Openwrt/target/linux/lantiq/patches-3.2/0050-MIPS-adds-gptu-driver.patch

From ce8fccecad845349cc5f6783b3812a17a074d39c Mon Sep 17 00:00:00 2001
From: John Crispin <blogic@openwrt.org>
Date: Wed, 14 Mar 2012 15:37:19 +0100
Subject: [PATCH 50/73] MIPS: adds gptu driver

---
 arch/mips/lantiq/xway/gptu.c |  176 ++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 176 insertions(+), 0 deletions(-)
 create mode 100644 arch/mips/lantiq/xway/gptu.c

--- /dev/null
+++ b/arch/mips/lantiq/xway/gptu.c
@@ -0,0 +1,176 @@
+/*
+ *  This program is free software; you can redistribute it and/or modify it
+ *  under the terms of the GNU General Public License version 2 as published
+ *  by the Free Software Foundation.
+ *
+ *  Copyright (C) 2012 John Crispin <blogic@openwrt.org>
+ */
+
+#include <linux/init.h>
+#include <linux/io.h>
+#include <linux/ioport.h>
+#include <linux/pm.h>
+#include <linux/export.h>
+#include <linux/delay.h>
+#include <linux/interrupt.h>
+#include <asm/reboot.h>
+
+#include <lantiq_soc.h>
+#include "../clk.h"
+
+#include "../devices.h"
+
+#define ltq_gptu_w32(x, y)	ltq_w32((x), ltq_gptu_membase + (y))
+#define ltq_gptu_r32(x)		ltq_r32(ltq_gptu_membase + (x))
+
+
+/* the magic ID byte of the core */
+#define GPTU_MAGIC	0x59
+/* clock control register */
+#define GPTU_CLC	0x00
+/* id register */
+#define GPTU_ID		0x08
+/* interrupt node enable */
+#define GPTU_IRNEN	0xf4
+/* interrupt control register */
+#define GPTU_IRCR	0xf8
+/* interrupt capture register */
+#define GPTU_IRNCR	0xfc
+/* there are 3 identical blocks of 2 timers. calculate register offsets */
+#define GPTU_SHIFT(x)	(x % 2 ? 4 : 0)
+#define GPTU_BASE(x)	(((x >> 1) * 0x20) + 0x10)
+/* timer control register */
+#define GPTU_CON(x)	(GPTU_BASE(x) + GPTU_SHIFT(x) + 0x00)
+/* timer auto reload register */
+#define GPTU_RUN(x)	(GPTU_BASE(x) + GPTU_SHIFT(x) + 0x08)
+/* timer manual reload register */
+#define GPTU_RLD(x)	(GPTU_BASE(x) + GPTU_SHIFT(x) + 0x10)
+/* timer count register */
+#define GPTU_CNT(x)	(GPTU_BASE(x) + GPTU_SHIFT(x) + 0x18)
+
+/* GPTU_CON(x) */
+#define CON_CNT		BIT(2)
+#define CON_EDGE_FALL	BIT(7)
+#define CON_SYNC	BIT(8)
+#define CON_CLK_INT	BIT(10)
+
+/* GPTU_RUN(x) */
+#define RUN_SEN		BIT(0)
+#define RUN_RL		BIT(2)
+
+/* set clock to runmode */
+#define CLC_RMC		BIT(8)
+/* bring core out of suspend */
+#define CLC_SUSPEND	BIT(4)
+/* the disable bit */
+#define CLC_DISABLE	BIT(0)
+
+#define TIMER_INTERRUPT	(INT_NUM_IM3_IRL0 + 22)
+
+enum gptu_timer {
+	TIMER1A = 0,
+	TIMER1B,
+	TIMER2A,
+	TIMER2B,
+	TIMER3A,
+	TIMER3B
+};
+
