V4L/DVB (11342): au0828: better document i2c registers
Devin Heitmueller [Wed, 1 Apr 2009 02:58:49 +0000 (23:58 -0300)]
Change the #define entries for the i2c registers to be more meaningful, and
document the valid values for the registers.  Note that this changeset makes
*no* functional changes to the code.

Signed-off-by: Devin Heitmueller <dheitmueller@linuxtv.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/video/au0828/au0828-i2c.c
drivers/media/video/au0828/au0828-reg.h

index f9a958d..27dcfc6 100644 (file)
@@ -39,13 +39,15 @@ MODULE_PARM_DESC(i2c_scan, "scan i2c bus at insmod time");
 static inline int i2c_slave_did_write_ack(struct i2c_adapter *i2c_adap)
 {
        struct au0828_dev *dev = i2c_adap->algo_data;
-       return au0828_read(dev, REG_201) & 0x08 ? 0 : 1;
+       return au0828_read(dev, AU0828_I2C_STATUS_201) &
+               AU0828_I2C_STATUS_NO_WRITE_ACK ? 0 : 1;
 }
 
 static inline int i2c_slave_did_read_ack(struct i2c_adapter *i2c_adap)
 {
        struct au0828_dev *dev = i2c_adap->algo_data;
-       return au0828_read(dev, REG_201) & 0x02 ? 0 : 1;
+       return au0828_read(dev, AU0828_I2C_STATUS_201) &
+               AU0828_I2C_STATUS_NO_READ_ACK ? 0 : 1;
 }
 
 static int i2c_wait_read_ack(struct i2c_adapter *i2c_adap)
@@ -67,7 +69,8 @@ static int i2c_wait_read_ack(struct i2c_adapter *i2c_adap)
 static inline int i2c_is_read_busy(struct i2c_adapter *i2c_adap)
 {
        struct au0828_dev *dev = i2c_adap->algo_data;
-       return au0828_read(dev, REG_201) & 0x01 ? 0 : 1;
+       return au0828_read(dev, AU0828_I2C_STATUS_201) &
+               AU0828_I2C_STATUS_READ_DONE ? 0 : 1;
 }
 
 static int i2c_wait_read_done(struct i2c_adapter *i2c_adap)
@@ -89,7 +92,8 @@ static int i2c_wait_read_done(struct i2c_adapter *i2c_adap)
 static inline int i2c_is_write_done(struct i2c_adapter *i2c_adap)
 {
        struct au0828_dev *dev = i2c_adap->algo_data;
-       return au0828_read(dev, REG_201) & 0x04 ? 1 : 0;
+       return au0828_read(dev, AU0828_I2C_STATUS_201) &
+               AU0828_I2C_STATUS_WRITE_DONE ? 1 : 0;
 }
 
 static int i2c_wait_write_done(struct i2c_adapter *i2c_adap)
@@ -111,7 +115,8 @@ static int i2c_wait_write_done(struct i2c_adapter *i2c_adap)
 static inline int i2c_is_busy(struct i2c_adapter *i2c_adap)
 {
        struct au0828_dev *dev = i2c_adap->algo_data;
-       return au0828_read(dev, REG_201) & 0x10 ? 1 : 0;
+       return au0828_read(dev, AU0828_I2C_STATUS_201) &
+               AU0828_I2C_STATUS_BUSY ? 1 : 0;
 }
 
 static int i2c_wait_done(struct i2c_adapter *i2c_adap)
@@ -139,19 +144,21 @@ static int i2c_sendbytes(struct i2c_adapter *i2c_adap,
 
        dprintk(4, "%s()\n", __func__);
 
-       au0828_write(dev, REG_2FF, 0x01);
+       au0828_write(dev, AU0828_I2C_MULTIBYTE_MODE_2FF, 0x01);
 
        /* FIXME: There is a problem with i2c communications with xc5000 that
           requires us to slow down the i2c clock until we have a better
           strategy (such as using the secondary i2c bus to do firmware
           loading */
        if ((msg->addr << 1) == 0xc2)
-               au0828_write(dev, REG_202, 0x40);
+               au0828_write(dev, AU0828_I2C_CLK_DIVIDER_202,
+                            AU0828_I2C_CLK_30KHZ);
        else
-               au0828_write(dev, REG_202, 0x07);
+               au0828_write(dev, AU0828_I2C_CLK_DIVIDER_202,
+                            AU0828_I2C_CLK_250KHZ);
 
        /* Hardware needs 8 bit addresses */
-       au0828_write(dev, REG_203, msg->addr << 1);
+       au0828_write(dev, AU0828_I2C_DEST_ADDR_203, msg->addr << 1);
 
        dprintk(4, "SEND: %02x\n", msg->addr);
 
@@ -163,7 +170,9 @@ static int i2c_sendbytes(struct i2c_adapter *i2c_adap,
                   actual bytes to the bus, just do a read check.  This is
                   consistent with how I saw i2c device checking done in the
                   USB trace of the Windows driver */
-               au0828_write(dev, REG_200, 0x20);
+               au0828_write(dev, AU0828_I2C_TRIGGER_200,
+                            AU0828_I2C_TRIGGER_READ);
+
                if (!i2c_wait_done(i2c_adap))
                        return -EIO;
 
@@ -177,7 +186,7 @@ static int i2c_sendbytes(struct i2c_adapter *i2c_adap,
 
                dprintk(4, " %02x\n", msg->buf[i]);
 
