[U-Boot] [PATCH v3 7/9] tegra: i2c: Add function to know about current bus

4 May 2013

From: Simon Glass sjg@chromium.org
Rather than using a variable in various places, add a single function,
tegra_i2c_get_bus(), which returns a pointer to information about a
bus.
This will make it easier to move to the new i2c framework.
Signed-off-by: Simon Glass sjg@chromium.org
---
- changes for v2:
  new in v2
  posted from Simon Glass here:
  http://patchwork.ozlabs.org/patch/195569/
added to this patchserie, just rebased to current head
---
 drivers/i2c/tegra_i2c.c | 78 ++++++++++++++++++++++++++++++++++++++-----------
 1 Datei geändert, 61 Zeilen hinzugefügt(+), 17 Zeilen entfernt(-)

diff --git a/drivers/i2c/tegra_i2c.c b/drivers/i2c/tegra_i2c.c
index ca71cd3..8fa1cda 100644
--- a/drivers/i2c/tegra_i2c.c
+++ b/drivers/i2c/tegra_i2c.c
@@ -284,7 +284,8 @@ exit:
    return error;
 }
-static int tegra_i2c_write_data(u32 addr, u8 *data, u32 len)
+static int tegra_i2c_write_data(struct i2c_bus *bus, u32 addr, u8 *data,
+				u32 len)
 {
    int error;
    struct i2c_trans_info trans_info;
@@ -295,14 +296,15 @@ static int tegra_i2c_write_data(u32 addr, u8 *data, u32 len)
    trans_info.num_bytes = len;
    trans_info.is_10bit_address = 0;
-	error = send_recv_packets(&i2c_controllers[i2c_bus_num], &trans_info);
+	error = send_recv_packets(bus, &trans_info);
    if (error)
    	debug("tegra_i2c_write_data: Error (%d) !!!\n", error);
return error;
 }
-static int tegra_i2c_read_data(u32 addr, u8 *data, u32 len)
+static int tegra_i2c_read_data(struct i2c_bus *bus, u32 addr, u8 *data,
+			       u32 len)
 {
    int error;
    struct i2c_trans_info trans_info;
@@ -313,7 +315,7 @@ static int tegra_i2c_read_data(u32 addr, u8 *data, u32 len)
    trans_info.num_bytes = len;
    trans_info.is_10bit_address = 0;
-	error = send_recv_packets(&i2c_controllers[i2c_bus_num], &trans_info);
+	error = send_recv_packets(bus, &trans_info);
    if (error)
    	debug("tegra_i2c_read_data: Error (%d) !!!\n", error);
@@ -324,18 +326,48 @@ static int tegra_i2c_read_data(u32 addr, u8 *data, u32 len)
 #error "Please enable device tree support to use this driver"
 #endif
+/**
+ * Check that a bus number is valid and return a pointer to it
+ *
+ * @param bus_num	Bus number to check / return
+ * @return pointer to bus, if valid, else NULL
+ */
+static struct i2c_bus *tegra_i2c_get_bus(unsigned int bus_num)
+{
+	struct i2c_bus *bus;
+
+	if (bus_num >= TEGRA_I2C_NUM_CONTROLLERS) {
+		debug("%s: Invalid bus number %u\n", __func__, bus_num);
+		return NULL;
+	}
+	bus = &i2c_controllers[bus_num];
+	if (!bus->inited) {
+		debug("%s: Bus %u not available\n", __func__, bus_num);
+		return NULL;
+	}
+
+	return bus;
+}
+
 unsigned int i2c_get_bus_speed(void)
 {
-	return i2c_controllers[i2c_bus_num].speed;
+	struct i2c_bus *bus;
+
+	bus = tegra_i2c_get_bus(i2c_bus_num);
+	if (!bus)
+		return 0;
+	return bus->speed;
 }
int i2c_set_bus_speed(unsigned int speed)
 {
-	struct i2c_bus *i2c_bus;
+	struct i2c_bus *bus;
-	i2c_bus = &i2c_controllers[i2c_bus_num];
-	i2c_bus->speed = speed;
-	i2c_init_controller(i2c_bus);
+	bus = tegra_i2c_get_bus(i2c_bus_num);
+	if (!bus)
+		return 0;
+	bus->speed = speed;
+	i2c_init_controller(bus);
return 0;
 }
@@ -458,7 +490,7 @@ void i2c_init(int speed, int slaveaddr)
 }
/* i2c write version without the register address */
-int i2c_write_data(uchar chip, uchar *buffer, int len)
