /* If the protocol needs command code, copy it */ + if (info->cmd_valid) + iproc_i2c_reg_write(&base->mstr_datawr, info->command); + + /* Depending on the SMBus protocol, we need to write additional + * transaction data in to Tx FIFO. Refer to section 5.5 of SMBus + * spec for sequence for a transaction + */ + switch (info->smb_proto) { + case SMBUS_PROT_RECV_BYTE: + /* No additional data to be written */ + num_data_bytes = 0; + break; + + case SMBUS_PROT_SEND_BYTE: + num_data_bytes = info->size; + break; + + case SMBUS_PROT_RD_BYTE: + case SMBUS_PROT_RD_WORD: + case SMBUS_PROT_BLK_RD: + /* Write slave address with R/W~ set (bit #0) */ + iproc_i2c_reg_write(&base->mstr_datawr, + dev_addr | 0x1); + num_data_bytes = 0; + break; + + case SMBUS_PROT_BLK_WR_BLK_RD_PROC_CALL: + iproc_i2c_reg_write(&base->mstr_datawr, + dev_addr | 0x1 | + CCB_SMB_MSTRWRSTS_MASK); + num_data_bytes = 0; + break; + + case SMBUS_PROT_WR_BYTE: + case SMBUS_PROT_WR_WORD: + /* No additional bytes to be written. + * Data portion is written in the + * 'for' loop below + */ + num_data_bytes = info->size; + break; + + case SMBUS_PROT_BLK_WR: + /* 3rd byte is byte count */ + iproc_i2c_reg_write(&base->mstr_datawr, info->size); + num_data_bytes = info->size; + break; + + default: + return; + } + + /* Copy actual data from caller, next. In general, for reads, + * no data is copied + */ + for (i = 0; num_data_bytes; --num_data_bytes, i++) { + /* For the last byte, set MASTER_WR_STATUS bit */ + regval = (num_data_bytes == 1) ? + info->data[i] | CCB_SMB_MSTRWRSTS_MASK : + info->data[i]; + + iproc_i2c_reg_write(&base->mstr_datawr, regval); + } +} + +static int iproc_i2c_data_send(struct iproc_i2c *bus_prvdata, + unsigned short addr, + struct iproc_xact_info *info) +{ + struct iproc_i2c_regs *base = bus_prvdata->base; + int rc, retry = 3; + unsigned int regval; + + /* Make sure the previous transaction completed */ + rc = iproc_i2c_startbusy_wait(bus_prvdata); + + if (rc < 0) { + pr_err("%s: Send: bus is busy, exiting\n", __func__); + return rc; + } + + /* Write transaction bytes to Tx FIFO */ + iproc_i2c_write_trans_data(bus_prvdata, addr, info); + + /* Program master command register (0x30) with protocol type and set + * start_busy_command bit to initiate the write transaction + */ + regval = (info->smb_proto << CCB_SMB_MSTRSMBUSPROTO_SHIFT) | + CCB_SMB_MSTRSTARTBUSYCMD_MASK; + + iproc_i2c_reg_write(&base->mstr_cmd, regval); + + /* Check for Master status */ + regval = iproc_i2c_reg_read(&base->mstr_cmd); + while (regval & CCB_SMB_MSTRSTARTBUSYCMD_MASK) { + mdelay(10); + if (retry-- <= 0) + break; + regval = iproc_i2c_reg_read(&base->mstr_cmd); + } + + /* If start_busy bit cleared, check if there are any errors */ + if (!(regval & CCB_SMB_MSTRSTARTBUSYCMD_MASK)) { + /* start_busy bit cleared, check master_status field now */ + regval &= CCB_SMB_MSTRSTS_MASK; + regval >>= CCB_SMB_MSTRSTS_SHIFT; + + if (regval != MSTR_STS_XACT_SUCCESS) { + /* Error We can flush Tx FIFO here */ + pr_err("%s: ERROR: Error in transaction %u, exiting\n", + __func__, regval); + return -EREMOTEIO; + } + } + + return 0; +} + +static int iproc_i2c_data_recv(struct iproc_i2c *bus_prvdata, + unsigned short addr, + struct iproc_xact_info *info, + unsigned int *num_bytes_read) +{ + struct iproc_i2c_regs *base = bus_prvdata->base; + int rc, retry = 3; + unsigned int regval; + + /* Make sure the previous transaction completed */ + rc = iproc_i2c_startbusy_wait(bus_prvdata); + + if (rc < 0) { + pr_err("%s: Receive: Bus is busy, exiting\n", __func__); + return rc; + } + + /* Program all transaction bytes into master Tx FIFO */ + iproc_i2c_write_trans_data(bus_prvdata, addr, info); + + /* Program master command register (0x30) with protocol type and set + * start_busy_command bit to initiate the write transaction + */ + regval = (info->smb_proto << CCB_SMB_MSTRSMBUSPROTO_SHIFT) | + CCB_SMB_MSTRSTARTBUSYCMD_MASK | info->size; + + iproc_i2c_reg_write(&base->mstr_cmd, regval); + + /* Check for Master status */ + regval = iproc_i2c_reg_read(&base->mstr_cmd); + while (regval & CCB_SMB_MSTRSTARTBUSYCMD_MASK) { + udelay(1000); + if (retry-- <= 0) + break; + regval = iproc_i2c_reg_read(&base->mstr_cmd); + } + + /* If start_busy bit cleared, check if there are any errors */ + if (!(regval & CCB_SMB_MSTRSTARTBUSYCMD_MASK)) { + /* start_busy bit cleared, check master_status field now */ + regval &= CCB_SMB_MSTRSTS_MASK; + regval >>= CCB_SMB_MSTRSTS_SHIFT; + + if (regval != MSTR_STS_XACT_SUCCESS) { + /* We can flush Tx FIFO here */ + pr_err("%s: Error in transaction %d, exiting\n", + __func__, regval); + return -EREMOTEIO; + } + } + + /* Read received byte(s), after TX out address etc */ + regval = iproc_i2c_reg_read(&base->mstr_datard); + + /* For block read, protocol (hw) returns byte count, + * as the first byte + */ + if (info->smb_proto == SMBUS_PROT_BLK_RD) { + int i; + + *num_bytes_read = regval & CCB_SMB_MSTRRDDATA_MASK; + + /* Limit to reading a max of 32 bytes only; just a safeguard. + * If # bytes read is a number > 32, check transaction set up, + * and contact hw engg. Assumption: PEC is disabled + */ + for (i = 0; + (i < *num_bytes_read) && (i < I2C_SMBUS_BLOCK_MAX); + i++) { + /* Read Rx FIFO for data bytes */ + regval = iproc_i2c_reg_read(&base->mstr_datard); + info->data[i] = regval & CCB_SMB_MSTRRDDATA_MASK; + } + } else { + /* 1 Byte data */ + *info->data = regval & CCB_SMB_MSTRRDDATA_MASK; + *num_bytes_read = 1; + } + + return 0; +} + +static int i2c_write_byte(struct iproc_i2c *bus_prvdata, + u8 devaddr, u8 regoffset, u8 value) +{ + int rc; + struct iproc_xact_info info; + + devaddr <<= 1; + + info.cmd_valid = 1; + info.command = (unsigned char)regoffset; + info.data = &value; + info.size = 1; + info.flags = 0; + info.smb_proto = SMBUS_PROT_WR_BYTE; + /* Refer to i2c_smbus_write_byte params passed. */ + rc = iproc_i2c_data_send(bus_prvdata, devaddr, &info); + + if (rc < 0) { + pr_err("%s: %s error accessing device 0x%X\n", + __func__, "Write", devaddr); + return -EREMOTEIO; + } + + return 0; +} + +int i2c_write(struct udevice *bus, + uchar chip, uint regaddr, int alen, uchar *buffer, int len) +{ + struct iproc_i2c *bus_prvdata = dev_get_priv(bus); + int i, data_len; + u8 *data; + + if (len > 256) { + pr_err("I2C write: address out of range\n"); + return 1; + } + + if (len < 1) { + pr_err("I2C write: Need offset addr and value\n"); + return 1; + } + + /* buffer contains offset addr followed by value to be written */ + regaddr = buffer[0]; + data = &buffer[1]; + data_len = len - 1; + + for (i = 0; i < data_len; i++) { + if (i2c_write_byte(bus_prvdata, chip, regaddr + i, data[i])) { + pr_err("I2C write (%d): I/O error\n", i); + iproc_i2c_init(bus); + return 1; + } + } + + return 0; +} + +static int i2c_read_byte(struct iproc_i2c *bus_prvdata, + u8 devaddr, u8 regoffset, u8 *value) +{ + int rc; + struct iproc_xact_info info; + unsigned int num_bytes_read = 0; + + devaddr <<= 1; + + info.cmd_valid = 1; + info.command = (unsigned char)regoffset; + info.data = value; + info.size = 1; + info.flags = 0; + info.smb_proto = SMBUS_PROT_RD_BYTE; + /* Refer to i2c_smbus_read_byte for params passed. */ + rc = iproc_i2c_data_recv(bus_prvdata, devaddr, &info, &num_bytes_read); + + if (rc < 0) { + pr_err("%s: %s error accessing device 0x%X\n", + __func__, "Read", devaddr); + return -EREMOTEIO; + } + + return 0; +} + +int i2c_read(struct udevice *bus, + uchar chip, uint