From e873c74132f0c5f1452816cd9bb26208f0bba1e1 Mon Sep 17 00:00:00 2001
From: Shivank Garg <shivankg@amd.com>
Date: Sat, 22 Aug 2026 19:22:05 +0000
Subject: dmaengine: fix use-after-free in dma_chan_put() and
 dma_release_channel()

When dma_device_put() drops the last reference on chan->device->ref,
dma_device_release() runs and may free the dma_device along with its
channels.

dma_chan_put() then still reads chan->device->owner via
dma_chan_to_owner() for the trailing module_put(). KASAN catches it:

	slab-use-after-free in dma_chan_put+0x3e6/0x4c0
	Read of size 8 by task insmod/6319
	Freed by task 6319:
	  kfree+0x225/0x470
	  dma_chan_put+0x395/0x4c0
	  dmaengine_put+0xf8/0x160

Cache the module owner in dma_chan_put() before the put so the trailing
module_put() does not need chan->device.

Fixes: 8ad342a86359 ("dmaengine: Add reference counting to dma_device struct")
Suggested-by: Sashiko <sashiko-bot@kernel.org>
Link: https://sashiko.dev/#/patchset/20260518-dmaengine-kref-fix-v1-1-4d6125048fb7@amd.com
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
Signed-off-by: Shivank Garg <shivankg@amd.com>
Link: https://patch.msgid.link/20260822-dmaengine-kref-fix-v5-3-d4a4ee47d927@amd.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
---
 drivers/video/fbdev/broadsheetfb.c | 1169 ++++++++++++++++++++++++++++++++++++
 1 file changed, 1169 insertions(+)
 create mode 100644 drivers/video/fbdev/broadsheetfb.c

(limited to 'drivers/video/fbdev/broadsheetfb.c')

diff --git a/drivers/video/fbdev/broadsheetfb.c b/drivers/video/fbdev/broadsheetfb.c
new file mode 100644
index 000000000..582f1ee4c
--- /dev/null
+++ b/drivers/video/fbdev/broadsheetfb.c
@@ -0,0 +1,1169 @@
+/*
+ * broadsheetfb.c -- FB driver for E-Ink Broadsheet controller
+ *
+ * Copyright (C) 2008, Jaya Kumar
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file COPYING in the main directory of this archive for
+ * more details.
+ *
+ * Layout is based on skeletonfb.c by James Simmons and Geert Uytterhoeven.
+ *
+ * This driver is written to be used with the Broadsheet display controller.
+ *
+ * It is intended to be architecture independent. A board specific driver
+ * must be used to perform all the physical IO interactions.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/mm.h>
+#include <linux/slab.h>
+#include <linux/vmalloc.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/fb.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/list.h>
+#include <linux/firmware.h>
+#include <linux/uaccess.h>
+
+#include <video/broadsheetfb.h>
+
+/* track panel specific parameters */
+struct panel_info {
+	int w;
+	int h;
+	u16 sdcfg;
+	u16 gdcfg;
+	u16 lutfmt;
+	u16 fsynclen;
+	u16 fendfbegin;
+	u16 lsynclen;
+	u16 lendlbegin;
+	u16 pixclk;
+};
+
+/* table of panel specific parameters to be indexed into by the board drivers */
+static struct panel_info panel_table[] = {
+	{	/* standard 6" on TFT backplane */
+		.w = 800,
+		.h = 600,
+		.sdcfg = (100 | (1 << 8) | (1 << 9)),
+		.gdcfg = 2,
+		.lutfmt = (4 | (1 << 7)),
+		.fsynclen = 4,
+		.fendfbegin = (10 << 8) | 4,
+		.lsynclen = 10,
+		.lendlbegin = (100 << 8) | 4,
+		.pixclk = 6,
+	},
+	{	/* custom 3.7" flexible on PET or steel */
+		.w = 320,
+		.h = 240,
+		.sdcfg = (67 | (0 << 8) | (0 << 9) | (0 << 10) | (0 << 12)),
+		.gdcfg = 3,
+		.lutfmt = (4 | (1 << 7)),
+		.fsynclen = 0,
+		.fendfbegin = (80 << 8) | 4,
+		.lsynclen = 10,
+		.lendlbegin = (80 << 8) | 20,
+		.pixclk = 14,
+	},
+	{	/* standard 9.7" on TFT backplane */
+		.w = 1200,
+		.h = 825,
+		.sdcfg = (100 | (1 << 8) | (1 << 9) | (0 << 10) | (0 << 12)),
+		.gdcfg = 2,
+		.lutfmt = (4 | (1 << 7)),
+		.fsynclen = 0,
+		.fendfbegin = (4 << 8) | 4,
+		.lsynclen = 4,
+		.lendlbegin = (60 << 8) | 10,
+		.pixclk = 3,
+	},
+};
+
+#define DPY_W 800
+#define DPY_H 600
+
+static struct fb_fix_screeninfo broadsheetfb_fix = {
+	.id =		"broadsheetfb",
+	.type =		FB_TYPE_PACKED_PIXELS,