+int i2c_write_data(struct i2c_bus *bus, uchar chip, uchar *buffer, int len)
 {
    int rc;
@@ -470,7 +502,7 @@ int i2c_write_data(uchar chip, uchar *buffer, int len)
    debug("\n");
/* Shift 7-bit address over for lower-level i2c functions */
-	rc = tegra_i2c_write_data(chip << 1, buffer, len);
+	rc = tegra_i2c_write_data(bus, chip << 1, buffer, len);
    if (rc)
    	debug("i2c_write_data(): rc=%d\n", rc);
@@ -478,13 +510,13 @@ int i2c_write_data(uchar chip, uchar *buffer, int len)
 }
/* i2c read version without the register address */
-int i2c_read_data(uchar chip, uchar *buffer, int len)
+int i2c_read_data(struct i2c_bus *bus, uchar chip, uchar *buffer, int len)
 {
    int rc;
debug("inside i2c_read_data():\n");
    /* Shift 7-bit address over for lower-level i2c functions */
-	rc = tegra_i2c_read_data(chip << 1, buffer, len);
+	rc = tegra_i2c_read_data(bus, chip << 1, buffer, len);
    if (rc) {
    	debug("i2c_read_data(): rc=%d\n", rc);
    	return rc;
@@ -502,12 +534,16 @@ int i2c_read_data(uchar chip, uchar *buffer, int len)
 /* Probe to see if a chip is present. */
 int i2c_probe(uchar chip)
 {
+	struct i2c_bus *bus;
    int rc;
    uchar reg;
debug("i2c_probe: addr=0x%x\n", chip);
+	bus = tegra_i2c_get_bus(i2c_get_bus_num());
+	if (!bus)
+		return 1;
    reg = 0;
-	rc = i2c_write_data(chip, &reg, 1);
+	rc = i2c_write_data(bus, chip, &reg, 1);
    if (rc) {
    	debug("Error probing 0x%x.\n", chip);
    	return 1;
@@ -524,11 +560,15 @@ static int i2c_addr_ok(const uint addr, const int alen)
 /* Read bytes */
 int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len)
 {
+	struct i2c_bus *bus;
    uint offset;
    int i;
debug("i2c_read: chip=0x%x, addr=0x%x, len=0x%x\n",
    			chip, addr, len);
+	bus = tegra_i2c_get_bus(i2c_bus_num);
+	if (!bus)
+		return 1;
    if (!i2c_addr_ok(addr, alen)) {
    	debug("i2c_read: Bad address %x.%d.\n", addr, alen);
    	return 1;
@@ -540,13 +580,13 @@ int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len)
    			data[alen - i - 1] =
    				(addr + offset) >> (8 * i);
    		}
-			if (i2c_write_data(chip, data, alen)) {
+			if (i2c_write_data(bus, chip, data, alen)) {
    			debug("i2c_read: error sending (0x%x)\n",
    				addr);
    			return 1;
    		}
    	}
-		if (i2c_read_data(chip, buffer + offset, 1)) {
+		if (i2c_read_data(bus, chip, buffer + offset, 1)) {
    		debug("i2c_read: error reading (0x%x)\n", addr);
    		return 1;
    	}
@@ -558,11 +598,15 @@ int i2c_read(uchar chip, uint addr, int alen, uchar *buffer, int len)
 /* Write bytes */
 int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len)
 {
+	struct i2c_bus *bus;
    uint offset;
    int i;
debug("i2c_write: chip=0x%x, addr=0x%x, len=0x%x\n",
    			chip, addr, len);
+	bus = tegra_i2c_get_bus(i2c_bus_num);
+	if (!bus)
+		return 1;
    if (!i2c_addr_ok(addr, alen)) {
    	debug("i2c_write: Bad address %x.%d.\n", addr, alen);
    	return 1;
@@ -572,7 +616,7 @@ int i2c_write(uchar chip, uint addr, int alen, uchar *buffer, int len)
    	for (i = 0; i < alen; i++)
    		data[alen - i - 1] = (addr + offset) >> (8 * i);
    	data[alen] = buffer[offset];
-		if (i2c_write_data(chip, data, alen + 1)) {
+		if (i2c_write_data(bus, chip, data, alen + 1)) {
    		debug("i2c_write: error sending (0x%x)\n", addr);
    		return 1;
    	}
-- 
1.7.11.7


    

[U-Boot] [PATCH v3 7/9] tegra: i2c: Add function to know about current bus

Heiko Schocher