diff options
Diffstat (limited to 'drivers/i2c/fti2c010.c')
| -rw-r--r-- | drivers/i2c/fti2c010.c | 368 |
1 files changed, 368 insertions, 0 deletions
diff --git a/drivers/i2c/fti2c010.c b/drivers/i2c/fti2c010.c new file mode 100644 index 0000000000..ddeb941faf --- /dev/null +++ b/drivers/i2c/fti2c010.c @@ -0,0 +1,368 @@ +/* + * Faraday I2C Controller + * + * (C) Copyright 2010 Faraday Technology + * Dante Su <dantesu@faraday-tech.com> + * + * SPDX-License-Identifier: GPL-2.0+ + */ + +#include <common.h> +#include <asm/io.h> +#include <i2c.h> + +#include "fti2c010.h" + +#ifndef CONFIG_HARD_I2C +#error "fti2c010: CONFIG_HARD_I2C is not defined" +#endif + +#ifndef CONFIG_SYS_I2C_SPEED +#define CONFIG_SYS_I2C_SPEED 50000 +#endif + +#ifndef CONFIG_FTI2C010_FREQ +#define CONFIG_FTI2C010_FREQ clk_get_rate("I2C") +#endif + +/* command timeout */ +#define CFG_CMD_TIMEOUT 10 /* ms */ + +/* 7-bit chip address + 1-bit read/write */ +#define I2C_RD(chip) ((((chip) << 1) & 0xff) | 1) +#define I2C_WR(chip) (((chip) << 1) & 0xff) + +struct fti2c010_chip { + void __iomem *regs; + uint bus; + uint speed; +}; + +static struct fti2c010_chip chip_list[] = { + { + .bus = 0, + .regs = (void __iomem *)CONFIG_FTI2C010_BASE, + }, +#ifdef CONFIG_I2C_MULTI_BUS +# ifdef CONFIG_FTI2C010_BASE1 + { + .bus = 1, + .regs = (void __iomem *)CONFIG_FTI2C010_BASE1, + }, +# endif +# ifdef CONFIG_FTI2C010_BASE2 + { + .bus = 2, + .regs = (void __iomem *)CONFIG_FTI2C010_BASE2, + }, +# endif +# ifdef CONFIG_FTI2C010_BASE3 + { + .bus = 3, + .regs = (void __iomem *)CONFIG_FTI2C010_BASE3, + }, +# endif +#endif /* #ifdef CONFIG_I2C_MULTI_BUS */ +}; + +static struct fti2c010_chip *curr = chip_list; + +static int fti2c010_wait(uint32_t mask) +{ + int ret = -1; + uint32_t stat, ts; + struct fti2c010_regs *regs = curr->regs; + + for (ts = get_timer(0); get_timer(ts) < CFG_CMD_TIMEOUT; ) { + stat = readl(®s->sr); + if ((stat & mask) == mask) { + ret = 0; + break; + } + } + + return ret; +} + +/* + * u-boot I2C API + */ + +/* + * Initialization, must be called once on start up, may be called + * repeatedly to change the speed and slave addresses. + */ +void i2c_init(int speed, int slaveaddr) +{ + if (speed || !curr->speed) + i2c_set_bus_speed(speed); + + /* if slave mode disabled */ + if (!slaveaddr) + return; + + /* + * TODO: + * Implement slave mode, but is it really necessary? + */ +} + +/* + * Probe the given I2C chip address. Returns 0 if a chip responded, + * not 0 on failure. + */ +int i2c_probe(uchar chip) +{ + int ret; + struct fti2c010_regs *regs = curr->regs; + + i2c_init(0, 0); + + /* 1. Select slave device (7bits Address + 1bit R/W) */ + writel(I2C_WR(chip), ®s->dr); + writel(CR_ENABLE | CR_TBEN | CR_START, ®s->cr); + ret = fti2c010_wait(SR_DT); + if (ret) + return ret; + + /* 2. Select device register */ + writel(0, ®s->dr); + writel(CR_ENABLE | CR_TBEN, ®s->cr); + ret = fti2c010_wait(SR_DT); + + return ret; +} + +/* + * Read/Write interface: + * chip: I2C chip address, range 0..127 + * addr: Memory (register) address within the chip + * alen: Number of bytes to use for addr (typically 1, 2 for larger + * memories, 0 for register type devices with only one + * register) + * buffer: Where to read/write the data + * len: How many bytes to read/write + * + * Returns: 0 on success, not 0 on failure + */ +int i2c_read(uchar chip, uint addr, int alen, uchar *buf, int len) +{ + int ret, pos; + uchar paddr[4]; + struct fti2c010_regs *regs = curr->regs; + + i2c_init(0, 0); + + paddr[0] = (addr >> 0) & 0xFF; + paddr[1] = (addr >> 8) & 0xFF; + paddr[2] = (addr >> 16) & 0xFF; + paddr[3] = (addr >> 24) & 0xFF; + + /* + * Phase A. Set register address + */ + + /* A.1 Select slave device (7bits Address + 1bit R/W) */ + writel(I2C_WR(chip), ®s->dr); + writel(CR_ENABLE | CR_TBEN | CR_START, ®s->cr); + ret = fti2c010_wait(SR_DT); + if (ret) + return ret; + + /* A.2 