[PATCH 2/6] HID: picoLCD: rework hid-fbdev interaction
From: Bruno PrÃmont
Date: Sun Aug 19 2012 - 13:32:43 EST
Split out all FB related data out of struct picolcd_data into a struct
picolcd_fb_data that is allocated with fb_info. This way fb_info may
cleanly outlive struct picolcd_data for as long as needed for its last
user to drop his reference.
Access to struct picolcd_data is now protected with struct
picolcd_fb_data's lock and tile update reports are only generated
while picolcd_fbdata->picolcd is not NULL and is not marked as failed
(which indicates unplug in progress).
Signed-off-by: Bruno PrÃmont <bonbons@xxxxxxxxxxxxxxxxx>
---
drivers/hid/hid-picolcd.h | 19 +++-
drivers/hid/hid-picolcd_fb.c | 216 ++++++++++++++++++++++--------------------
2 files changed, 126 insertions(+), 109 deletions(-)
diff --git a/drivers/hid/hid-picolcd.h b/drivers/hid/hid-picolcd.h
index 9200be1..dc4c795 100644
--- a/drivers/hid/hid-picolcd.h
+++ b/drivers/hid/hid-picolcd.h
@@ -90,11 +90,6 @@ struct picolcd_data {
#ifdef CONFIG_HID_PICOLCD_FB
/* Framebuffer stuff */
- u8 fb_update_rate;
- u8 fb_bpp;
- u8 fb_force;
- u8 *fb_vbitmap; /* local copy of what was sent to PicoLCD */
- u8 *fb_bitmap; /* framebuffer */
struct fb_info *fb_info;
#endif /* CONFIG_HID_PICOLCD_FB */
#ifdef CONFIG_HID_PICOLCD_LCD
@@ -119,9 +114,21 @@ struct picolcd_data {
int status;
#define PICOLCD_BOOTLOADER 1
#define PICOLCD_FAILED 2
-#define PICOLCD_READY_FB 4
};
+#ifdef CONFIG_HID_PICOLCD_FB
+struct picolcd_fb_data {
+ /* Framebuffer stuff */
+ spinlock_t lock;
+ struct picolcd_data *picolcd;
+ u8 update_rate;
+ u8 bpp;
+ u8 force;
+ u8 ready;
+ u8 *vbitmap; /* local copy of what was sent to PicoLCD */
+ u8 *bitmap; /* framebuffer */
+};
+#endif /* CONFIG_HID_PICOLCD_FB */
/* Find a given report */
#define picolcd_in_report(id, dev) picolcd_report(id, dev, HID_INPUT_REPORT)
diff --git a/drivers/hid/hid-picolcd_fb.c b/drivers/hid/hid-picolcd_fb.c
index 4d8e22c..5905bbd 100644
--- a/drivers/hid/hid-picolcd_fb.c
+++ b/drivers/hid/hid-picolcd_fb.c
@@ -98,19 +98,26 @@ static const struct fb_var_screeninfo picolcdfb_var = {
};
/* Send a given tile to PicoLCD */
-static int picolcd_fb_send_tile(struct hid_device *hdev, int chip, int tile)
+static int picolcd_fb_send_tile(struct picolcd_data *data, u8 *vbitmap,
+ int chip, int tile)
{
- struct picolcd_data *data = hid_get_drvdata(hdev);
- struct hid_report *report1 = picolcd_out_report(REPORT_LCD_CMD_DATA, hdev);
- struct hid_report *report2 = picolcd_out_report(REPORT_LCD_DATA, hdev);
+ struct hid_report *report1, *report2;
unsigned long flags;
u8 *tdata;
int i;
- if (!report1 || report1->maxfield != 1 || !report2 || report2->maxfield != 1)