+	.visual =	FB_VISUAL_STATIC_PSEUDOCOLOR,
+	.xpanstep =	0,
+	.ypanstep =	0,
+	.ywrapstep =	0,
+	.line_length =	DPY_W,
+	.accel =	FB_ACCEL_NONE,
+};
+
+static struct fb_var_screeninfo broadsheetfb_var = {
+	.xres		= DPY_W,
+	.yres		= DPY_H,
+	.xres_virtual	= DPY_W,
+	.yres_virtual	= DPY_H,
+	.bits_per_pixel	= 8,
+	.grayscale	= 1,
+	.red =		{ 0, 4, 0 },
+	.green =	{ 0, 4, 0 },
+	.blue =		{ 0, 4, 0 },
+	.transp =	{ 0, 0, 0 },
+};
+
+/* main broadsheetfb functions */
+static void broadsheet_gpio_issue_data(struct broadsheetfb_par *par, u16 data)
+{
+	par->board->set_ctl(par, BS_WR, 0);
+	par->board->set_hdb(par, data);
+	par->board->set_ctl(par, BS_WR, 1);
+}
+
+static void broadsheet_gpio_issue_cmd(struct broadsheetfb_par *par, u16 data)
+{
+	par->board->set_ctl(par, BS_DC, 0);
+	broadsheet_gpio_issue_data(par, data);
+}
+
+static void broadsheet_gpio_send_command(struct broadsheetfb_par *par, u16 data)
+{
+	par->board->wait_for_rdy(par);
+
+	par->board->set_ctl(par, BS_CS, 0);
+	broadsheet_gpio_issue_cmd(par, data);
+	par->board->set_ctl(par, BS_DC, 1);
+	par->board->set_ctl(par, BS_CS, 1);
+}
+
+static void broadsheet_gpio_send_cmdargs(struct broadsheetfb_par *par, u16 cmd,
+					int argc, u16 *argv)
+{
+	int i;
+
+	par->board->wait_for_rdy(par);
+
+	par->board->set_ctl(par, BS_CS, 0);
+	broadsheet_gpio_issue_cmd(par, cmd);
+	par->board->set_ctl(par, BS_DC, 1);
+
+	for (i = 0; i < argc; i++)
+		broadsheet_gpio_issue_data(par, argv[i]);
+	par->board->set_ctl(par, BS_CS, 1);
+}
+
+static void broadsheet_mmio_send_cmdargs(struct broadsheetfb_par *par, u16 cmd,
+				    int argc, u16 *argv)
+{
+	int i;
+
+	par->board->mmio_write(par, BS_MMIO_CMD, cmd);
+
+	for (i = 0; i < argc; i++)
+		par->board->mmio_write(par, BS_MMIO_DATA, argv[i]);
+}
+
+static void broadsheet_send_command(struct broadsheetfb_par *par, u16 data)
+{
+	if (par->board->mmio_write)
+		par->board->mmio_write(par, BS_MMIO_CMD, data);
+	else
+		broadsheet_gpio_send_command(par, data);
+}
+
+static void broadsheet_send_cmdargs(struct broadsheetfb_par *par, u16 cmd,
+				    int argc, u16 *argv)
+{
+	if (par->board->mmio_write)
+		broadsheet_mmio_send_cmdargs(par, cmd, argc, argv);
+	else
+		broadsheet_gpio_send_cmdargs(par, cmd, argc, argv);
+}
+
+static void broadsheet_gpio_burst_write(struct broadsheetfb_par *par, int size,
+					u16 *data)
+{
+	int i;
+	u16 tmp;
+
+	par->board->set_ctl(par, BS_CS, 0);
+	par->board->set_ctl(par, BS_DC, 1);
+
+	for (i = 0; i < size; i++) {
+		par->board->set_ctl(par, BS_WR, 0);
+		tmp = (data[i] & 0x0F) << 4;
+		tmp |= (data[i] & 0x0F00) << 4;
+		par->board->set_hdb(par, tmp);
+		par->board->set_ctl(par, BS_WR, 1);
+	}
+
+	par->board->set_ctl(par, BS_CS, 1);
+}
+
+static void broadsheet_mmio_burst_write(struct broadsheetfb_par *par, int size,
+				   u16 *data)
+{
+	int i;
+	u16 tmp;
+
+	for (i = 0; i < size; i++) {
+		tmp = (data[i] & 0x0F) << 4;
+		tmp |= (data[i] & 0x0F00) << 4;
+		par->board->mmio_write(par, BS_MMIO_DATA, tmp);
+	}
+
+}
+
+static void broadsheet_burst_write(struct broadsheetfb_par *par, int size,
+				   u16 *data)
+{
+	if (par->board->mmio_write)
+		broadsheet_mmio_burst_write(par, size, data);
+	else
+		broadsheet_gpio_burst_write(par, size, data);
+}
+
+static u16 broadsheet_gpio_get_data(struct broadsheetfb_par *par)
+{
+	u16 res;
+	/* wait for ready to go hi. (lo is busy) */
+	par->board->wait_for_rdy(par);
+
+	/* cs lo, dc lo for cmd, we lo for each data, db as usual */
+	par->board->set_ctl(par, BS_DC, 1);
+	par->board->set_ctl(par, BS_CS, 0);
+	par->board->set_ctl(par, BS_WR, 0);
+
+	res = par->board->get_hdb(par);
+
+	/* strobe wr */
+	par->board->set_ctl(par, BS_WR, 1);
+	par->board->set_ctl(par, BS_CS, 1);
+
+	return res;
+}
+
+
+static u16 broadsheet_get_data(struct broadsheetfb_par *par)
+{
+	if (par->board->mmio_read)
+		return par->board->mmio_read(par);
+	else
+		return broadsheet_gpio_get_data(par);
