linux_dsm_epyc7002/drivers/gpu/drm/sti/sti_vtg.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

488 lines
12 KiB
C

/*
* Copyright (C) STMicroelectronics SA 2014
* Authors: Benjamin Gaignard <benjamin.gaignard@st.com>
* Fabien Dessenne <fabien.dessenne@st.com>
* Vincent Abriou <vincent.abriou@st.com>
* for STMicroelectronics.
* License terms: GNU General Public License (GPL), version 2
*/
#include <linux/module.h>
#include <linux/notifier.h>
#include <linux/platform_device.h>
#include <drm/drmP.h>
#include "sti_vtg.h"
#define VTG_MODE_MASTER 0
#define VTG_MODE_SLAVE_BY_EXT0 1
/* registers offset */
#define VTG_MODE 0x0000
#define VTG_CLKLN 0x0008
#define VTG_HLFLN 0x000C
#define VTG_DRST_AUTOC 0x0010
#define VTG_VID_TFO 0x0040
#define VTG_VID_TFS 0x0044
#define VTG_VID_BFO 0x0048
#define VTG_VID_BFS 0x004C
#define VTG_HOST_ITS 0x0078
#define VTG_HOST_ITS_BCLR 0x007C
#define VTG_HOST_ITM_BCLR 0x0088
#define VTG_HOST_ITM_BSET 0x008C
#define VTG_H_HD_1 0x00C0
#define VTG_TOP_V_VD_1 0x00C4
#define VTG_BOT_V_VD_1 0x00C8
#define VTG_TOP_V_HD_1 0x00CC
#define VTG_BOT_V_HD_1 0x00D0
#define VTG_H_HD_2 0x00E0
#define VTG_TOP_V_VD_2 0x00E4
#define VTG_BOT_V_VD_2 0x00E8
#define VTG_TOP_V_HD_2 0x00EC
#define VTG_BOT_V_HD_2 0x00F0
#define VTG_H_HD_3 0x0100
#define VTG_TOP_V_VD_3 0x0104
#define VTG_BOT_V_VD_3 0x0108
#define VTG_TOP_V_HD_3 0x010C
#define VTG_BOT_V_HD_3 0x0110
#define VTG_H_HD_4 0x0120
#define VTG_TOP_V_VD_4 0x0124
#define VTG_BOT_V_VD_4 0x0128
#define VTG_TOP_V_HD_4 0x012c
#define VTG_BOT_V_HD_4 0x0130
#define VTG_IRQ_BOTTOM BIT(0)
#define VTG_IRQ_TOP BIT(1)
#define VTG_IRQ_MASK (VTG_IRQ_TOP | VTG_IRQ_BOTTOM)
/* Delay introduced by the HDMI in nb of pixel */
#define HDMI_DELAY (5)
/* Delay introduced by the DVO in nb of pixel */
#define DVO_DELAY (2)
/* delay introduced by the Arbitrary Waveform Generator in nb of pixels */
#define AWG_DELAY_HD (-9)
#define AWG_DELAY_ED (-8)
#define AWG_DELAY_SD (-7)
LIST_HEAD(vtg_lookup);
/*
* STI VTG register offset structure
*
*@h_hd: stores the VTG_H_HD_x register offset
*@top_v_vd: stores the VTG_TOP_V_VD_x register offset
*@bot_v_vd: stores the VTG_BOT_V_VD_x register offset
*@top_v_hd: stores the VTG_TOP_V_HD_x register offset
*@bot_v_hd: stores the VTG_BOT_V_HD_x register offset
*/
struct sti_vtg_regs_offs {
u32 h_hd;
u32 top_v_vd;
u32 bot_v_vd;
u32 top_v_hd;
u32 bot_v_hd;
};
#define VTG_MAX_SYNC_OUTPUT 4
static const struct sti_vtg_regs_offs vtg_regs_offs[VTG_MAX_SYNC_OUTPUT] = {
{ VTG_H_HD_1,
VTG_TOP_V_VD_1, VTG_BOT_V_VD_1, VTG_TOP_V_HD_1, VTG_BOT_V_HD_1 },
{ VTG_H_HD_2,
VTG_TOP_V_VD_2, VTG_BOT_V_VD_2, VTG_TOP_V_HD_2, VTG_BOT_V_HD_2 },
{ VTG_H_HD_3,
VTG_TOP_V_VD_3, VTG_BOT_V_VD_3, VTG_TOP_V_HD_3, VTG_BOT_V_HD_3 },
{ VTG_H_HD_4,
VTG_TOP_V_VD_4, VTG_BOT_V_VD_4, VTG_TOP_V_HD_4, VTG_BOT_V_HD_4 }
};
/*
* STI VTG synchronisation parameters structure
*
*@hsync: sample number falling and rising edge
*@vsync_line_top: vertical top field line number falling and rising edge
