linux/drivers/gpu/drm/tilcdc/tilcdc_tfp410.c
Arnd Bergmann 287980e49f remove lots of IS_ERR_VALUE abuses
Most users of IS_ERR_VALUE() in the kernel are wrong, as they
pass an 'int' into a function that takes an 'unsigned long'
argument. This happens to work because the type is sign-extended
on 64-bit architectures before it gets converted into an
unsigned type.

However, anything that passes an 'unsigned short' or 'unsigned int'
argument into IS_ERR_VALUE() is guaranteed to be broken, as are
8-bit integers and types that are wider than 'unsigned long'.

Andrzej Hajda has already fixed a lot of the worst abusers that
were causing actual bugs, but it would be nice to prevent any
users that are not passing 'unsigned long' arguments.

This patch changes all users of IS_ERR_VALUE() that I could find
on 32-bit ARM randconfig builds and x86 allmodconfig. For the
moment, this doesn't change the definition of IS_ERR_VALUE()
because there are probably still architecture specific users
elsewhere.

Almost all the warnings I got are for files that are better off
using 'if (err)' or 'if (err < 0)'.
The only legitimate user I could find that we get a warning for
is the (32-bit only) freescale fman driver, so I did not remove
the IS_ERR_VALUE() there but changed the type to 'unsigned long'.
For 9pfs, I just worked around one user whose calling conventions
are so obscure that I did not dare change the behavior.

I was using this definition for testing:

 #define IS_ERR_VALUE(x) ((unsigned long*)NULL == (typeof (x)*)NULL && \
       unlikely((unsigned long long)(x) >= (unsigned long long)(typeof(x))-MAX_ERRNO))

which ends up making all 16-bit or wider types work correctly with
the most plausible interpretation of what IS_ERR_VALUE() was supposed
to return according to its users, but also causes a compile-time
warning for any users that do not pass an 'unsigned long' argument.

I suggested this approach earlier this year, but back then we ended
up deciding to just fix the users that are obviously broken. After
the initial warning that caused me to get involved in the discussion
(fs/gfs2/dir.c) showed up again in the mainline kernel, Linus
asked me to send the whole thing again.

[ Updated the 9p parts as per Al Viro  - Linus ]

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Andrzej Hajda <a.hajda@samsung.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: https://lkml.org/lkml/2016/1/7/363
Link: https://lkml.org/lkml/2016/5/27/486
Acked-by: Srinivas Kandagatla <srinivas.kandagatla@linaro.org> # For nvmem part
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-27 15:26:11 -07:00