+ report1 = picolcd_out_report(REPORT_LCD_CMD_DATA, data->hdev);
+ if (!report1 || report1->maxfield != 1)
+ return -ENODEV;
+ report2 = picolcd_out_report(REPORT_LCD_DATA, data->hdev);
+ if (!report2 || report2->maxfield != 1)
return -ENODEV;
spin_lock_irqsave(&data->lock, flags);
+ if ((data->status & PICOLCD_FAILED)) {
+ spin_unlock_irqrestore(&data->lock, flags);
+ return -ENODEV;
+ }
hid_set_field(report1->field[0], 0, chip << 2);
hid_set_field(report1->field[0], 1, 0x02);
hid_set_field(report1->field[0], 2, 0x00);
@@ -128,7 +135,7 @@ static int picolcd_fb_send_tile(struct hid_device *hdev, int chip, int tile)
hid_set_field(report2->field[0], 2, 0x00);
hid_set_field(report2->field[0], 3, 32);
- tdata = data->fb_vbitmap + (tile * 4 + chip) * 64;
+ tdata = vbitmap + (tile * 4 + chip) * 64;
for (i = 0; i < 64; i++)
if (i < 32)
hid_set_field(report1->field[0], 11 + i, tdata[i]);
@@ -189,6 +196,7 @@ void picolcd_fb_refresh(struct picolcd_data *data)
int picolcd_fb_reset(struct picolcd_data *data, int clear)
{
struct hid_report *report = picolcd_out_report(REPORT_LCD_CMD, data->hdev);
+ struct picolcd_fb_data *fbdata = data->fb_info->par;
int i, j;
unsigned long flags;
static const u8 mapcmd[8] = { 0x00, 0x02, 0x00, 0x64, 0x3f, 0x00, 0x64, 0xc0 };
@@ -207,20 +215,19 @@ int picolcd_fb_reset(struct picolcd_data *data, int clear)
hid_set_field(report->field[0], j, 0);
usbhid_submit_report(data->hdev, report, USB_DIR_OUT);
}
-
- data->status |= PICOLCD_READY_FB;
spin_unlock_irqrestore(&data->lock, flags);
- if (data->fb_bitmap) {
- if (clear) {
- memset(data->fb_vbitmap, 0, PICOLCDFB_SIZE);
- memset(data->fb_bitmap, 0, PICOLCDFB_SIZE*data->fb_bpp);
- }
- data->fb_force = 1;
+ if (clear) {
+ memset(fbdata->vbitmap, 0, PICOLCDFB_SIZE);
+ memset(fbdata->bitmap, 0, PICOLCDFB_SIZE*fbdata->bpp);
}
+ fbdata->force = 1;
/* schedule first output of framebuffer */
- picolcd_fb_refresh(data);
+ if (fbdata->ready)
+ schedule_delayed_work(&data->fb_info->deferred_work, 0);
+ else
+ fbdata->ready = 1;
return 0;
}
@@ -230,20 +237,15 @@ static void picolcd_fb_update(struct fb_info *info)
{
int chip, tile, n;
unsigned long flags;
+ struct picolcd_fb_data *fbdata = info->par;
struct picolcd_data *data;
mutex_lock(&info->lock);
- data = info->par;
- if (!data)
- goto out;
- spin_lock_irqsave(&data->lock, flags);
- if (!(data->status & PICOLCD_READY_FB)) {
- spin_unlock_irqrestore(&data->lock, flags);
- picolcd_fb_reset(data, 0);
- } else {
- spin_unlock_irqrestore(&data->lock, flags);
- }
+ spin_lock_irqsave(&fbdata->lock, flags);
+ if (!fbdata->ready && fbdata->picolcd)
+ picolcd_fb_reset(fbdata->picolcd, 0);
+ spin_unlock_irqrestore(&fbdata->lock, flags);
/*
* Translate the framebuffer into the format needed by the PicoLCD.
