| // SPDX-License-Identifier: GPL-2.0+ |
| /* |
| * LPC32xx I2C interface driver |
| * |
| * (C) Copyright 2014-2015 DENX Software Engineering GmbH |
| * Written-by: Albert ARIBAUD - 3ADEV <albert.aribaud@3adev.fr> |
| */ |
| |
| #include <config.h> |
| #include <log.h> |
| #include <asm/io.h> |
| #include <i2c.h> |
| #include <linux/errno.h> |
| #include <asm/arch/clk.h> |
| #include <asm/arch/i2c.h> |
| #include <dm.h> |
| #include <mapmem.h> |
| |
| /* |
| * Provide default speed and slave if target did not |
| */ |
| |
| #if !defined(CFG_SYS_I2C_LPC32XX_SPEED) |
| #define CFG_SYS_I2C_LPC32XX_SPEED 350000 |
| #endif |
| |
| #if !defined(CFG_SYS_I2C_LPC32XX_SLAVE) |
| #define CFG_SYS_I2C_LPC32XX_SLAVE 0 |
| #endif |
| |
| /* TX register fields */ |
| #define LPC32XX_I2C_TX_START 0x00000100 |
| #define LPC32XX_I2C_TX_STOP 0x00000200 |
| |
| /* Control register values */ |
| #define LPC32XX_I2C_SOFT_RESET 0x00000100 |
| |
| /* Status register values */ |
| #define LPC32XX_I2C_STAT_TFF 0x00000400 |
| #define LPC32XX_I2C_STAT_RFE 0x00000200 |
| #define LPC32XX_I2C_STAT_NAI 0x00000004 |
| #define LPC32XX_I2C_STAT_TDI 0x00000001 |
| |
| #if !CONFIG_IS_ENABLED(DM_I2C) |
| static struct lpc32xx_i2c_base *lpc32xx_i2c[] = { |
| (struct lpc32xx_i2c_base *)I2C1_BASE, |
| (struct lpc32xx_i2c_base *)I2C2_BASE, |
| (struct lpc32xx_i2c_base *)(USB_BASE + 0x300) |
| }; |
| #endif |
| |
| /* Set I2C bus speed */ |
| static unsigned int __i2c_set_bus_speed(struct lpc32xx_i2c_base *base, |
| unsigned int speed, unsigned int chip) |
| { |
| int half_period; |
| |
| if (speed == 0) |
| return -EINVAL; |
| |
| /* OTG I2C clock source and CLK registers are different */ |
| if (chip == 2) { |
| half_period = (get_periph_clk_rate() / speed) / 2; |
| if (half_period > 0xFF) |
| return -EINVAL; |
| } else { |
| half_period = (get_hclk_clk_rate() / speed) / 2; |
| if (half_period > 0x3FF) |
| return -EINVAL; |
| } |
| |
| writel(half_period, &base->clk_hi); |
| writel(half_period, &base->clk_lo); |
| return 0; |
| } |
| |
| /* I2C init called by cmd_i2c when doing 'i2c reset'. */ |
| static void __i2c_init(struct lpc32xx_i2c_base *base, |
| int requested_speed, int slaveadd, unsigned int chip) |
| { |
| /* soft reset (auto-clears) */ |
| writel(LPC32XX_I2C_SOFT_RESET, &base->ctrl); |
| /* set HI and LO periods for half of the default speed */ |
| __i2c_set_bus_speed(base, requested_speed, chip); |
| } |
| |
| /* I2C probe called by cmd_i2c when doing 'i2c probe'. */ |
| static int __i2c_probe_chip(struct lpc32xx_i2c_base *base, u8 dev) |
| { |
| int stat; |
| |
| /* Soft-reset the controller */ |
| writel(LPC32XX_I2C_SOFT_RESET, &base->ctrl); |
| while (readl(&base->ctrl) & LPC32XX_I2C_SOFT_RESET) |
| ; |
| /* Addre slave for write with start before and stop after */ |
| writel((dev<<1) | LPC32XX_I2C_TX_START | LPC32XX_I2C_TX_STOP, |
| &base->tx); |
| /* wait for end of transation */ |
| while (!((stat = readl(&base->stat)) & LPC32XX_I2C_STAT_TDI)) |
| ; |
| /* was there no acknowledge? */ |
| return (stat & LPC32XX_I2C_STAT_NAI) ? -1 : 0; |
| } |
| |
| /* |
| * I2C read called by cmd_i2c when doing 'i2c read' and by cmd_eeprom.c |
| * Begin write, send address byte(s), begin read, receive data bytes, end. |
| */ |
| static int __i2c_read(struct lpc32xx_i2c_base *base, u8 dev, uint addr, |
| int alen, u8 *data, int length) |
| { |
| int stat, wlen; |
| |
| /* Soft-reset the controller */ |
| writel(LPC32XX_I2C_SOFT_RESET, &base->ctrl); |
| while (readl(&base->ctrl) & LPC32XX_I2C_SOFT_RESET) |
| ; |