+}
+
+static void broadsheet_gpio_write_reg(struct broadsheetfb_par *par, u16 reg,
+					u16 data)
+{
+	/* wait for ready to go hi. (lo is busy) */
+	par->board->wait_for_rdy(par);
+
+	/* cs lo, dc lo for cmd, we lo for each data, db as usual */
+	par->board->set_ctl(par, BS_CS, 0);
+
+	broadsheet_gpio_issue_cmd(par, BS_CMD_WR_REG);
+
+	par->board->set_ctl(par, BS_DC, 1);
+
+	broadsheet_gpio_issue_data(par, reg);
+	broadsheet_gpio_issue_data(par, data);
+
+	par->board->set_ctl(par, BS_CS, 1);
+}
+
+static void broadsheet_mmio_write_reg(struct broadsheetfb_par *par, u16 reg,
+				 u16 data)
+{
+	par->board->mmio_write(par, BS_MMIO_CMD, BS_CMD_WR_REG);
+	par->board->mmio_write(par, BS_MMIO_DATA, reg);
+	par->board->mmio_write(par, BS_MMIO_DATA, data);
+
+}
+
+static void broadsheet_write_reg(struct broadsheetfb_par *par, u16 reg,
+					u16 data)
+{
+	if (par->board->mmio_write)
+		broadsheet_mmio_write_reg(par, reg, data);
+	else
+		broadsheet_gpio_write_reg(par, reg, data);
+}
+
+static void broadsheet_write_reg32(struct broadsheetfb_par *par, u16 reg,
+					u32 data)
+{
+	broadsheet_write_reg(par, reg, cpu_to_le32(data) & 0xFFFF);
+	broadsheet_write_reg(par, reg + 2, (cpu_to_le32(data) >> 16) & 0xFFFF);
+}
+
+
+static u16 broadsheet_read_reg(struct broadsheetfb_par *par, u16 reg)
+{
+	broadsheet_send_cmdargs(par, BS_CMD_RD_REG, 1, &reg);
+	par->board->wait_for_rdy(par);
+	return broadsheet_get_data(par);
+}
+
+/* functions for waveform manipulation */
+static int is_broadsheet_pll_locked(struct broadsheetfb_par *par)
+{
+	return broadsheet_read_reg(par, 0x000A) & 0x0001;
+}
+
+static int broadsheet_setup_plls(struct broadsheetfb_par *par)
+{
+	int retry_count = 0;
+	u16 tmp;
+
+	/* disable arral saemipu mode */
+	broadsheet_write_reg(par, 0x0006, 0x0000);
+
+	broadsheet_write_reg(par, 0x0010, 0x0004);
+	broadsheet_write_reg(par, 0x0012, 0x5949);
+	broadsheet_write_reg(par, 0x0014, 0x0040);
+	broadsheet_write_reg(par, 0x0016, 0x0000);
+
+	do {
+		if (retry_count++ > 100)
+			return -ETIMEDOUT;
+		mdelay(1);
+	} while (!is_broadsheet_pll_locked(par));
+
+	tmp = broadsheet_read_reg(par, 0x0006);
+	tmp &= ~0x1;
+	broadsheet_write_reg(par, 0x0006, tmp);
+
+	return 0;
+}
+
+static int broadsheet_setup_spi(struct broadsheetfb_par *par)
+{
+
+	broadsheet_write_reg(par, 0x0204, ((3 << 3) | 1));
+	broadsheet_write_reg(par, 0x0208, 0x0001);
+
+	return 0;
+}
+
+static int broadsheet_setup_spiflash(struct broadsheetfb_par *par,
+						u16 *orig_sfmcd)
+{
+
+	*orig_sfmcd = broadsheet_read_reg(par, 0x0204);
+	broadsheet_write_reg(par, 0x0208, 0);
+	broadsheet_write_reg(par, 0x0204, 0);
+	broadsheet_write_reg(par, 0x0204, ((3 << 3) | 1));
+
+	return 0;
+}
+
+static int broadsheet_spiflash_wait_for_bit(struct broadsheetfb_par *par,
+						u16 reg, int bitnum, int val,
+						int timeout)
+{
+	u16 tmp;
+
+	do {
+		tmp = broadsheet_read_reg(par, reg);
+		if (((tmp >> bitnum) & 1) == val)
+			return 0;
+		mdelay(1);
+	} while (timeout--);
+
+	return -ETIMEDOUT;
+}
+
+static int broadsheet_spiflash_write_byte(struct broadsheetfb_par *par, u8 data)
+{
+	broadsheet_write_reg(par, 0x0202, (data | 0x100));
+
+	return broadsheet_spiflash_wait_for_bit(par, 0x0206, 3, 0, 100);
+}
+
+static int broadsheet_spiflash_read_byte(struct broadsheetfb_par *par, u8 *data)
+{
+	int err;
+	u16 tmp;
+
+	broadsheet_write_reg(par, 0x0202, 0);
+
+	err = broadsheet_spiflash_wait_for_bit(par, 0x0206, 3, 0, 100);
+	if (err)
+		return err;
+
+	tmp = broadsheet_read_reg(par, 0x200);
+
+	*data = tmp & 0xFF;
+
+	return 0;
+}
+
+static int broadsheet_spiflash_wait_for_status(struct broadsheetfb_par *par,
+								int timeout)
+{
+	u8 tmp;
+	int err;
+
+	do {
+		broadsheet_write_reg(par, 0x0208, 1);
+
+		err = broadsheet_spiflash_write_byte(par, 0x05);
+		if (err)
+			goto failout;
+
+		err = broadsheet_spiflash_read_byte(par, &tmp);
+		if (err)
+			goto failout;
+
