1 /*
2 * OMAP gate clock support
3 *
4 * Copyright (C) 2013 Texas Instruments, Inc.
5 *
6 * Tero Kristo <t-kristo@ti.com>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 *
12 * This program is distributed "as is" WITHOUT ANY WARRANTY of any
13 * kind, whether express or implied; without even the implied warranty
14 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 */
17
18 #include <linux/clk-provider.h>
19 #include <linux/slab.h>
20 #include <linux/io.h>
21 #include <linux/of.h>
22 #include <linux/of_address.h>
23 #include <linux/clk/ti.h>
24
25 #include "clock.h"
26
27 #undef pr_fmt
28 #define pr_fmt(fmt) "%s: " fmt, __func__
29
30 static int omap36xx_gate_clk_enable_with_hsdiv_restore(struct clk_hw *clk);
31
32 static const struct clk_ops omap_gate_clkdm_clk_ops = {
33 .init = &omap2_init_clk_clkdm,
34 .enable = &omap2_clkops_enable_clkdm,
35 .disable = &omap2_clkops_disable_clkdm,
36 .restore_context = clk_gate_restore_context,
37 };
38
39 const struct clk_ops omap_gate_clk_ops = {
40 .init = &omap2_init_clk_clkdm,
41 .enable = &omap2_dflt_clk_enable,
42 .disable = &omap2_dflt_clk_disable,
43 .is_enabled = &omap2_dflt_clk_is_enabled,
44 .restore_context = clk_gate_restore_context,
45 };
46
47 static const struct clk_ops omap_gate_clk_hsdiv_restore_ops = {
48 .init = &omap2_init_clk_clkdm,
49 .enable = &omap36xx_gate_clk_enable_with_hsdiv_restore,
50 .disable = &omap2_dflt_clk_disable,
51 .is_enabled = &omap2_dflt_clk_is_enabled,
52 .restore_context = clk_gate_restore_context,
53 };
54
55 /**
56 * omap36xx_gate_clk_enable_with_hsdiv_restore - enable clocks suffering
57 * from HSDivider PWRDN problem Implements Errata ID: i556.
58 * @clk: DPLL output struct clk
59 *
60 * 3630 only: dpll3_m3_ck, dpll4_m2_ck, dpll4_m3_ck, dpll4_m4_ck,
61 * dpll4_m5_ck & dpll4_m6_ck dividers gets loaded with reset
62 * valueafter their respective PWRDN bits are set. Any dummy write
63 * (Any other value different from the Read value) to the
64 * corresponding CM_CLKSEL register will refresh the dividers.
65 */
omap36xx_gate_clk_enable_with_hsdiv_restore(struct clk_hw * hw)66 static int omap36xx_gate_clk_enable_with_hsdiv_restore(struct clk_hw *hw)
67 {
68 struct clk_omap_divider *parent;
69 struct clk_hw *parent_hw;
70 u32 dummy_v, orig_v;
71 int ret;
72
73 /* Clear PWRDN bit of HSDIVIDER */
74 ret = omap2_dflt_clk_enable(hw);
75
76 /* Parent is the x2 node, get parent of parent for the m2 div */
77 parent_hw = clk_hw_get_parent(clk_hw_get_parent(hw));
78 parent = to_clk_omap_divider(parent_hw);
79
80 /* Restore the dividers */
81 if (!ret) {
82 orig_v = ti_clk_ll_ops->clk_readl(&parent->reg);
83 dummy_v = orig_v;
84
85 /* Write any other value different from the Read value */
86 dummy_v ^= (1 << parent->shift);
87 ti_clk_ll_ops->clk_writel(dummy_v, &parent->reg);
88
89 /* Write the original divider */
90 ti_clk_ll_ops->clk_writel(orig_v, &parent->reg);
91 }
92
93 return ret;
94 }
95
