add an i2c driver for mx31

This patch adds an i2c driver for Freescale i.MX processors Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de> Signed-off-by: Guennadi Liakhovetski <lg@denx.de>

add an i2c driver for mx31
This patch adds an i2c driver for Freescale i.MX processors Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de> Signed-off-by: Guennadi Liakhovetski <lg@denx.de>
Sascha Hauer · Peter Pearse
1 parent c98b47ad24
Showing 2 changed files with 208 additions and 0 deletions Side-by-side Diff
drivers/i2c/Makefile
drivers/i2c/mxc_i2c.c
@@ -29,6 +29,7 @@
 COBJS-y += omap1510_i2c.o
 COBJS-y += omap24xx_i2c.o
 COBJS-y += tsi108_i2c.o
+COBJS-y += mxc_i2c.o
  
 COBJS	:= $(COBJS-y)
 SRCS 	:= $(COBJS:.o=.c)
+/*
+ * i2c driver for Freescale mx31
+ *
+ * (c) 2007 Pengutronix, Sascha Hauer <s.hauer@pengutronix.de>
+ *
+ * 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>
+
+#if defined(CONFIG_HARD_I2C) && defined(CONFIG_I2C_MXC)
+
+#include <asm/arch/mx31.h>
+#include <asm/arch/mx31-regs.h>
+
+#define IADR	0x00
+#define IFDR	0x04
+#define I2CR	0x08
+#define I2SR	0x0c
+#define I2DR	0x10
+
+#define I2CR_IEN	(1 << 7)
+#define I2CR_IIEN	(1 << 6)
+#define I2CR_MSTA	(1 << 5)
+#define I2CR_MTX	(1 << 4)
+#define I2CR_TX_NO_AK	(1 << 3)
+#define I2CR_RSTA	(1 << 2)
+
+#define I2SR_ICF	(1 << 7)
+#define I2SR_IBB	(1 << 5)
+#define I2SR_IIF	(1 << 1)
+#define I2SR_RX_NO_AK	(1 << 0)
+
+#ifdef CFG_I2C_MX31_PORT1
+#define I2C_BASE	0x43f80000
+#elif defined(CFG_I2C_MX31_PORT2)
+#define I2C_BASE	0x43f98000
+#elif defined(CFG_I2C_MX31_PORT3)
+#define I2C_BASE	0x43f84000
+#else
+#error "define CFG_I2C_MX31_PORTx to use the mx31 I2C driver"
+#endif
+
+#ifdef DEBUG
+#define DPRINTF(args...)  printf(args)
+#else
+#define DPRINTF(args...)
+#endif
+
+static u16 div[] = { 30, 32, 36, 42, 48, 52, 60, 72, 80, 88, 104, 128, 144,
+			160, 192, 240, 288, 320, 384, 480, 576, 640, 768, 960,
+			1152, 1280, 1536, 1920, 2304, 2560, 3072, 3840};
+
+void i2c_init(int speed, int unused)
+{
+	int freq = mx31_get_ipg_clk();
+	int i;
+
+	for (i = 0; i < 0x1f; i++)
+		if (freq / div[i] <= speed)
+			break;
+
+	DPRINTF("%s: speed: %d\n", __FUNCTION__, speed);
+
+	__REG16(I2C_BASE + I2CR) = 0; /* Reset module */
+	__REG16(I2C_BASE + IFDR) = i;
+	__REG16(I2C_BASE + I2CR) = I2CR_IEN;
+	__REG16(I2C_BASE + I2SR) = 0;
+}
+
+static int wait_busy(void)
+{
+	int timeout = 10000;
+
+	while (!(__REG16(I2C_BASE + I2SR) & I2SR_IIF) && --timeout)
+		udelay(1);
+	__REG16(I2C_BASE + I2SR) = 0; /* clear interrupt */
+
+	return timeout;
+}
+
+static int tx_byte(u8 byte)
+{
+	__REG16(I2C_BASE + I2DR) = byte;
