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authorTroy Kisky <troy.kisky@boundarydevices.com>2012-07-19 08:18:18 +0000
committerHeiko Schocher <hs@denx.de>2012-07-31 07:57:04 +0200
commite4ff525f91f813456cf42a29227ee4a0fe01788b (patch)
tree88245d9201bb195a13705323a4927fa1b702e378 /drivers/i2c
parent27a5da02c094c9b73c01aa699f13591b824d5436 (diff)
mxc_i2c: prep work for multiple busses support
Signed-off-by: Troy Kisky <troy.kisky@boundarydevices.com>
Diffstat (limited to 'drivers/i2c')
-rw-r--r--drivers/i2c/mxc_i2c.c125
1 files changed, 104 insertions, 21 deletions
diff --git a/drivers/i2c/mxc_i2c.c b/drivers/i2c/mxc_i2c.c
index 44a04b57d6..ead6e209b2 100644
--- a/drivers/i2c/mxc_i2c.c
+++ b/drivers/i2c/mxc_i2c.c
@@ -59,9 +59,7 @@ struct mxc_i2c_regs {
#define I2SR_IIF (1 << 1)
#define I2SR_RX_NO_AK (1 << 0)
-#ifdef CONFIG_SYS_I2C_BASE
-#define I2C_BASE CONFIG_SYS_I2C_BASE
-#else
+#if defined(CONFIG_HARD_I2C) && !defined(CONFIG_SYS_I2C_BASE)
#error "define CONFIG_SYS_I2C_BASE to use the mxc_i2c driver"
#endif
@@ -115,11 +113,11 @@ static uint8_t i2c_imx_get_clk(unsigned int rate)
}
/*
- * Init I2C Bus
+ * Set I2C Bus speed
*/
-void i2c_init(int speed, int unused)
+int bus_i2c_set_bus_speed(void *base, int speed)
{
- struct mxc_i2c_regs *i2c_regs = (struct mxc_i2c_regs *)I2C_BASE;
+ struct mxc_i2c_regs *i2c_regs = (struct mxc_i2c_regs *)base;
u8 clk_idx = i2c_imx_get_clk(speed);
u8 idx = i2c_clk_div[clk_idx][1];
@@ -129,23 +127,15 @@ void i2c_init(int speed, int unused)
/* Reset module */
writeb(0, &i2c_regs->i2cr);
writeb(0, &i2c_regs->i2sr);
-}
-
-/*
- * Set I2C Speed
- */
-int i2c_set_bus_speed(unsigned int speed)
-{
- i2c_init(speed, 0);
return 0;
}
/*
* Get I2C Speed
*/
-unsigned int i2c_get_bus_speed(void)
+unsigned int bus_i2c_get_bus_speed(void *base)
{
- struct mxc_i2c_regs *i2c_regs = (struct mxc_i2c_regs *)I2C_BASE;
+ struct mxc_i2c_regs *i2c_regs = (struct mxc_i2c_regs *)base;
u8 clk_idx = readb(&i2c_regs->ifdr);
u8 clk_div;
@@ -287,12 +277,13 @@ static int i2c_init_transfer(struct mxc_i2c_regs *i2c_regs,
/*
* Read data from I2C device
*/
-int i2c_read(uchar chip, uint addr, int alen, uchar *buf, int len)
+int bus_i2c_read(void *base, uchar chip, uint addr, int alen, uchar *buf,
+ int len)
{
- struct mxc_i2c_regs *i2c_regs = (struct mxc_i2c_regs *)I2C_BASE;
int ret;
unsigned int temp;
int i;
+ struct mxc_i2c_regs *i2c_regs = (struct mxc_i2c_regs *)base;
ret = i2c_init_transfer(i2c_regs, chip, addr, alen);
if (ret < 0)
@@ -346,11 +337,12 @@ int i2c_read(uchar chip, uint addr, int alen, uchar *buf, int len)
/*
* Write data to I2C device
*/
-int i2c_write(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)
{
- struct mxc_i2c_regs *i2c_regs = (struct mxc_i2c_regs *)I2C_BASE;
int ret;
int i;
+ struct mxc_i2c_regs *i2c_regs = (struct mxc_i2c_regs *)base;
ret = i2c_init_transfer(i2c_regs, chip, addr, alen);
if (ret < 0)
@@ -365,10 +357,101 @@ int i2c_write(uchar chip, uint addr, int alen, uchar *buf, int len)
return ret;
}
+struct i2c_parms {
+ void *base;
+ void *idle_bus_data;
+ int (*idle_bus_fn)(void *p);
+};
+
+struct sram_data {
+ unsigned curr_i2c_bus;
+ struct i2c_parms i2c_data[3];
+};
+
+/*
+ * For SPL boot some boards need i2c before SDRAM is initialized so force
+ * variables to live in SRAM
+ */
+static struct sram_data __attribute__((section(".data"))) srdata;
+
+void *get_base(void)
+{
+#ifdef CONFIG_SYS_I2C_BASE
+#ifdef CONFIG_I2C_MULTI_BUS
+ void *ret = srdata.i2c_data[srdata.curr_i2c_bus].base;
+ if (ret)
+ return ret;
+#endif
+ return (void *)CONFIG_SYS_I2C_BASE;
+#elif defined(CONFIG_I2C_MULTI_BUS)
+ return srdata.i2c_data[srdata.curr_i2c_bus].base;
+#else
+ return srdata.i2c_data[0].base;
+#endif
+}
+
+int i2c_read(uchar chip, uint addr, int alen, uchar *buf, int len)
+{
+ return bus_i2c_read(get_base(), chip, addr, alen, buf, len);
+}
+
+int i2c_write(uchar chip, uint addr, int alen, uchar *buf, int len)
+{
+ return bus_i2c_write(get_base(), chip, addr, alen, buf, len);
+}
+
/*
* Test if a chip at a given address responds (probe the chip)
*/
int i2c_probe(uchar chip)
{
- return i2c_write(chip, 0, 0, NULL, 0);
+ return bus_i2c_write(get_base(), chip, 0, 0, NULL, 0);
+}
+
+void bus_i2c_init(void *base, int speed, int unused,
+ int (*idle_bus_fn)(void *p), void *idle_bus_data)
+{
+ int i = 0;
+ struct i2c_parms *p = srdata.i2c_data;
+ if (!base)
+ return;
+ for (;;) {
+ if (!p->base || (p->base == base)) {
+ p->base = base;
+ if (idle_bus_fn) {
+ p->idle_bus_fn = idle_bus_fn;
+ p->idle_bus_data = idle_bus_data;
+ }
+ break;
+ }
+ p++;
+ i++;
+ if (i >= ARRAY_SIZE(srdata.i2c_data))
+ return;
+ }
+ bus_i2c_set_bus_speed(base, speed);
+}
+
+/*
+ * Init I2C Bus
+ */
+void i2c_init(int speed, int unused)
+{
+ bus_i2c_init(get_base(), speed, unused, NULL, NULL);
+}
+
+/*
+ * Set I2C Speed
+ */
+int i2c_set_bus_speed(unsigned int speed)
+{
+ return bus_i2c_set_bus_speed(get_base(), speed);
+}
+
+/*
+ * Get I2C Speed
+ */
+unsigned int i2c_get_bus_speed(void)
+{
+ return bus_i2c_get_bus_speed(get_base());
}