1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Andestech ATCPIT100 timer driver
4  *
5  * (C) Copyright 2016
6  * Rick Chen, NDS32 Software Engineering, rick@andestech.com
7  */
8 #include <common.h>
9 #include <dm.h>
10 #include <errno.h>
11 #include <timer.h>
12 #include <linux/io.h>
13 
14 #define REG32_TMR(x)	(*(u32 *)	((plat->regs) + (x>>2)))
15 
16 /*
17  * Definition of register offsets
18  */
19 
20 /* ID and Revision Register */
21 #define ID_REV		0x0
22 
23 /* Configuration Register */
24 #define CFG		0x10
25 
26 /* Interrupt Enable Register */
27 #define INT_EN		0x14
28 #define CH_INT_EN(c , i)	((1<<i)<<(4*c))
29 
30 /* Interrupt Status Register */
31 #define INT_STA		0x18
32 #define CH_INT_STA(c , i)	((1<<i)<<(4*c))
33 
34 /* Channel Enable Register */
35 #define CH_EN		0x1C
36 #define CH_TMR_EN(c , t)	((1<<t)<<(4*c))
37 
38 /* Ch n Control REgister */
39 #define CH_CTL(n)	(0x20+0x10*n)
40 /* Channel clock source , bit 3 , 0:External clock , 1:APB clock */
41 #define APB_CLK		(1<<3)
42 /* Channel mode , bit 0~2 */
43 #define TMR_32		1
44 #define TMR_16		2
45 #define TMR_8		3
46 #define PWM		4
47 
48 #define CH_REL(n)	(0x24+0x10*n)
49 #define CH_CNT(n)	(0x28+0x10*n)
50 
51 struct atctmr_timer_regs {
52 	u32	id_rev;		/* 0x00 */
53 	u32	reservd[3];	/* 0x04 ~ 0x0c */
54 	u32	cfg;		/* 0x10 */
55 	u32	int_en;		/* 0x14 */
56 	u32	int_st;		/* 0x18 */
57 	u32	ch_en;		/* 0x1c */
58 	u32	ch0_ctrl;	/* 0x20 */
59 	u32	ch0_reload;	/* 0x24 */
60 	u32	ch0_cntr;	/* 0x28 */
61 	u32	reservd1;	/* 0x2c */
62 	u32	ch1_ctrl;	/* 0x30 */
63 	u32	ch1_reload;	/* 0x34 */
64 	u32	int_mask;	/* 0x38 */
65 };
66 
67 struct atcpit_timer_plat {
68 	u32 *regs;
69 };
70 
atcpit_timer_get_count(struct udevice * dev)71 static u64 atcpit_timer_get_count(struct udevice *dev)
72 {
73 	struct atcpit_timer_plat *plat = dev_get_plat(dev);
74 	u32 val;
75 	val = ~(REG32_TMR(CH_CNT(1))+0xffffffff);
76 	return timer_conv_64(val);
77 }
78 
atcpit_timer_probe(struct udevice * dev)79 static int atcpit_timer_probe(struct udevice *dev)
80 {
81 	struct atcpit_timer_plat *plat = dev_get_plat(dev);
82 	REG32_TMR(CH_REL(1)) = 0xffffffff;
83 	REG32_TMR(CH_CTL(1)) = APB_CLK|TMR_32;
84 	REG32_TMR(CH_EN) |= CH_TMR_EN(1 , 0);
85 	return 0;
86 }
87 
atcpit_timer_of_to_plat(struct udevice * dev)88 static int atcpit_timer_of_to_plat(struct udevice *dev)
89 {
90 	struct atcpit_timer_plat *plat = dev_get_plat(dev);
91 	plat->regs = map_physmem(dev_read_addr(dev), 0x100 , MAP_NOCACHE);
92 	return 0;
93 }
94 
95 static const struct timer_ops atcpit_timer_ops = {
96 	.get_count = atcpit_timer_get_count,
97 };
98 
99 static const struct udevice_id atcpit_timer_ids[] = {
100 	{ .compatible = "andestech,atcpit100" },
101 	{}
102 };
103 
104 U_BOOT_DRIVER(atcpit100_timer) = {
105 	.name	= "atcpit100_timer",
106 	.id	= UCLASS_TIMER,
107 	.of_match = atcpit_timer_ids,
108 	.of_to_plat = atcpit_timer_of_to_plat,
109 	.plat_auto	= sizeof(struct atcpit_timer_plat),
110 	.probe = atcpit_timer_probe,
111 	.ops	= &atcpit_timer_ops,
112 };
113