+		broadsheet_write_reg(par, 0x0208, 0);
+
+		if (!(tmp & 0x1))
+			return 0;
+
+		mdelay(5);
+	} while (timeout--);
+
+	dev_err(par->info->device, "Timed out waiting for spiflash status\n");
+	return -ETIMEDOUT;
+
+failout:
+	broadsheet_write_reg(par, 0x0208, 0);
+	return err;
+}
+
+static int broadsheet_spiflash_op_on_address(struct broadsheetfb_par *par,
+							u8 op, u32 addr)
+{
+	int i;
+	u8 tmp;
+	int err;
+
+	broadsheet_write_reg(par, 0x0208, 1);
+
+	err = broadsheet_spiflash_write_byte(par, op);
+	if (err)
+		return err;
+
+	for (i = 2; i >= 0; i--) {
+		tmp = ((addr >> (i * 8)) & 0xFF);
+		err = broadsheet_spiflash_write_byte(par, tmp);
+		if (err)
+			return err;
+	}
+
+	return err;
+}
+
+static int broadsheet_verify_spiflash(struct broadsheetfb_par *par,
+						int *flash_type)
+{
+	int err = 0;
+	u8 sig;
+
+	err = broadsheet_spiflash_op_on_address(par, 0xAB, 0x00000000);
+	if (err)
+		goto failout;
+
+	err = broadsheet_spiflash_read_byte(par, &sig);
+	if (err)
+		goto failout;
+
+	if ((sig != 0x10) && (sig != 0x11)) {
+		dev_err(par->info->device, "Unexpected flash type\n");
+		err = -EINVAL;
+		goto failout;
+	}
+
+	*flash_type = sig;
+
+failout:
+	broadsheet_write_reg(par, 0x0208, 0);
+	return err;
+}
+
+static int broadsheet_setup_for_wfm_write(struct broadsheetfb_par *par,
+					u16 *initial_sfmcd, int *flash_type)
+
+{
+	int err;
+
+	err = broadsheet_setup_plls(par);
+	if (err)
+		return err;
+
+	broadsheet_write_reg(par, 0x0106, 0x0203);
+
+	err = broadsheet_setup_spi(par);
+	if (err)
+		return err;
+
+	err = broadsheet_setup_spiflash(par, initial_sfmcd);
+	if (err)
+		return err;
+
+	return broadsheet_verify_spiflash(par, flash_type);
+}
+
+static int broadsheet_spiflash_write_control(struct broadsheetfb_par *par,
+						int mode)
+{
+	int err;
+
+	broadsheet_write_reg(par, 0x0208, 1);
+	if (mode)
+		err = broadsheet_spiflash_write_byte(par, 0x06);
+	else
+		err = broadsheet_spiflash_write_byte(par, 0x04);
+
+	broadsheet_write_reg(par, 0x0208, 0);
+	return err;
+}
+
+static int broadsheet_spiflash_erase_sector(struct broadsheetfb_par *par,
+						int addr)
+{
+	int err;
+
+	broadsheet_spiflash_write_control(par, 1);
+
+	err = broadsheet_spiflash_op_on_address(par, 0xD8, addr);
+
+	broadsheet_write_reg(par, 0x0208, 0);
+
+	if (err)
+		return err;
+
+	err = broadsheet_spiflash_wait_for_status(par, 1000);
+
+	return err;
+}
+
+static int broadsheet_spiflash_read_range(struct broadsheetfb_par *par,
+						int addr, int size, char *data)
+{
+	int err;
+	int i;
+
+	err = broadsheet_spiflash_op_on_address(par, 0x03, addr);
+	if (err)
+		goto failout;
+
+	for (i = 0; i < size; i++) {
+		err = broadsheet_spiflash_read_byte(par, &data[i]);
+		if (err)
+			goto failout;
+	}
+
+failout:
+	broadsheet_write_reg(par, 0x0208, 0);
+	return err;
+}
+
+#define BS_SPIFLASH_PAGE_SIZE 256
+static int broadsheet_spiflash_write_page(struct broadsheetfb_par *par,
+						int addr, const char *data)
+{
+	int err;
+	int i;
+
+	broadsheet_spiflash_write_control(par, 1);
+
+	err = broadsheet_spiflash_op_on_address(par, 0x02, addr);
+	if (err)
+		goto failout;
+
+	for (i = 0; i < BS_SPIFLASH_PAGE_SIZE; i++) {
+		err = broadsheet_spiflash_write_byte(par, data[i]);
+		if (err)
+			goto failout;
+	}
+
+	broadsheet_write_reg(par, 0x0208, 0);
+
+	err = broadsheet_spiflash_wait_for_status(par, 100);
+
+failout:
+	return err;
+}
+
+static int broadsheet_spiflash_write_sector(struct broadsheetfb_par *par,
+				int addr, const char *data, int sector_size)
+{
+	int i;
+	int err;
+
+	for (i = 0; i < sector_size; i += BS_SPIFLASH_PAGE_SIZE) {
+		err = broadsheet_spiflash_write_page(par, addr + i, &data[i]);
+		if (err)
+			return err;
+	}
+	return 0;
+}
+
+/*
+ * The caller must guarantee that the data to be rewritten is entirely
+ * contained within this sector. That is, data_start_addr + data_len
+ * must be less than sector_start_addr + sector_size.
