[U-Boot] [PATCH V2 24/25] imx-common: add i2c.c for bus recovery support
Troy Kisky
troy.kisky at boundarydevices.com
Thu Jul 5 21:54:02 CEST 2012
Signed-off-by: Troy Kisky <troy.kisky at boundarydevices.com>
---
v2: do nothing if bus is already idle
print failure message if appropriate
change enable_i2c_clock to enable_i2c_clk
clear non-idle bus before calling bus_i2c_init.
wait .2 seconds for bus to clear before returning error
fix compiler warnings
---
arch/arm/cpu/armv7/imx-common/Makefile | 4 +-
arch/arm/cpu/armv7/imx-common/i2c.c | 98 +++++++++++++++++++++++++++++
arch/arm/cpu/armv7/mx5/clock.c | 20 ++++++
arch/arm/cpu/armv7/mx6/clock.c | 20 ++++++
arch/arm/include/asm/arch-mx5/clock.h | 1 +
arch/arm/include/asm/arch-mx6/clock.h | 1 +
arch/arm/include/asm/imx-common/mxc_i2c.h | 42 +++++++++++++
7 files changed, 185 insertions(+), 1 deletion(-)
create mode 100644 arch/arm/cpu/armv7/imx-common/i2c.c
create mode 100644 arch/arm/include/asm/imx-common/mxc_i2c.h
diff --git a/arch/arm/cpu/armv7/imx-common/Makefile b/arch/arm/cpu/armv7/imx-common/Makefile
index 53296fa..bf36be5 100644
--- a/arch/arm/cpu/armv7/imx-common/Makefile
+++ b/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))
diff --git a/arch/arm/cpu/armv7/imx-common/i2c.c b/arch/arm/cpu/armv7/imx-common/i2c.c
new file mode 100644
index 0000000..e32062d
--- /dev/null
+++ b/arch/arm/cpu/armv7/imx-common/i2c.c
@@ -0,0 +1,98 @@
+/*
+ * 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 toggle_scl(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: toggle 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 */
+ toggle_scl(p);
+ bus_i2c_init(i2c_bases[i2c_index], speed, slave_addr, toggle_scl, p);
+}
diff --git a/arch/arm/cpu/armv7/mx5/clock.c b/arch/arm/cpu/armv7/mx5/clock.c
index e92f106..c2220b0 100644
--- a/arch/arm/cpu/armv7/mx5/clock.c
+++ b/arch/arm/cpu/armv7/mx5/clock.c
@@ -80,6 +80,26 @@ 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;
diff --git a/arch/arm/cpu/armv7/mx6/clock.c b/arch/arm/cpu/armv7/mx6/clock.c
index ef98563..24f1e89 100644
--- a/arch/arm/cpu/armv7/mx6/clock.c
+++ b/arch/arm/cpu/armv7/mx6/clock.c
@@ -49,6 +49,26 @@ 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;
diff --git a/arch/arm/include/asm/arch-mx5/clock.h b/arch/arm/include/asm/arch-mx5/clock.h
index ea972a3..da604bf 100644
--- a/arch/arm/include/asm/arch-mx5/clock.h
+++ b/arch/arm/include/asm/arch-mx5/clock.h
@@ -44,5 +44,6 @@ void set_usb_phy2_clk(void);
void enable_usb_phy2_clk(unsigned char enable);
void set_usboh3_clk(void);
void enable_usboh3_clk(unsigned char enable);
+int enable_i2c_clk(unsigned char enable, unsigned i2c_num);
#endif /* __ASM_ARCH_CLOCK_H */
diff --git a/arch/arm/include/asm/arch-mx6/clock.h b/arch/arm/include/asm/arch-mx6/clock.h
index 613809b..04daf36 100644
--- a/arch/arm/include/asm/arch-mx6/clock.h
+++ b/arch/arm/include/asm/arch-mx6/clock.h
@@ -47,5 +47,6 @@ u32 imx_get_uartclk(void);
u32 imx_get_fecclk(void);
unsigned int mxc_get_clock(enum mxc_clock clk);
void enable_usboh3_clk(unsigned char enable);
+int enable_i2c_clk(unsigned char enable, unsigned i2c_num);
#endif /* __ASM_ARCH_CLOCK_H */
diff --git a/arch/arm/include/asm/imx-common/mxc_i2c.h b/arch/arm/include/asm/imx-common/mxc_i2c.h
new file mode 100644
index 0000000..e10b6af
--- /dev/null
+++ b/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 (*toggle_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
--
1.7.9.5
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