xref: /openbmc/linux/drivers/clk/imx/clk.c (revision 9a29f5fc)
1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/bits.h>
3 #include <linux/clk.h>
4 #include <linux/clk-provider.h>
5 #include <linux/err.h>
6 #include <linux/io.h>
7 #include <linux/module.h>
8 #include <linux/of.h>
9 #include <linux/slab.h>
10 #include <linux/spinlock.h>
11 #include "clk.h"
12 
13 #define CCM_CCDR			0x4
14 #define CCDR_MMDC_CH0_MASK		BIT(17)
15 #define CCDR_MMDC_CH1_MASK		BIT(16)
16 
17 DEFINE_SPINLOCK(imx_ccm_lock);
18 EXPORT_SYMBOL_GPL(imx_ccm_lock);
19 
20 bool mcore_booted;
21 EXPORT_SYMBOL_GPL(mcore_booted);
22 
23 void imx_unregister_clocks(struct clk *clks[], unsigned int count)
24 {
25 	unsigned int i;
26 
27 	for (i = 0; i < count; i++)
28 		clk_unregister(clks[i]);
29 }
30 
31 void imx_unregister_hw_clocks(struct clk_hw *hws[], unsigned int count)
32 {
33 	unsigned int i;
34 
35 	for (i = 0; i < count; i++)
36 		clk_hw_unregister(hws[i]);
37 }
38 EXPORT_SYMBOL_GPL(imx_unregister_hw_clocks);
39 
40 void imx_mmdc_mask_handshake(void __iomem *ccm_base,
41 				    unsigned int chn)
42 {
43 	unsigned int reg;
44 
45 	reg = readl_relaxed(ccm_base + CCM_CCDR);
46 	reg |= chn == 0 ? CCDR_MMDC_CH0_MASK : CCDR_MMDC_CH1_MASK;
47 	writel_relaxed(reg, ccm_base + CCM_CCDR);
48 }
49 
50 void imx_check_clocks(struct clk *clks[], unsigned int count)
51 {
52 	unsigned i;
53 
54 	for (i = 0; i < count; i++)
55 		if (IS_ERR(clks[i]))
56 			pr_err("i.MX clk %u: register failed with %ld\n",
57 			       i, PTR_ERR(clks[i]));
58 }
59 
60 void imx_check_clk_hws(struct clk_hw *clks[], unsigned int count)
61 {
62 	unsigned int i;
63 
64 	for (i = 0; i < count; i++)
65 		if (IS_ERR(clks[i]))
66 			pr_err("i.MX clk %u: register failed with %ld\n",
67 			       i, PTR_ERR(clks[i]));
68 }
69 EXPORT_SYMBOL_GPL(imx_check_clk_hws);
70 
71 static struct clk *imx_obtain_fixed_clock_from_dt(const char *name)
72 {
73 	struct of_phandle_args phandle;
74 	struct clk *clk = ERR_PTR(-ENODEV);
75 	char *path;
76 
77 	path = kasprintf(GFP_KERNEL, "/clocks/%s", name);
78 	if (!path)
79 		return ERR_PTR(-ENOMEM);
80 
81 	phandle.np = of_find_node_by_path(path);
82 	kfree(path);
83 
84 	if (phandle.np) {
85 		clk = of_clk_get_from_provider(&phandle);
86 		of_node_put(phandle.np);
87 	}
88 	return clk;
89 }
90 
91 struct clk *imx_obtain_fixed_clock(
92 			const char *name, unsigned long rate)
93 {
94 	struct clk *clk;
95 
96 	clk = imx_obtain_fixed_clock_from_dt(name);
97 	if (IS_ERR(clk))
98 		clk = imx_clk_fixed(name, rate);
99 	return clk;
100 }
101 
102 struct clk_hw *imx_obtain_fixed_clock_hw(
103 			const char *name, unsigned long rate)
104 {
105 	struct clk *clk;
106 
107 	clk = imx_obtain_fixed_clock_from_dt(name);
108 	if (IS_ERR(clk))
109 		clk = imx_clk_fixed(name, rate);
110 	return __clk_get_hw(clk);
111 }
112 
113 struct clk_hw * imx_obtain_fixed_clk_hw(struct device_node *np,
114 					const char *name)
115 {
116 	struct clk *clk;
117 
118 	clk = of_clk_get_by_name(np, name);
119 	if (IS_ERR(clk))
120 		return ERR_PTR(-ENOENT);
121 
122 	return __clk_get_hw(clk);
123 }
124 EXPORT_SYMBOL_GPL(imx_obtain_fixed_clk_hw);
125 
126 /*
127  * This fixups the register CCM_CSCMR1 write value.
