kernel-ark/sound/soc/tegra/tegra_asoc_utils.c
Stephen Warren 422650e65a ASoC: tegra: s/IS_ERR_OR_NULL/IS_ERR/ for clk_get_sys
A recent discussion on linux-arm-kernel noted that the value returned by
clk_get_sys is an opaque token, and not strictly a pointer; it is
meaningful only to the clock API, clients should not dereference the value,
and the clock API must accept any non-IS_ERR value it returned.

Hence, only IS_ERR is appropriate to interpret the result, not
IS_ERR_OR_NULL.

I checked that clk_get_sys in both ASoC's for-next and Tegra's for-next
do behave as described; NULL is not returned in the case of error.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
2011-01-13 14:18:03 +00:00

153 lines
3.1 KiB
C

/*
* tegra_asoc_utils.c - Harmony machine ASoC driver
*
* Author: Stephen Warren <swarren@nvidia.com>
* Copyright (C) 2010 - NVIDIA, Inc.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* version 2 as published by the Free Software Foundation.
*
* 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., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA
*
*/
#include <linux/clk.h>
#include <linux/err.h>
#include <linux/kernel.h>
#include "tegra_asoc_utils.h"
#define PREFIX "ASoC Tegra: "
static struct clk *clk_pll_a;
static struct clk *clk_pll_a_out0;
static struct clk *clk_cdev1;
static int set_baseclock, set_mclk;
int tegra_asoc_utils_set_rate(int srate, int mclk, int *mclk_change)
{
int new_baseclock;
int err;
switch (srate) {
case 11025:
case 22050:
case 44100:
case 88200:
new_baseclock = 56448000;
break;
case 8000:
case 16000:
case 32000:
case 48000:
case 64000:
case 96000:
new_baseclock = 73728000;
break;
default:
return -EINVAL;
}
*mclk_change = ((new_baseclock != set_baseclock) ||
(mclk != set_mclk));
if (!*mclk_change)
return 0;
set_baseclock = 0;
set_mclk = 0;
clk_disable(clk_cdev1);
clk_disable(clk_pll_a_out0);
clk_disable(clk_pll_a);
err = clk_set_rate(clk_pll_a, new_baseclock);
if (err) {
pr_err(PREFIX "Can't set pll_a rate: %d\n", err);
return err;
}
err = clk_set_rate(clk_pll_a_out0, mclk);
if (err) {
pr_err(PREFIX "Can't set pll_a_out0 rate: %d\n", err);
return err;
}
/* Don't set cdev1 rate; its locked to pll_a_out0 */
err = clk_enable(clk_pll_a);
if (err) {
pr_err(PREFIX "Can't enable pll_a: %d\n", err);
return err;
}
err = clk_enable(clk_pll_a_out0);
if (err) {
pr_err(PREFIX "Can't enable pll_a_out0: %d\n", err);
return err;
}
err = clk_enable(clk_cdev1);
if (err) {
pr_err(PREFIX "Can't enable cdev1: %d\n", err);
return err;
}
set_baseclock = new_baseclock;
set_mclk = mclk;
return 0;
}
int tegra_asoc_utils_init(void)
{
int ret;
clk_pll_a = clk_get_sys(NULL, "pll_a");
if (IS_ERR(clk_pll_a)) {
pr_err(PREFIX "Can't retrieve clk pll_a\n");
ret = PTR_ERR(clk_pll_a);
goto err;
}
clk_pll_a_out0 = clk_get_sys(NULL, "pll_a_out0");
if (IS_ERR(clk_pll_a_out0)) {
pr_err(PREFIX "Can't retrieve clk pll_a_out0\n");
ret = PTR_ERR(clk_pll_a_out0);
goto err_put_pll_a;
}
clk_cdev1 = clk_get_sys(NULL, "cdev1");
if (IS_ERR(clk_cdev1)) {
pr_err(PREFIX "Can't retrieve clk cdev1\n");
ret = PTR_ERR(clk_cdev1);
goto err_put_pll_a_out0;
}
return 0;
err_put_pll_a_out0:
clk_put(clk_pll_a_out0);
err_put_pll_a:
clk_put(clk_pll_a);
err:
return ret;
}
void tegra_asoc_utils_fini(void)
{
clk_put(clk_cdev1);
clk_put(clk_pll_a_out0);
clk_put(clk_pll_a);
}