*@vsync_line_bot: vertical bottom field line number falling and rising edge
*@vsync_off_top: vertical top field sample number rising and falling edge
*@vsync_off_bot: vertical bottom field sample number rising and falling edge
*/
struct sti_vtg_sync_params {
u32 hsync;
u32 vsync_line_top;
u32 vsync_line_bot;
u32 vsync_off_top;
u32 vsync_off_bot;
};
/**
* STI VTG structure
*
* @dev: pointer to device driver
* @np: device node
* @regs: register mapping
* @sync_params: synchronisation parameters used to generate timings
* @irq: VTG irq
* @irq_status: store the IRQ status value
* @notifier_list: notifier callback
* @crtc: the CRTC for vblank event
* @slave: slave vtg
* @link: List node to link the structure in lookup list
*/
struct sti_vtg {
struct device *dev;
struct device_node *np;
void __iomem *regs;
struct sti_vtg_sync_params sync_params[VTG_MAX_SYNC_OUTPUT];
int irq;
u32 irq_status;
struct raw_notifier_head notifier_list;
struct drm_crtc *crtc;
struct sti_vtg *slave;
struct list_head link;
};
static void vtg_register(struct sti_vtg *vtg)
{
list_add_tail(&vtg->link, &vtg_lookup);
}
struct sti_vtg *of_vtg_find(struct device_node *np)
{
struct sti_vtg *vtg;
list_for_each_entry(vtg, &vtg_lookup, link) {
if (vtg->np == np)
return vtg;
}
return NULL;
}
static void vtg_reset(struct sti_vtg *vtg)
{
/* reset slave and then master */
if (vtg->slave)
vtg_reset(vtg->slave);
writel(1, vtg->regs + VTG_DRST_AUTOC);
}
static void vtg_set_output_window(void __iomem *regs,
const struct drm_display_mode *mode)
{
u32 video_top_field_start;
u32 video_top_field_stop;
u32 video_bottom_field_start;
u32 video_bottom_field_stop;
u32 xstart = sti_vtg_get_pixel_number(*mode, 0);
u32 ystart = sti_vtg_get_line_number(*mode, 0);
u32 xstop = sti_vtg_get_pixel_number(*mode, mode->hdisplay - 1);
u32 ystop = sti_vtg_get_line_number(*mode, mode->vdisplay - 1);
/* Set output window to fit the display mode selected */
video_top_field_start = (ystart << 16) | xstart;
video_top_field_stop = (ystop << 16) | xstop;
/* Only progressive supported for now */
video_bottom_field_start = video_top_field_start;
video_bottom_field_stop = video_top_field_stop;
writel(video_top_field_start, regs + VTG_VID_TFO);
writel(video_top_field_stop, regs + VTG_VID_TFS);
writel(video_bottom_field_start, regs + VTG_VID_BFO);
writel(video_bottom_field_stop, regs + VTG_VID_BFS);
}
static void vtg_set_hsync_vsync_pos(struct sti_vtg_sync_params *sync,
int delay,
const struct drm_display_mode *mode)
{
long clocksperline, start, stop;
u32 risesync_top, fallsync_top;
u32 risesync_offs_top, fallsync_offs_top;
clocksperline = mode->htotal;
/* Get the hsync position */
start = 0;
stop = mode->hsync_end - mode->hsync_start;
start += delay;
stop += delay;
if (start < 0)
start += clocksperline;
else if (start >= clocksperline)
start -= clocksperline;
if (stop < 0)
stop += clocksperline;
else if (stop >= clocksperline)
stop -= clocksperline;
sync->hsync = (stop << 16) | start;
/* Get the vsync position */