+ */
+static int broadsheet_spiflash_rewrite_sector(struct broadsheetfb_par *par,
+					int sector_size, int data_start_addr,
+					int data_len, const char *data)
+{
+	int err;
+	char *sector_buffer;
+	int tail_start_addr;
+	int start_sector_addr;
+
+	sector_buffer = kzalloc(sector_size, GFP_KERNEL);
+	if (!sector_buffer)
+		return -ENOMEM;
+
+	/* the start address of the sector is the 0th byte of that sector */
+	start_sector_addr = (data_start_addr / sector_size) * sector_size;
+
+	/*
+	 * check if there is head data that we need to readback into our sector
+	 * buffer first
+	 */
+	if (data_start_addr != start_sector_addr) {
+		/*
+		 * we need to read every byte up till the start address of our
+		 * data and we put it into our sector buffer.
+		 */
+		err = broadsheet_spiflash_read_range(par, start_sector_addr,
+						data_start_addr, sector_buffer);
+		if (err)
+			goto out;
+	}
+
+	/* now we copy our data into the right place in the sector buffer */
+	memcpy(sector_buffer + data_start_addr, data, data_len);
+
+	/*
+	 * now we check if there is a tail section of the sector that we need to
+	 * readback.
+	 */
+	tail_start_addr = (data_start_addr + data_len) % sector_size;
+
+	if (tail_start_addr) {
+		int tail_len;
+
+		tail_len = sector_size - tail_start_addr;
+
+		/* now we read this tail into our sector buffer */
+		err = broadsheet_spiflash_read_range(par, tail_start_addr,
+			tail_len, sector_buffer + tail_start_addr);
+		if (err)
+			goto out;
+	}
+
+	/* if we got here we have the full sector that we want to rewrite. */
+
+	/* first erase the sector */
+	err = broadsheet_spiflash_erase_sector(par, start_sector_addr);
+	if (err)
+		goto out;
+
+	/* now write it */
+	err = broadsheet_spiflash_write_sector(par, start_sector_addr,
+					sector_buffer, sector_size);
+out:
+	kfree(sector_buffer);
+	return err;
+}
+
+static int broadsheet_write_spiflash(struct broadsheetfb_par *par, u32 wfm_addr,
+				const u8 *wfm, int bytecount, int flash_type)
+{
+	int sector_size;
+	int err;
+	int cur_addr;
+	int writecount;
+	int maxlen;
+	int offset = 0;
+
+	switch (flash_type) {
+	case 0x10:
+		sector_size = 32*1024;
+		break;
+	case 0x11:
+	default:
+		sector_size = 64*1024;
+		break;
+	}
+
+	while (bytecount) {
+		cur_addr = wfm_addr + offset;
+		maxlen = roundup(cur_addr, sector_size) - cur_addr;
+		writecount = min(bytecount, maxlen);
+
+		err = broadsheet_spiflash_rewrite_sector(par, sector_size,
+				cur_addr, writecount, wfm + offset);
+		if (err)
+			return err;
+
+		offset += writecount;
+		bytecount -= writecount;
+	}
+
+	return 0;
+}
+
+static int broadsheet_store_waveform_to_spiflash(struct broadsheetfb_par *par,
+						const u8 *wfm, size_t wfm_size)
+{
+	int err = 0;
+	u16 initial_sfmcd = 0;
+	int flash_type = 0;
+
+	err = broadsheet_setup_for_wfm_write(par, &initial_sfmcd, &flash_type);
+	if (err)
+		goto failout;
+
+	err = broadsheet_write_spiflash(par, 0x886, wfm, wfm_size, flash_type);
+
+failout:
+	broadsheet_write_reg(par, 0x0204, initial_sfmcd);
+	return err;
+}
+
+static ssize_t broadsheet_loadstore_waveform(struct device *dev,
+						struct device_attribute *attr,
+						const char *buf, size_t len)
+{
+	int err;
+	struct fb_info *info = dev_get_drvdata(dev);
+	struct broadsheetfb_par *par = info->par;
+	const struct firmware *fw_entry;
+
+	if (len < 1)
+		return -EINVAL;
+
+	err = request_firmware(&fw_entry, "broadsheet.wbf", dev);
+	if (err < 0) {
+		dev_err(dev, "Failed to get broadsheet waveform\n");
+		goto err_failed;
+	}
+
+	/* try to enforce reasonable min max on waveform */
+	if ((fw_entry->size < 8*1024) || (fw_entry->size > 64*1024)) {
+		dev_err(dev, "Invalid waveform\n");