+
+	if (!wait_busy() || __REG16(I2C_BASE + I2SR) & I2SR_RX_NO_AK)
+		return -1;
+	return 0;
+}
+
+static int rx_byte(void)
+{
+	if (!wait_busy())
+		return -1;
+
+	return __REG16(I2C_BASE + I2DR);
+}
+
+int i2c_probe(uchar chip)
+{
+	int ret;
+
+	__REG16(I2C_BASE + I2CR) = 0; /* Reset module */
+	__REG16(I2C_BASE + I2CR) = I2CR_IEN;
+
+	__REG16(I2C_BASE + I2CR) = I2CR_IEN |  I2CR_MSTA | I2CR_MTX;
+	ret = tx_byte(chip << 1);
+	__REG16(I2C_BASE + I2CR) = I2CR_IEN | I2CR_MTX;
+
+	return ret;
+}
+
+static int i2c_addr(uchar chip, uint addr, int alen)
+{
+	__REG16(I2C_BASE + I2SR) = 0; /* clear interrupt */
+	__REG16(I2C_BASE + I2CR) = I2CR_IEN |  I2CR_MSTA | I2CR_MTX;
+
+	if (tx_byte(chip << 1))
+		return -1;
+
+	while (alen--)
+		if (tx_byte((addr >> (alen * 8)) & 0xff))
+			return -1;
+	return 0;
+}
+
+int i2c_read(uchar chip, uint addr, int alen, uchar *buf, int len)
+{
+	int timeout = 10000;
+	int ret;
+
+	DPRINTF("%s chip: 0x%02x addr: 0x%04x alen: %d len: +%d\n", \
+				__FUNCTION__, chip, addr, alen, len);
+
+	if (i2c_addr(chip, addr, alen)) {
+		printf("i2c_addr failed\n");
+		return -1;
+	}
+
+	__REG16(I2C_BASE + I2CR) = I2CR_IEN |  I2CR_MSTA |	\
+					I2CR_MTX | I2CR_RSTA;
+
+	if (tx_byte(chip << 1 | 1))
+		return -1;
+
+	__REG16(I2C_BASE + I2CR) = I2CR_IEN |  I2CR_MSTA | ((len == 1)	\
+							? I2CR_TX_NO_AK : 0);
+
+	ret = __REG16(I2C_BASE + I2DR);
+
+	while (len--) {
+		if ((ret = rx_byte()) < 0)
+			return -1;
+		*buf++ = ret;
+		if (len <= 1)
+			__REG16(I2C_BASE + I2CR) = I2CR_IEN |	\
+					I2CR_MSTA | I2CR_TX_NO_AK;
+	}
+
+	wait_busy();
+
+	__REG16(I2C_BASE + I2CR) = I2CR_IEN;
+
+	while (__REG16(I2C_BASE + I2SR) & I2SR_IBB && --timeout)
+		udelay(1);
+
+	return 0;
+}
+
+int i2c_write(uchar chip, uint addr, int alen, uchar *buf, int len)
+{
+	int timeout = 10000;
+	DPRINTF("%s chip: 0x%02x addr: 0x%04x alen: %d len: %d\n",	\
+					__FUNCTION__, chip, addr, alen, len);
+
+	if (i2c_addr(chip, addr, alen))
+		return -1;
+
+	while (len--)
+		if (tx_byte(*buf++))
+			return -1;
+
+	__REG16(I2C_BASE + I2CR) = I2CR_IEN;
+
+	while (__REG16(I2C_BASE + I2SR) & I2SR_IBB && --timeout)
+		udelay(1);
+
+	return 0;
+}
+
+#endif /* CONFIG_HARD_I2C */
...	...	@@ -29,6 +29,7 @@
29	29	COBJS-y += omap1510_i2c.o
30	30	COBJS-y += omap24xx_i2c.o
31	31	COBJS-y += tsi108_i2c.o
	32	+COBJS-y += mxc_i2c.o
32	33
33	34	COBJS := $(COBJS-y)
34	35	SRCS := $(COBJS:.o=.c)
	1	+/*
	2	+ * i2c driver for Freescale mx31
	3	+ *
	4	+ * (c) 2007 Pengutronix, Sascha Hauer <s.hauer@pengutronix.de>
	5	+ *
	6	+ * See file CREDITS for list of people who contributed to this
	7	+ * project.
