1 /*
2  * (C) Copyright 2010
3  * Marvell Semiconductor <www.marvell.com>
4  * Written-by: Prafulla Wadaskar <prafulla@marvell.com>
5  * Contributor: Mahavir Jain <mjain@marvell.com>
6  *
7  * See file CREDITS for list of people who contributed to this
8  * project.
9  *
10  * This program is free software; you can redistribute it and/or
11  * modify it under the terms of the GNU General Public License as
12  * published by the Free Software Foundation; either version 2 of
13  * the License, or (at your option) any later version.
14  *
15  * This program is distributed in the hope that it will be useful,
16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18  * GNU General Public License for more details.
19  *
20  * You should have received a copy of the GNU General Public License
21  * along with this program; if not, write to the Free Software
22  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
23  * MA 02110-1301 USA
24  */
25 
26 #include <common.h>
27 #include <asm/arch/armada100.h>
28 
29 /*
30  * Timer registers
31  * Refer Section A.6 in Datasheet
32  */
33 struct armd1tmr_registers {
34 	u32 clk_ctrl;	/* Timer clk control reg */
35 	u32 match[9];	/* Timer match registers */
36 	u32 count[3];	/* Timer count registers */
37 	u32 status[3];
38 	u32 ie[3];
39 	u32 preload[3];	/* Timer preload value */
40 	u32 preload_ctrl[3];
41 	u32 wdt_match_en;
42 	u32 wdt_match_r;
43 	u32 wdt_val;
44 	u32 wdt_sts;
45 	u32 icr[3];
46 	u32 wdt_icr;
47 	u32 cer;	/* Timer count enable reg */
48 	u32 cmr;
49 	u32 ilr[3];
50 	u32 wcr;
51 	u32 wfar;
52 	u32 wsar;
53 	u32 cvwr;
54 };
55 
56 #define TIMER			0	/* Use TIMER 0 */
57 /* Each timer has 3 match registers */
58 #define MATCH_CMP(x)		((3 * TIMER) + x)
59 #define TIMER_LOAD_VAL 		0xffffffff
60 #define	COUNT_RD_REQ		0x1
61 
62 DECLARE_GLOBAL_DATA_PTR;
63 /* Using gd->tbu from timestamp and gd->tbl for lastdec */
64 
65 /* For preventing risk of instability in reading counter value,
66  * first set read request to register cvwr and then read same
67  * register after it captures counter value.
68  */
69 ulong read_timer(void)
70 {
71 	struct armd1tmr_registers *armd1timers =
72 		(struct armd1tmr_registers *) ARMD1_TIMER_BASE;
73 	volatile int loop=100;
74 
75 	writel(COUNT_RD_REQ, &armd1timers->cvwr);
76 	while (loop--);
77 	return(readl(&armd1timers->cvwr));
78 }
79 
80 ulong get_timer_masked(void)
81 {
82 	ulong now = read_timer();
83 
84 	if (now >= gd->tbl) {
85 		/* normal mode */
86 		gd->tbu += now - gd->tbl;
87 	} else {
88 		/* we have an overflow ... */
89 		gd->tbu += now + TIMER_LOAD_VAL - gd->tbl;
90 	}
91 	gd->tbl = now;
92 
93 	return gd->tbu;
94 }
95 
96 ulong get_timer(ulong base)
97 {
98 	return ((get_timer_masked() / (CONFIG_SYS_HZ_CLOCK / 1000)) -
99 		base);
100 }
101 
102 void __udelay(unsigned long usec)
103 {
104 	ulong delayticks;
105 	ulong endtime;
106 
107 	delayticks = (usec * (CONFIG_SYS_HZ_CLOCK / 1000000));
108 	endtime = get_timer_masked() + delayticks;
109 
110 	while (get_timer_masked() < endtime);
111 }
112 
113 /*
114  * init the Timer
115  */
116 int timer_init(void)
117 {
118 	struct armd1apb1_registers *apb1clkres =
119 		(struct armd1apb1_registers *) ARMD1_APBC1_BASE;
120 	struct armd1tmr_registers *armd1timers =
121 		(struct armd1tmr_registers *) ARMD1_TIMER_BASE;
122 
123 	/* Enable Timer clock at 3.25 MHZ */
124 	writel(APBC_APBCLK | APBC_FNCLK | APBC_FNCLKSEL(3), &apb1clkres->timers);
125 
126 	/* load value into timer */
127 	writel(0x0, &armd1timers->clk_ctrl);
128 	/* Use Timer 0 Match Resiger 0 */
129 	writel(TIMER_LOAD_VAL, &armd1timers->match[MATCH_CMP(0)]);
130 	/* Preload value is 0 */
131 	writel(0x0, &armd1timers->preload[TIMER]);
132 	/* Enable match comparator 0 for Timer 0 */
133 	writel(0x1, &armd1timers->preload_ctrl[TIMER]);
134 
135 	/* Enable timer 0 */
136 	writel(0x1, &armd1timers->cer);
137 	/* init the gd->tbu and gd->tbl value */
138 	gd->tbl = read_timer();
139 	gd->tbu = 0;
140 
141 	return 0;
142 }
143 
144 #define MPMU_APRR_WDTR	(1<<4)
145 #define TMR_WFAR	0xbaba	/* WDT Register First key */
146 #define TMP_WSAR	0xeb10	/* WDT Register Second key */
147 
148 /*
149  * This function uses internal Watchdog Timer
150  * based reset mechanism.
151  * Steps to write watchdog registers (protected access)
152  * 1. Write key value to TMR_WFAR reg.
153  * 2. Write key value to TMP_WSAR reg.
154  * 3. Perform write operation.
155  */
156 void reset_cpu (unsigned long ignored)
157 {
158 	struct armd1mpmu_registers *mpmu =
159 		(struct armd1mpmu_registers *) ARMD1_MPMU_BASE;
160 	struct armd1tmr_registers *armd1timers =
161 		(struct armd1tmr_registers *) ARMD1_TIMER_BASE;
162 	u32 val;
163 
164 	/* negate hardware reset to the WDT after system reset */
165 	val = readl(&mpmu->aprr);
166 	val = val | MPMU_APRR_WDTR;
167 	writel(val, &mpmu->aprr);
168 
169 	/* reset/enable WDT clock */
170 	writel(APBC_APBCLK | APBC_FNCLK | APBC_RST, &mpmu->wdtpcr);
171 	readl(&mpmu->wdtpcr);
172 	writel(APBC_APBCLK | APBC_FNCLK, &mpmu->wdtpcr);
173 	readl(&mpmu->wdtpcr);
174 
175 	/* clear previous WDT status */
176 	writel(TMR_WFAR, &armd1timers->wfar);
177 	writel(TMP_WSAR, &armd1timers->wsar);
178 	writel(0, &armd1timers->wdt_sts);
179 
180 	/* set match counter */
181 	writel(TMR_WFAR, &armd1timers->wfar);
182 	writel(TMP_WSAR, &armd1timers->wsar);
183 	writel(0xf, &armd1timers->wdt_match_r);
184 
185 	/* enable WDT reset */
186 	writel(TMR_WFAR, &armd1timers->wfar);
187 	writel(TMP_WSAR, &armd1timers->wsar);
188 	writel(0x3, &armd1timers->wdt_match_en);
189 
190 	while(1);
191 }
192