+		err = -EINVAL;
+		goto err_fw;
+	}
+
+	mutex_lock(&(par->io_lock));
+	err = broadsheet_store_waveform_to_spiflash(par, fw_entry->data,
+							fw_entry->size);
+
+	mutex_unlock(&(par->io_lock));
+	if (err < 0) {
+		dev_err(dev, "Failed to store broadsheet waveform\n");
+		goto err_fw;
+	}
+
+	dev_info(dev, "Stored broadsheet waveform, size %zd\n", fw_entry->size);
+
+	err = len;
+
+err_fw:
+	release_firmware(fw_entry);
+err_failed:
+	return err;
+}
+static DEVICE_ATTR(loadstore_waveform, S_IWUSR, NULL,
+			broadsheet_loadstore_waveform);
+
+/* upper level functions that manipulate the display and other stuff */
+static void broadsheet_init_display(struct broadsheetfb_par *par)
+{
+	u16 args[5];
+	int xres = par->info->var.xres;
+	int yres = par->info->var.yres;
+
+	args[0] = panel_table[par->panel_index].w;
+	args[1] = panel_table[par->panel_index].h;
+	args[2] = panel_table[par->panel_index].sdcfg;
+	args[3] = panel_table[par->panel_index].gdcfg;
+	args[4] = panel_table[par->panel_index].lutfmt;
+	broadsheet_send_cmdargs(par, BS_CMD_INIT_DSPE_CFG, 5, args);
+
+	/* did the controller really set it? */
+	broadsheet_send_cmdargs(par, BS_CMD_INIT_DSPE_CFG, 5, args);
+
+	args[0] = panel_table[par->panel_index].fsynclen;
+	args[1] = panel_table[par->panel_index].fendfbegin;
+	args[2] = panel_table[par->panel_index].lsynclen;
+	args[3] = panel_table[par->panel_index].lendlbegin;
+	args[4] = panel_table[par->panel_index].pixclk;
+	broadsheet_send_cmdargs(par, BS_CMD_INIT_DSPE_TMG, 5, args);
+
+	broadsheet_write_reg32(par, 0x310, xres*yres*2);
+
+	/* setup waveform */
+	args[0] = 0x886;
+	args[1] = 0;
+	broadsheet_send_cmdargs(par, BS_CMD_RD_WFM_INFO, 2, args);
+
+	broadsheet_send_command(par, BS_CMD_UPD_GDRV_CLR);
+
+	broadsheet_send_command(par, BS_CMD_WAIT_DSPE_TRG);
+
+	broadsheet_write_reg(par, 0x330, 0x84);
+
+	broadsheet_send_command(par, BS_CMD_WAIT_DSPE_TRG);
+
+	args[0] = (0x3 << 4);
+	broadsheet_send_cmdargs(par, BS_CMD_LD_IMG, 1, args);
+
+	args[0] = 0x154;
+	broadsheet_send_cmdargs(par, BS_CMD_WR_REG, 1, args);
+
+	broadsheet_burst_write(par, (panel_table[par->panel_index].w *
+					panel_table[par->panel_index].h)/2,
+					(u16 *)par->info->screen_buffer);
+
+	broadsheet_send_command(par, BS_CMD_LD_IMG_END);
+
+	args[0] = 0x4300;
+	broadsheet_send_cmdargs(par, BS_CMD_UPD_FULL, 1, args);
+
+	broadsheet_send_command(par, BS_CMD_WAIT_DSPE_TRG);
+
+	broadsheet_send_command(par, BS_CMD_WAIT_DSPE_FREND);
+
+	par->board->wait_for_rdy(par);
+}
+
+static void broadsheet_identify(struct broadsheetfb_par *par)
+{
+	u16 rev, prc;
+	struct device *dev = par->info->device;
+
+	rev = broadsheet_read_reg(par, BS_REG_REV);
+	prc = broadsheet_read_reg(par, BS_REG_PRC);
+	dev_info(dev, "Broadsheet Rev 0x%x, Product Code 0x%x\n", rev, prc);
+
+	if (prc != 0x0047)
+		dev_warn(dev, "Unrecognized Broadsheet Product Code\n");
+	if (rev != 0x0100)
+		dev_warn(dev, "Unrecognized Broadsheet Revision\n");
+}
+
+static void broadsheet_init(struct broadsheetfb_par *par)
+{
+	broadsheet_send_command(par, BS_CMD_INIT_SYS_RUN);
+	/* the controller needs a second */
+	msleep(1000);
+	broadsheet_init_display(par);
+}
+
+static void broadsheetfb_dpy_update_pages(struct broadsheetfb_par *par,
+						u16 y1, u16 y2)
+{
+	u16 args[5];
+	unsigned char *buf = par->info->screen_buffer;
+
+	mutex_lock(&(par->io_lock));
+	/* y1 must be a multiple of 4 so drop the lower bits */
+	y1 &= 0xFFFC;
+	/* y2 must be a multiple of 4 , but - 1 so up the lower bits */
+	y2 |= 0x0003;
+
+	args[0] = 0x3 << 4;
+	args[1] = 0;
+	args[2] = y1;
+	args[3] = cpu_to_le16(par->info->var.xres);
+	args[4] = y2;
+	broadsheet_send_cmdargs(par, BS_CMD_LD_IMG_AREA, 5, args);
