[ARM] 5200/1: am200epd: use fb notifiers and gpio api

The original am200epd driver was designed with bad assumptions. It
manipulated GPSR/GPLR registers directly. It relied on direct access to the
pxa LCDC registers which have since conflicted with commit
ce4fb7b . This patch moves it into mach-pxa
and overhauls it to use a fb obtained through fb notifiers. It now uses the
generic GPIO api.

Signed-off-by: Jaya Kumar <jayakumar.lkml@gmail.com>
Acked-by: Krzysztof Helt <krzysztof.h1@wp.pl>
Acked-by: Eric Miao <eric.miao@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/mach-pxa/Kconfig

@@ -256,6 +256,9 @@ config PCM990_DISPLAY_NONE
 
 endchoice
 
+config MACH_AM200EPD
+	depends on MACH_GUMSTIX_F
+	bool "Enable AM200EPD board support"
 
 config PXA_EZX
 	bool "Motorola EZX Platform"

arch/arm/mach-pxa/Makefile

@@ -22,6 +22,7 @@ obj-$(CONFIG_CPU_PXA930)	+= pxa930.o
 
 # Specific board support
 obj-$(CONFIG_ARCH_GUMSTIX)	+= gumstix.o
+obj-$(CONFIG_MACH_AM200EPD)	+= am200epd.o
 obj-$(CONFIG_ARCH_LUBBOCK)	+= lubbock.o
 obj-$(CONFIG_MACH_LOGICPD_PXA270) += lpd270.o
 obj-$(CONFIG_MACH_MAINSTONE)	+= mainstone.o