Select device register */ + for (pos = 0; pos < alen; ++pos) { + uint32_t ctrl = CR_ENABLE | CR_TBEN; + + writel(paddr[pos], ®s->dr); + writel(ctrl, ®s->cr); + ret = fti2c010_wait(SR_DT); + if (ret) + return ret; + } + + /* + * Phase B. Get register data + */ + + /* B.1 Select slave device (7bits Address + 1bit R/W) */ + writel(I2C_RD(chip), ®s->dr); + writel(CR_ENABLE | CR_TBEN | CR_START, ®s->cr); + ret = fti2c010_wait(SR_DT); + if (ret) + return ret; + + /* B.2 Get register data */ + for (pos = 0; pos < len; ++pos) { + uint32_t ctrl = CR_ENABLE | CR_TBEN; + uint32_t stat = SR_DR; + + if (pos == len - 1) { + ctrl |= CR_NAK | CR_STOP; + stat |= SR_ACK; + } + writel(ctrl, ®s->cr); + ret = fti2c010_wait(stat); + if (ret) + break; + buf[pos] = (uchar)(readl(®s->dr) & 0xFF); + } + + return ret; +} + +/* + * Read/Write interface: + * chip: I2C chip address, range 0..127 + * addr: Memory (register) address within the chip + * alen: Number of bytes to use for addr (typically 1, 2 for larger + * memories, 0 for register type devices with only one + * register) + * buffer: Where to read/write the data + * len: How many bytes to read/write + * + * Returns: 0 on success, not 0 on failure + */ +int i2c_write(uchar chip, uint addr, int alen, uchar *buf, int len) +{ + int ret, pos; + uchar paddr[4]; + struct fti2c010_regs *regs = curr->regs; + + i2c_init(0, 0); + + paddr[0] = (addr >> 0) & 0xFF; + paddr[1] = (addr >> 8) & 0xFF; + paddr[2] = (addr >> 16) & 0xFF; + paddr[3] = (addr >> 24) & 0xFF; + + /* + * Phase A. Set register address + * + * A.1 Select slave device (7bits Address + 1bit R/W) + */ + writel(I2C_WR(chip), ®s->dr); + writel(CR_ENABLE | CR_TBEN | CR_START, ®s->cr); + ret = fti2c010_wait(SR_DT); + if (ret) + return ret; + + /* A.2 Select device register */ + for (pos = 0; pos < alen; ++pos) { + uint32_t ctrl = CR_ENABLE | CR_TBEN; + + writel(paddr[pos], ®s->dr); + writel(ctrl, ®s->cr); + ret = fti2c010_wait(SR_DT); + if (ret) + return ret; + } + + /* + * Phase B. Set register data + */ + for (pos = 0; pos < len; ++pos) { + uint32_t ctrl = CR_ENABLE | CR_TBEN; + + if (pos == len - 1) + ctrl |= CR_STOP; + writel(buf[pos], ®s->dr); + writel(ctrl, ®s->cr); + ret = fti2c010_wait(SR_DT); + if (ret) + break; + } + + return ret; +} + +/* + * Functions for setting the current I2C bus and its speed + */ +#ifdef CONFIG_I2C_MULTI_BUS + +/* + * i2c_set_bus_num: + * + * Change the active I2C bus. Subsequent read/write calls will + * go to this one. + * + * bus - bus index, zero based + * + * Returns: 0 on success, not 0 on failure + */ +int i2c_set_bus_num(uint bus) +{ + if (bus >= ARRAY_SIZE(chip_list)) + return -1; + curr = chip_list + bus; + i2c_init(0, 0); + return 0; +} + +/* + * i2c_get_bus_num: + * + * Returns index of currently active I2C bus. Zero-based. + */ + +uint i2c_get_bus_num(void) +{ + return curr->bus; +} + +#endif /* #ifdef CONFIG_I2C_MULTI_BUS */ + +/* + * i2c_set_bus_speed: + * + * Change the speed of the active I2C bus + * + * speed - bus speed in Hz + * + * Returns: 0 on success, not 0 on failure + */ +int i2c_set_bus_speed(uint speed) +{ + struct fti2c010_regs *regs = curr->regs; + uint clk = CONFIG_FTI2C010_FREQ; + uint gsr = 0, tsr = 32; + uint spd, div; + + if (!speed) + speed = CONFIG_SYS_I2C_SPEED; + + for (div = 0; div < 0x3ffff; ++div) { + /* SCLout = PCLK/(2*(COUNT + 2) + GSR) */ + spd = clk / (2 * (div + 2) + gsr); + if (spd <= speed) + break; + } + + if (curr->speed == spd) + return 0; + + writel(CR_I2CRST, ®s->cr); + mdelay(100); + if (readl(®s->cr) & CR_I2CRST) { + printf("fti2c010: reset timeout\n"); + return -1; + } + + curr->speed = spd; + + writel(TGSR_GSR(gsr) | TGSR_TSR(tsr), ®s->tgsr); + writel(CDR_DIV(div), ®s->cdr); + + return 0; +} + +/* + * i2c_get_bus_speed: + * + * Returns speed of currently active I2C bus in Hz + */ + +uint i2c_get_bus_speed(void) +{ + return curr->speed; +} |