+
+	args[0] = 0x154;
+	broadsheet_send_cmdargs(par, BS_CMD_WR_REG, 1, args);
+
+	buf += y1 * par->info->var.xres;
+	broadsheet_burst_write(par, ((1 + y2 - y1) * par->info->var.xres)/2,
+				(u16 *) buf);
+
+	broadsheet_send_command(par, BS_CMD_LD_IMG_END);
+
+	args[0] = 0x4300;
+	broadsheet_send_cmdargs(par, BS_CMD_UPD_FULL, 1, args);
+
+	broadsheet_send_command(par, BS_CMD_WAIT_DSPE_TRG);
+
+	broadsheet_send_command(par, BS_CMD_WAIT_DSPE_FREND);
+
+	par->board->wait_for_rdy(par);
+	mutex_unlock(&(par->io_lock));
+
+}
+
+static void broadsheetfb_dpy_update(struct broadsheetfb_par *par)
+{
+	u16 args[5];
+
+	mutex_lock(&(par->io_lock));
+	args[0] = 0x3 << 4;
+	broadsheet_send_cmdargs(par, BS_CMD_LD_IMG, 1, args);
+
+	args[0] = 0x154;
+	broadsheet_send_cmdargs(par, BS_CMD_WR_REG, 1, args);
+	broadsheet_burst_write(par, (panel_table[par->panel_index].w *
+					panel_table[par->panel_index].h)/2,
+					(u16 *)par->info->screen_buffer);
+
+	broadsheet_send_command(par, BS_CMD_LD_IMG_END);
+
+	args[0] = 0x4300;
+	broadsheet_send_cmdargs(par, BS_CMD_UPD_FULL, 1, args);
+
+	broadsheet_send_command(par, BS_CMD_WAIT_DSPE_TRG);
+
+	broadsheet_send_command(par, BS_CMD_WAIT_DSPE_FREND);
+
+	par->board->wait_for_rdy(par);
+	mutex_unlock(&(par->io_lock));
+}
+
+/* this is called back from the deferred io workqueue */
+static void broadsheetfb_dpy_deferred_io(struct fb_info *info, struct list_head *pagereflist)
+{
+	u16 y1 = 0, h = 0;
+	unsigned long prev_offset = ULONG_MAX;
+	struct fb_deferred_io_pageref *pageref;
+	int h_inc;
+	u16 yres = info->var.yres;
+	u16 xres = info->var.xres;
+
+	/* height increment is fixed per page */
+	h_inc = DIV_ROUND_UP(PAGE_SIZE , xres);
+
+	/* walk the written page list and swizzle the data */
+	list_for_each_entry(pageref, pagereflist, list) {
+		if (prev_offset == ULONG_MAX) {
+			/* just starting so assign first page */
+			y1 = pageref->offset / xres;
+			h = h_inc;
+		} else if ((prev_offset + PAGE_SIZE) == pageref->offset) {
+			/* this page is consecutive so increase our height */
+			h += h_inc;
+		} else {
+			/* page not consecutive, issue previous update first */
+			broadsheetfb_dpy_update_pages(info->par, y1, y1 + h);
+			/* start over with our non consecutive page */
+			y1 = pageref->offset / xres;
+			h = h_inc;
+		}
+		prev_offset = pageref->offset;
+	}
+
+	/* if we still have any pages to update we do so now */
+	if (h >= yres) {
+		/* its a full screen update, just do it */
+		broadsheetfb_dpy_update(info->par);
+	} else {
+		broadsheetfb_dpy_update_pages(info->par, y1,
+						min((u16) (y1 + h), yres));
+	}
+}
+
+static void broadsheetfb_defio_damage_range(struct fb_info *info, off_t off, size_t len)
+{
+	struct broadsheetfb_par *par = info->par;
+
+	broadsheetfb_dpy_update(par);
+}
+
+static void broadsheetfb_defio_damage_area(struct fb_info *info, u32 x, u32 y,
+					   u32 width, u32 height)
+{
+	struct broadsheetfb_par *par = info->par;
+
+	broadsheetfb_dpy_update(par);
+}
+
+FB_GEN_DEFAULT_DEFERRED_SYSMEM_OPS(broadsheetfb,
+				   broadsheetfb_defio_damage_range,
+				   broadsheetfb_defio_damage_area)
+
+static const struct fb_ops broadsheetfb_ops = {
+	.owner	= THIS_MODULE,
+	FB_DEFAULT_DEFERRED_OPS(broadsheetfb),
+};
+
+static struct fb_deferred_io broadsheetfb_defio = {
+	.delay			= HZ/4,
+	.sort_pagereflist	= true,
+	.deferred_io		= broadsheetfb_dpy_deferred_io,
+};
+
+static int broadsheetfb_probe(struct platform_device *dev)
+{
+	struct fb_info *info;
+	struct broadsheet_board *board;
+	int retval = -ENOMEM;
+	int videomemorysize;
+	unsigned char *videomemory;
+	struct broadsheetfb_par *par;
+	int i;
+	int dpyw, dpyh;
