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linux-next/drivers/media/dvb-frontends/zl10039.c
Mauro Carvalho Chehab 8393796dfa [media] dvb-frontends: Don't use dynamic static allocation
Dynamic static allocation is evil, as Kernel stack is too low, and
compilation complains about it on some archs:
	drivers/media/dvb-frontends/bcm3510.c:230:1: warning: 'bcm3510_do_hab_cmd' uses dynamic stack allocation [enabled by default]
	drivers/media/dvb-frontends/itd1000.c:69:1: warning: 'itd1000_write_regs.constprop.0' uses dynamic stack allocation [enabled by default]
	drivers/media/dvb-frontends/mt312.c:126:1: warning: 'mt312_write' uses dynamic stack allocation [enabled by default]
	drivers/media/dvb-frontends/nxt200x.c:111:1: warning: 'nxt200x_writebytes' uses dynamic stack allocation [enabled by default]
	drivers/media/dvb-frontends/stb6100.c:216:1: warning: 'stb6100_write_reg_range.constprop.3' uses dynamic stack allocation [enabled by default]
	drivers/media/dvb-frontends/stv6110.c:98:1: warning: 'stv6110_write_regs' uses dynamic stack allocation [enabled by default]
	drivers/media/dvb-frontends/stv6110x.c:85:1: warning: 'stv6110x_write_regs' uses dynamic stack allocation [enabled by default]
	drivers/media/dvb-frontends/tda18271c2dd.c:147:1: warning: 'WriteRegs' uses dynamic stack allocation [enabled by default]
	drivers/media/dvb-frontends/zl10039.c:119:1: warning: 'zl10039_write' uses dynamic stack allocation [enabled by default]
Instead, let's enforce a limit for the buffer. Considering that I2C
transfers are generally limited, and that devices used on USB has a
max data length of 64 bytes for the control URBs.
So, it seem safe to use 64 bytes as the hard limit for all those devices.
 On most cases, the limit is a way lower than that, but this limit
is small enough to not affect the Kernel stack, and it is a no brain
limit, as using smaller ones would require to either carefully each
driver or to take a look on each datasheet.

Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
Reviewed-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>
2013-11-08 09:45:38 -02:00

