1// SPDX-License-Identifier: GPL-2.0-only
  2#include <linux/clk.h>
  3#include <linux/err.h>
  4#include <linux/init.h>
  5#include <linux/io.h>
  6#include <linux/ioport.h>
  7#include <linux/kernel.h>
  8#include <linux/platform_device.h>
  9#include <linux/module.h>
 10#include <linux/slab.h>
 11#include <linux/export.h>
 12#include <linux/of.h>
 13#include <soc/at91/atmel_tcb.h>
 14
 15/*
 16 * This is a thin library to solve the problem of how to portably allocate
 17 * one of the TC blocks.  For simplicity, it doesn't currently expect to
 18 * share individual timers between different drivers.
 19 */
 20
 21#if defined(CONFIG_AVR32)
 22/* AVR32 has these divide PBB */
 23const u8 atmel_tc_divisors[5] = { 0, 4, 8, 16, 32, };
 24EXPORT_SYMBOL(atmel_tc_divisors);
 25
 26#elif defined(CONFIG_ARCH_AT91)
 27/* AT91 has these divide MCK */
 28const u8 atmel_tc_divisors[5] = { 2, 8, 32, 128, 0, };
 29EXPORT_SYMBOL(atmel_tc_divisors);
 30
 31#endif
 32
 33static DEFINE_SPINLOCK(tc_list_lock);
 34static LIST_HEAD(tc_list);
 35
 36/**
 37 * atmel_tc_alloc - allocate a specified TC block
 38 * @block: which block to allocate
 39 *
 40 * Caller allocates a block.  If it is available, a pointer to a
 41 * pre-initialized struct atmel_tc is returned. The caller can access
 42 * the registers directly through the "regs" field.
 43 */
 44struct atmel_tc *atmel_tc_alloc(unsigned block)
 45{
 46	struct atmel_tc		*tc;
 47	struct platform_device	*pdev = NULL;
 48
 49	spin_lock(&tc_list_lock);
 50	list_for_each_entry(tc, &tc_list, node) {
 51		if (tc->allocated)
 52			continue;
 53
 54		if ((tc->pdev->dev.of_node && tc->id == block) ||
 55		    (tc->pdev->id == block)) {
 56			pdev = tc->pdev;
 57			tc->allocated = true;
 58			break;
 59		}
 60	}
 61	spin_unlock(&tc_list_lock);
 62
 63	return pdev ? tc : NULL;
 64}
 65EXPORT_SYMBOL_GPL(atmel_tc_alloc);
 66
 67/**
 68 * atmel_tc_free - release a specified TC block
 69 * @tc: Timer/counter block that was returned by atmel_tc_alloc()
 70 *
 71 * This reverses the effect of atmel_tc_alloc(), invalidating the resource
 72 * returned by that routine and making the TC available to other drivers.
 73 */
 74void atmel_tc_free(struct atmel_tc *tc)
 75{
 76	spin_lock(&tc_list_lock);
 77	if (tc->allocated)
 78		tc->allocated = false;
 79	spin_unlock(&tc_list_lock);
 80}
 81EXPORT_SYMBOL_GPL(atmel_tc_free);
 82
 83#if defined(CONFIG_OF)
 84static struct atmel_tcb_config tcb_rm9200_config = {
 85	.counter_width = 16,
 86};
 87
 88static struct atmel_tcb_config tcb_sam9x5_config = {
 89	.counter_width = 32,
 90};
 91
 92static const struct of_device_id atmel_tcb_dt_ids[] = {
 93	{
 94		.compatible = "atmel,at91rm9200-tcb",
 95		.data = &tcb_rm9200_config,
 96	}, {
 97		.compatible = "atmel,at91sam9x5-tcb",
 98		.data = &tcb_sam9x5_config,
 99	}, {
100		/* sentinel */
101	}
102};
103
104MODULE_DEVICE_TABLE(of, atmel_tcb_dt_ids);
105#endif
106
107static int __init tc_probe(struct platform_device *pdev)
108{
109	struct atmel_tc *tc;
110	struct clk	*clk;
111	int		irq;
112	unsigned int	i;
113
114	if (of_get_child_count(pdev->dev.of_node))
115		return -EBUSY;
116
117	irq = platform_get_irq(pdev, 0);
118	if (irq < 0)
119		return -EINVAL;
120
121	tc = devm_kzalloc(&pdev->dev, sizeof(struct atmel_tc), GFP_KERNEL);
122	if (!tc)
123		return -ENOMEM;
124
125	tc->pdev = pdev;
126
127	clk = devm_clk_get(&pdev->dev, "t0_clk");
128	if (IS_ERR(clk))
129		return PTR_ERR(clk);
130
131	tc->slow_clk = devm_clk_get(&pdev->dev, "slow_clk");
132	if (IS_ERR(tc->slow_clk))
133		return PTR_ERR(tc->slow_clk);
134
135	tc->regs = devm_platform_ioremap_resource(pdev, 0);
136	if (IS_ERR(tc->regs))
137		return PTR_ERR(tc->regs);
138
139	/* Now take SoC information if available */
140	if (pdev->dev.of_node) {
141		const struct of_device_id *match;
142		match = of_match_node(atmel_tcb_dt_ids, pdev->dev.of_node);
143		if (match)
144			tc->tcb_config = match->data;
145
146		tc->id = of_alias_get_id(tc->pdev->dev.of_node, "tcb");
147	} else {
148		tc->id = pdev->id;
149	}
150
151	tc->clk[0] = clk;
152	tc->clk[1] = devm_clk_get(&pdev->dev, "t1_clk");
153	if (IS_ERR(tc->clk[1]))
154		tc->clk[1] = clk;
155	tc->clk[2] = devm_clk_get(&pdev->dev, "t2_clk");
156	if (IS_ERR(tc->clk[2]))
157		tc->clk[2] = clk;
158
159	tc->irq[0] = irq;
160	tc->irq[1] = platform_get_irq(pdev, 1);
161	if (tc->irq[1] < 0)
162		tc->irq[1] = irq;
163	tc->irq[2] = platform_get_irq(pdev, 2);
164	if (tc->irq[2] < 0)
165		tc->irq[2] = irq;
166
167	for (i = 0; i < 3; i++)
168		writel(ATMEL_TC_ALL_IRQ, tc->regs + ATMEL_TC_REG(i, IDR));
169
170	spin_lock(&tc_list_lock);
171	list_add_tail(&tc->node, &tc_list);
172	spin_unlock(&tc_list_lock);
173
174	platform_set_drvdata(pdev, tc);
175
176	return 0;
177}
178
179static void tc_shutdown(struct platform_device *pdev)
180{
181	int i;
182	struct atmel_tc *tc = platform_get_drvdata(pdev);
183
184	for (i = 0; i < 3; i++)
185		writel(ATMEL_TC_ALL_IRQ, tc->regs + ATMEL_TC_REG(i, IDR));
186}
187
188static struct platform_driver tc_driver = {
189	.driver = {
190		.name	= "atmel_tcb",
191		.of_match_table	= of_match_ptr(atmel_tcb_dt_ids),
192	},
193	.shutdown = tc_shutdown,
194};
195
196static int __init tc_init(void)
197{
198	return platform_driver_probe(&tc_driver, tc_probe);
199}
200arch_initcall(tc_init);