+static struct resource ltq_gptu_resource =
+	MEM_RES("GPTU", LTQ_GPTU_BASE_ADDR, LTQ_GPTU_SIZE);
+
+static void __iomem *ltq_gptu_membase;
+
+static irqreturn_t timer_irq_handler(int irq, void *priv)
+{
+	int timer = irq - TIMER_INTERRUPT;
+	ltq_gptu_w32(1 << timer, GPTU_IRNCR);
+	return IRQ_HANDLED;
+}
+
+static void gptu_hwinit(void)
+{
+	struct clk *clk = clk_get_sys("ltq_gptu", NULL);
+	clk_enable(clk);
+	ltq_gptu_w32(0x00, GPTU_IRNEN);
+	ltq_gptu_w32(0xff, GPTU_IRNCR);
+	ltq_gptu_w32(CLC_RMC | CLC_SUSPEND, GPTU_CLC);
+}
+
+static void gptu_hwexit(void)
+{
+	ltq_gptu_w32(0x00, GPTU_IRNEN);
+	ltq_gptu_w32(0xff, GPTU_IRNCR);
+	ltq_gptu_w32(CLC_DISABLE, GPTU_CLC);
+}
+
+static int ltq_gptu_enable(struct clk *clk)
+{
+	int ret = request_irq(TIMER_INTERRUPT + clk->bits, timer_irq_handler,
+		IRQF_TIMER, "timer", NULL);
+	if (ret) {
+		pr_err("gptu: failed to request irq\n");
+		return ret;
+	}
+
+        ltq_gptu_w32(CON_CNT | CON_EDGE_FALL | CON_SYNC | CON_CLK_INT,
+		GPTU_CON(clk->bits));
+	ltq_gptu_w32(1, GPTU_RLD(clk->bits));
+	ltq_gptu_w32(ltq_gptu_r32(GPTU_IRNEN) | clk->bits, GPTU_IRNEN);
+	ltq_gptu_w32(RUN_SEN | RUN_RL, GPTU_RUN(clk->bits));
+	return 0;
+}
+
+static void ltq_gptu_disable(struct clk *clk)
+{
+	ltq_gptu_w32(0, GPTU_RUN(clk->bits));
+	ltq_gptu_w32(0,	GPTU_CON(clk->bits));
+	ltq_gptu_w32(0, GPTU_RLD(clk->bits));
+	ltq_gptu_w32(ltq_gptu_r32(GPTU_IRNEN) & ~clk->bits, GPTU_IRNEN);
+	free_irq(TIMER_INTERRUPT + clk->bits, NULL);
+}
+
+static inline void clkdev_add_gptu(const char *con, unsigned int timer)
+{
+	struct clk *clk = kzalloc(sizeof(struct clk), GFP_KERNEL);
+
+	clk->cl.dev_id = "ltq_gptu";
+	clk->cl.con_id = con;
+	clk->cl.clk = clk;
+	clk->enable = ltq_gptu_enable;
+	clk->disable = ltq_gptu_disable;
+	clk->bits = timer;
+	clkdev_add(&clk->cl);
+}
+
+static int __init gptu_setup(void)
+{
+	/* remap gptu register range */
+	ltq_gptu_membase = ltq_remap_resource(&ltq_gptu_resource);
+	if (!ltq_gptu_membase)
+		panic("Failed to remap gptu memory");
+
+	/* power up the core */
+	gptu_hwinit();
+
+	/* the gptu has a ID register */
+	if (((ltq_gptu_r32(GPTU_ID) >> 8) & 0xff) != GPTU_MAGIC) {
+		pr_err("gptu: failed to find magic\n");
+		gptu_hwexit();
+		return -ENAVAIL;
+	}
+
+	/* register the clocks */
+	clkdev_add_gptu("timer1a", TIMER1A);
+	clkdev_add_gptu("timer1b", TIMER1B);
+	clkdev_add_gptu("timer2a", TIMER2A);
+	clkdev_add_gptu("timer2b", TIMER2B);
+	clkdev_add_gptu("timer3a", TIMER3A);
+	clkdev_add_gptu("timer3b", TIMER3B);
+
+	pr_info("gptu: 6 timers loaded\n");
+
+	return 0;
+}
+
+arch_initcall(gptu_setup);