@@ -254,32 +256,38 @@ static void picolcd_fb_update(struct fb_info *info)
*/
n = 0;
for (chip = 0; chip < 4; chip++)
- for (tile = 0; tile < 8; tile++)
- if (picolcd_fb_update_tile(data->fb_vbitmap,
- data->fb_bitmap, data->fb_bpp, chip, tile) ||
- data->fb_force) {
- n += 2;
- if (n >= HID_OUTPUT_FIFO_SIZE / 2) {
- mutex_unlock(&info->lock);
- usbhid_wait_io(data->hdev);
- mutex_lock(&info->lock);
- data = info->par;
- if (!data)
- goto out;
- spin_lock_irqsave(&data->lock, flags);
- if (data->status & PICOLCD_FAILED) {
- spin_unlock_irqrestore(&data->lock, flags);
- goto out;
- }
- spin_unlock_irqrestore(&data->lock, flags);
- n = 0;
- }
- picolcd_fb_send_tile(data->hdev, chip, tile);
+ for (tile = 0; tile < 8; tile++) {
+ if (!fbdata->force && !picolcd_fb_update_tile(
+ fbdata->vbitmap, fbdata->bitmap,
+ fbdata->bpp, chip, tile))
+ continue;
+ n += 2;
+ if (n >= HID_OUTPUT_FIFO_SIZE / 2) {
+ spin_lock_irqsave(&fbdata->lock, flags);
+ data = fbdata->picolcd;
+ spin_unlock_irqrestore(&fbdata->lock, flags);
+ mutex_unlock(&info->lock);
+ if (!data)
+ return;
+ usbhid_wait_io(data->hdev);
+ mutex_lock(&info->lock);
+ n = 0;
}
- data->fb_force = false;
+ spin_lock_irqsave(&fbdata->lock, flags);
+ data = fbdata->picolcd;
+ spin_unlock_irqrestore(&fbdata->lock, flags);
+ if (!data || picolcd_fb_send_tile(data,
+ fbdata->vbitmap, chip, tile))
+ goto out;
+ }
+ fbdata->force = false;
if (n) {
+ spin_lock_irqsave(&fbdata->lock, flags);
+ data = fbdata->picolcd;
+ spin_unlock_irqrestore(&fbdata->lock, flags);
mutex_unlock(&info->lock);
- usbhid_wait_io(data->hdev);
+ if (data)
+ usbhid_wait_io(data->hdev);
return;
}
out:
@@ -336,20 +344,22 @@ static ssize_t picolcd_fb_write(struct fb_info *info, const char __user *buf,
static int picolcd_fb_blank(int blank, struct fb_info *info)
{
- if (!info->par)
- return -ENODEV;
/* We let fb notification do this for us via lcd/backlight device */
return 0;
}
static void picolcd_fb_destroy(struct fb_info *info)
{
+ struct picolcd_fb_data *fbdata = info->par;
+
/* make sure no work is deferred */
fb_deferred_io_cleanup(info);
+ /* No thridparty should ever unregister our framebuffer! */
+ WARN_ON(fbdata->picolcd != NULL);
+
vfree((u8 *)info->fix.smem_start);
framebuffer_release(info);
- printk(KERN_DEBUG "picolcd_fb_destroy(%p)\n", info);
}
static int picolcd_fb_check_var(struct fb_var_screeninfo *var, struct fb_info *info)
@@ -376,17 +386,15 @@ static int picolcd_fb_check_var(struct fb_var_screeninfo *var, struct fb_info *i
static int picolcd_set_par(struct fb_info *info)
{
- struct picolcd_data *data = info->par;
+ struct picolcd_fb_data *fbdata = info->par;
u8 *tmp_fb, *o_fb;
- if (!data)
- return -ENODEV;
- if (info->var.bits_per_pixel == data->fb_bpp)
+ if (info->var.bits_per_pixel == fbdata->bpp)
return 0;
/* switch between 1/8 bit depths */