| /* do we need to write an address at all? */ |
| if (alen) { |
| /* Address slave in write mode */ |
| writel((dev<<1) | LPC32XX_I2C_TX_START, &base->tx); |
| /* write address bytes */ |
| while (alen--) { |
| /* compute address byte + stop for the last one */ |
| int a = (addr >> (8 * alen)) & 0xff; |
| if (!alen) |
| a |= LPC32XX_I2C_TX_STOP; |
| /* Send address byte */ |
| writel(a, &base->tx); |
| } |
| /* wait for end of transation */ |
| while (!((stat = readl(&base->stat)) & LPC32XX_I2C_STAT_TDI)) |
| ; |
| /* clear end-of-transaction flag */ |
| writel(1, &base->stat); |
| } |
| /* do we have to read data at all? */ |
| if (length) { |
| /* Address slave in read mode */ |
| writel(1 | (dev<<1) | LPC32XX_I2C_TX_START, &base->tx); |
| wlen = length; |
| /* get data */ |
| while (length | wlen) { |
| /* read status for TFF and RFE */ |
| stat = readl(&base->stat); |
| /* must we, can we write a trigger byte? */ |
| if ((wlen > 0) |
| & (!(stat & LPC32XX_I2C_STAT_TFF))) { |
| wlen--; |
| /* write trigger byte + stop if last */ |
| writel(wlen ? 0 : |
| LPC32XX_I2C_TX_STOP, &base->tx); |
| } |
| /* must we, can we read a data byte? */ |
| if ((length > 0) |
| & (!(stat & LPC32XX_I2C_STAT_RFE))) { |
| length--; |
| /* read byte */ |
| *(data++) = readl(&base->rx); |
| } |
| } |
| /* wait for end of transation */ |
| while (!((stat = readl(&base->stat)) & LPC32XX_I2C_STAT_TDI)) |
| ; |
| /* clear end-of-transaction flag */ |
| writel(1, &base->stat); |
| } |
| /* success */ |
| return 0; |
| } |
| |
| /* |
| * I2C write called by cmd_i2c when doing 'i2c write' and by cmd_eeprom.c |
| * Begin write, send address byte(s), send data bytes, end. |
| */ |
| static int __i2c_write(struct lpc32xx_i2c_base *base, u8 dev, uint addr, |
| int alen, u8 *data, int length) |
| { |
| int stat; |
| |
| /* Soft-reset the controller */ |
| writel(LPC32XX_I2C_SOFT_RESET, &base->ctrl); |
| while (readl(&base->ctrl) & LPC32XX_I2C_SOFT_RESET) |
| ; |
| /* do we need to write anything at all? */ |
| if (alen | length) |
| /* Address slave in write mode */ |
| writel((dev<<1) | LPC32XX_I2C_TX_START, &base->tx); |
| else |
| return 0; |
| /* write address bytes */ |
| while (alen) { |
| /* wait for transmit fifo not full */ |
| stat = readl(&base->stat); |
| if (!(stat & LPC32XX_I2C_STAT_TFF)) { |
| alen--; |
| int a = (addr >> (8 * alen)) & 0xff; |
| if (!(alen | length)) |
| a |= LPC32XX_I2C_TX_STOP; |
| /* Send address byte */ |
| writel(a, &base->tx); |
| } |
| } |
| while (length) { |
| /* wait for transmit fifo not full */ |
| stat = readl(&base->stat); |
| if (!(stat & LPC32XX_I2C_STAT_TFF)) { |
| /* compute data byte, add stop if length==0 */ |
| length--; |
| int d = *(data++); |
| if (!length) |
| d |= LPC32XX_I2C_TX_STOP; |
| /* Send data byte */ |
| writel(d, &base->tx); |
| } |
| } |
| /* wait for end of transation */ |
| while (!((stat = readl(&base->stat)) & LPC32XX_I2C_STAT_TDI)) |
| ; |
| /* clear end-of-transaction flag */ |
| writel(1, &base->stat); |
| return 0; |
| } |
| |
| #if !CONFIG_IS_ENABLED(DM_I2C) |
| static void lpc32xx_i2c_init(struct i2c_adapter *adap, |
| int requested_speed, int slaveadd) |
| { |
| __i2c_init(lpc32xx_i2c[adap->hwadapnr], requested_speed, slaveadd, |
| adap->hwadapnr); |
| } |
| |
| static int lpc32xx_i2c_probe_chip(struct i2c_adapter *adap, u8 dev) |
| { |
| return __i2c_probe_chip(lpc32xx_i2c[adap->hwadapnr], dev); |
| } |
| |
| static int lpc32xx_i2c_read(struct i2c_adapter *adap, u8 dev, uint addr, |
| int alen, u8 *data, int length) |
| { |
| return __i2c_read(lpc32xx_i2c[adap->hwadapnr], dev, addr, |