if (delay >= 0) {
risesync_top = 1;
fallsync_top = risesync_top;
fallsync_top += mode->vsync_end - mode->vsync_start;
fallsync_offs_top = (u32)delay;
risesync_offs_top = (u32)delay;
} else {
risesync_top = mode->vtotal;
fallsync_top = mode->vsync_end - mode->vsync_start;
fallsync_offs_top = clocksperline + delay;
risesync_offs_top = clocksperline + delay;
}
sync->vsync_line_top = (fallsync_top << 16) | risesync_top;
sync->vsync_off_top = (fallsync_offs_top << 16) | risesync_offs_top;
/* Only progressive supported for now */
sync->vsync_line_bot = sync->vsync_line_top;
sync->vsync_off_bot = sync->vsync_off_top;
}
static void vtg_set_mode(struct sti_vtg *vtg,
int type,
struct sti_vtg_sync_params *sync,
const struct drm_display_mode *mode)
{
unsigned int i;
if (vtg->slave)
vtg_set_mode(vtg->slave, VTG_MODE_SLAVE_BY_EXT0,
vtg->sync_params, mode);
/* Set the number of clock cycles per line */
writel(mode->htotal, vtg->regs + VTG_CLKLN);
/* Set Half Line Per Field (only progressive supported for now) */
writel(mode->vtotal * 2, vtg->regs + VTG_HLFLN);
/* Program output window */
vtg_set_output_window(vtg->regs, mode);
/* Set hsync and vsync position for HDMI */
vtg_set_hsync_vsync_pos(&sync[VTG_SYNC_ID_HDMI - 1], HDMI_DELAY, mode);
/* Set hsync and vsync position for HD DCS */
vtg_set_hsync_vsync_pos(&sync[VTG_SYNC_ID_HDDCS - 1], 0, mode);
/* Set hsync and vsync position for HDF */
vtg_set_hsync_vsync_pos(&sync[VTG_SYNC_ID_HDF - 1], AWG_DELAY_HD, mode);
/* Set hsync and vsync position for DVO */
vtg_set_hsync_vsync_pos(&sync[VTG_SYNC_ID_DVO - 1], DVO_DELAY, mode);
/* Progam the syncs outputs */
for (i = 0; i < VTG_MAX_SYNC_OUTPUT ; i++) {
writel(sync[i].hsync,
vtg->regs + vtg_regs_offs[i].h_hd);
writel(sync[i].vsync_line_top,
vtg->regs + vtg_regs_offs[i].top_v_vd);
writel(sync[i].vsync_line_bot,
vtg->regs + vtg_regs_offs[i].bot_v_vd);
writel(sync[i].vsync_off_top,
vtg->regs + vtg_regs_offs[i].top_v_hd);
writel(sync[i].vsync_off_bot,
vtg->regs + vtg_regs_offs[i].bot_v_hd);
}
/* mode */
writel(type, vtg->regs + VTG_MODE);
}
static void vtg_enable_irq(struct sti_vtg *vtg)
{
/* clear interrupt status and mask */
writel(0xFFFF, vtg->regs + VTG_HOST_ITS_BCLR);
writel(0xFFFF, vtg->regs + VTG_HOST_ITM_BCLR);
writel(VTG_IRQ_MASK, vtg->regs + VTG_HOST_ITM_BSET);
}
void sti_vtg_set_config(struct sti_vtg *vtg,
const struct drm_display_mode *mode)
{
/* write configuration */
vtg_set_mode(vtg, VTG_MODE_MASTER, vtg->sync_params, mode);
vtg_reset(vtg);
/* enable irq for the vtg vblank synchro */
if (vtg->slave)
vtg_enable_irq(vtg->slave);
else
vtg_enable_irq(vtg);
}
/**
* sti_vtg_get_line_number
*
* @mode: display mode to be used
* @y: line
*
* Return the line number according to the display mode taking
* into account the Sync and Back Porch information.
* Video frame line numbers start at 1, y starts at 0.
* In interlaced modes the start line is the field line number of the odd
* field, but y is still defined as a progressive frame.