402 lines
9.7 KiB
C

/*
* Copyright (C) 2012 Texas Instruments
* Author: Rob Clark <robdclark@gmail.com>
*
* 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, see <http://www.gnu.org/licenses/>.
*/
#include <linux/i2c.h>
#include <linux/gpio.h>
#include <linux/of_gpio.h>
#include <linux/pinctrl/pinmux.h>
#include <linux/pinctrl/consumer.h>
#include "tilcdc_drv.h"
struct tfp410_module {
struct tilcdc_module base;
struct i2c_adapter *i2c;
int gpio;
};
#define to_tfp410_module(x) container_of(x, struct tfp410_module, base)
static const struct tilcdc_panel_info dvi_info = {
.ac_bias = 255,
.ac_bias_intrpt = 0,
.dma_burst_sz = 16,
.bpp = 16,
.fdd = 0x80,
.tft_alt_mode = 0,
.sync_edge = 0,
.sync_ctrl = 1,
.raster_order = 0,
};
/*
* Encoder:
*/
struct tfp410_encoder {
struct drm_encoder base;
struct tfp410_module *mod;
int dpms;
};
#define to_tfp410_encoder(x) container_of(x, struct tfp410_encoder, base)
static void tfp410_encoder_dpms(struct drm_encoder *encoder, int mode)
{
struct tfp410_encoder *tfp410_encoder = to_tfp410_encoder(encoder);
if (tfp410_encoder->dpms == mode)
return;
if (mode == DRM_MODE_DPMS_ON) {
DBG("Power on");
gpio_direction_output(tfp410_encoder->mod->gpio, 1);
} else {
DBG("Power off");
gpio_direction_output(tfp410_encoder->mod->gpio, 0);
}
tfp410_encoder->dpms = mode;
}
static void tfp410_encoder_prepare(struct drm_encoder *encoder)
{
tfp410_encoder_dpms(encoder, DRM_MODE_DPMS_OFF);
tilcdc_crtc_set_panel_info(encoder->crtc, &dvi_info);
}
static void tfp410_encoder_commit(struct drm_encoder *encoder)
{
tfp410_encoder_dpms(encoder, DRM_MODE_DPMS_ON);
}
static void tfp410_encoder_mode_set(struct drm_encoder *encoder,
struct drm_display_mode *mode,
struct drm_display_mode *adjusted_mode)
{
/* nothing needed */
}
static const struct drm_encoder_funcs tfp410_encoder_funcs = {
.destroy = drm_encoder_cleanup,
};
static const struct drm_encoder_helper_funcs tfp410_encoder_helper_funcs = {
.dpms = tfp410_encoder_dpms,
.prepare = tfp410_encoder_prepare,
.commit = tfp410_encoder_commit,
.mode_set = tfp410_encoder_mode_set,
};
static struct drm_encoder *tfp410_encoder_create(struct drm_device *dev,
struct tfp410_module *mod)
{
struct tfp410_encoder *tfp410_encoder;
struct drm_encoder *encoder;
int ret;
tfp410_encoder = devm_kzalloc(dev->dev, sizeof(*tfp410_encoder),
GFP_KERNEL);
if (!tfp410_encoder) {
dev_err(dev->dev, "allocation failed\n");
return NULL;
}
tfp410_encoder->dpms = DRM_MODE_DPMS_OFF;
tfp410_encoder->mod = mod;
encoder = &tfp410_encoder->base;
encoder->possible_crtcs = 1;
ret = drm_encoder_init(dev, encoder, &tfp410_encoder_funcs,
DRM_MODE_ENCODER_TMDS, NULL);
if (ret < 0)
goto fail;
drm_encoder_helper_add(encoder, &tfp410_encoder_helper_funcs);
return encoder;
fail:
drm_encoder_cleanup(encoder);
return NULL;
}
/*
* Connector:
*/
struct tfp410_connector {
struct drm_connector base;
struct drm_encoder *encoder; /* our connected encoder */
struct tfp410_module *mod;
};
#define to_tfp410_connector(x) container_of(x, struct tfp410_connector, base)
static void tfp410_connector_destroy(struct drm_connector *connector)
{
drm_connector_unregister(connector);
drm_connector_cleanup(connector);
}
static enum drm_connector_status tfp410_connector_detect(
struct drm_connector *connector,
bool force)
{
struct tfp410_connector *tfp410_connector = to_tfp410_connector(connector);
if (drm_probe_ddc(tfp410_connector->mod->i2c))
return connector_status_connected;
return connector_status_unknown;
}
static int tfp410_connector_get_modes(struct drm_connector *connector)
{
struct tfp410_connector *tfp410_connector = to_tfp410_connector(connector);
struct edid *edid;
int ret = 0;
edid = drm_get_edid(connector, tfp410_connector->mod->i2c);
drm_mode_connector_update_edid_property(connector, edid);
if (edid) {
ret = drm_add_edid_modes(connector, edid);
kfree(edid);
}
return ret;
}
static int tfp410_connector_mode_valid(struct drm_connector *connector,
struct drm_display_mode *mode)
{
struct tilcdc_drm_private *priv = connector->dev->dev_private;
/* our only constraints are what the crtc can generate: */
return tilcdc_crtc_mode_valid(priv->crtc, mode);
}
static struct drm_encoder *tfp410_connector_best_encoder(
struct drm_connector *connector)
{
struct tfp410_connector *tfp410_connector = to_tfp410_connector(connector);
return tfp410_connector->encoder;
}
static const struct drm_connector_funcs tfp410_connector_funcs = {