arch/arm/mach-pxa/am200epd.c

@@ -0,0 +1,374 @@
+/*
+ * am200epd.c -- Platform device for AM200 EPD kit
+ *
+ * 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 work was made possible by help and equipment support from E-Ink
+ * Corporation. http://support.eink.com/community
+ *
+ * This driver is written to be used with the Metronome display controller.
+ * on the AM200 EPD prototype kit/development kit with an E-Ink 800x600
+ * Vizplex EPD on a Gumstix board using the Lyre interface board.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <linux/fb.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/irq.h>
+#include <linux/gpio.h>
+
+#include <mach/pxafb.h>
+
+#include <video/metronomefb.h>
+
+static unsigned int panel_type = 6;
+static struct platform_device *am200_device;
+static struct metronome_board am200_board;
+
+static struct pxafb_mode_info am200_fb_mode_9inch7 = {
+	.pixclock	= 40000,
+	.xres		= 1200,
+	.yres		= 842,
+	.bpp		= 16,
+	.hsync_len	= 2,
+	.left_margin	= 2,
+	.right_margin	= 2,
+	.vsync_len	= 1,
+	.upper_margin	= 2,
+	.lower_margin	= 25,
+	.sync		= FB_SYNC_HOR_HIGH_ACT | FB_SYNC_VERT_HIGH_ACT,
+};
+
+static struct pxafb_mode_info am200_fb_mode_8inch = {
+	.pixclock	= 40000,
+	.xres		= 1088,
+	.yres		= 791,
+	.bpp		= 16,
+	.hsync_len	= 28,
+	.left_margin	= 8,
+	.right_margin	= 30,
+	.vsync_len	= 8,
+	.upper_margin	= 10,
+	.lower_margin	= 8,
+	.sync		= FB_SYNC_HOR_HIGH_ACT | FB_SYNC_VERT_HIGH_ACT,
+};
+
+static struct pxafb_mode_info am200_fb_mode_6inch = {
+	.pixclock	= 40189,
+	.xres		= 832,
+	.yres		= 622,
+	.bpp		= 16,
+	.hsync_len	= 28,
+	.left_margin	= 34,
+	.right_margin	= 34,
+	.vsync_len	= 25,
+	.upper_margin	= 0,
+	.lower_margin	= 2,
+	.sync		= FB_SYNC_HOR_HIGH_ACT | FB_SYNC_VERT_HIGH_ACT,
+};
+
+static struct pxafb_mach_info am200_fb_info = {
+	.modes		= &am200_fb_mode_6inch,
+	.num_modes	= 1,
+	.lcd_conn	= LCD_TYPE_COLOR_TFT | LCD_PCLK_EDGE_FALL |
+			  LCD_AC_BIAS_FREQ(24),
+};
+
+/* register offsets for gpio control */
+#define LED_GPIO_PIN 51
+#define STDBY_GPIO_PIN 48
+#define RST_GPIO_PIN 49
+#define RDY_GPIO_PIN 32
+#define ERR_GPIO_PIN 17
+#define PCBPWR_GPIO_PIN 16
+static int gpios[] = { LED_GPIO_PIN , STDBY_GPIO_PIN , RST_GPIO_PIN,
+			RDY_GPIO_PIN, ERR_GPIO_PIN, PCBPWR_GPIO_PIN };
+static char *gpio_names[] = { "LED" , "STDBY" , "RST", "RDY", "ERR", "PCBPWR" };
+
+static int am200_init_gpio_regs(struct metronomefb_par *par)
+{
+	int i;
+	int err;
+
+	for (i = 0; i < ARRAY_SIZE(gpios); i++) {
+		err = gpio_request(gpios[i], gpio_names[i]);
+		if (err) {
+			dev_err(&am200_device->dev, "failed requesting "
+				"gpio %s, err=%d\n", gpio_names[i], err);
+			goto err_req_gpio;
+		}
+	}
+
+	gpio_direction_output(LED_GPIO_PIN, 0);
+	gpio_direction_output(STDBY_GPIO_PIN, 0);
+	gpio_direction_output(RST_GPIO_PIN, 0);
+
+	gpio_direction_input(RDY_GPIO_PIN);
+	gpio_direction_input(ERR_GPIO_PIN);
+
+	gpio_direction_output(PCBPWR_GPIO_PIN, 0);
+
+	return 0;
+
+err_req_gpio:
+	while (i > 0)
+		gpio_free(gpios[i--]);
+
+	return err;
+}
+
+static void am200_cleanup(struct metronomefb_par *par)
+{
+	int i;
+
+	free_irq(IRQ_GPIO(RDY_GPIO_PIN), par);
+
+	for (i = 0; i < ARRAY_SIZE(gpios); i++)
+		gpio_free(gpios[i]);
+}
+
+static int am200_share_video_mem(struct fb_info *info)
+{
+	/* rough check if this is our desired fb and not something else */
+	if ((info->var.xres != am200_fb_info.modes->xres)
+		|| (info->var.yres != am200_fb_info.modes->yres))
+		return 0;
+
+	/* we've now been notified that we have our new fb */
+	am200_board.metromem = info->screen_base;
+	am200_board.host_fbinfo = info;
+
+	/* try to refcount host drv since we are the consumer after this */
+	if (!try_module_get(info->fbops->owner))
+		return -ENODEV;
+
+	return 0;
+}
+
+static int am200_unshare_video_mem(struct fb_info *info)
+{
+	dev_dbg(&am200_device->dev, "ENTER %s\n", __func__);
+
+	if (info != am200_board.host_fbinfo)
+		return 0;
+
+	module_put(am200_board.host_fbinfo->fbops->owner);
+	return 0;
+}
+
+static int am200_fb_notifier_callback(struct notifier_block *self,
+				 unsigned long event, void *data)
+{
+	struct fb_event *evdata = data;
+	struct fb_info *info = evdata->info;
+
+	dev_dbg(&am200_device->dev, "ENTER %s\n", __func__);
+
+	if (event == FB_EVENT_FB_REGISTERED)
+		return am200_share_video_mem(info);
+	else if (event == FB_EVENT_FB_UNREGISTERED)
+		return am200_unshare_video_mem(info);
+
+	return 0;
+}
+
+static struct notifier_block am200_fb_notif = {
+	.notifier_call = am200_fb_notifier_callback,
+};
+
+/* this gets called as part of our init. these steps must be done now so
+ * that we can use set_pxa_fb_info */
+static void __init am200_presetup_fb(void)
+{
+	int fw;
+	int fh;
+	int padding_size;