if (info->var.bits_per_pixel != 1 && info->var.bits_per_pixel != 8)
return -EINVAL;
- o_fb = data->fb_bitmap;
+ o_fb = fbdata->bitmap;
tmp_fb = kmalloc(PICOLCDFB_SIZE*info->var.bits_per_pixel, GFP_KERNEL);
if (!tmp_fb)
return -ENOMEM;
@@ -415,7 +423,7 @@ static int picolcd_set_par(struct fb_info *info)
}
kfree(tmp_fb);
- data->fb_bpp = info->var.bits_per_pixel;
+ fbdata->bpp = info->var.bits_per_pixel;
return 0;
}
@@ -453,7 +461,8 @@ static ssize_t picolcd_fb_update_rate_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct picolcd_data *data = dev_get_drvdata(dev);
- unsigned i, fb_update_rate = data->fb_update_rate;
+ struct picolcd_fb_data *fbdata = data->fb_info->par;
+ unsigned i, fb_update_rate = fbdata->update_rate;
size_t ret = 0;
for (i = 1; i <= PICOLCDFB_UPDATE_RATE_LIMIT; i++)
@@ -472,6 +481,7 @@ static ssize_t picolcd_fb_update_rate_store(struct device *dev,
struct device_attribute *attr, const char *buf, size_t count)
{
struct picolcd_data *data = dev_get_drvdata(dev);
+ struct picolcd_fb_data *fbdata = data->fb_info->par;
int i;
unsigned u;
@@ -487,8 +497,8 @@ static ssize_t picolcd_fb_update_rate_store(struct device *dev,
else if (u == 0)
u = PICOLCDFB_UPDATE_RATE_DEFAULT;
- data->fb_update_rate = u;
- data->fb_info->fbdefio->delay = HZ / data->fb_update_rate;
+ fbdata->update_rate = u;
+ data->fb_info->fbdefio->delay = HZ / fbdata->update_rate;
return count;
}
@@ -500,30 +510,18 @@ int picolcd_init_framebuffer(struct picolcd_data *data)
{
struct device *dev = &data->hdev->dev;
struct fb_info *info = NULL;
+ struct picolcd_fb_data *fbdata = NULL;
int i, error = -ENOMEM;
- u8 *fb_vbitmap = NULL;
- u8 *fb_bitmap = NULL;
u32 *palette;
- fb_bitmap = vmalloc(PICOLCDFB_SIZE*8);
- if (fb_bitmap == NULL) {
- dev_err(dev, "can't get a free page for framebuffer\n");
- goto err_nomem;
- }
-
- fb_vbitmap = kmalloc(PICOLCDFB_SIZE, GFP_KERNEL);
- if (fb_vbitmap == NULL) {
- dev_err(dev, "can't alloc vbitmap image buffer\n");
- goto err_nomem;
- }
-
- data->fb_update_rate = PICOLCDFB_UPDATE_RATE_DEFAULT;
/* The extra memory is:
* - 256*u32 for pseudo_palette
* - struct fb_deferred_io
*/
info = framebuffer_alloc(256 * sizeof(u32) +
- sizeof(struct fb_deferred_io), dev);
+ sizeof(struct fb_deferred_io) +
+ sizeof(struct picolcd_fb_data) +
+ PICOLCDFB_SIZE, dev);
if (info == NULL) {
dev_err(dev, "failed to allocate a framebuffer\n");
goto err_nomem;
@@ -531,74 +529,86 @@ int picolcd_init_framebuffer(struct picolcd_data *data)
info->fbdefio = info->par;
*info->fbdefio = picolcd_fb_defio;
- palette = info->par + sizeof(struct fb_deferred_io);
+ info->par += sizeof(struct fb_deferred_io);
+ palette = info->par;
+ info->par += 256 * sizeof(u32);
for (i = 0; i < 256; i++)
palette[i] = i > 0 && i < 16 ? 0xff : 0;
info->pseudo_palette = palette;
- info->screen_base = (char __force __iomem *)fb_bitmap;
