Re: [RFC 2.6.26-rc9 4/5] am200epd: convert to shared fb and use 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
ce4fb7b892a6d6c6a0f87366b26fd834d2923dd7 . This patch moves it into mach-pxa
and overhauls it to use pxafb's fb. It now uses the generic GPIO api.

Signed-off-by: Jaya Kumar <redacted>
---
 arch/arm/mach-pxa/Kconfig    |    3 +
 arch/arm/mach-pxa/Makefile   |    1 +
 arch/arm/mach-pxa/am200epd.c |  323 ++++++++++++++++++++++++++++++++++++++++++
 drivers/video/Kconfig        |   13 --
 drivers/video/Makefile       |    1 -
 drivers/video/am200epd.c     |  295 --------------------------------------
 6 files changed, 327 insertions(+), 309 deletions(-)
 create mode 100644 arch/arm/mach-pxa/am200epd.c
 delete mode 100644 drivers/video/am200epd.c

diff --git a/arch/arm/mach-pxa/Kconfig b/arch/arm/mach-pxa/Kconfig
index 3e28521..945014e 100644
--- a/arch/arm/mach-pxa/Kconfig
+++ b/arch/arm/mach-pxa/Kconfig

@@ -243,6 +243,9 @@ 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"

diff --git a/arch/arm/mach-pxa/Makefile b/arch/arm/mach-pxa/Makefile
index 5220a5c..618fe96 100644
--- a/arch/arm/mach-pxa/Makefile
+++ b/arch/arm/mach-pxa/Makefile

@@ -21,6 +21,7 @@ obj-$(CONFIG_CPU_PXA320)	+= pxa320.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

diff --git a/arch/arm/mach-pxa/am200epd.c b/arch/arm/mach-pxa/am200epd.c
new file mode 100644
index 0000000..f5bb902
--- /dev/null
+++ b/arch/arm/mach-pxa/am200epd.c

@@ -0,0 +1,323 @@
+/*
+ * 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 <asm/arch/pxafb.h>
+
+#include <video/metronomefb.h>
+
+#include "generic.h"
+#include "devices.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		= 1200/2,
+	.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		= 1088/2,
+	.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		= 832/2,
+	.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->info);
+
+	for (i = 0; i < ARRAY_SIZE(gpios); i++)
+		gpio_free(gpios[i]);
+}
+
+static char __iomem *am200_metromem;
+static dma_addr_t am200_metromem_dma;

+static int am200_preshare_video_mem(char __iomem *video_mem, dma_addr_t dma,
+					struct module *fbmaster, void *data)
+{
+
+	/* try to refcount the caller since we are the consumer after this */
+	if (!try_module_get(fbmaster))
+		return -ENODEV;
+
+	dev_dbg(&am200_device->dev, "mod_get %p\n", fbmaster);
+	am200_board.fbmaster = fbmaster;
+	am200_metromem = video_mem;
+	am200_metromem_dma = dma;
+
+	return 0;
+}
+
+static void am200_unshare_video_mem(void *data)
+{
+	struct metronomefb_par *par = data;
+
+	dev_dbg(&am200_device->dev, "ENTER %s\n", __func__);
+	par->metromem = NULL;
+	par->metromem_dma = 0;
+	dev_dbg(&am200_device->dev, "mod_put %p\n", am200_board.fbmaster);
+	module_put(am200_board.fbmaster);
+}
+
+/* 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 wfm_size;
+	int padding_size;
+
+	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;
+	}
+
+	fw = am200_fb_info.modes->xres;
+	wfm_size = ((16*1024 + 2 + fw - 1) / fw) * fw;
+	padding_size = PAGE_SIZE + (4 * fw);
+	am200_fb_info.extra_video_mem = fw + wfm_size + padding_size;
+	am200_fb_info.share_video_mem = am200_preshare_video_mem;
+	am200_fb_info.unshare_video_mem = NULL;
+
+	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 assign the parameters for completeness */
+static int am200_setup_fb(struct metronomefb_par *par)
+{
+
+	am200_fb_info.extra_video_mem = par->extra_size;
+	am200_fb_info.extra_data = (void *) par;
+	am200_fb_info.unshare_video_mem = am200_unshare_video_mem;
+
+	par->metromem = (unsigned char __force *) am200_metromem;
+	par->metromem_dma = am200_metromem_dma;
+
+	return 0;
+}
+
+static int am200_get_panel_type(void)
+{
+	return panel_type;
+}
+
+static irqreturn_t am200_handle_irq(int irq, void *dev_id)
+{

+	struct fb_info *info = dev_id;
+	struct metronomefb_par *par = info->par;
+
+	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);
+	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)
+{
+	int ret;
+
+	ret = wait_event_interruptible_timeout(par->waitq,
+					gpio_get_value(RDY_GPIO_PIN), HZ);
+	return ret;
+}

+
+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;
+
+	/* request our platform independent driver */
+	request_module("metronomefb");
+
+	am200_device = platform_device_alloc("metronomefb", -1);

+	if (!am200_device)
+		return -ENOMEM;
+
+	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);
+
+	am200_presetup_fb();

+
+	return ret;
+}
+
+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");