2 * Moschip MCS814x clock routines
4 * Copyright (C) 2012, Florian Fainelli <florian@openwrt.org>
8 #include <linux/kernel.h>
9 #include <linux/init.h>
10 #include <linux/export.h>
11 #include <linux/spinlock.h>
12 #include <linux/err.h>
14 #include <linux/clkdev.h>
15 #include <linux/clk.h>
17 #include <mach/mcs814x.h>
20 #define MHZ (KHZ * KHZ)
23 unsigned long (*get_rate)(struct clk *clk);
24 int (*set_rate)(struct clk *clk, unsigned long rate);
25 struct clk *(*get_parent)(struct clk *clk);
26 int (*enable)(struct clk *clk, int enable);
30 struct clk *parent; /* parent clk */
31 unsigned long rate; /* clock rate in Hz */
32 unsigned long divider; /* clock divider */
33 u32 usecount; /* reference count */
34 struct clk_ops *ops; /* clock operation */
35 void __iomem *enable_reg; /* clock enable register */
36 u32 enable_mask; /* clock enable mask */
39 static unsigned long clk_divide_parent(struct clk *clk)
41 if (clk->parent && clk->divider)
42 return clk_get_rate(clk->parent) / clk->divider;
47 static int clk_local_onoff_enable(struct clk *clk, int enable)
51 /* no enable_reg means the clock is always enabled */
55 tmp = __raw_readl(clk->enable_reg);
57 tmp &= ~clk->enable_mask;
59 tmp |= clk->enable_mask;
61 __raw_writel(tmp, clk->enable_reg);
66 static struct clk_ops default_clk_ops = {
67 .get_rate = clk_divide_parent,
68 .enable = clk_local_onoff_enable,
71 static DEFINE_SPINLOCK(clocks_lock);
73 static const unsigned long cpu_freq_table[] = {
92 static struct clk clk_cpu;
94 /* System clock is fixed at 50Mhz */
95 static struct clk clk_sys = {
99 static struct clk clk_sdram;
101 static struct clk clk_timer0 = {
102 .parent = &clk_sdram,
104 .ops = &default_clk_ops,
107 static struct clk clk_timer1_2 = {
111 /* Watchdog clock is system clock / 128 */
112 static struct clk clk_wdt = {
115 .ops = &default_clk_ops,
118 static struct clk clk_emac = {
119 .ops = &default_clk_ops,
120 .enable_reg = (void __iomem *)(_CONFADDR_SYSDBG + SYSDBG_SYSCTL),
121 .enable_mask = SYSCTL_EMAC,
124 static struct clk clk_ephy = {
125 .ops = &default_clk_ops,
126 .enable_reg = (void __iomem *)(_CONFADDR_SYSDBG + SYSDBG_PLL_CTL),
127 .enable_mask = ~(1 << 0),
130 static struct clk clk_cipher = {
131 .ops = &default_clk_ops,
132 .enable_reg = (void __iomem *)(_CONFADDR_SYSDBG + SYSDBG_SYSCTL),
133 .enable_mask = SYSCTL_CIPHER,
136 #define CLK(_dev, _con, _clk) \
137 { .dev_id = (_dev), .con_id = (_con), .clk = (_clk) },
139 static struct clk_lookup mcs814x_chip_clks[] = {
140 CLK("cpu", NULL, &clk_cpu)
141 CLK("sys", NULL, &clk_sys)
142 CLK("sdram", NULL, &clk_sdram)
144 CLK("timer0", NULL, &clk_timer0)
146 CLK("timer1", NULL, &clk_timer1_2)
147 /* 64-bits timer2, same as timer 1 */
148 CLK("timer2", NULL, &clk_timer1_2)
149 CLK(NULL, "wdt", &clk_wdt)
150 CLK(NULL, "emac", &clk_emac)
151 CLK(NULL, "ephy", &clk_ephy)
152 CLK(NULL, "cipher", &clk_cipher)
155 static void local_clk_disable(struct clk *clk)
157 WARN_ON(!clk->usecount);
159 if (clk->usecount > 0) {
162 if ((clk->usecount == 0) && (clk->ops->enable))
163 clk->ops->enable(clk, 0);
166 local_clk_disable(clk->parent);
170 static int local_clk_enable(struct clk *clk)
175 ret = local_clk_enable(clk->parent);
180 if ((clk->usecount == 0) && (clk->ops->enable))
181 ret = clk->ops->enable(clk, 1);
185 else if (clk->parent && clk->parent->ops->enable)
186 local_clk_disable(clk->parent);
191 int clk_enable(struct clk *clk)
196 spin_lock_irqsave(&clocks_lock, flags);
197 ret = local_clk_enable(clk);
198 spin_unlock_irqrestore(&clocks_lock, flags);
202 EXPORT_SYMBOL(clk_enable);
204 void clk_disable(struct clk *clk)
208 spin_lock_irqsave(&clocks_lock, flags);
209 local_clk_disable(clk);
210 spin_unlock_irqrestore(&clocks_lock, flags);
212 EXPORT_SYMBOL(clk_disable);
214 unsigned long clk_get_rate(struct clk *clk)
216 if (unlikely(IS_ERR_OR_NULL(clk)))
222 if (clk->ops && clk->ops->get_rate)
223 return clk->ops->get_rate(clk);
225 return clk_get_rate(clk->parent);
227 EXPORT_SYMBOL(clk_get_rate);
229 struct clk *clk_get_parent(struct clk *clk)
233 if (unlikely(IS_ERR_OR_NULL(clk)))
236 if (!clk->ops || !clk->ops->get_parent)
239 spin_lock_irqsave(&clocks_lock, flags);
240 clk->parent = clk->ops->get_parent(clk);
241 spin_unlock_irqrestore(&clocks_lock, flags);
245 EXPORT_SYMBOL(clk_get_parent);
247 void __init mcs814x_clk_init(void)
252 clkdev_add_table(mcs814x_chip_clks, ARRAY_SIZE(mcs814x_chip_clks));
254 /* read the bootstrap registers to know the exact clocking scheme */
255 bs1 = __raw_readl(_CONFADDR_SYSDBG + SYSDBG_BS1);
256 cpu_freq = (bs1 >> CPU_FREQ_SHIFT) & CPU_FREQ_MASK;
258 pr_info("CPU frequency: %lu (kHz)\n", cpu_freq_table[cpu_freq]);
259 clk_cpu.rate = cpu_freq * KHZ;
261 /* read SDRAM frequency */
262 if (bs1 & SDRAM_FREQ_BIT)
263 clk_sdram.rate = 100 * MHZ;
265 clk_sdram.rate = 133 * MHZ;
267 pr_info("SDRAM frequency: %lu (MHz)\n", clk_sdram.rate / MHZ);