_register_gate(struct device_node * node,const char * name,const char * parent_name,unsigned long flags,struct clk_omap_reg * reg,u8 bit_idx,u8 clk_gate_flags,const struct clk_ops * ops,const struct clk_hw_omap_ops * hw_ops)96 static struct clk *_register_gate(struct device_node *node, const char *name,
97 const char *parent_name, unsigned long flags,
98 struct clk_omap_reg *reg, u8 bit_idx,
99 u8 clk_gate_flags, const struct clk_ops *ops,
100 const struct clk_hw_omap_ops *hw_ops)
101 {
102 struct clk_init_data init = { NULL };
103 struct clk_hw_omap *clk_hw;
104 struct clk *clk;
105
106 clk_hw = kzalloc(sizeof(*clk_hw), GFP_KERNEL);
107 if (!clk_hw)
108 return ERR_PTR(-ENOMEM);
109
110 clk_hw->hw.init = &init;
111
112 init.name = name;
113 init.ops = ops;
114
115 memcpy(&clk_hw->enable_reg, reg, sizeof(*reg));
116 clk_hw->enable_bit = bit_idx;
117 clk_hw->ops = hw_ops;
118
119 clk_hw->flags = clk_gate_flags;
120
121 init.parent_names = &parent_name;
122 init.num_parents = 1;
123
124 init.flags = flags;
125
126 clk = of_ti_clk_register_omap_hw(node, &clk_hw->hw, name);
127
128 if (IS_ERR(clk))
129 kfree(clk_hw);
130
131 return clk;
132 }
133
_of_ti_gate_clk_setup(struct device_node * node,const struct clk_ops * ops,const struct clk_hw_omap_ops * hw_ops)134 static void __init _of_ti_gate_clk_setup(struct device_node *node,
135 const struct clk_ops *ops,
136 const struct clk_hw_omap_ops *hw_ops)
137 {
138 struct clk *clk;
139 const char *parent_name;
140 struct clk_omap_reg reg;
141 const char *name;
142 u8 enable_bit = 0;
143 u32 val;
144 u32 flags = 0;
145 u8 clk_gate_flags = 0;
146
147 if (ops != &omap_gate_clkdm_clk_ops) {
148 if (ti_clk_get_reg_addr(node, 0, ®))
149 return;
150
151 if (!of_property_read_u32(node, "ti,bit-shift", &val))
152 enable_bit = val;
153 }
154
155 if (of_clk_get_parent_count(node) != 1) {
156 pr_err("%pOFn must have 1 parent\n", node);
157 return;
158 }
159
160 parent_name = of_clk_get_parent_name(node, 0);
161
162 if (of_property_read_bool(node, "ti,set-rate-parent"))
163 flags |= CLK_SET_RATE_PARENT;
164
165 if (of_property_read_bool(node, "ti,set-bit-to-disable"))
166 clk_gate_flags |= INVERT_ENABLE;
167
168 name = ti_dt_clk_name(node);
169 clk = _register_gate(node, name, parent_name, flags, ®,
170 enable_bit, clk_gate_flags, ops, hw_ops);
171
172 if (!IS_ERR(clk))
173 of_clk_add_provider(node, of_clk_src_simple_get, clk);
174 }
175
176 static void __init
_of_ti_composite_gate_clk_setup(struct device_node * node,const struct clk_hw_omap_ops * hw_ops)177 _of_ti_composite_gate_clk_setup(struct device_node *node,
178 const struct clk_hw_omap_ops *hw_ops)
179 {
180 struct clk_hw_omap *gate;
181 u32 val = 0;
182
183 gate = kzalloc(sizeof(*gate), GFP_KERNEL);
184 if (!gate)
185 return;
186
187 if (ti_clk_get_reg_addr(node, 0, &gate->enable_reg))
188 goto cleanup;
189
190 of_property_read_u32(node, "ti,bit-shift", &val);
191
192 gate->enable_bit = val;
193 gate->ops = hw_ops;
194
195 if (!ti_clk_add_component(node, &gate->hw, CLK_COMPONENT_TYPE_GATE))
196 return;
197
198 cleanup:
199 kfree(gate);
