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/*
* 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 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);
/* remap gptu register range */
gptu_membase = devm_ioremap_resource(&pdev->dev, res);
if (IS_ERR(gptu_membase))
return PTR_ERR(gptu_membase);
/* 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();
clk_disable(clk);
clk_put(clk);
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);
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