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authorJohn Crispin <blogic@openwrt.org>2012-08-16 11:31:02 +0000
committerJohn Crispin <blogic@openwrt.org>2012-08-23 00:18:25 +0200
commit30404aec4d093942ba67ded8e1926cbf4472d4f7 (patch)
tree9ffa8993db6cfdf1d87f49aa793682a28326eeeb /arch/mips/lantiq/xway/gptu.c
parentf40e1f9d856ec417468c090c4b56826171daa670 (diff)
downloadlinux-30404aec4d093942ba67ded8e1926cbf4472d4f7.tar.bz2
MIPS: lantiq: adds support for gptu timers
Lantiq socs have a General Purpose Timer Unit (GPTU). This driver allows us to initialize the timers. The voice firmware needs these timers as a reference. Signed-off-by: John Crispin <blogic@openwrt.org> Patchwork: http://patchwork.linux-mips.org/patch/4236/
Diffstat (limited to 'arch/mips/lantiq/xway/gptu.c')
-rw-r--r--arch/mips/lantiq/xway/gptu.c214
1 files changed, 214 insertions, 0 deletions
diff --git a/arch/mips/lantiq/xway/gptu.c b/arch/mips/lantiq/xway/gptu.c
new file mode 100644
index 000000000000..cbb56fc022bc
--- /dev/null
+++ b/arch/mips/lantiq/xway/gptu.c
@@ -0,0 +1,214 @@
+/*
+ * 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>
+ * Copyright (C) 2012 Lantiq GmbH
+ */
+
+#include <linux/interrupt.h>
+#include <linux/ioport.h>
+#include <linux/module.h>
+#include <linux/of_platform.h>
+#include <linux/of_irq.h>
+
+#include <lantiq_soc.h>
+#include "../clk.h"
+
+/* 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_ANY (BIT(7) | BIT(6))
+#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 gptu_w32(x, y) ltq_w32((x), gptu_membase + (y))
+#define gptu_r32(x) ltq_r32(gptu_membase + (x))
+
+enum gptu_timer {
+ TIMER1A = 0,
+ TIMER1B,
+ TIMER2A,
+ TIMER2B,
+ TIMER3A,
+ TIMER3B
+};
+
+static void __iomem *gptu_membase;
+static struct resource irqres[6];
+
+static irqreturn_t timer_irq_handler(int irq, void *priv)
+{
+ int timer = irq - irqres[0].start;
+ gptu_w32(1 << timer, GPTU_IRNCR);
+ return IRQ_HANDLED;
+}
+
+static void gptu_hwinit(void)
+{
+ gptu_w32(0x00, GPTU_IRNEN);
+ gptu_w32(0xff, GPTU_IRNCR);
+ gptu_w32(CLC_RMC | CLC_SUSPEND, GPTU_CLC);
+}
+
+static void gptu_hwexit(void)
+{
+ gptu_w32(0x00, GPTU_IRNEN);
+ gptu_w32(0xff, GPTU_IRNCR);
+ gptu_w32(CLC_DISABLE, GPTU_CLC);
+}
+
+static int gptu_enable(struct clk *clk)
+{
+ int ret = request_irq(irqres[clk->bits].start, timer_irq_handler,
+ IRQF_TIMER, "gtpu", NULL);
+ if (ret) {
+ pr_err("gptu: failed to request irq\n");
+ return ret;
+ }
+
+ gptu_w32(CON_CNT | CON_EDGE_ANY | CON_SYNC | CON_CLK_INT,
+ GPTU_CON(clk->bits));
+ gptu_w32(1, GPTU_RLD(clk->bits));
+ gptu_w32(gptu_r32(GPTU_IRNEN) | BIT(clk->bits), GPTU_IRNEN);
+ gptu_w32(RUN_SEN | RUN_RL, GPTU_RUN(clk->bits));
+ return 0;
+}
+
+static void gptu_disable(struct clk *clk)
+{
+ gptu_w32(0, GPTU_RUN(clk->bits));
+ gptu_w32(0, GPTU_CON(clk->bits));
+ gptu_w32(0, GPTU_RLD(clk->bits));
+ gptu_w32(gptu_r32(GPTU_IRNEN) & ~BIT(clk->bits), GPTU_IRNEN);
+ free_irq(irqres[clk->bits].start, NULL);
+}
+
+static inline void clkdev_add_gptu(struct device *dev, const char *con,
+ unsigned int timer)
+{
+ struct clk *clk = kzalloc(sizeof(struct clk), GFP_KERNEL);
+
+ clk->cl.dev_id = dev_name(dev);
+ clk->cl.con_id = con;
+ clk->cl.clk = clk;
+ clk->enable = gptu_enable;
+ clk->disable = gptu_disable;
+ clk->bits = timer;
+ clkdev_add(&clk->cl);
+}
+
+static int __devinit gptu_probe(struct platform_device *pdev)
+{
+ struct clk *clk;
+ struct resource *res;
+
+ if (of_irq_to_resource_table(pdev->dev.of_node, irqres, 6) != 6) {
+ dev_err(&pdev->dev, "Failed to get IRQ list\n");
+ return -EINVAL;
+ }
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res) {
+ dev_err(&pdev->dev, "Failed to get resource\n");
+ return -ENOMEM;
+ }
+
+ /* remap gptu register range */
+ gptu_membase = devm_request_and_ioremap(&pdev->dev, res);
+ if (!gptu_membase) {
+ dev_err(&pdev->dev, "Failed to remap resource\n");
+ return -ENOMEM;
+ }
+
+ /* enable our clock */
+ clk = clk_get(&pdev->dev, NULL);
+ if (IS_ERR(clk)) {
+ dev_err(&pdev->dev, "Failed to get clock\n");
+ return -ENOENT;
+ }
+ clk_enable(clk);
+
+ /* power up the core */
+ gptu_hwinit();
+
+ /* the gptu has a ID register */
+ if (((gptu_r32(GPTU_ID) >> 8) & 0xff) != GPTU_MAGIC) {
+ dev_err(&pdev->dev, "Failed to find magic\n");
+ gptu_hwexit();
+ return -ENAVAIL;
+ }
+
+ /* register the clocks */
+ clkdev_add_gptu(&pdev->dev, "timer1a", TIMER1A);
+ clkdev_add_gptu(&pdev->dev, "timer1b", TIMER1B);
+ clkdev_add_gptu(&pdev->dev, "timer2a", TIMER2A);
+ clkdev_add_gptu(&pdev->dev, "timer2b", TIMER2B);
+ clkdev_add_gptu(&pdev->dev, "timer3a", TIMER3A);
+ clkdev_add_gptu(&pdev->dev, "timer3b", TIMER3B);
+
+ dev_info(&pdev->dev, "gptu: 6 timers loaded\n");
+
+ return 0;
+}
+
+static const struct of_device_id gptu_match[] = {
+ { .compatible = "lantiq,gptu-xway" },
+ {},
+};
+MODULE_DEVICE_TABLE(of, dma_match);
+
+static struct platform_driver dma_driver = {
+ .probe = gptu_probe,
+ .driver = {
+ .name = "gptu-xway",
+ .owner = THIS_MODULE,
+ .of_match_table = gptu_match,
+ },
+};
+
+int __init gptu_init(void)
+{
+ int ret = platform_driver_register(&dma_driver);
+
+ if (ret)
+ pr_info("gptu: Error registering platform driver\n");
+ return ret;
+}
+
+arch_initcall(gptu_init);