i2c: add Faraday FTI2C010 I2C controller support

Faraday FTI2C010 is a multi-function I2C controller
which supports both master and slave mode.
This patch simplily implements the master mode only.

Signed-off-by: Kuo-Jung Su <dantesu@faraday-tech.com>
CC: Heiko Schocher <hs@denx.de>

drivers/i2c/Makefile

@@ -44,6 +44,7 @@ COBJS-$(CONFIG_SH_I2C) += sh_i2c.o
 COBJS-$(CONFIG_SH_SH7734_I2C) += sh_sh7734_i2c.o
 COBJS-$(CONFIG_SYS_I2C) += i2c_core.o
 COBJS-$(CONFIG_SYS_I2C_FSL) += fsl_i2c.o
+COBJS-$(CONFIG_SYS_I2C_FTI2C010) += fti2c010.o
 COBJS-$(CONFIG_SYS_I2C_PPC4XX) += ppc4xx_i2c.o
 COBJS-$(CONFIG_SYS_I2C_SOFT) += soft_i2c.o
 COBJS-$(CONFIG_SYS_I2C_TEGRA) += tegra_i2c.o

drivers/i2c/fti2c010.c

+/*
+ * Faraday I2C Controller
+ *
+ * (C) Copyright 2010 Faraday Technology
+ * Dante Su <dantesu@faraday-tech.com>
+ *
+ * This file is released under the terms of GPL v2 and any later version.
+ * See the file COPYING in the root directory of the source tree for details.
+ */
+
+#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(&regs->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), &regs->dr);
+	writel(CR_ENABLE | CR_TBEN | CR_START, &regs->cr);
+	ret = fti2c010_wait(SR_DT);
+	if (ret)
+		return ret;
+
+	/* 2. Select device register */
+	writel(0, &regs->dr);
+	writel(CR_ENABLE | CR_TBEN, &regs->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), &regs->dr);
+	writel(CR_ENABLE | CR_TBEN | CR_START, &regs->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], &regs->dr);
+		writel(ctrl, &regs->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), &regs->dr);
+	writel(CR_ENABLE | CR_TBEN | CR_START, &regs->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, &regs->cr);
+		ret = fti2c010_wait(stat);
+		if (ret)
+			break;
+		buf[pos] = (uchar)(readl(&regs->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), &regs->dr);
+	writel(CR_ENABLE | CR_TBEN | CR_START, &regs->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], &regs->dr);
+		writel(ctrl, &regs->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], &regs->dr);
+		writel(ctrl, &regs->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, &regs->cr);
+	mdelay(100);
+	if (readl(&regs->cr) & CR_I2CRST) {
+		printf("fti2c010: reset timeout\n");
+		return -1;
+	}
+
+	curr->speed = spd;
+
+	writel(TGSR_GSR(gsr) | TGSR_TSR(tsr), &regs->tgsr);
+	writel(CDR_DIV(div), &regs->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;
+}

drivers/i2c/fti2c010.h

+/*
+ * Faraday I2C Controller
+ *
+ * (C) Copyright 2010 Faraday Technology
+ * Dante Su <dantesu@faraday-tech.com>
+ *
+ * This file is released under the terms of GPL v2 and any later version.
+ * See the file COPYING in the root directory of the source tree for details.
+ */
+
+#ifndef __FTI2C010_H
+#define __FTI2C010_H
+
+/*
+ * FTI2C010 registers
+ */
+struct fti2c010_regs {
+	uint32_t cr;  /* 0x00: control register */
+	uint32_t sr;  /* 0x04: status register */
+	uint32_t cdr; /* 0x08: clock division register */
+	uint32_t dr;  /* 0x0c: data register */
+	uint32_t sar; /* 0x10: slave address register */
+	uint32_t tgsr;/* 0x14: time & glitch suppression register */
+	uint32_t bmr; /* 0x18: bus monitor register */
+	uint32_t rsvd[5];
+	uint32_t revr;/* 0x30: revision register */
+};
+
+/*
+ * control register
+ */
+#define CR_ALIRQ      0x2000  /* arbitration lost interrupt (master) */
+#define CR_SAMIRQ     0x1000  /* slave address match interrupt (slave) */
+#define CR_STOPIRQ    0x800   /* stop condition interrupt (slave) */
+#define CR_NAKRIRQ    0x400   /* NACK response interrupt (master) */
+#define CR_DRIRQ      0x200   /* rx interrupt (both) */
+#define CR_DTIRQ      0x100   /* tx interrupt (both) */
+#define CR_TBEN       0x80    /* tx enable (both) */
+#define CR_NAK        0x40    /* NACK (both) */
+#define CR_STOP       0x20    /* stop (master) */
+#define CR_START      0x10    /* start (master) */
+#define CR_GCEN       0x8     /* general call support (slave) */
+#define CR_SCLEN      0x4     /* enable clock out (master) */
+#define CR_I2CEN      0x2     /* enable I2C (both) */
+#define CR_I2CRST     0x1     /* reset I2C (both) */
+#define CR_ENABLE     \
+	(CR_ALIRQ | CR_NAKRIRQ | CR_DRIRQ | CR_DTIRQ | CR_SCLEN | CR_I2CEN)
+
+/*
+ * status register
+ */
+#define SR_CLRAL      0x400    /* clear arbitration lost */
+#define SR_CLRGC      0x200    /* clear general call */
+#define SR_CLRSAM     0x100    /* clear slave address match */
+#define SR_CLRSTOP    0x80     /* clear stop */
+#define SR_CLRNAKR    0x40     /* clear NACK respond */
+#define SR_DR         0x20     /* rx ready */
+#define SR_DT         0x10     /* tx done */
+#define SR_BB         0x8      /* bus busy */
+#define SR_BUSY       0x4      /* chip busy */
+#define SR_ACK        0x2      /* ACK/NACK received */
+#define SR_RW         0x1      /* set when master-rx or slave-tx mode */
+
+/*
+ * clock division register
+ */
+#define CDR_DIV(n)    ((n) & 0x3ffff)
+
+/*
+ * time & glitch suppression register
+ */
+#define TGSR_GSR(n)   (((n) & 0x7) << 10)
+#define TGSR_TSR(n)   ((n) & 0x3ff)
+
+/*
+ * bus monitor register
+ */
+#define BMR_SCL       0x2      /* SCL is pull-up */
+#define BMR_SDA       0x1      /* SDA is pull-up */
+
+#endif /* __FTI2C010_H */