addr, int alen, uchar *buffer, int len) +{ + struct iproc_i2c *bus_prvdata = dev_get_priv(bus); + int i; + + if (len > 256) { + pr_err("I2C read: address out of range\n"); + return 1; + } + + for (i = 0; i < len; i++) { + if (i2c_read_byte(bus_prvdata, chip, addr + i, &buffer[i])) { + pr_err("I2C read: I/O error\n"); + iproc_i2c_init(bus); + return 1; + } + } + + return 0; +} + +static int iproc_i2c_xfer(struct udevice *bus, struct i2c_msg *msg, int nmsgs) +{ + int ret = 0; + + debug("%s: %d messages\n", __func__, nmsgs); + + for (; nmsgs > 0; nmsgs--, msg++) { + if (msg->flags & I2C_M_RD) + ret = i2c_read(bus, msg->addr, 0, 0, + msg->buf, msg->len); + else + ret = i2c_write(bus, msg->addr, 0, 0, + msg->buf, msg->len); + } + + return ret; +} + +static int iproc_i2c_probe_chip(struct udevice *bus, uint chip_addr, + uint chip_flags) +{ + struct iproc_i2c *bus_prvdata = dev_get_priv(bus); + struct iproc_i2c_regs *base = bus_prvdata->base; + u32 regval; + + debug("\n%s: Entering chip probe\n", __func__); + + /* Init internal regs, disable intrs (and then clear intrs), set fifo + * thresholds, etc. + */ + if (!bus_prvdata->i2c_init_done) + iproc_i2c_init(bus); + + regval = (chip_addr << 1); + iproc_i2c_reg_write(&base->mstr_datawr, regval); + regval = ((SMBUS_PROT_QUICK_CMD << CCB_SMB_MSTRSMBUSPROTO_SHIFT) | + (1 << CCB_SMB_MSTRSTARTBUSYCMD_SHIFT)); + iproc_i2c_reg_write(&base->mstr_cmd, regval); + + do { + udelay(100); + regval = iproc_i2c_reg_read(&base->mstr_cmd); + regval &= CCB_SMB_MSTRSTARTBUSYCMD_MASK; + } while (regval); + + regval = iproc_i2c_reg_read(&base->mstr_cmd); + + if ((regval & CCB_SMB_MSTRSTS_MASK) != 0) + return -1; + + iproc_dump_i2c_regs(bus_prvdata); + debug("%s: chip probe successful\n", __func__); + + return 0; +} + +static int iproc_i2c_set_bus_speed(struct udevice *bus, unsigned int speed) +{ + struct iproc_i2c *bus_prvdata = dev_get_priv(bus); + + bus_prvdata->bus_speed = speed; + return iproc_i2c_set_clk_freq(bus_prvdata); +} + +/** + * i2c_get_bus_speed - get i2c bus speed + * + * This function returns the speed of operation in Hz + */ +int iproc_i2c_get_bus_speed(struct udevice *bus) +{ + struct iproc_i2c *bus_prvdata = dev_get_priv(bus); + struct iproc_i2c_regs *base = bus_prvdata->base; + unsigned int regval; + int ret = 0; + + regval = iproc_i2c_reg_read(&base->timg_cfg); + regval = (regval & CCB_SMB_TIMGCFG_MODE400_MASK) >> + CCB_SMB_TIMGCFG_MODE400_SHIFT; + + switch (regval) { + case 0: + ret = I2C_SPEED_STANDARD_RATE; + break; + case 1: + ret = I2C_SPEED_FAST_RATE; + break; + default: + ret = -EINVAL; + break; + } + + return ret; +} + +static int iproc_i2c_probe(struct udevice *bus) +{ + return iproc_i2c_init(bus); +} + +static int iproc_i2c_ofdata_to_platdata(struct udevice *bus) +{ + struct iproc_i2c *bus_prvdata = dev_get_priv(bus); + int node = dev_of_offset(bus); + const void *blob = gd->fdt_blob; + + bus_prvdata->base = map_physmem(devfdt_get_addr(bus), + sizeof(void *), + MAP_NOCACHE); + + bus_prvdata->bus_speed = + fdtdec_get_int(blob, node, "bus-frequency", + I2C_SPEED_STANDARD_RATE); + + return 0; +} + +static const struct dm_i2c_ops iproc_i2c_ops = { + .xfer = iproc_i2c_xfer, + .probe_chip = iproc_i2c_probe_chip, + .set_bus_speed = iproc_i2c_set_bus_speed, + .get_bus_speed = iproc_i2c_get_bus_speed, +}; + +static const struct udevice_id iproc_i2c_ids[] = { + { .compatible = "brcm,iproc-i2c" }, + { } +}; + +U_BOOT_DRIVER(iproc_i2c) = { + .name = "iproc_i2c", + .id = UCLASS_I2C, + .of_match = iproc_i2c_ids, + .ofdata_to_platdata = iproc_i2c_ofdata_to_platdata, + .probe = iproc_i2c_probe, + .priv_auto_alloc_size = sizeof(struct iproc_i2c), + .ops = &iproc_i2c_ops, + .flags = DM_FLAG_PRE_RELOC, +}; -- cgit