+	int panel_index;
+
+	/* pick up board specific routines */
+	board = dev->dev.platform_data;
+	if (!board)
+		return -EINVAL;
+
+	/* try to count device specific driver, if can't, platform recalls */
+	if (!try_module_get(board->owner))
+		return -ENODEV;
+
+	info = framebuffer_alloc(sizeof(struct broadsheetfb_par), &dev->dev);
+	if (!info)
+		goto err;
+
+	switch (board->get_panel_type()) {
+	case 37:
+		panel_index = 1;
+		break;
+	case 97:
+		panel_index = 2;
+		break;
+	case 6:
+	default:
+		panel_index = 0;
+		break;
+	}
+
+	dpyw = panel_table[panel_index].w;
+	dpyh = panel_table[panel_index].h;
+
+	videomemorysize = roundup((dpyw*dpyh), PAGE_SIZE);
+
+	videomemory = vzalloc(videomemorysize);
+	if (!videomemory)
+		goto err_fb_rel;
+
+	info->screen_buffer = videomemory;
+	info->fbops = &broadsheetfb_ops;
+
+	broadsheetfb_var.xres = dpyw;
+	broadsheetfb_var.yres = dpyh;
+	broadsheetfb_var.xres_virtual = dpyw;
+	broadsheetfb_var.yres_virtual = dpyh;
+	info->var = broadsheetfb_var;
+
+	broadsheetfb_fix.line_length = dpyw;
+	info->fix = broadsheetfb_fix;
+	info->fix.smem_len = videomemorysize;
+	par = info->par;
+	par->panel_index = panel_index;
+	par->info = info;
+	par->board = board;
+	par->write_reg = broadsheet_write_reg;
+	par->read_reg = broadsheet_read_reg;
+	init_waitqueue_head(&par->waitq);
+
+	mutex_init(&par->io_lock);
+
+	info->flags = FBINFO_VIRTFB;
+
+	info->fbdefio = &broadsheetfb_defio;
+	retval = fb_deferred_io_init(info);
+	if (retval)
+		goto err_vfree;
+
+	retval = fb_alloc_cmap(&info->cmap, 16, 0);
+	if (retval < 0) {
+		dev_err(&dev->dev, "Failed to allocate colormap\n");
+		goto err_fbdefio;
+	}
+
+	/* set cmap */
+	for (i = 0; i < 16; i++)
+		info->cmap.red[i] = (((2*i)+1)*(0xFFFF))/32;
+	memcpy(info->cmap.green, info->cmap.red, sizeof(u16)*16);
+	memcpy(info->cmap.blue, info->cmap.red, sizeof(u16)*16);
+
+	retval = par->board->setup_irq(info);
+	if (retval < 0)
+		goto err_cmap;
+
+	/* this inits the dpy */
+	retval = board->init(par);
+	if (retval < 0)
+		goto err_free_irq;
+
+	broadsheet_identify(par);
+
+	broadsheet_init(par);
+
+	retval = register_framebuffer(info);
+	if (retval < 0)
+		goto err_free_irq;
+
+	platform_set_drvdata(dev, info);
+
+	retval = device_create_file(&dev->dev, &dev_attr_loadstore_waveform);
+	if (retval < 0)
+		goto err_unreg_fb;
+
+	fb_info(info, "Broadsheet frame buffer, using %dK of video memory\n",
+		videomemorysize >> 10);
+
+
+	return 0;
+
+err_unreg_fb:
+	unregister_framebuffer(info);
+err_free_irq:
+	board->cleanup(par);
+err_cmap:
+	fb_dealloc_cmap(&info->cmap);
+err_fbdefio:
+	fb_deferred_io_cleanup(info);
+err_vfree:
+	vfree(videomemory);
+err_fb_rel:
+	framebuffer_release(info);
+err:
+	module_put(board->owner);
+	return retval;
+
+}
+
+static void broadsheetfb_remove(struct platform_device *dev)
+{
+	struct fb_info *info = platform_get_drvdata(dev);
+
+	if (info) {
+		struct broadsheetfb_par *par = info->par;
+
+		device_remove_file(info->device, &dev_attr_loadstore_waveform);
+		unregister_framebuffer(info);
+		fb_deferred_io_cleanup(info);
+		par->board->cleanup(par);
+		fb_dealloc_cmap(&info->cmap);
+		vfree(info->screen_buffer);
+		module_put(par->board->owner);
+		framebuffer_release(info);
+	}
+}
+
+static struct platform_driver broadsheetfb_driver = {
+	.probe	= broadsheetfb_probe,
+	.remove	= broadsheetfb_remove,
+	.driver	= {
+		.name	= "broadsheetfb",
+	},
+};
+module_platform_driver(broadsheetfb_driver);
+
+MODULE_DESCRIPTION("fbdev driver for Broadsheet controller");
+MODULE_AUTHOR("Jaya Kumar");
+MODULE_LICENSE("GPL");
+
+MODULE_FIRMWARE("broadsheet.wbf");
-- 
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