Revert "Staging: olpc_dcon: Remove obsolete driver"

This reverts commit 82ef33af9dd30075adbd9f3dd161b606b8ba88ac.  It turns
out these machines are still out there, and the original patch broke
them.  So revert it, adding back the driver, so people's machines still
work properly.

Reported-by: James Cameron <quozl@laptop.org>
Cc: Shraddha Barke <shraddha.6596@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 205 insertions, 0 deletions

diff --git a/drivers/staging/olpc_dcon/olpc_dcon_xo_1.c b/drivers/staging/olpc_dcon/olpc_dcon_xo_1.c
new file mode 100644
index 000000000000..0c5a10c69401
--- /dev/null
+++ b/drivers/staging/olpc_dcon/olpc_dcon_xo_1.c
@@ -0,0 +1,205 @@
+/*
+ * Mainly by David Woodhouse, somewhat modified by Jordan Crouse
+ *
+ * Copyright © 2006-2007  Red Hat, Inc.
+ * Copyright © 2006-2007  Advanced Micro Devices, Inc.
+ * Copyright © 2009       VIA Technology, Inc.
+ * Copyright (c) 2010  Andres Salomon <dilinger@queued.net>
+ *
+ * This program is free software.  You can redistribute it and/or
+ * modify it under the terms of version 2 of the GNU General Public
+ * License as published by the Free Software Foundation.
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/cs5535.h>
+#include <linux/gpio.h>
+#include <linux/delay.h>
+#include <asm/olpc.h>
+
+#include "olpc_dcon.h"
+
+static int dcon_init_xo_1(struct dcon_priv *dcon)
+{
+	unsigned char lob;
+
+	if (gpio_request(OLPC_GPIO_DCON_STAT0, "OLPC-DCON")) {
+		pr_err("failed to request STAT0 GPIO\n");
+		return -EIO;
+	}
+	if (gpio_request(OLPC_GPIO_DCON_STAT1, "OLPC-DCON")) {
+		pr_err("failed to request STAT1 GPIO\n");
+		goto err_gp_stat1;
+	}
+	if (gpio_request(OLPC_GPIO_DCON_IRQ, "OLPC-DCON")) {
+		pr_err("failed to request IRQ GPIO\n");
+		goto err_gp_irq;
+	}
+	if (gpio_request(OLPC_GPIO_DCON_LOAD, "OLPC-DCON")) {
+		pr_err("failed to request LOAD GPIO\n");
+		goto err_gp_load;
+	}
+	if (gpio_request(OLPC_GPIO_DCON_BLANK, "OLPC-DCON")) {
+		pr_err("failed to request BLANK GPIO\n");
+		goto err_gp_blank;
+	}
+
+	/* Turn off the event enable for GPIO7 just to be safe */
+	cs5535_gpio_clear(OLPC_GPIO_DCON_IRQ, GPIO_EVENTS_ENABLE);
+
+	/*
+	 * Determine the current state by reading the GPIO bit; earlier
+	 * stages of the boot process have established the state.
+	 *
+	 * Note that we read GPIO_OUTPUT_VAL rather than GPIO_READ_BACK here;
+	 * this is because OFW will disable input for the pin and set a value..
+	 * READ_BACK will only contain a valid value if input is enabled and
+	 * then a value is set.  So, future readings of the pin can use
+	 * READ_BACK, but the first one cannot.  Awesome, huh?