-               au0828_write(dev, REG_205, msg->buf[i]);
+               au0828_write(dev, AU0828_I2C_WRITE_FIFO_205, msg->buf[i]);
 
                strobe++;
                i++;
@@ -186,9 +195,12 @@ static int i2c_sendbytes(struct i2c_adapter *i2c_adap,
 
                        /* Strobe the byte into the bus */
                        if (i < msg->len)
-                               au0828_write(dev, REG_200, 0x41);
+                               au0828_write(dev, AU0828_I2C_TRIGGER_200,
+                                            AU0828_I2C_TRIGGER_WRITE |
+                                            AU0828_I2C_TRIGGER_HOLD);
                        else
-                               au0828_write(dev, REG_200, 0x01);
+                               au0828_write(dev, AU0828_I2C_TRIGGER_200,
+                                            AU0828_I2C_TRIGGER_WRITE);
 
                        /* Reset strobe trigger */
                        strobe = 0;
@@ -216,25 +228,29 @@ static int i2c_readbytes(struct i2c_adapter *i2c_adap,
 
        dprintk(4, "%s()\n", __func__);
 
-       au0828_write(dev, REG_2FF, 0x01);
+       au0828_write(dev, AU0828_I2C_MULTIBYTE_MODE_2FF, 0x01);
 
        /* FIXME: There is a problem with i2c communications with xc5000 that
           requires us to slow down the i2c clock until we have a better
           strategy (such as using the secondary i2c bus to do firmware
           loading */
        if ((msg->addr << 1) == 0xc2)
-               au0828_write(dev, REG_202, 0x40);
+               au0828_write(dev, AU0828_I2C_CLK_DIVIDER_202,
+                            AU0828_I2C_CLK_30KHZ);
        else
-               au0828_write(dev, REG_202, 0x07);
+               au0828_write(dev, AU0828_I2C_CLK_DIVIDER_202,
+                            AU0828_I2C_CLK_250KHZ);
 
        /* Hardware needs 8 bit addresses */
-       au0828_write(dev, REG_203, msg->addr << 1);
+       au0828_write(dev, AU0828_I2C_DEST_ADDR_203, msg->addr << 1);
 
        dprintk(4, " RECV:\n");
 
        /* Deal with i2c_scan */
        if (msg->len == 0) {
-               au0828_write(dev, REG_200, 0x20);
+               au0828_write(dev, AU0828_I2C_TRIGGER_200,
+                            AU0828_I2C_TRIGGER_READ);
+
                if (i2c_wait_read_ack(i2c_adap))
                        return -EIO;
                return 0;
@@ -245,14 +261,18 @@ static int i2c_readbytes(struct i2c_adapter *i2c_adap,
                i++;
 
                if (i < msg->len)
-                       au0828_write(dev, REG_200, 0x60);
+                       au0828_write(dev, AU0828_I2C_TRIGGER_200,
+                                    AU0828_I2C_TRIGGER_READ |
+                                    AU0828_I2C_TRIGGER_HOLD);
                else
-                       au0828_write(dev, REG_200, 0x20);
+                       au0828_write(dev, AU0828_I2C_TRIGGER_200,
+                                    AU0828_I2C_TRIGGER_READ);
 
                if (!i2c_wait_read_done(i2c_adap))
                        return -EIO;
 
-               msg->buf[i-1] = au0828_read(dev, REG_209) & 0xff;
+               msg->buf[i-1] = au0828_read(dev, AU0828_I2C_READ_FIFO_209) &
+                       0xff;
 
                dprintk(4, " %02x\n", msg->buf[i-1]);
        }
index b15e4a3..c39f3d2 100644 (file)
 #define AU0828_SENSORCTRL_100 0x100
 #define AU0828_SENSORCTRL_VBI_103 0x103
 
-#define REG_200 0x200
-#define REG_201 0x201
-#define REG_202 0x202
-#define REG_203 0x203
-#define REG_205 0x205
-#define REG_209 0x209
-#define REG_2FF 0x2ff
+/* I2C registers */
+#define AU0828_I2C_TRIGGER_200         0x200
+#define AU0828_I2C_STATUS_201          0x201
+#define AU0828_I2C_CLK_DIVIDER_202     0x202
+#define AU0828_I2C_DEST_ADDR_203       0x203
+#define AU0828_I2C_WRITE_FIFO_205      0x205
+#define AU0828_I2C_READ_FIFO_209       0x209
+#define AU0828_I2C_MULTIBYTE_MODE_2FF  0x2ff
 
 /* Audio registers */
 #define AU0828_AUDIOCTRL_50C 0x50C
 
 #define REG_600 0x600
+
+/*********************************************************************/
+/* Here are constants for values associated with the above registers */
+
+/* I2C Trigger (Reg 0x200) */
+#define AU0828_I2C_TRIGGER_WRITE       0x01
+#define AU0828_I2C_TRIGGER_READ                0x20
+#define AU0828_I2C_TRIGGER_HOLD                0x40
+
+/* I2C Status (Reg 0x201) */
+#define AU0828_I2C_STATUS_READ_DONE    0x01
+#define AU0828_I2C_STATUS_NO_READ_ACK  0x02
+#define AU0828_I2C_STATUS_WRITE_DONE   0x04
+#define AU0828_I2C_STATUS_NO_WRITE_ACK 0x08
+#define AU0828_I2C_STATUS_BUSY         0x10
+
+/* I2C Clock Divider (Reg 0x202) */
+#define AU0828_I2C_CLK_250KHZ 0x07
+#define AU0828_I2C_CLK_100KHZ 0x14
+#define AU0828_I2C_CLK_30KHZ  0x40