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, 161 insertions, 0 deletions

diff --git a/drivers/staging/olpc_dcon/olpc_dcon_xo_1_5.c b/drivers/staging/olpc_dcon/olpc_dcon_xo_1_5.c
new file mode 100644
index 000000000000..6a4d379c16a3
--- /dev/null
+++ b/drivers/staging/olpc_dcon/olpc_dcon_xo_1_5.c
@@ -0,0 +1,161 @@
+/*
+ * Copyright (c) 2009,2010       One Laptop per Child
+ *
+ * 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/acpi.h>
+#include <linux/delay.h>
+#include <linux/gpio.h>
+#include <asm/olpc.h>
+
+/* TODO: this eventually belongs in linux/vx855.h */
+#define NR_VX855_GPI    14
+#define NR_VX855_GPO    13
+#define NR_VX855_GPIO   15
+
+#define VX855_GPI(n)    (n)
+#define VX855_GPO(n)    (NR_VX855_GPI + (n))
+#define VX855_GPIO(n)   (NR_VX855_GPI + NR_VX855_GPO + (n))
+
+#include "olpc_dcon.h"
+
+/* Hardware setup on the XO 1.5:
+ *	DCONLOAD connects to VX855_GPIO1 (not SMBCK2)
+ *	DCONBLANK connects to VX855_GPIO8 (not SSPICLK)  unused in driver
+ *	DCONSTAT0 connects to VX855_GPI10 (not SSPISDI)
+ *	DCONSTAT1 connects to VX855_GPI11 (not nSSPISS)
+ *	DCONIRQ connects to VX855_GPIO12
+ *	DCONSMBDATA connects to VX855 graphics CRTSPD
+ *	DCONSMBCLK connects to VX855 graphics CRTSPCLK
+ */
+
+#define VX855_GENL_PURPOSE_OUTPUT 0x44c /* PMIO_Rx4c-4f */
+#define VX855_GPI_STATUS_CHG 0x450  /* PMIO_Rx50 */
+#define VX855_GPI_SCI_SMI 0x452  /* PMIO_Rx52 */
+#define BIT_GPIO12 0x40
+
+#define PREFIX "OLPC DCON:"
+
+static void dcon_clear_irq(void)
+{
+	/* irq status will appear in PMIO_Rx50[6] (RW1C) on gpio12 */
+	outb(BIT_GPIO12, VX855_GPI_STATUS_CHG);
+}
+
+static int dcon_was_irq(void)
+{
+	u_int8_t tmp;
+
+	/* irq status will appear in PMIO_Rx50[6] on gpio12 */
+	tmp = inb(VX855_GPI_STATUS_CHG);
+	return !!(tmp & BIT_GPIO12);
+
+	return 0;
+}
+
+static int dcon_init_xo_1_5(struct dcon_priv *dcon)
+{
+	unsigned int irq;
+
+	dcon_clear_irq();
+
+	/* set   PMIO_Rx52[6] to enable SCI/SMI on gpio12 */
+	outb(inb(VX855_GPI_SCI_SMI)|BIT_GPIO12, VX855_GPI_SCI_SMI);
+
+	/* Determine the current state of DCONLOAD, likely set by firmware */
+	/* GPIO1 */
+	dcon->curr_src = (inl(VX855_GENL_PURPOSE_OUTPUT) & 0x1000) ?
+			DCON_SOURCE_CPU : DCON_SOURCE_DCON;
+	dcon->pending_src = dcon->curr_src;
+
+	/* we're sharing the IRQ with ACPI */
+	irq = acpi_gbl_FADT.sci_interrupt;
+	if (request_irq(irq, &dcon_interrupt, IRQF_SHARED, "DCON", dcon)) {
+		pr_err("DCON (IRQ%d) allocation failed\n", irq);
+		return 1;
+	}
+
+	return 0;
+}
+
+static void set_i2c_line(int sda, int scl)
+{
+	unsigned char tmp;
+	unsigned int port = 0x26;
+
+	/* FIXME: This directly accesses the CRT GPIO controller !!! */
+	outb(port, 0x3c4);
+	tmp = inb(0x3c5);
+
+	if (scl)
+		tmp |= 0x20;
+	else
+		tmp &= ~0x20;
+
+	if (sda)
+		tmp |= 0x10;
+	else
+		tmp &= ~0x10;
+
+	tmp |= 0x01;
+
+	outb(port, 0x3c4);
+	outb(tmp, 0x3c5);
+}
+
+
+static void dcon_wiggle_xo_1_5(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.
+	 */
+	set_i2c_line(1, 1);
+
+	for (x = 0; x < 16; x++) {
+		udelay(5);
+		set_i2c_line(1, 0);
+		udelay(5);
+		set_i2c_line(1, 1);
+	}
+	udelay(5);
+
+	/* set   PMIO_Rx52[6] to enable SCI/SMI on gpio12 */
+	outb(inb(VX855_GPI_SCI_SMI)|BIT_GPIO12, VX855_GPI_SCI_SMI);
+}
+
+static void dcon_set_dconload_xo_1_5(int val)
+{
+	gpio_set_value(VX855_GPIO(1), val);
+}
+
+static int dcon_read_status_xo_1_5(u8 *status)
+{
+	if (!dcon_was_irq())
+		return -1;
+
+	/* i believe this is the same as "inb(0x44b) & 3" */
+	*status = gpio_get_value(VX855_GPI(10));
+	*status |= gpio_get_value(VX855_GPI(11)) << 1;
+
+	dcon_clear_irq();
+
+	return 0;
+}
+
+struct dcon_platform_data dcon_pdata_xo_1_5 = {
+	.init = dcon_init_xo_1_5,
+	.bus_stabilize_wiggle = dcon_wiggle_xo_1_5,
+	.set_dconload = dcon_set_dconload_xo_1_5,
+	.read_status = dcon_read_status_xo_1_5,
+};