info->fbops = &picolcdfb_ops;
info->var = picolcdfb_var;
info->fix = picolcdfb_fix;
info->fix.smem_len = PICOLCDFB_SIZE*8;
- info->fix.smem_start = (unsigned long)fb_bitmap;
- info->par = data;
info->flags = FBINFO_FLAG_DEFAULT;
- data->fb_vbitmap = fb_vbitmap;
- data->fb_bitmap = fb_bitmap;
- data->fb_bpp = picolcdfb_var.bits_per_pixel;
+ fbdata = info->par;
+ spin_lock_init(&fbdata->lock);
+ fbdata->picolcd = data;
+ fbdata->update_rate = PICOLCDFB_UPDATE_RATE_DEFAULT;
+ fbdata->bpp = picolcdfb_var.bits_per_pixel;
+ fbdata->force = 1;
+ fbdata->vbitmap = info->par + sizeof(struct picolcd_fb_data);
+ fbdata->bitmap = vmalloc(PICOLCDFB_SIZE*8);
+ if (fbdata->bitmap == NULL) {
+ dev_err(dev, "can't get a free page for framebuffer\n");
+ goto err_nomem;
+ }
+ info->screen_base = (char __force __iomem *)fbdata->bitmap;
+ info->fix.smem_start = (unsigned long)fbdata->bitmap;
+ memset(fbdata->vbitmap, 0xff, PICOLCDFB_SIZE);
+ data->fb_info = info;
+
error = picolcd_fb_reset(data, 1);
if (error) {
dev_err(dev, "failed to configure display\n");
goto err_cleanup;
}
+
error = device_create_file(dev, &dev_attr_fb_update_rate);
if (error) {
dev_err(dev, "failed to create sysfs attributes\n");
goto err_cleanup;
}
+
fb_deferred_io_init(info);
- data->fb_info = info;
error = register_framebuffer(info);
if (error) {
dev_err(dev, "failed to register framebuffer\n");
goto err_sysfs;
}
- /* schedule first output of framebuffer */
- data->fb_force = 1;
- schedule_delayed_work(&info->deferred_work, 0);
return 0;
err_sysfs:
- fb_deferred_io_cleanup(info);
device_remove_file(dev, &dev_attr_fb_update_rate);
+ fb_deferred_io_cleanup(info);
err_cleanup:
- data->fb_vbitmap = NULL;
- data->fb_bitmap = NULL;
- data->fb_bpp = 0;
data->fb_info = NULL;
err_nomem:
+ if (fbdata)
+ vfree(fbdata->bitmap);
framebuffer_release(info);
- vfree(fb_bitmap);
- kfree(fb_vbitmap);
return error;
}
void picolcd_exit_framebuffer(struct picolcd_data *data)
{
struct fb_info *info = data->fb_info;
- u8 *fb_vbitmap = data->fb_vbitmap;
-
- if (!info)
- return;
+ struct picolcd_fb_data *fbdata = info->par;
+ unsigned long flags;
device_remove_file(&data->hdev->dev, &dev_attr_fb_update_rate);
- info->par = NULL;
+
+ /* disconnect framebuffer from HID dev */
+ spin_lock_irqsave(&fbdata->lock, flags);
+ fbdata->picolcd = NULL;
+ spin_unlock_irqrestore(&fbdata->lock, flags);
+
+ /* make sure there is no running update - thus that fbdata->picolcd
+ * once obtained under lock is guaranteed not to get free() under
+ * the feet of the deferred work */
+ flush_delayed_work_sync(&info->deferred_work);
+
+ data->fb_info = NULL;
unregister_framebuffer(info);
- data->fb_vbitmap = NULL;
- data->fb_bitmap = NULL;
- data->fb_bpp = 0;
- data->fb_info = NULL;
- kfree(fb_vbitmap);
}
--
1.7.8.6
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