imx-common: add i2c.c for bus recovery support

Signed-off-by: Troy Kisky <troy.kisky@boundarydevices.com>

arch/arm/cpu/armv7/imx-common/Makefile

@@ -27,7 +27,9 @@ include $(TOPDIR)/config.mk
 
 LIB     = $(obj)libimx-common.o
 
-COBJS	= iomux-v3.o timer.o cpu.o speed.o
+COBJS-y	= iomux-v3.o timer.o cpu.o speed.o
+COBJS-$(CONFIG_I2C_MXC) += i2c.o
+COBJS	:= $(sort $(COBJS-y))
 
 SRCS	:= $(SOBJS:.o=.S) $(COBJS:.o=.c)
 OBJS	:= $(addprefix $(obj),$(SOBJS) $(COBJS))

arch/arm/cpu/armv7/imx-common/i2c.c

@@ -0,0 +1,99 @@
+/*
+ * Copyright (C) 2012 Boundary Devices Inc.
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+#include <common.h>
+#include <asm/arch/clock.h>
+#include <asm/arch/imx-regs.h>
+#include <asm/errno.h>
+#include <asm/gpio.h>
+#include <asm/imx-common/mxc_i2c.h>
+#include <watchdog.h>
+
+static int force_idle_bus(void *priv)
+{
+	int i;
+	int sda, scl;
+	ulong elapsed, start_time;
+	struct i2c_pads_info *p = (struct i2c_pads_info *)priv;
+	int ret = 0;
+
+	gpio_direction_input(p->sda.gp);
+	gpio_direction_input(p->scl.gp);
+
+	imx_iomux_v3_setup_pad(p->sda.gpio_mode);
+	imx_iomux_v3_setup_pad(p->scl.gpio_mode);
+
+	sda = gpio_get_value(p->sda.gp);
+	scl = gpio_get_value(p->scl.gp);
+	if ((sda & scl) == 1)
+		goto exit;		/* Bus is idle already */
+
+	printf("%s: sda=%d scl=%d sda.gp=0x%x scl.gp=0x%x\n", __func__,
+		sda, scl, p->sda.gp, p->scl.gp);
+	/* Send high and low on the SCL line */
+	for (i = 0; i < 9; i++) {
+		gpio_direction_output(p->scl.gp, 0);
+		udelay(50);
+		gpio_direction_input(p->scl.gp);
+		udelay(50);
+	}
+	start_time = get_timer(0);
+	for (;;) {
+		sda = gpio_get_value(p->sda.gp);
+		scl = gpio_get_value(p->scl.gp);
+		if ((sda & scl) == 1)
+			break;
+		WATCHDOG_RESET();
+		elapsed = get_timer(start_time);
+		if (elapsed > (CONFIG_SYS_HZ / 5)) {	/* .2 seconds */
+			ret = -EBUSY;
+			printf("%s: failed to clear bus, sda=%d scl=%d\n",
+					__func__, sda, scl);
+			break;
+		}
+	}
+exit:
+	imx_iomux_v3_setup_pad(p->sda.i2c_mode);
+	imx_iomux_v3_setup_pad(p->scl.i2c_mode);
+	return ret;
+}
+
+static void * const i2c_bases[] = {
+	(void *)I2C1_BASE_ADDR,
+	(void *)I2C2_BASE_ADDR,
+#ifdef I2C3_BASE_ADDR
+	(void *)I2C3_BASE_ADDR,
+#endif
+};
+
+/* i2c_index can be from 0 - 2 */
+void setup_i2c(unsigned i2c_index, int speed, int slave_addr,
+		struct i2c_pads_info *p)
+{
+	if (i2c_index >= ARRAY_SIZE(i2c_bases))
+		return;
+	/* Enable i2c clock */
+	enable_i2c_clk(1, i2c_index);
+	/* Make sure bus is idle */
+	force_idle_bus(p);
+	bus_i2c_init(i2c_bases[i2c_index], speed, slave_addr,
+			force_idle_bus, p);
+}

arch/arm/cpu/armv7/mx5/clock.c

@@ -117,6 +117,26 @@ void enable_usboh3_clk(unsigned char enable)
 	writel(reg, &mxc_ccm->CCGR2);
 }
 
