Re: [PATCH 1/2] mn88473: calculate the IF register values

[Antti Palosaari]

On 01/13/2015 01:23 AM, Benjamin Larsson wrote:

Add xtal as a configuration parameter so it can be used
in the IF register value calculation. If not set in the
configuration then use a default value.

Signed-off-by: Benjamin Larsson <benja...@southpole.se>

Reviewed-by: Antti Palosaari <cr...@iki.fi>

Antti

---
  drivers/media/dvb-frontends/mn88473.h        |  6 ++++++
  drivers/staging/media/mn88473/mn88473.c      | 26 +++++++++++---------------
  drivers/staging/media/mn88473/mn88473_priv.h |  1 +
  3 files changed, 18 insertions(+), 15 deletions(-)

diff --git a/drivers/media/dvb-frontends/mn88473.h 
b/drivers/media/dvb-frontends/mn88473.h
index a373ec9..c717ebed 100644
--- a/drivers/media/dvb-frontends/mn88473.h
+++ b/drivers/media/dvb-frontends/mn88473.h
@@ -33,6 +33,12 @@ struct mn88473_config {
         * DVB frontend.
         */
        struct dvb_frontend **fe;
+
+       /*
+        * Xtal frequency.
+        * Hz
+        */
+       u32 xtal;
  };

  #endif
diff --git a/drivers/staging/media/mn88473/mn88473.c 
b/drivers/staging/media/mn88473/mn88473.c
index 1659335..b65e519 100644
--- a/drivers/staging/media/mn88473/mn88473.c
+++ b/drivers/staging/media/mn88473/mn88473.c
@@ -30,6 +30,7 @@ static int mn88473_set_frontend(struct dvb_frontend *fe)
        struct dtv_frontend_properties *c = &fe->dtv_property_cache;
        int ret, i;
        u32 if_frequency;
+       u64 tmp;
        u8 delivery_system_val, if_val[3], bw_val[7];

        dev_dbg(&client->dev,
@@ -63,15 +64,12 @@ static int mn88473_set_frontend(struct dvb_frontend *fe)
        case SYS_DVBT2:
                if (c->bandwidth_hz <= 6000000) {
                        /* IF 3570000 Hz, BW 6000000 Hz */
-                       memcpy(if_val, "\x24\x8e\x8a", 3);
                        memcpy(bw_val, "\xe9\x55\x55\x1c\x29\x1c\x29", 7);
                } else if (c->bandwidth_hz <= 7000000) {
                        /* IF 4570000 Hz, BW 7000000 Hz */
-                       memcpy(if_val, "\x2e\xcb\xfb", 3);
                        memcpy(bw_val, "\xc8\x00\x00\x17\x0a\x17\x0a", 7);
                } else if (c->bandwidth_hz <= 8000000) {
                        /* IF 4570000 Hz, BW 8000000 Hz */
-                       memcpy(if_val, "\x2e\xcb\xfb", 3);
                        memcpy(bw_val, "\xaf\x00\x00\x11\xec\x11\xec", 7);
                } else {
                        ret = -EINVAL;
@@ -80,7 +78,6 @@ static int mn88473_set_frontend(struct dvb_frontend *fe)
                break;
        case SYS_DVBC_ANNEX_A:
                /* IF 5070000 Hz, BW 8000000 Hz */
-               memcpy(if_val, "\x33\xea\xb3", 3);
                memcpy(bw_val, "\xaf\x00\x00\x11\xec\x11\xec", 7);
                break;
        default:
@@ -105,17 +102,12 @@ static int mn88473_set_frontend(struct dvb_frontend *fe)
                if_frequency = 0;
        }

-       switch (if_frequency) {
-       case 3570000:
-       case 4570000:
-       case 5070000:
-               break;
-       default:
-               dev_err(&client->dev, "IF frequency %d not supported\n",
-                               if_frequency);
-               ret = -EINVAL;
-               goto err;
-       }
+       /* Calculate IF registers ( (1<<24)*IF / Xtal ) */
+       tmp =  div_u64(if_frequency * (u64)(1<<24) + (dev->xtal / 2),
+                                  dev->xtal);
+       if_val[0] = ((tmp >> 16) & 0xff);
+       if_val[1] = ((tmp >>  8) & 0xff);
+       if_val[2] = ((tmp >>  0) & 0xff);

        ret = regmap_write(dev->regmap[2], 0x05, 0x00);
        ret = regmap_write(dev->regmap[2], 0xfb, 0x13);
@@ -352,6 +344,10 @@ static int mn88473_probe(struct i2c_client *client,
        }

        dev->i2c_wr_max = config->i2c_wr_max;
+       if (!config->xtal)
+               dev->xtal = 25000000;
+       else
+               dev->xtal = config->xtal;
        dev->client[0] = client;
        dev->regmap[0] = regmap_init_i2c(dev->client[0], &regmap_config);
        if (IS_ERR(dev->regmap[0])) {
diff --git a/drivers/staging/media/mn88473/mn88473_priv.h 
b/drivers/staging/media/mn88473/mn88473_priv.h
index 78af112..ef6f013 100644
--- a/drivers/staging/media/mn88473/mn88473_priv.h
+++ b/drivers/staging/media/mn88473/mn88473_priv.h
@@ -31,6 +31,7 @@ struct mn88473_dev {
        u16 i2c_wr_max;
        fe_delivery_system_t delivery_system;
        bool warm; /* FW running */
+       u32 xtal;
  };

  #endif

--
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