+	int totalsize;
+
+	switch (panel_type) {
+	case 6:
+		am200_fb_info.modes = &am200_fb_mode_6inch;
+		break;
+	case 8:
+		am200_fb_info.modes = &am200_fb_mode_8inch;
+		break;
+	case 97:
+		am200_fb_info.modes = &am200_fb_mode_9inch7;
+		break;
+	default:
+		dev_err(&am200_device->dev, "invalid panel_type selection,"
+						" setting to 6\n");
+		am200_fb_info.modes = &am200_fb_mode_6inch;
+		break;
+	}
+
+	/* the frame buffer is divided as follows:
+	command | CRC | padding
+	16kb waveform data | CRC | padding
+	image data | CRC
+	*/
+
+	fw = am200_fb_info.modes->xres;
+	fh = am200_fb_info.modes->yres;
+
+	/* waveform must be 16k + 2 for checksum */
+	am200_board.wfm_size = roundup(16*1024 + 2, fw);
+
+	padding_size = PAGE_SIZE + (4 * fw);
+
+	/* total is 1 cmd , 1 wfm, padding and image */
+	totalsize = fw + am200_board.wfm_size + padding_size + (fw*fh);
+
+	/* save this off because we're manipulating fw after this and
+	 * we'll need it when we're ready to setup the framebuffer */
+	am200_board.fw = fw;
+	am200_board.fh = fh;
+
+	/* the reason we do this adjustment is because we want to acquire
+	 * more framebuffer memory without imposing custom awareness on the
+	 * underlying pxafb driver */
+	am200_fb_info.modes->yres = DIV_ROUND_UP(totalsize, fw);
+
+	/* we divide since we told the LCD controller we're 16bpp */
+	am200_fb_info.modes->xres /= 2;
+
+	set_pxa_fb_info(&am200_fb_info);
+
+}
+
+/* this gets called by metronomefb as part of its init, in our case, we
+ * have already completed initial framebuffer init in presetup_fb so we
+ * can just setup the fb access pointers */
+static int am200_setup_fb(struct metronomefb_par *par)
+{
+	int fw;
+	int fh;
+
+	fw = am200_board.fw;
+	fh = am200_board.fh;
+
+	/* metromem was set up by the notifier in share_video_mem so now
+	 * we can use its value to calculate the other entries */
+	par->metromem_cmd = (struct metromem_cmd *) am200_board.metromem;
+	par->metromem_wfm = am200_board.metromem + fw;
+	par->metromem_img = par->metromem_wfm + am200_board.wfm_size;
+	par->metromem_img_csum = (u16 *) (par->metromem_img + (fw * fh));
+	par->metromem_dma = am200_board.host_fbinfo->fix.smem_start;
+
+	return 0;
+}
+
+static int am200_get_panel_type(void)
+{
+	return panel_type;
+}
+
+static irqreturn_t am200_handle_irq(int irq, void *dev_id)
+{
+	struct metronomefb_par *par = dev_id;
+
+	wake_up_interruptible(&par->waitq);
+	return IRQ_HANDLED;
+}
+
+static int am200_setup_irq(struct fb_info *info)
+{
+	int ret;
+
+	ret = request_irq(IRQ_GPIO(RDY_GPIO_PIN), am200_handle_irq,
+				IRQF_DISABLED|IRQF_TRIGGER_FALLING,
+				"AM200", info->par);
+	if (ret)
+		dev_err(&am200_device->dev, "request_irq failed: %d\n", ret);
+
+	return ret;
+}
+
+static void am200_set_rst(struct metronomefb_par *par, int state)
+{
+	gpio_set_value(RST_GPIO_PIN, state);
+}
+
+static void am200_set_stdby(struct metronomefb_par *par, int state)
+{
+	gpio_set_value(STDBY_GPIO_PIN, state);
+}
+
+static int am200_wait_event(struct metronomefb_par *par)
+{
+	return wait_event_timeout(par->waitq, gpio_get_value(RDY_GPIO_PIN), HZ);
+}
+
+static int am200_wait_event_intr(struct metronomefb_par *par)
+{
+	return wait_event_interruptible_timeout(par->waitq,
+					gpio_get_value(RDY_GPIO_PIN), HZ);
+}
+
+static struct metronome_board am200_board = {
+	.owner			= THIS_MODULE,
+	.setup_irq		= am200_setup_irq,
+	.setup_io		= am200_init_gpio_regs,
+	.setup_fb		= am200_setup_fb,
+	.set_rst		= am200_set_rst,
+	.set_stdby		= am200_set_stdby,
+	.met_wait_event		= am200_wait_event,
+	.met_wait_event_intr	= am200_wait_event_intr,
+	.get_panel_type		= am200_get_panel_type,
+	.cleanup		= am200_cleanup,
+};
+
+static int __init am200_init(void)
+{
+	int ret;
+
+	/* before anything else, we request notification for any fb
+	 * creation events */
+	fb_register_client(&am200_fb_notif);
+
+	/* request our platform independent driver */
+	request_module("metronomefb");
+
+	am200_device = platform_device_alloc("metronomefb", -1);
+	if (!am200_device)
+		return -ENOMEM;
+
+	/* the am200_board that will be seen by metronomefb is a copy */
+	platform_device_add_data(am200_device, &am200_board,
+					sizeof(am200_board));
+
+	/* this _add binds metronomefb to am200. metronomefb refcounts am200 */
+	ret = platform_device_add(am200_device);
+
+	if (ret) {
+		platform_device_put(am200_device);
+		fb_unregister_client(&am200_fb_notif);
+		return ret;
+	}
+
+	am200_presetup_fb();
+
+	return 0;
+}
+
+module_param(panel_type, uint, 0);
+MODULE_PARM_DESC(panel_type, "Select the panel type: 6, 8, 97");
+
+module_init(am200_init);
+
+MODULE_DESCRIPTION("board driver for am200 metronome epd kit");
+MODULE_AUTHOR("Jaya Kumar");
+MODULE_LICENSE("GPL");