.destroy = tfp410_connector_destroy,
.dpms = drm_helper_connector_dpms,
.detect = tfp410_connector_detect,
.fill_modes = drm_helper_probe_single_connector_modes,
};
static const struct drm_connector_helper_funcs tfp410_connector_helper_funcs = {
.get_modes = tfp410_connector_get_modes,
.mode_valid = tfp410_connector_mode_valid,
.best_encoder = tfp410_connector_best_encoder,
};
static struct drm_connector *tfp410_connector_create(struct drm_device *dev,
struct tfp410_module *mod, struct drm_encoder *encoder)
{
struct tfp410_connector *tfp410_connector;
struct drm_connector *connector;
int ret;
tfp410_connector = devm_kzalloc(dev->dev, sizeof(*tfp410_connector),
GFP_KERNEL);
if (!tfp410_connector) {
dev_err(dev->dev, "allocation failed\n");
return NULL;
}
tfp410_connector->encoder = encoder;
tfp410_connector->mod = mod;
connector = &tfp410_connector->base;
drm_connector_init(dev, connector, &tfp410_connector_funcs,
DRM_MODE_CONNECTOR_DVID);
drm_connector_helper_add(connector, &tfp410_connector_helper_funcs);
connector->polled = DRM_CONNECTOR_POLL_CONNECT |
DRM_CONNECTOR_POLL_DISCONNECT;
connector->interlace_allowed = 0;
connector->doublescan_allowed = 0;
ret = drm_mode_connector_attach_encoder(connector, encoder);
if (ret)
goto fail;
drm_connector_register(connector);
return connector;
fail:
tfp410_connector_destroy(connector);
return NULL;
}
/*
* Module:
*/
static int tfp410_modeset_init(struct tilcdc_module *mod, struct drm_device *dev)
{
struct tfp410_module *tfp410_mod = to_tfp410_module(mod);
struct tilcdc_drm_private *priv = dev->dev_private;
struct drm_encoder *encoder;
struct drm_connector *connector;
encoder = tfp410_encoder_create(dev, tfp410_mod);
if (!encoder)
return -ENOMEM;
connector = tfp410_connector_create(dev, tfp410_mod, encoder);
if (!connector)
return -ENOMEM;
priv->encoders[priv->num_encoders++] = encoder;
priv->connectors[priv->num_connectors++] = connector;
return 0;
}
static const struct tilcdc_module_ops tfp410_module_ops = {
.modeset_init = tfp410_modeset_init,
};
/*
* Device:
*/
static struct of_device_id tfp410_of_match[];
static int tfp410_probe(struct platform_device *pdev)
{
struct device_node *node = pdev->dev.of_node;
struct device_node *i2c_node;
struct tfp410_module *tfp410_mod;
struct tilcdc_module *mod;
struct pinctrl *pinctrl;
uint32_t i2c_phandle;
int ret = -EINVAL;
/* bail out early if no DT data: */
if (!node) {
dev_err(&pdev->dev, "device-tree data is missing\n");
return -ENXIO;
}
tfp410_mod = devm_kzalloc(&pdev->dev, sizeof(*tfp410_mod), GFP_KERNEL);
if (!tfp410_mod)
return -ENOMEM;
mod = &tfp410_mod->base;
pdev->dev.platform_data = mod;
tilcdc_module_init(mod, "tfp410", &tfp410_module_ops);
pinctrl = devm_pinctrl_get_select_default(&pdev->dev);
if (IS_ERR(pinctrl))
dev_warn(&pdev->dev, "pins are not configured\n");
if (of_property_read_u32(node, "i2c", &i2c_phandle)) {
dev_err(&pdev->dev, "could not get i2c bus phandle\n");
goto fail;
}
mod->preferred_bpp = dvi_info.bpp;
i2c_node = of_find_node_by_phandle(i2c_phandle);
if (!i2c_node) {
dev_err(&pdev->dev, "could not get i2c bus node\n");
goto fail;
}
tfp410_mod->i2c = of_find_i2c_adapter_by_node(i2c_node);
if (!tfp410_mod->i2c) {
dev_err(&pdev->dev, "could not get i2c\n");
of_node_put(i2c_node);
goto fail;
}
of_node_put(i2c_node);
tfp410_mod->gpio = of_get_named_gpio_flags(node, "powerdn-gpio",
0, NULL);
if (tfp410_mod->gpio < 0) {
dev_warn(&pdev->dev, "No power down GPIO\n");
} else {
ret = gpio_request(tfp410_mod->gpio, "DVI_PDn");
if (ret) {
dev_err(&pdev->dev, "could not get DVI_PDn gpio\n");
goto fail_adapter;
}
}
return 0;
fail_adapter:
i2c_put_adapter(tfp410_mod->i2c);
fail:
tilcdc_module_cleanup(mod);
return ret;
}
static int tfp410_remove(struct platform_device *pdev)
{
struct tilcdc_module *mod = dev_get_platdata(&pdev->dev);
struct tfp410_module *tfp410_mod = to_tfp410_module(mod);
i2c_put_adapter(tfp410_mod->i2c);
gpio_free(tfp410_mod->gpio);
tilcdc_module_cleanup(mod);
return 0;
}
static struct of_device_id tfp410_of_match[] = {
{ .compatible = "ti,tilcdc,tfp410", },
{ },
};
struct platform_driver tfp410_driver = {
.probe = tfp410_probe,
.remove = tfp410_remove,
.driver = {
.owner = THIS_MODULE,
.name = "tfp410",
.of_match_table = tfp410_of_match,
},
};
int __init tilcdc_tfp410_init(void)
{
return platform_driver_register(&tfp410_driver);
}
void __exit tilcdc_tfp410_fini(void)
{
platform_driver_unregister(&tfp410_driver);
}