128  * The write/read/divider values of the aclk_podf field
129  * of that register have the relationship described by
130  * the following table:
131  *
132  * write value       read value        divider
133  * 3b'000            3b'110            7
134  * 3b'001            3b'111            8
135  * 3b'010            3b'100            5
136  * 3b'011            3b'101            6
137  * 3b'100            3b'010            3
138  * 3b'101            3b'011            4
139  * 3b'110            3b'000            1
140  * 3b'111            3b'001            2(default)
141  *
142  * That's why we do the xor operation below.
143  */
144 #define CSCMR1_FIXUP	0x00600000
145 
146 void imx_cscmr1_fixup(u32 *val)
147 {
148 	*val ^= CSCMR1_FIXUP;
149 	return;
150 }
151 
152 #ifndef MODULE
153 
154 static bool imx_keep_uart_clocks;
155 static int imx_enabled_uart_clocks;
156 static struct clk **imx_uart_clocks;
157 
158 static int __init imx_keep_uart_clocks_param(char *str)
159 {
160 	imx_keep_uart_clocks = 1;
161 
162 	return 0;
163 }
164 __setup_param("earlycon", imx_keep_uart_earlycon,
165 	      imx_keep_uart_clocks_param, 0);
166 __setup_param("earlyprintk", imx_keep_uart_earlyprintk,
167 	      imx_keep_uart_clocks_param, 0);
168 
169 void imx_register_uart_clocks(unsigned int clk_count)
170 {
171 	imx_enabled_uart_clocks = 0;
172 
173 /* i.MX boards use device trees now.  For build tests without CONFIG_OF, do nothing */
174 #ifdef CONFIG_OF
175 	if (imx_keep_uart_clocks) {
176 		int i;
177 
178 		imx_uart_clocks = kcalloc(clk_count, sizeof(struct clk *), GFP_KERNEL);
179 		if (!imx_uart_clocks)
180 			return;
181 
182 		if (!of_stdout)
183 			return;
184 
185 		for (i = 0; i < clk_count; i++) {
186 			imx_uart_clocks[imx_enabled_uart_clocks] = of_clk_get(of_stdout, i);
187 
188 			/* Stop if there are no more of_stdout references */
189 			if (IS_ERR(imx_uart_clocks[imx_enabled_uart_clocks]))
190 				return;
191 
192 			/* Only enable the clock if it's not NULL */
193 			if (imx_uart_clocks[imx_enabled_uart_clocks])
194 				clk_prepare_enable(imx_uart_clocks[imx_enabled_uart_clocks++]);
195 		}
196 	}
197 #endif
198 }
199 
200 static int __init imx_clk_disable_uart(void)
201 {
202 	if (imx_keep_uart_clocks && imx_enabled_uart_clocks) {
203 		int i;
204 
205 		for (i = 0; i < imx_enabled_uart_clocks; i++) {
206 			clk_disable_unprepare(imx_uart_clocks[i]);
207 			clk_put(imx_uart_clocks[i]);
208 		}
209 		kfree(imx_uart_clocks);
210 	}
211 
212 	return 0;
213 }
214 late_initcall_sync(imx_clk_disable_uart);
215 #endif
216 
217 MODULE_LICENSE("GPL v2");
218