	8	+ *
	9	+ * This program is free software; you can redistribute it and/or
	10	+ * modify it under the terms of the GNU General Public License as
	11	+ * published by the Free Software Foundation; either version 2 of
	12	+ * the License, or (at your option) any later version.
	13	+ *
	14	+ * This program is distributed in the hope that it will be useful,
	15	+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
	16	+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	17	+ * GNU General Public License for more details.
	18	+ *
	19	+ * You should have received a copy of the GNU General Public License
	20	+ * along with this program; if not, write to the Free Software
	21	+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
	22	+ * MA 02111-1307 USA
	23	+ */
	24	+
	25	+#include <common.h>
	26	+
	27	+#if defined(CONFIG_HARD_I2C) && defined(CONFIG_I2C_MXC)
	28	+
	29	+#include <asm/arch/mx31.h>
	30	+#include <asm/arch/mx31-regs.h>
	31	+
	32	+#define IADR 0x00
	33	+#define IFDR 0x04
	34	+#define I2CR 0x08
	35	+#define I2SR 0x0c
	36	+#define I2DR 0x10
	37	+
	38	+#define I2CR_IEN (1 << 7)
	39	+#define I2CR_IIEN (1 << 6)
	40	+#define I2CR_MSTA (1 << 5)
	41	+#define I2CR_MTX (1 << 4)
	42	+#define I2CR_TX_NO_AK (1 << 3)
	43	+#define I2CR_RSTA (1 << 2)
	44	+
	45	+#define I2SR_ICF (1 << 7)
	46	+#define I2SR_IBB (1 << 5)
	47	+#define I2SR_IIF (1 << 1)
	48	+#define I2SR_RX_NO_AK (1 << 0)
	49	+
	50	+#ifdef CFG_I2C_MX31_PORT1
	51	+#define I2C_BASE 0x43f80000
	52	+#elif defined(CFG_I2C_MX31_PORT2)
	53	+#define I2C_BASE 0x43f98000
	54	+#elif defined(CFG_I2C_MX31_PORT3)
	55	+#define I2C_BASE 0x43f84000
	56	+#else
	57	+#error "define CFG_I2C_MX31_PORTx to use the mx31 I2C driver"
	58	+#endif
	59	+
	60	+#ifdef DEBUG
	61	+#define DPRINTF(args...) printf(args)
	62	+#else
	63	+#define DPRINTF(args...)
	64	+#endif
	65	+
	66	+static u16 div[] = { 30, 32, 36, 42, 48, 52, 60, 72, 80, 88, 104, 128, 144,
	67	+ 160, 192, 240, 288, 320, 384, 480, 576, 640, 768, 960,
	68	+ 1152, 1280, 1536, 1920, 2304, 2560, 3072, 3840};
	69	+
	70	+void i2c_init(int speed, int unused)
	71	+{
	72	+ int freq = mx31_get_ipg_clk();
	73	+ int i;
	74	+
	75	+ for (i = 0; i < 0x1f; i++)
	76	+ if (freq / div[i] <= speed)
	77	+ break;
	78	+
	79	+ DPRINTF("%s: speed: %d\n", __FUNCTION__, speed);
	80	+
	81	+ __REG16(I2C_BASE + I2CR) = 0; /* Reset module */
	82	+ __REG16(I2C_BASE + IFDR) = i;
	83	+ __REG16(I2C_BASE + I2CR) = I2CR_IEN;
	84	+ __REG16(I2C_BASE + I2SR) = 0;
	85	+}
	86	+
	87	+static int wait_busy(void)
	88	+{
	89	+ int timeout = 10000;
	90	+
	91	+ while (!(__REG16(I2C_BASE + I2SR) & I2SR_IIF) && --timeout)
	92	+ udelay(1);
	93	+ __REG16(I2C_BASE + I2SR) = 0; /* clear interrupt */
	94	+
	95	+ return timeout;
	96	+}
	97	+
	98	+static int tx_byte(u8 byte)