*/
u32 sti_vtg_get_line_number(struct drm_display_mode mode, int y)
{
u32 start_line = mode.vtotal - mode.vsync_start + 1;
if (mode.flags & DRM_MODE_FLAG_INTERLACE)
start_line *= 2;
return start_line + y;
}
/**
* sti_vtg_get_pixel_number
*
* @mode: display mode to be used
* @x: row
*
* Return the pixel number according to the display mode taking
* into account the Sync and Back Porch information.
* Pixels are counted from 0.
*/
u32 sti_vtg_get_pixel_number(struct drm_display_mode mode, int x)
{
return mode.htotal - mode.hsync_start + x;
}
int sti_vtg_register_client(struct sti_vtg *vtg, struct notifier_block *nb,
struct drm_crtc *crtc)
{
if (vtg->slave)
return sti_vtg_register_client(vtg->slave, nb, crtc);
vtg->crtc = crtc;
return raw_notifier_chain_register(&vtg->notifier_list, nb);
}
int sti_vtg_unregister_client(struct sti_vtg *vtg, struct notifier_block *nb)
{
if (vtg->slave)
return sti_vtg_unregister_client(vtg->slave, nb);
return raw_notifier_chain_unregister(&vtg->notifier_list, nb);
}
static irqreturn_t vtg_irq_thread(int irq, void *arg)
{
struct sti_vtg *vtg = arg;
u32 event;
event = (vtg->irq_status & VTG_IRQ_TOP) ?
VTG_TOP_FIELD_EVENT : VTG_BOTTOM_FIELD_EVENT;
raw_notifier_call_chain(&vtg->notifier_list, event, vtg->crtc);
return IRQ_HANDLED;
}
static irqreturn_t vtg_irq(int irq, void *arg)
{
struct sti_vtg *vtg = arg;
vtg->irq_status = readl(vtg->regs + VTG_HOST_ITS);
writel(vtg->irq_status, vtg->regs + VTG_HOST_ITS_BCLR);
/* force sync bus write */
readl(vtg->regs + VTG_HOST_ITS);
return IRQ_WAKE_THREAD;
}
static int vtg_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct device_node *np;
struct sti_vtg *vtg;
struct resource *res;
int ret;
vtg = devm_kzalloc(dev, sizeof(*vtg), GFP_KERNEL);
if (!vtg)
return -ENOMEM;
vtg->dev = dev;
vtg->np = pdev->dev.of_node;
/* Get Memory ressources */
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!res) {
DRM_ERROR("Get memory resource failed\n");
return -ENOMEM;
}
vtg->regs = devm_ioremap_nocache(dev, res->start, resource_size(res));
np = of_parse_phandle(pdev->dev.of_node, "st,slave", 0);
if (np) {
vtg->slave = of_vtg_find(np);
if (!vtg->slave)
return -EPROBE_DEFER;
} else {
vtg->irq = platform_get_irq(pdev, 0);
if (vtg->irq < 0) {
DRM_ERROR("Failed to get VTG interrupt\n");
return vtg->irq;
}
RAW_INIT_NOTIFIER_HEAD(&vtg->notifier_list);
ret = devm_request_threaded_irq(dev, vtg->irq, vtg_irq,
vtg_irq_thread, IRQF_ONESHOT,
dev_name(dev), vtg);
if (ret < 0) {
DRM_ERROR("Failed to register VTG interrupt\n");
return ret;
}
}
vtg_register(vtg);
platform_set_drvdata(pdev, vtg);
DRM_INFO("%s %s\n", __func__, dev_name(vtg->dev));
return 0;
}
static int vtg_remove(struct platform_device *pdev)
{
return 0;
}
static const struct of_device_id vtg_of_match[] = {
{ .compatible = "st,vtg", },
{ /* sentinel */ }
};
MODULE_DEVICE_TABLE(of, vtg_of_match);
struct platform_driver sti_vtg_driver = {
.driver = {
.name = "sti-vtg",
.owner = THIS_MODULE,
.of_match_table = vtg_of_match,
},
.probe = vtg_probe,
.remove = vtg_remove,
};
MODULE_AUTHOR("Benjamin Gaignard <benjamin.gaignard@st.com>");
MODULE_DESCRIPTION("STMicroelectronics SoC DRM driver");
MODULE_LICENSE("GPL");