+#ifdef CONFIG_I2C_MXC
+/* i2c_num can be from 0 - 2 */
+int enable_i2c_clk(unsigned char enable, unsigned i2c_num)
+{
+	u32 reg;
+	u32 mask;
+
+	if (i2c_num > 2)
+		return -EINVAL;
+	mask = MXC_CCM_CCGR_CG_MASK << ((i2c_num + 9) << 1);
+	reg = __raw_readl(&mxc_ccm->CCGR1);
+	if (enable)
+		reg |= mask;
+	else
+		reg &= ~mask;
+	__raw_writel(reg, &mxc_ccm->CCGR1);
+	return 0;
+}
+#endif
+
 void set_usb_phy1_clk(void)
 {
 	unsigned int reg;

arch/arm/cpu/armv7/mx6/clock.c

@@ -50,6 +50,26 @@ void enable_usboh3_clk(unsigned char enable)
 
 }
 
+#ifdef CONFIG_I2C_MXC
+/* i2c_num can be from 0 - 2 */
+int enable_i2c_clk(unsigned char enable, unsigned i2c_num)
+{
+	u32 reg;
+	u32 mask;
+
+	if (i2c_num > 2)
+		return -EINVAL;
+	mask = MXC_CCM_CCGR_CG_MASK << ((i2c_num + 3) << 1);
+	reg = __raw_readl(&imx_ccm->CCGR2);
+	if (enable)
+		reg |= mask;
+	else
+		reg &= ~mask;
+	__raw_writel(reg, &imx_ccm->CCGR2);
+	return 0;
+}
+#endif
+
 static u32 decode_pll(enum pll_clocks pll, u32 infreq)
 {
 	u32 div;

arch/arm/include/asm/arch-mx5/clock.h

@@ -49,5 +49,6 @@ void enable_usb_phy2_clk(unsigned char enable);
 void set_usboh3_clk(void);
 void enable_usboh3_clk(unsigned char enable);
 void mxc_set_sata_internal_clock(void);
+int enable_i2c_clk(unsigned char enable, unsigned i2c_num);
 
 #endif /* __ASM_ARCH_CLOCK_H */

arch/arm/include/asm/arch-mx6/clock.h

@@ -48,5 +48,6 @@ u32 imx_get_fecclk(void);
 unsigned int mxc_get_clock(enum mxc_clock clk);
 void enable_usboh3_clk(unsigned char enable);
 int enable_sata_clock(void);
+int enable_i2c_clk(unsigned char enable, unsigned i2c_num);
 
 #endif /* __ASM_ARCH_CLOCK_H */

arch/arm/include/asm/imx-common/mxc_i2c.h

@@ -0,0 +1,42 @@
+/*
+ * Copyright (C) 2011 Freescale Semiconductor, Inc. All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+#ifndef __ASM_ARCH_MXC_MXC_I2C_H__
+#define __ASM_ARCH_MXC_MXC_I2C_H__
+#include <asm/imx-common/iomux-v3.h>
+
+struct i2c_pin_ctrl {
+	iomux_v3_cfg_t i2c_mode;
+	iomux_v3_cfg_t gpio_mode;
+	unsigned char gp;
+	unsigned char spare;
+};
+
+struct i2c_pads_info {
+	struct i2c_pin_ctrl scl;
+	struct i2c_pin_ctrl sda;
+};
+
+void setup_i2c(unsigned i2c_index, int speed, int slave_addr,
+		struct i2c_pads_info *p);
+void bus_i2c_init(void *base, int speed, int slave_addr,
+		int (*idle_bus_fn)(void *p), void *p);
+int bus_i2c_read(void *base, uchar chip, uint addr, int alen, uchar *buf,
+		int len);
+int bus_i2c_write(void *base, uchar chip, uint addr, int alen,
+		const uchar *buf, int len);
+#endif