| alen, data, length); |
| } |
| |
| static int lpc32xx_i2c_write(struct i2c_adapter *adap, u8 dev, uint addr, |
| int alen, u8 *data, int length) |
| { |
| return __i2c_write(lpc32xx_i2c[adap->hwadapnr], dev, addr, |
| alen, data, length); |
| } |
| |
| static unsigned int lpc32xx_i2c_set_bus_speed(struct i2c_adapter *adap, |
| unsigned int speed) |
| { |
| return __i2c_set_bus_speed(lpc32xx_i2c[adap->hwadapnr], speed, |
| adap->hwadapnr); |
| } |
| |
| U_BOOT_I2C_ADAP_COMPLETE(lpc32xx_0, lpc32xx_i2c_init, lpc32xx_i2c_probe_chip, |
| lpc32xx_i2c_read, lpc32xx_i2c_write, |
| lpc32xx_i2c_set_bus_speed, |
| CFG_SYS_I2C_LPC32XX_SPEED, |
| CFG_SYS_I2C_LPC32XX_SLAVE, |
| 0) |
| |
| U_BOOT_I2C_ADAP_COMPLETE(lpc32xx_1, lpc32xx_i2c_init, lpc32xx_i2c_probe_chip, |
| lpc32xx_i2c_read, lpc32xx_i2c_write, |
| lpc32xx_i2c_set_bus_speed, |
| CFG_SYS_I2C_LPC32XX_SPEED, |
| CFG_SYS_I2C_LPC32XX_SLAVE, |
| 1) |
| |
| U_BOOT_I2C_ADAP_COMPLETE(lpc32xx_2, lpc32xx_i2c_init, NULL, |
| lpc32xx_i2c_read, lpc32xx_i2c_write, |
| lpc32xx_i2c_set_bus_speed, |
| 100000, |
| 0, |
| 2) |
| #else /* CONFIG_DM_I2C */ |
| static int lpc32xx_i2c_probe(struct udevice *bus) |
| { |
| struct lpc32xx_i2c_dev *dev = dev_get_plat(bus); |
| |
| dev->base = dev_read_addr_ptr(bus); |
| __i2c_init(dev->base, dev->speed, 0, dev->index); |
| return 0; |
| } |
| |
| static int lpc32xx_i2c_probe_chip(struct udevice *bus, u32 chip_addr, |
| u32 chip_flags) |
| { |
| struct lpc32xx_i2c_dev *dev = dev_get_plat(bus); |
| return __i2c_probe_chip(dev->base, chip_addr); |
| } |
| |
| static int lpc32xx_i2c_xfer(struct udevice *bus, struct i2c_msg *msg, |
| int nmsgs) |
| { |
| struct lpc32xx_i2c_dev *dev = dev_get_plat(bus); |
| struct i2c_msg *dmsg, *omsg, dummy; |
| uint i = 0, address = 0; |
| |
| memset(&dummy, 0, sizeof(struct i2c_msg)); |
| |
| /* We expect either two messages (one with an offset and one with the |
| * actual data) or one message (just data) |
| */ |
| if (nmsgs > 2 || nmsgs == 0) { |
| debug("%s: Only one or two messages are supported.", __func__); |
| return -1; |
| } |
| |
| omsg = nmsgs == 1 ? &dummy : msg; |
| dmsg = nmsgs == 1 ? msg : msg + 1; |
| |
| /* the address is expected to be a uint, not a array. */ |
| address = omsg->buf[0]; |
| for (i = 1; i < omsg->len; i++) |
| address = (address << 8) + omsg->buf[i]; |
| |
| if (dmsg->flags & I2C_M_RD) |
| return __i2c_read(dev->base, dmsg->addr, address, |
| omsg->len, dmsg->buf, dmsg->len); |
| else |
| return __i2c_write(dev->base, dmsg->addr, address, |
| omsg->len, dmsg->buf, dmsg->len); |
| } |
| |
| static int lpc32xx_i2c_set_bus_speed(struct udevice *bus, unsigned int speed) |
| { |
| struct lpc32xx_i2c_dev *dev = dev_get_plat(bus); |
| return __i2c_set_bus_speed(dev->base, speed, dev->index); |
| } |
| |
| static int lpc32xx_i2c_reset(struct udevice *bus) |
| { |
| struct lpc32xx_i2c_dev *dev = dev_get_plat(bus); |
| |
| __i2c_init(dev->base, dev->speed, 0, dev->index); |
| return 0; |
| } |
| |
| static const struct dm_i2c_ops lpc32xx_i2c_ops = { |
| .xfer = lpc32xx_i2c_xfer, |
| .probe_chip = lpc32xx_i2c_probe_chip, |
| .deblock = lpc32xx_i2c_reset, |
| .set_bus_speed = lpc32xx_i2c_set_bus_speed, |
| }; |
| |
| static const struct udevice_id lpc32xx_i2c_ids[] = { |
| { .compatible = "nxp,pnx-i2c" }, |
| { } |
| }; |
| |
| U_BOOT_DRIVER(i2c_lpc32xx) = { |
| .name = "i2c_lpc32xx", |
| .id = UCLASS_I2C, |
| .of_match = lpc32xx_i2c_ids, |
| .probe = lpc32xx_i2c_probe, |
| .ops = &lpc32xx_i2c_ops, |
| }; |
| #endif /* CONFIG_DM_I2C */ |