[U-Boot] [PATCH 5/6 V4] I2C: Driver changes for FDT support

[Rajeshwari Shinde]

Functions added to get the I2C bus number and reset I2C bus using
FDT node.

Signed-off-by: Rajeshwari Shinde <rajeshwari.s at samsung.com>
Acked-by: Simon Glass <sjg at chromium.org>
---
Changes in V2:
        - Added periph id to I2C bus structure.
        - Modified i2c_get_bus_num_fdt function to compare with node.
        - Board i2c init moved to driver in case of FDT.
Chnages in V3:
        - peripheral id decoded based on interrupts.
        - removed compat id check in i2c_get_bus_num_fdt.
Changes in V4:
	- Renamed decode_periph_id to pinmux_decode_periph_id. 
 drivers/i2c/s3c24x0_i2c.c |   83 ++++++++++++++++++++++++++++++++++++++++++++-
 drivers/i2c/s3c24x0_i2c.h |    8 ++++
 include/i2c.h             |   26 ++++++++++++++
 3 files changed, 116 insertions(+), 1 deletions(-)

diff --git a/drivers/i2c/s3c24x0_i2c.c b/drivers/i2c/s3c24x0_i2c.c
index 9bc4c7f..94a093e 100644
--- a/drivers/i2c/s3c24x0_i2c.c
+++ b/drivers/i2c/s3c24x0_i2c.c
@@ -27,9 +27,11 @@
  */
 
 #include <common.h>
+#include <fdtdec.h>
 #ifdef CONFIG_EXYNOS5
 #include <asm/arch/clk.h>
 #include <asm/arch/cpu.h>
+#include <asm/arch/pinmux.h>
 #else
 #include <asm/arch/s3c24x0_cpu.h>
 #endif
@@ -60,7 +62,14 @@
 #define I2C_TIMEOUT 1		/* 1 second */
 
 
-static unsigned int g_current_bus;	/* Stores Current I2C Bus */
+/*
+ * For SPL boot some boards need i2c before SDRAM is initialised so force
+ * variables to live in SRAM
+ */
+static unsigned int g_current_bus __attribute__((section(".data")));
+static struct s3c24x0_i2c_bus i2c_bus[CONFIG_MAX_I2C_NUM]
+			__attribute__((section(".data")));
+static int i2c_busses __attribute__((section(".data")));
 
 #ifndef CONFIG_EXYNOS5
 static int GetI2CSDA(void)
@@ -507,4 +516,76 @@ int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len)
 		(i2c, I2C_WRITE, chip << 1, &xaddr[4 - alen], alen, buffer,
 		 len) != 0);
 }
+
+#ifdef CONFIG_OF_CONTROL
+void board_i2c_init(const void *blob)
+{
+
+	int node_list[CONFIG_MAX_I2C_NUM];
+	int count, i;
+
+	count = fdtdec_find_aliases_for_id(blob, "i2c",
+		COMPAT_SAMSUNG_S3C2440_I2C, node_list,
+		CONFIG_MAX_I2C_NUM);
+	for (i = 0; i < count; i++) {
+		struct s3c24x0_i2c_bus *bus;
+		int node = node_list[i];
+
+		if (node < 0)
+			continue;
+		bus = &i2c_bus[i];
+		bus->regs = (struct s3c24x0_i2c *)
+			fdtdec_get_addr(blob, node, "reg");
+		bus->id = pinmux_decode_periph_id(blob, node);
+		bus->node = node;
+		bus->bus_num = i2c_busses++;
+		exynos_pinmux_config(bus->id, 0);
+	}
+
+}
+
+static struct s3c24x0_i2c_bus *get_bus(unsigned int bus_idx)
+{
+	if (bus_idx < i2c_busses)
+		return &i2c_bus[bus_idx];
+	debug("Undefined bus: %d\n", bus_idx);
+	return NULL;
+}
+
+int i2c_get_bus_num_fdt(int node)
+{
+	int i;
+
+	for (i = 0; i < i2c_busses; i++) {
+		if (node == i2c_bus[i].node)
+			return i;
+	}
+
+	debug("%s: Can't find any matched I2C bus\n", __func__);
+	return -1;
+}
+
+int i2c_reset_port_fdt(const void *blob, int node)
+{
+	struct s3c24x0_i2c_bus *i2c;
+
+	int bus;
+
+	bus = i2c_get_bus_num_fdt(node);
+	if (bus < 0) {
+		debug("could not get bus for node %d\n", node);
+		return -1;
+	}
+	i2c = get_bus(bus);
+	if (!i2c) {
+		debug("get_bus() failed for node node %d\n", node);
+		return -1;
+	}
+
+	i2c_ch_init(i2c->regs, CONFIG_SYS_I2C_SPEED, CONFIG_SYS_I2C_SLAVE);
+
+	return 0;
+}
+#endif
+
 #endif /* CONFIG_HARD_I2C */
diff --git a/drivers/i2c/s3c24x0_i2c.h b/drivers/i2c/s3c24x0_i2c.h
index 2dd4b06..1243bf1 100644
--- a/drivers/i2c/s3c24x0_i2c.h
+++ b/drivers/i2c/s3c24x0_i2c.h
@@ -30,4 +30,12 @@ struct s3c24x0_i2c {
 	u32	iicds;
 	u32	iiclc;
 };
+
+struct s3c24x0_i2c_bus {
+	int node;	/* device tree node */
+	int bus_num;	/* i2c bus number */
+	struct s3c24x0_i2c *regs;
+	enum periph_id id;
+};
+
 #endif /* _S3C24X0_I2C_H */
diff --git a/include/i2c.h b/include/i2c.h
index 16f099d..c60d075 100644
--- a/include/i2c.h
+++ b/include/i2c.h
@@ -262,4 +262,30 @@ extern int get_multi_scl_pin(void);
 extern int get_multi_sda_pin(void);
 extern int multi_i2c_init(void);
 #endif
+
+/**
+ * Get FDT values for i2c bus.
+ *
+ * @param blob  Device tree blbo
+ * @return the number of I2C bus
+ */
+void board_i2c_init(const void *blob);
+
+/**
+ * Find the I2C bus number by given a FDT I2C node.
+ *
+ * @param blob  Device tree blbo
+ * @param node  FDT I2C node to find
+ * @return the number of I2C bus (zero based), or -1 on error
+ */
+int i2c_get_bus_num_fdt(int node);
+
+/**
+ * Reset the I2C bus represented by the given a FDT I2C node.
+ *
+ * @param blob  Device tree blbo
+ * @param node  FDT I2C node to find
+ * @return 0 if port was reset, -1 if not found
+ */
+int i2c_reset_port_fdt(const void *blob, int node);
 #endif	/* _I2C_H_ */
-- 
1.7.4.4