200 }
201
202 static void __init
of_ti_composite_no_wait_gate_clk_setup(struct device_node * node)203 of_ti_composite_no_wait_gate_clk_setup(struct device_node *node)
204 {
205 _of_ti_composite_gate_clk_setup(node, NULL);
206 }
207 CLK_OF_DECLARE(ti_composite_no_wait_gate_clk, "ti,composite-no-wait-gate-clock",
208 of_ti_composite_no_wait_gate_clk_setup);
209
210 #if defined(CONFIG_ARCH_OMAP2) || defined(CONFIG_ARCH_OMAP3)
of_ti_composite_interface_clk_setup(struct device_node * node)211 static void __init of_ti_composite_interface_clk_setup(struct device_node *node)
212 {
213 _of_ti_composite_gate_clk_setup(node, &clkhwops_iclk_wait);
214 }
215 CLK_OF_DECLARE(ti_composite_interface_clk, "ti,composite-interface-clock",
216 of_ti_composite_interface_clk_setup);
217 #endif
218
of_ti_composite_gate_clk_setup(struct device_node * node)219 static void __init of_ti_composite_gate_clk_setup(struct device_node *node)
220 {
221 _of_ti_composite_gate_clk_setup(node, &clkhwops_wait);
222 }
223 CLK_OF_DECLARE(ti_composite_gate_clk, "ti,composite-gate-clock",
224 of_ti_composite_gate_clk_setup);
225
226
of_ti_clkdm_gate_clk_setup(struct device_node * node)227 static void __init of_ti_clkdm_gate_clk_setup(struct device_node *node)
228 {
229 _of_ti_gate_clk_setup(node, &omap_gate_clkdm_clk_ops, NULL);
230 }
231 CLK_OF_DECLARE(ti_clkdm_gate_clk, "ti,clkdm-gate-clock",
232 of_ti_clkdm_gate_clk_setup);
233
of_ti_hsdiv_gate_clk_setup(struct device_node * node)234 static void __init of_ti_hsdiv_gate_clk_setup(struct device_node *node)
235 {
236 _of_ti_gate_clk_setup(node, &omap_gate_clk_hsdiv_restore_ops,
237 &clkhwops_wait);
238 }
239 CLK_OF_DECLARE(ti_hsdiv_gate_clk, "ti,hsdiv-gate-clock",
240 of_ti_hsdiv_gate_clk_setup);
241
of_ti_gate_clk_setup(struct device_node * node)242 static void __init of_ti_gate_clk_setup(struct device_node *node)
243 {
244 _of_ti_gate_clk_setup(node, &omap_gate_clk_ops, NULL);
245 }
246 CLK_OF_DECLARE(ti_gate_clk, "ti,gate-clock", of_ti_gate_clk_setup);
247
of_ti_wait_gate_clk_setup(struct device_node * node)248 static void __init of_ti_wait_gate_clk_setup(struct device_node *node)
249 {
250 _of_ti_gate_clk_setup(node, &omap_gate_clk_ops, &clkhwops_wait);
251 }
252 CLK_OF_DECLARE(ti_wait_gate_clk, "ti,wait-gate-clock",
253 of_ti_wait_gate_clk_setup);
254
255 #ifdef CONFIG_ARCH_OMAP3
of_ti_am35xx_gate_clk_setup(struct device_node * node)256 static void __init of_ti_am35xx_gate_clk_setup(struct device_node *node)
257 {
258 _of_ti_gate_clk_setup(node, &omap_gate_clk_ops,
259 &clkhwops_am35xx_ipss_module_wait);
260 }
261 CLK_OF_DECLARE(ti_am35xx_gate_clk, "ti,am35xx-gate-clock",
262 of_ti_am35xx_gate_clk_setup);
263
of_ti_dss_gate_clk_setup(struct device_node * node)264 static void __init of_ti_dss_gate_clk_setup(struct device_node *node)
265 {
266 _of_ti_gate_clk_setup(node, &omap_gate_clk_ops,
267 &clkhwops_omap3430es2_dss_usbhost_wait);
268 }
269 CLK_OF_DECLARE(ti_dss_gate_clk, "ti,dss-gate-clock",
270 of_ti_dss_gate_clk_setup);
271 #endif
272