linux-stable/drivers/gpu/drm/fsl-dcu/fsl_tcon.c
Fabio Estevam ef15d36154 drm/fsl-dcu: check for clk_prepare_enable() error
clk_prepare_enable() may fail, so we should better check its return
value.

Also place the of_node_put() function right after clk_prepare_enable(),
in order to avoid calling of_node_put() twice in case clk_prepare_enable()
fails.

Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Stefan Agner <stefan@agner.ch>
2017-02-07 20:28:04 -08:00

111 lines
2.4 KiB
C

/*
* Copyright 2015 Toradex AG
*
* Stefan Agner <stefan@agner.ch>
*
* Freescale TCON device driver
*
* 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.
*/
#include <linux/clk.h>
#include <linux/io.h>
#include <linux/mm.h>
#include <linux/of_address.h>
#include <linux/platform_device.h>
#include <linux/regmap.h>
#include "fsl_tcon.h"
void fsl_tcon_bypass_disable(struct fsl_tcon *tcon)
{
regmap_update_bits(tcon->regs, FSL_TCON_CTRL1,
FSL_TCON_CTRL1_TCON_BYPASS, 0);
}
void fsl_tcon_bypass_enable(struct fsl_tcon *tcon)
{
regmap_update_bits(tcon->regs, FSL_TCON_CTRL1,
FSL_TCON_CTRL1_TCON_BYPASS,
FSL_TCON_CTRL1_TCON_BYPASS);
}
static struct regmap_config fsl_tcon_regmap_config = {
.reg_bits = 32,
.reg_stride = 4,
.val_bits = 32,
.name = "tcon",
};
static int fsl_tcon_init_regmap(struct device *dev,
struct fsl_tcon *tcon,
struct device_node *np)
{
struct resource res;
void __iomem *regs;
if (of_address_to_resource(np, 0, &res))
return -EINVAL;
regs = devm_ioremap_resource(dev, &res);
if (IS_ERR(regs))
return PTR_ERR(regs);
tcon->regs = devm_regmap_init_mmio(dev, regs,
&fsl_tcon_regmap_config);
return PTR_ERR_OR_ZERO(tcon->regs);
}
struct fsl_tcon *fsl_tcon_init(struct device *dev)
{
struct fsl_tcon *tcon;
struct device_node *np;
int ret;
/* TCON node is not mandatory, some devices do not provide TCON */
np = of_parse_phandle(dev->of_node, "fsl,tcon", 0);
if (!np)
return NULL;
tcon = devm_kzalloc(dev, sizeof(*tcon), GFP_KERNEL);
if (!tcon)
goto err_node_put;
ret = fsl_tcon_init_regmap(dev, tcon, np);
if (ret) {
dev_err(dev, "Couldn't create the TCON regmap\n");
goto err_node_put;
}
tcon->ipg_clk = of_clk_get_by_name(np, "ipg");
if (IS_ERR(tcon->ipg_clk)) {
dev_err(dev, "Couldn't get the TCON bus clock\n");
goto err_node_put;
}
ret = clk_prepare_enable(tcon->ipg_clk);
if (ret) {
dev_err(dev, "Couldn't enable the TCON clock\n");
goto err_node_put;
}
of_node_put(np);
dev_info(dev, "Using TCON in bypass mode\n");
return tcon;
err_node_put:
of_node_put(np);
return NULL;
}
void fsl_tcon_free(struct fsl_tcon *tcon)
{
clk_disable_unprepare(tcon->ipg_clk);
clk_put(tcon->ipg_clk);
}