xref: /openbmc/linux/arch/mips/bcm63xx/clk.c (revision a09d2831)
1 /*
2  * This file is subject to the terms and conditions of the GNU General Public
3  * License.  See the file "COPYING" in the main directory of this archive
4  * for more details.
5  *
6  * Copyright (C) 2008 Maxime Bizon <mbizon@freebox.fr>
7  */
8 
9 #include <linux/module.h>
10 #include <linux/mutex.h>
11 #include <linux/err.h>
12 #include <linux/clk.h>
13 #include <bcm63xx_cpu.h>
14 #include <bcm63xx_io.h>
15 #include <bcm63xx_regs.h>
16 #include <bcm63xx_clk.h>
17 
18 static DEFINE_MUTEX(clocks_mutex);
19 
20 
21 static void clk_enable_unlocked(struct clk *clk)
22 {
23 	if (clk->set && (clk->usage++) == 0)
24 		clk->set(clk, 1);
25 }
26 
27 static void clk_disable_unlocked(struct clk *clk)
28 {
29 	if (clk->set && (--clk->usage) == 0)
30 		clk->set(clk, 0);
31 }
32 
33 static void bcm_hwclock_set(u32 mask, int enable)
34 {
35 	u32 reg;
36 
37 	reg = bcm_perf_readl(PERF_CKCTL_REG);
38 	if (enable)
39 		reg |= mask;
40 	else
41 		reg &= ~mask;
42 	bcm_perf_writel(reg, PERF_CKCTL_REG);
43 }
44 
45 /*
46  * Ethernet MAC "misc" clock: dma clocks and main clock on 6348
47  */
48 static void enet_misc_set(struct clk *clk, int enable)
49 {
50 	u32 mask;
51 
52 	if (BCMCPU_IS_6338())
53 		mask = CKCTL_6338_ENET_EN;
54 	else if (BCMCPU_IS_6345())
55 		mask = CKCTL_6345_ENET_EN;
56 	else if (BCMCPU_IS_6348())
57 		mask = CKCTL_6348_ENET_EN;
58 	else
59 		/* BCMCPU_IS_6358 */
60 		mask = CKCTL_6358_EMUSB_EN;
61 	bcm_hwclock_set(mask, enable);
62 }
63 
64 static struct clk clk_enet_misc = {
65 	.set	= enet_misc_set,
66 };
67 
68 /*
69  * Ethernet MAC clocks: only revelant on 6358, silently enable misc
70  * clocks
71  */
72 static void enetx_set(struct clk *clk, int enable)
73 {
74 	if (enable)
75 		clk_enable_unlocked(&clk_enet_misc);
76 	else
77 		clk_disable_unlocked(&clk_enet_misc);
78 
79 	if (BCMCPU_IS_6358()) {
80 		u32 mask;
81 
82 		if (clk->id == 0)
83 			mask = CKCTL_6358_ENET0_EN;
84 		else
85 			mask = CKCTL_6358_ENET1_EN;
86 		bcm_hwclock_set(mask, enable);
87 	}
88 }
89 
90 static struct clk clk_enet0 = {
91 	.id	= 0,
92 	.set	= enetx_set,
93 };
94 
95 static struct clk clk_enet1 = {
96 	.id	= 1,
97 	.set	= enetx_set,
98 };
99 
100 /*
101  * Ethernet PHY clock
102  */
103 static void ephy_set(struct clk *clk, int enable)
104 {
105 	if (!BCMCPU_IS_6358())
106 		return;
107 	bcm_hwclock_set(CKCTL_6358_EPHY_EN, enable);
108 }
109 
110 
111 static struct clk clk_ephy = {
112 	.set	= ephy_set,
113 };
114 
115 /*
116  * PCM clock
117  */
118 static void pcm_set(struct clk *clk, int enable)
119 {
120 	if (!BCMCPU_IS_6358())
121 		return;
122 	bcm_hwclock_set(CKCTL_6358_PCM_EN, enable);
123 }
124 
125 static struct clk clk_pcm = {
126 	.set	= pcm_set,
127 };
128 
129 /*
130  * USB host clock
131  */
132 static void usbh_set(struct clk *clk, int enable)
133 {
134 	if (!BCMCPU_IS_6348())
135 		return;
136 	bcm_hwclock_set(CKCTL_6348_USBH_EN, enable);
137 }
138 
139 static struct clk clk_usbh = {
140 	.set	= usbh_set,
141 };
142 
143 /*
144  * SPI clock
145  */
146 static void spi_set(struct clk *clk, int enable)
147 {
148 	u32 mask;
149 
150 	if (BCMCPU_IS_6338())
151 		mask = CKCTL_6338_SPI_EN;
152 	else if (BCMCPU_IS_6348())
153 		mask = CKCTL_6348_SPI_EN;
154 	else
155 		/* BCMCPU_IS_6358 */
156 		mask = CKCTL_6358_SPI_EN;
157 	bcm_hwclock_set(mask, enable);
158 }
159 
160 static struct clk clk_spi = {
161 	.set	= spi_set,
162 };
163 
164 /*
165  * Internal peripheral clock
166  */
167 static struct clk clk_periph = {
168 	.rate	= (50 * 1000 * 1000),
169 };
170 
171 
172 /*
173  * Linux clock API implementation
174  */
175 int clk_enable(struct clk *clk)
176 {
177 	mutex_lock(&clocks_mutex);
178 	clk_enable_unlocked(clk);
179 	mutex_unlock(&clocks_mutex);
180 	return 0;
181 }
182 
183 EXPORT_SYMBOL(clk_enable);
184 
185 void clk_disable(struct clk *clk)
186 {
187 	mutex_lock(&clocks_mutex);
188 	clk_disable_unlocked(clk);
189 	mutex_unlock(&clocks_mutex);
190 }
191 
192 EXPORT_SYMBOL(clk_disable);
193 
194 unsigned long clk_get_rate(struct clk *clk)
195 {
196 	return clk->rate;
197 }
198 
199 EXPORT_SYMBOL(clk_get_rate);
200 
201 struct clk *clk_get(struct device *dev, const char *id)
202 {
203 	if (!strcmp(id, "enet0"))
204 		return &clk_enet0;
205 	if (!strcmp(id, "enet1"))
206 		return &clk_enet1;
207 	if (!strcmp(id, "ephy"))
208 		return &clk_ephy;
209 	if (!strcmp(id, "usbh"))
210 		return &clk_usbh;
211 	if (!strcmp(id, "spi"))
212 		return &clk_spi;
213 	if (!strcmp(id, "periph"))
214 		return &clk_periph;
215 	if (BCMCPU_IS_6358() && !strcmp(id, "pcm"))
216 		return &clk_pcm;
217 	return ERR_PTR(-ENOENT);
218 }
219 
220 EXPORT_SYMBOL(clk_get);
221 
222 void clk_put(struct clk *clk)
223 {
224 }
225 
226 EXPORT_SYMBOL(clk_put);
227