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Subject[PATCH] media: tua6100: Remove some ugly defines
Date
As reported by Stephen:

> After merging the i2c tree, today's linux-next build (x86_64 allmodconfig)
> produced this warning:
>
> drivers/media/dvb-frontends/tua6100.c: In function 'tua6100_set_params':
> drivers/media/dvb-frontends/tua6100.c:71: warning: "_P" redefined
> #define _P 32
>
> In file included from include/acpi/platform/aclinux.h:54,
> from include/acpi/platform/acenv.h:152,
> from include/acpi/acpi.h:22,
> from include/linux/acpi.h:21,
> from include/linux/i2c.h:17,
> from drivers/media/dvb-frontends/tua6100.h:22,
> from drivers/media/dvb-frontends/tua6100.c:24:
> include/linux/ctype.h:14: note: this is the location of the previous definition
> #define _P 0x10 /* punct */
>
> Exposed by commit
>
> 5213d7efc8ec ("i2c: acpi: export i2c_acpi_find_adapter_by_handle")
>
> Since that included <linux/acpi.h> from <linux/i2c.h>
>
> Originally introduced by commit
>
> 00be2e7c6415 ("V4L/DVB (4606): Add driver for TUA6100")
>
> The _P in <linux/ctype.h> has existed since before git.

The addition of include <linux/ctype.h> at the I2C code caused a
breakage at the tua6100 driver. The reason is that the code there
used defines for 3 parameters used at the calculus for the
divide ratio.

In thesis, those are board-dependent, but, as there's just one
driver using it (ttpci/budget-av), there was no need to make
the code more generic. While it sounds unlikely that this old
DVB-S frontend would ever be used on new projects, one might
some day come with a variant using a different configuration. So,
let's do the right thing and store those values at its private
struct.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
---
drivers/media/dvb-frontends/tua6100.c | 38 ++++++++++++++++-----------
1 file changed, 23 insertions(+), 15 deletions(-)

diff --git a/drivers/media/dvb-frontends/tua6100.c b/drivers/media/dvb-frontends/tua6100.c
index b233b7be0b84..2990eb3fd475 100644
--- a/drivers/media/dvb-frontends/tua6100.c
+++ b/drivers/media/dvb-frontends/tua6100.c
@@ -31,11 +31,24 @@

#include "tua6100.h"

+/**
+ * struct tua6100_priv - tuner's private data
+ *
+ * @i2c_address: I2C address
+ * @i2c: pointer to struct i2c_adapter
+ * @frequency: tuned frequency
+ * @prescaler_div: divide ratio of the prescaler (32 or 64)
+ * @ref_div: reference frequency divider
+ * @ref_inp: reference frequency input (XTAL osc)
+ */
struct tua6100_priv {
/* i2c details */
int i2c_address;
struct i2c_adapter *i2c;
u32 frequency;
+ int prescaler_div;
+ int ref_div;
+ u32 ref_inp;
};

static void tua6100_release(struct dvb_frontend *fe)
@@ -75,10 +88,6 @@ static int tua6100_set_params(struct dvb_frontend *fe)
struct i2c_msg msg1 = { .addr = priv->i2c_address, .flags = 0, .buf = reg1, .len = 4 };
struct i2c_msg msg2 = { .addr = priv->i2c_address, .flags = 0, .buf = reg2, .len = 3 };

-#define _R 4
-#define _P 32
-#define _ri 4000000
-
// setup register 0
if (c->frequency < 2000000)
reg0[1] = 0x03;
@@ -91,14 +100,14 @@ static int tua6100_set_params(struct dvb_frontend *fe)
else
reg1[1] = 0x0c;

- if (_P == 64)
+ if (priv->prescaler_div == 64)
reg1[1] |= 0x40;
if (c->frequency >= 1525000)
reg1[1] |= 0x80;

// register 2
- reg2[1] = (_R >> 8) & 0x03;
- reg2[2] = _R;
+ reg2[1] = (priv->ref_div >> 8) & 0x03;
+ reg2[2] = priv->ref_div;
if (c->frequency < 1455000)
reg2[1] |= 0x1c;
else if (c->frequency < 1630000)
@@ -110,19 +119,15 @@ static int tua6100_set_params(struct dvb_frontend *fe)
* The N divisor ratio (note: c->frequency is in kHz, but we
* need it in Hz)
*/
- prediv = (c->frequency * _R) / (_ri / 1000);
- div = prediv / _P;
+ prediv = (c->frequency * priv->ref_div) / (priv->ref_inp / 1000);
+ div = prediv / priv->prescaler_div;
reg1[1] |= (div >> 9) & 0x03;
reg1[2] = div >> 1;
reg1[3] = (div << 7);
- priv->frequency = ((div * _P) * (_ri / 1000)) / _R;
+ priv->frequency = ((div * priv->prescaler_div) * (priv->ref_inp / 1000)) / priv->ref_div;

// Finally, calculate and store the value for A
- reg1[3] |= (prediv - (div*_P)) & 0x7f;
-
-#undef _R
-#undef _P
-#undef _ri
+ reg1[3] |= (prediv - (div * priv->prescaler_div)) & 0x7f;

if (fe->ops.i2c_gate_ctrl)
fe->ops.i2c_gate_ctrl(fe, 1);
@@ -189,6 +194,9 @@ struct dvb_frontend *tua6100_attach(struct dvb_frontend *fe, int addr, struct i2

priv->i2c_address = addr;
priv->i2c = i2c;
+ priv->ref_div = 4;
+ priv->prescaler_div = 32;
+ priv->ref_inp = 4000000;

memcpy(&fe->ops.tuner_ops, &tua6100_tuner_ops, sizeof(struct dvb_tuner_ops));
fe->tuner_priv = priv;
--
2.21.0
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