tegra: i2c: Add function to know about current bus

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>

diff --git a/drivers/i2c/tegra_i2c.c b/drivers/i2c/tegra_i2c.c
index ca71cd3ee4ce60dd48dc23363cdab67d3c042736..8fa1cdac0252fe79d8f281384ba80a6a28583237 100644 (file)
--- 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;
                }