+	 */
+	dcon->curr_src = cs5535_gpio_isset(OLPC_GPIO_DCON_LOAD, GPIO_OUTPUT_VAL)
+		? DCON_SOURCE_CPU
+		: DCON_SOURCE_DCON;
+	dcon->pending_src = dcon->curr_src;
+
+	/* Set the directions for the GPIO pins */
+	gpio_direction_input(OLPC_GPIO_DCON_STAT0);
+	gpio_direction_input(OLPC_GPIO_DCON_STAT1);
+	gpio_direction_input(OLPC_GPIO_DCON_IRQ);
+	gpio_direction_input(OLPC_GPIO_DCON_BLANK);
+	gpio_direction_output(OLPC_GPIO_DCON_LOAD,
+			dcon->curr_src == DCON_SOURCE_CPU);
+
+	/* Set up the interrupt mappings */
+
+	/* Set the IRQ to pair 2 */
+	cs5535_gpio_setup_event(OLPC_GPIO_DCON_IRQ, 2, 0);
+
+	/* Enable group 2 to trigger the DCON interrupt */
+	cs5535_gpio_set_irq(2, DCON_IRQ);
+
+	/* Select edge level for interrupt (in PIC) */
+	lob = inb(0x4d0);
+	lob &= ~(1 << DCON_IRQ);
+	outb(lob, 0x4d0);
+
+	/* Register the interrupt handler */
+	if (request_irq(DCON_IRQ, &dcon_interrupt, 0, "DCON", dcon)) {
+		pr_err("failed to request DCON's irq\n");
+		goto err_req_irq;
+	}
+
+	/* Clear INV_EN for GPIO7 (DCONIRQ) */
+	cs5535_gpio_clear(OLPC_GPIO_DCON_IRQ, GPIO_INPUT_INVERT);
+
+	/* Enable filter for GPIO12 (DCONBLANK) */
+	cs5535_gpio_set(OLPC_GPIO_DCON_BLANK, GPIO_INPUT_FILTER);
+
+	/* Disable filter for GPIO7 */
+	cs5535_gpio_clear(OLPC_GPIO_DCON_IRQ, GPIO_INPUT_FILTER);
+
+	/* Disable event counter for GPIO7 (DCONIRQ) and GPIO12 (DCONBLANK) */
+	cs5535_gpio_clear(OLPC_GPIO_DCON_IRQ, GPIO_INPUT_EVENT_COUNT);
+	cs5535_gpio_clear(OLPC_GPIO_DCON_BLANK, GPIO_INPUT_EVENT_COUNT);
+
+	/* Add GPIO12 to the Filter Event Pair #7 */
+	cs5535_gpio_set(OLPC_GPIO_DCON_BLANK, GPIO_FE7_SEL);
+
+	/* Turn off negative Edge Enable for GPIO12 */
+	cs5535_gpio_clear(OLPC_GPIO_DCON_BLANK, GPIO_NEGATIVE_EDGE_EN);
+
+	/* Enable negative Edge Enable for GPIO7 */
+	cs5535_gpio_set(OLPC_GPIO_DCON_IRQ, GPIO_NEGATIVE_EDGE_EN);
+
+	/* Zero the filter amount for Filter Event Pair #7 */
+	cs5535_gpio_set(0, GPIO_FLTR7_AMOUNT);
+
+	/* Clear the negative edge status for GPIO7 and GPIO12 */
+	cs5535_gpio_set(OLPC_GPIO_DCON_IRQ, GPIO_NEGATIVE_EDGE_STS);
+	cs5535_gpio_set(OLPC_GPIO_DCON_BLANK, GPIO_NEGATIVE_EDGE_STS);
+
+	/* FIXME:  Clear the positive status as well, just to be sure */
+	cs5535_gpio_set(OLPC_GPIO_DCON_IRQ, GPIO_POSITIVE_EDGE_STS);
+	cs5535_gpio_set(OLPC_GPIO_DCON_BLANK, GPIO_POSITIVE_EDGE_STS);
+
+	/* Enable events for GPIO7 (DCONIRQ) and GPIO12 (DCONBLANK) */
+	cs5535_gpio_set(OLPC_GPIO_DCON_IRQ, GPIO_EVENTS_ENABLE);
+	cs5535_gpio_set(OLPC_GPIO_DCON_BLANK, GPIO_EVENTS_ENABLE);
+
+	return 0;
+
+err_req_irq:
+	gpio_free(OLPC_GPIO_DCON_BLANK);
+err_gp_blank:
+	gpio_free(OLPC_GPIO_DCON_LOAD);
+err_gp_load:
+	gpio_free(OLPC_GPIO_DCON_IRQ);
+err_gp_irq:
+	gpio_free(OLPC_GPIO_DCON_STAT1);
+err_gp_stat1:
+	gpio_free(OLPC_GPIO_DCON_STAT0);
+	return -EIO;
+}
+
+static void dcon_wiggle_xo_1(void)
+{
+	int x;
+
+	/*
+	 * According to HiMax, when powering the DCON up we should hold
+	 * SMB_DATA high for 8 SMB_CLK cycles.  This will force the DCON
+	 * state machine to reset to a (sane) initial state.  Mitch Bradley
+	 * did some testing and discovered that holding for 16 SMB_CLK cycles
+	 * worked a lot more reliably, so that's what we do here.
