V4L/DVB (6536): Add a hint for boards without unique USB ID

This patch adds a function to allow trying to detect boards that shares
the generic IDs.

The current detection method is based at eeprom checksum.

Signed-off-by: Mauro Carvalho Chehab <mchehab@infradead.org>

1 files changed, 34 insertions, 40 deletions

diff --git a/drivers/media/video/em28xx/em28xx-i2c.c b/drivers/media/video/em28xx/em28xx-i2c.c
index a33878e08799..e2003455f2b2 100644
--- a/drivers/media/video/em28xx/em28xx-i2c.c
+++ b/drivers/media/video/em28xx/em28xx-i2c.c
@@ -292,6 +292,31 @@ static int em28xx_i2c_xfer(struct i2c_adapter *i2c_adap,
         return rc;
 }
 
+/* based on linux/sunrpc/svcauth.h and linux/hash.h
+ * The original hash function returns a different value, if arch is x86_64
+ *  or i386.
+ */
+static inline unsigned long em28xx_hash_mem(char *buf, int length, int bits)
+{
+        unsigned long hash = 0;
+        unsigned long l = 0;
+        int len = 0;
+        unsigned char c;
+        do {
+                if (len == length) {
+                        c = (char)len;
+                        len = -1;
+                } else
+                        c = *buf++;
+                l = (l << 8) | c;
+                len++;
+                if ((len & (32 / 8 - 1)) == 0)
+                        hash = ((hash^l) * 0x9e370001UL);
+        } while (len);
+
+        return (hash >> (32 - bits)) & 0xffffffffUL;
+}
+
 static int em28xx_i2c_eeprom(struct em28xx *dev, unsigned char *eedata, int len)
 {
         unsigned char buf, *p = eedata;
@@ -335,7 +360,11 @@ static int em28xx_i2c_eeprom(struct em28xx *dev, unsigned char *eedata, int len)
                         printk("\n");
         }
 
-        printk(KERN_INFO "EEPROM ID= 0x%08x\n", em_eeprom->id);
+        if (em_eeprom->id == 0x9567eb1a)
+                dev->hash = em28xx_hash_mem(eedata, len, 32);
+
+        printk(KERN_INFO "EEPROM ID= 0x%08x, hash = 0x%08lx\n",
+               em_eeprom->id, dev->hash);
         printk(KERN_INFO "Vendor/Product ID= %04x:%04x\n", em_eeprom->vendor_ID,
                em_eeprom->product_ID);
 
@@ -392,43 +421,6 @@ static u32 functionality(struct i2c_adapter *adap)
 }
 
 
-static int em28xx_tuner_callback(void *ptr, int command, int arg)
-{
-        int rc = 0;
-        struct em28xx *dev = ptr;
-
-        if (dev->tuner_type != TUNER_XC2028)
-                return 0;
-
-        switch (command) {
-        case XC2028_TUNER_RESET:
-                /* FIXME: This is device-dependent */
-                dev->em28xx_write_regs_req(dev, 0x00, 0x48, "\x00", 1);
-                dev->em28xx_write_regs_req(dev, 0x00, 0x12, "\x67", 1);
-
-                msleep(140);
-                break;
-        }
-        return rc;
-}
-
-static int em28xx_set_tuner(int check_eeprom, struct i2c_client *client)
-{
-        struct em28xx *dev = client->adapter->algo_data;
-        struct tuner_setup tun_setup;
-
-        if (dev->has_tuner) {
-                tun_setup.mode_mask = T_ANALOG_TV | T_RADIO;
-                tun_setup.type = dev->tuner_type;
-                tun_setup.addr = dev->tuner_addr;
-                tun_setup.tuner_callback = em28xx_tuner_callback;
-
-                em28xx_i2c_call_clients(dev, TUNER_SET_TYPE_ADDR, &tun_setup);
-        }
-
-        return (0);
-}
-
 /*
  * attach_inform()
  * gets called when a device attaches to the i2c bus
@@ -487,9 +479,11 @@ static int attach_inform(struct i2c_client *client)
                         break;
 
                 default:
+                        if (!dev->tuner_addr)
+                                dev->tuner_addr = client->addr;
+
                         dprintk1(1,"attach inform: detected I2C address %x\n", client->addr << 1);
-                        dev->tuner_addr = client->addr;
-                        em28xx_set_tuner(-1, client);
+
         }
 
         return 0;