	99	+{
	100	+ __REG16(I2C_BASE + I2DR) = byte;
	101	+
	102	+ if (!wait_busy() \|\| __REG16(I2C_BASE + I2SR) & I2SR_RX_NO_AK)
	103	+ return -1;
	104	+ return 0;
	105	+}
	106	+
	107	+static int rx_byte(void)
	108	+{
	109	+ if (!wait_busy())
	110	+ return -1;
	111	+
	112	+ return __REG16(I2C_BASE + I2DR);
	113	+}
	114	+
	115	+int i2c_probe(uchar chip)
	116	+{
	117	+ int ret;
	118	+
	119	+ __REG16(I2C_BASE + I2CR) = 0; /* Reset module */
	120	+ __REG16(I2C_BASE + I2CR) = I2CR_IEN;
	121	+
	122	+ __REG16(I2C_BASE + I2CR) = I2CR_IEN \| I2CR_MSTA \| I2CR_MTX;
	123	+ ret = tx_byte(chip << 1);
	124	+ __REG16(I2C_BASE + I2CR) = I2CR_IEN \| I2CR_MTX;
	125	+
	126	+ return ret;
	127	+}
	128	+
	129	+static int i2c_addr(uchar chip, uint addr, int alen)
	130	+{
	131	+ __REG16(I2C_BASE + I2SR) = 0; /* clear interrupt */
	132	+ __REG16(I2C_BASE + I2CR) = I2CR_IEN \| I2CR_MSTA \| I2CR_MTX;
	133	+
	134	+ if (tx_byte(chip << 1))
	135	+ return -1;
	136	+
	137	+ while (alen--)
	138	+ if (tx_byte((addr >> (alen * 8)) & 0xff))
	139	+ return -1;
	140	+ return 0;
	141	+}
	142	+
	143	+int i2c_read(uchar chip, uint addr, int alen, uchar *buf, int len)
	144	+{
	145	+ int timeout = 10000;
	146	+ int ret;
	147	+
	148	+ DPRINTF("%s chip: 0x%02x addr: 0x%04x alen: %d len: +%d\n", \
	149	+ __FUNCTION__, chip, addr, alen, len);
	150	+
	151	+ if (i2c_addr(chip, addr, alen)) {
	152	+ printf("i2c_addr failed\n");
	153	+ return -1;
	154	+ }
	155	+
	156	+ __REG16(I2C_BASE + I2CR) = I2CR_IEN \| I2CR_MSTA \| \
	157	+ I2CR_MTX \| I2CR_RSTA;
	158	+
	159	+ if (tx_byte(chip << 1 \| 1))
	160	+ return -1;
	161	+
	162	+ __REG16(I2C_BASE + I2CR) = I2CR_IEN \| I2CR_MSTA \| ((len == 1) \
	163	+ ? I2CR_TX_NO_AK : 0);
	164	+
	165	+ ret = __REG16(I2C_BASE + I2DR);
	166	+
	167	+ while (len--) {
	168	+ if ((ret = rx_byte()) < 0)
	169	+ return -1;
	170	+ *buf++ = ret;
	171	+ if (len <= 1)
	172	+ __REG16(I2C_BASE + I2CR) = I2CR_IEN \| \
	173	+ I2CR_MSTA \| I2CR_TX_NO_AK;
	174	+ }
	175	+
	176	+ wait_busy();
	177	+
	178	+ __REG16(I2C_BASE + I2CR) = I2CR_IEN;
	179	+
	180	+ while (__REG16(I2C_BASE + I2SR) & I2SR_IBB && --timeout)
	181	+ udelay(1);
	182	+
	183	+ return 0;
	184	+}
	185	+
	186	+int i2c_write(uchar chip, uint addr, int alen, uchar *buf, int len)
	187	+{
	188	+ int timeout = 10000;
	189	+ DPRINTF("%s chip: 0x%02x addr: 0x%04x alen: %d len: %d\n", \
	190	+ __FUNCTION__, chip, addr, alen, len);
	191	+
	192	+ if (i2c_addr(chip, addr, alen))
	193	+ return -1;
	194	+
	195	+ while (len--)
	196	+ if (tx_byte(*buf++))
	197	+ return -1;
	198	+
	199	+ __REG16(I2C_BASE + I2CR) = I2CR_IEN;
	200	+
	201	+ while (__REG16(I2C_BASE + I2SR) & I2SR_IBB && --timeout)
	202	+ udelay(1);
	203	+
	204	+ return 0;
	205	+}
	206	+
	207	+#endif /* CONFIG_HARD_I2C */