+	 *
+	 * According to the cs5536 spec, to set GPIO14 to SMB_CLK we must
+	 * simultaneously set AUX1 IN/OUT to GPIO14; ditto for SMB_DATA and
+	 * GPIO15.
+	 */
+	cs5535_gpio_set(OLPC_GPIO_SMB_CLK, GPIO_OUTPUT_VAL);
+	cs5535_gpio_set(OLPC_GPIO_SMB_DATA, GPIO_OUTPUT_VAL);
+	cs5535_gpio_set(OLPC_GPIO_SMB_CLK, GPIO_OUTPUT_ENABLE);
+	cs5535_gpio_set(OLPC_GPIO_SMB_DATA, GPIO_OUTPUT_ENABLE);
+	cs5535_gpio_clear(OLPC_GPIO_SMB_CLK, GPIO_OUTPUT_AUX1);
+	cs5535_gpio_clear(OLPC_GPIO_SMB_DATA, GPIO_OUTPUT_AUX1);
+	cs5535_gpio_clear(OLPC_GPIO_SMB_CLK, GPIO_OUTPUT_AUX2);
+	cs5535_gpio_clear(OLPC_GPIO_SMB_DATA, GPIO_OUTPUT_AUX2);
+	cs5535_gpio_clear(OLPC_GPIO_SMB_CLK, GPIO_INPUT_AUX1);
+	cs5535_gpio_clear(OLPC_GPIO_SMB_DATA, GPIO_INPUT_AUX1);
+
+	for (x = 0; x < 16; x++) {
+		udelay(5);
+		cs5535_gpio_clear(OLPC_GPIO_SMB_CLK, GPIO_OUTPUT_VAL);
+		udelay(5);
+		cs5535_gpio_set(OLPC_GPIO_SMB_CLK, GPIO_OUTPUT_VAL);
+	}
+	udelay(5);
+	cs5535_gpio_set(OLPC_GPIO_SMB_CLK, GPIO_OUTPUT_AUX1);
+	cs5535_gpio_set(OLPC_GPIO_SMB_DATA, GPIO_OUTPUT_AUX1);
+	cs5535_gpio_set(OLPC_GPIO_SMB_CLK, GPIO_INPUT_AUX1);
+	cs5535_gpio_set(OLPC_GPIO_SMB_DATA, GPIO_INPUT_AUX1);
+}
+
+static void dcon_set_dconload_1(int val)
+{
+	gpio_set_value(OLPC_GPIO_DCON_LOAD, val);
+}
+
+static int dcon_read_status_xo_1(u8 *status)
+{
+	*status = gpio_get_value(OLPC_GPIO_DCON_STAT0);
+	*status |= gpio_get_value(OLPC_GPIO_DCON_STAT1) << 1;
+
+	/* Clear the negative edge status for GPIO7 */
+	cs5535_gpio_set(OLPC_GPIO_DCON_IRQ, GPIO_NEGATIVE_EDGE_STS);
+
+	return 0;
+}
+
+struct dcon_platform_data dcon_pdata_xo_1 = {
+	.init = dcon_init_xo_1,
+	.bus_stabilize_wiggle = dcon_wiggle_xo_1,
+	.set_dconload = dcon_set_dconload_1,
+	.read_status = dcon_read_status_xo_1,
+};