318 lines
7.0 KiB
C

/*
* Driver for Zarlink ZL10039 DVB-S tuner
*
* Copyright 2007 Jan D. Louw <jd.louw@mweb.co.za>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
*
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <linux/module.h>
#include <linux/init.h>
#include <linux/string.h>
#include <linux/slab.h>
#include <linux/dvb/frontend.h>
#include "dvb_frontend.h"
#include "zl10039.h"
static int debug;
/* Max transfer size done by I2C transfer functions */
#define MAX_XFER_SIZE 64
#define dprintk(args...) \
do { \
if (debug) \
printk(KERN_DEBUG args); \
} while (0)
enum zl10039_model_id {
ID_ZL10039 = 1
};
struct zl10039_state {
struct i2c_adapter *i2c;
u8 i2c_addr;
u8 id;
};
enum zl10039_reg_addr {
PLL0 = 0,
PLL1,
PLL2,
PLL3,
RFFE,
BASE0,
BASE1,
BASE2,
LO0,
LO1,
LO2,
LO3,
LO4,
LO5,
LO6,
GENERAL
};
static int zl10039_read(const struct zl10039_state *state,
const enum zl10039_reg_addr reg, u8 *buf,
const size_t count)
{
u8 regbuf[] = { reg };
struct i2c_msg msg[] = {
{/* Write register address */
.addr = state->i2c_addr,
.flags = 0,
.buf = regbuf,
.len = 1,
}, {/* Read count bytes */
.addr = state->i2c_addr,
.flags = I2C_M_RD,
.buf = buf,
.len = count,
},
};
dprintk("%s\n", __func__);
if (i2c_transfer(state->i2c, msg, 2) != 2) {
dprintk("%s: i2c read error\n", __func__);
return -EREMOTEIO;
}
return 0; /* Success */
}
static int zl10039_write(struct zl10039_state *state,
const enum zl10039_reg_addr reg, const u8 *src,
const size_t count)
{
u8 buf[MAX_XFER_SIZE];
struct i2c_msg msg = {
.addr = state->i2c_addr,
.flags = 0,
.buf = buf,
.len = count + 1,
};
if (1 + count > sizeof(buf)) {
printk(KERN_WARNING
"%s: i2c wr reg=%04x: len=%zd is too big!\n",
KBUILD_MODNAME, reg, count);
return -EINVAL;
}
dprintk("%s\n", __func__);
/* Write register address and data in one go */
buf[0] = reg;
memcpy(&buf[1], src, count);
if (i2c_transfer(state->i2c, &msg, 1) != 1) {
dprintk("%s: i2c write error\n", __func__);
return -EREMOTEIO;
}
return 0; /* Success */
}
static inline int zl10039_readreg(struct zl10039_state *state,
const enum zl10039_reg_addr reg, u8 *val)
{
return zl10039_read(state, reg, val, 1);
}
static inline int zl10039_writereg(struct zl10039_state *state,
const enum zl10039_reg_addr reg,
const u8 val)
{
return zl10039_write(state, reg, &val, 1);
}
static int zl10039_init(struct dvb_frontend *fe)
{
struct zl10039_state *state = fe->tuner_priv;
int ret;
dprintk("%s\n", __func__);
if (fe->ops.i2c_gate_ctrl)
fe->ops.i2c_gate_ctrl(fe, 1);
/* Reset logic */
ret = zl10039_writereg(state, GENERAL, 0x40);
if (ret < 0) {
dprintk("Note: i2c write error normal when resetting the "
"tuner\n");
}
/* Wake up */
ret = zl10039_writereg(state, GENERAL, 0x01);
if (ret < 0) {
dprintk("Tuner power up failed\n");
return ret;
}
if (fe->ops.i2c_gate_ctrl)
fe->ops.i2c_gate_ctrl(fe, 0);
return 0;
}
static int zl10039_sleep(struct dvb_frontend *fe)
{
struct zl10039_state *state = fe->tuner_priv;
int ret;
dprintk("%s\n", __func__);
if (fe->ops.i2c_gate_ctrl)
fe->ops.i2c_gate_ctrl(fe, 1);
ret = zl10039_writereg(state, GENERAL, 0x80);
if (ret < 0) {
dprintk("Tuner sleep failed\n");
return ret;
}
if (fe->ops.i2c_gate_ctrl)
fe->ops.i2c_gate_ctrl(fe, 0);
return 0;
}
static int zl10039_set_params(struct dvb_frontend *fe)
{
struct dtv_frontend_properties *c = &fe->dtv_property_cache;
struct zl10039_state *state = fe->tuner_priv;
u8 buf[6];
u8 bf;
u32 fbw;
u32 div;
int ret;
dprintk("%s\n", __func__);
dprintk("Set frequency = %d, symbol rate = %d\n",
c->frequency, c->symbol_rate);
/* Assumed 10.111 MHz crystal oscillator */
/* Cancelled num/den 80 to prevent overflow */
div = (c->frequency * 1000) / 126387;
fbw = (c->symbol_rate * 27) / 32000;
/* Cancelled num/den 10 to prevent overflow */
bf = ((fbw * 5088) / 1011100) - 1;
/*PLL divider*/
buf[0] = (div >> 8) & 0x7f;
buf[1] = (div >> 0) & 0xff;
/*Reference divider*/
/* Select reference ratio of 80 */
buf[2] = 0x1D;
/*PLL test modes*/
buf[3] = 0x40;
/*RF Control register*/
buf[4] = 0x6E; /* Bypass enable */
/*Baseband filter cutoff */
buf[5] = bf;
/* Open i2c gate */
if (fe->ops.i2c_gate_ctrl)
fe->ops.i2c_gate_ctrl(fe, 1);
/* BR = 10, Enable filter adjustment */
ret = zl10039_writereg(state, BASE1, 0x0A);
if (ret < 0)
goto error;
/* Write new config values */
ret = zl10039_write(state, PLL0, buf, sizeof(buf));
if (ret < 0)
goto error;
/* BR = 10, Disable filter adjustment */
ret = zl10039_writereg(state, BASE1, 0x6A);
if (ret < 0)
goto error;
/* Close i2c gate */
if (fe->ops.i2c_gate_ctrl)
fe->ops.i2c_gate_ctrl(fe, 0);
return 0;
error:
dprintk("Error setting tuner\n");
return ret;
}
static int zl10039_release(struct dvb_frontend *fe)
{
struct zl10039_state *state = fe->tuner_priv;
dprintk("%s\n", __func__);
kfree(state);
fe->tuner_priv = NULL;
return 0;
}
static struct dvb_tuner_ops zl10039_ops = {
.release = zl10039_release,
.init = zl10039_init,
.sleep = zl10039_sleep,
.set_params = zl10039_set_params,
};
struct dvb_frontend *zl10039_attach(struct dvb_frontend *fe,
u8 i2c_addr, struct i2c_adapter *i2c)
{
struct zl10039_state *state = NULL;
dprintk("%s\n", __func__);
state = kmalloc(sizeof(struct zl10039_state), GFP_KERNEL);
if (state == NULL)
goto error;
state->i2c = i2c;
state->i2c_addr = i2c_addr;
/* Open i2c gate */
if (fe->ops.i2c_gate_ctrl)
fe->ops.i2c_gate_ctrl(fe, 1);
/* check if this is a valid tuner */
if (zl10039_readreg(state, GENERAL, &state->id) < 0) {
/* Close i2c gate */
if (fe->ops.i2c_gate_ctrl)
fe->ops.i2c_gate_ctrl(fe, 0);
goto error;
}
/* Close i2c gate */
if (fe->ops.i2c_gate_ctrl)
fe->ops.i2c_gate_ctrl(fe, 0);
state->id = state->id & 0x0f;
switch (state->id) {
case ID_ZL10039:
strcpy(fe->ops.tuner_ops.info.name,
"Zarlink ZL10039 DVB-S tuner");
break;
default:
dprintk("Chip ID=%x does not match a known type\n", state->id);
goto error;
}
memcpy(&fe->ops.tuner_ops, &zl10039_ops, sizeof(struct dvb_tuner_ops));
fe->tuner_priv = state;
dprintk("Tuner attached @ i2c address 0x%02x\n", i2c_addr);
return fe;
error:
kfree(state);
return NULL;
}
EXPORT_SYMBOL(zl10039_attach);
module_param(debug, int, 0644);
MODULE_PARM_DESC(debug, "Turn on/off frontend debugging (default:off).");
MODULE_DESCRIPTION("Zarlink ZL10039 DVB-S tuner driver");
MODULE_AUTHOR("Jan D. Louw <jd.louw@mweb.co.za>");
MODULE_LICENSE("GPL");