imx-common: add i2c.c for bus recovery support
authorTroy Kisky <troy.kisky@boundarydevices.com>
Thu, 19 Jul 2012 08:18:25 +0000 (08:18 +0000)
committerHeiko Schocher <hs@denx.de>
Tue, 31 Jul 2012 06:00:57 +0000 (08:00 +0200)
Signed-off-by: Troy Kisky <troy.kisky@boundarydevices.com>
arch/arm/cpu/armv7/imx-common/Makefile
arch/arm/cpu/armv7/imx-common/i2c.c [new file with mode: 0644]
arch/arm/cpu/armv7/mx5/clock.c
arch/arm/cpu/armv7/mx6/clock.c
arch/arm/include/asm/arch-mx5/clock.h
arch/arm/include/asm/arch-mx6/clock.h
arch/arm/include/asm/imx-common/mxc_i2c.h [new file with mode: 0644]

index 53296fa..bf36be5 100644 (file)
@@ -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 (file)
index 0000000..da2b26f
--- /dev/null
@@ -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);
+}
index 64862b3..c67c3cf 100644 (file)
@@ -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;
index 52d5dc4..fddb373 100644 (file)
@@ -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;
index 35ee815..36ea030 100644 (file)
@@ -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 */
index b91d8bf..c55c18d 100644 (file)
@@ -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 */
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 (file)
index 0000000..9a5187d
--- /dev/null
@@ -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