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#define to_clk_divider(_hw) container_of(_hw, struct clk_divider, hw)
28
29#undef pr_fmt
30#define pr_fmt(fmt) "%s: " fmt, __func__
31
32static int omap36xx_gate_clk_enable_with_hsdiv_restore(struct clk_hw *clk);
33
34static const struct clk_ops omap_gate_clkdm_clk_ops = {
35	.init		= &omap2_init_clk_clkdm,
36	.enable		= &omap2_clkops_enable_clkdm,
37	.disable	= &omap2_clkops_disable_clkdm,
38};
39
40static const struct clk_ops omap_gate_clk_ops = {
41	.init		= &omap2_init_clk_clkdm,
42	.enable		= &omap2_dflt_clk_enable,
43	.disable	= &omap2_dflt_clk_disable,
44	.is_enabled	= &omap2_dflt_clk_is_enabled,
45};
46
47static 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};
53
54/**
55 * omap36xx_gate_clk_enable_with_hsdiv_restore - enable clocks suffering
56 *         from HSDivider PWRDN problem Implements Errata ID: i556.
57 * @clk: DPLL output struct clk
58 *
59 * 3630 only: dpll3_m3_ck, dpll4_m2_ck, dpll4_m3_ck, dpll4_m4_ck,
60 * dpll4_m5_ck & dpll4_m6_ck dividers gets loaded with reset
61 * valueafter their respective PWRDN bits are set.  Any dummy write
62 * (Any other value different from the Read value) to the
63 * corresponding CM_CLKSEL register will refresh the dividers.
64 */
65static int omap36xx_gate_clk_enable_with_hsdiv_restore(struct clk_hw *clk)
66{
67	struct clk_divider *parent;
68	struct clk_hw *parent_hw;
69	u32 dummy_v, orig_v;
70	int ret;
71
72	/* Clear PWRDN bit of HSDIVIDER */
73	ret = omap2_dflt_clk_enable(clk);
74
75	/* Parent is the x2 node, get parent of parent for the m2 div */
76	parent_hw = __clk_get_hw(__clk_get_parent(__clk_get_parent(clk->clk)));
77	parent = to_clk_divider(parent_hw);
78
79	/* Restore the dividers */
80	if (!ret) {
81		orig_v = ti_clk_ll_ops->clk_readl(parent->reg);
82		dummy_v = orig_v;
83
84		/* Write any other value different from the Read value */
85		dummy_v ^= (1 << parent->shift);
86		ti_clk_ll_ops->clk_writel(dummy_v, parent->reg);
87
88		/* Write the original divider */
89		ti_clk_ll_ops->clk_writel(orig_v, parent->reg);
90	}
91
92	return ret;
93}
94
95static struct clk *_register_gate(struct device *dev, const char *name,
96				  const char *parent_name, unsigned long flags,
97				  void __iomem *reg, u8 bit_idx,
98				  u8 clk_gate_flags, const struct clk_ops *ops,
99				  const struct clk_hw_omap_ops *hw_ops)
100{
101	struct clk_init_data init = { NULL };
102	struct clk_hw_omap *clk_hw;
103	struct clk *clk;
104
105	clk_hw = kzalloc(sizeof(*clk_hw), GFP_KERNEL);
106	if (!clk_hw)
107		return ERR_PTR(-ENOMEM);
108
109	clk_hw->hw.init = &init;
110
111	init.name = name;
112	init.ops = ops;
113
114	clk_hw->enable_reg = reg;
115	clk_hw->enable_bit = bit_idx;
116	clk_hw->ops = hw_ops;
117
118	clk_hw->flags = MEMMAP_ADDRESSING | clk_gate_flags;
119
120	init.parent_names = &parent_name;
121	init.num_parents = 1;
122
123	init.flags = flags;
124
125	clk = clk_register(NULL, &clk_hw->hw);
126
127	if (IS_ERR(clk))
128		kfree(clk_hw);
129
130	return clk;
131}
132
133#if defined(CONFIG_ARCH_OMAP3) && defined(CONFIG_ATAGS)
134struct clk *ti_clk_register_gate(struct ti_clk *setup)
135{
136	const struct clk_ops *ops = &omap_gate_clk_ops;
137	const struct clk_hw_omap_ops *hw_ops = NULL;
138	u32 reg;
139	struct clk_omap_reg *reg_setup;
140	u32 flags = 0;
141	u8 clk_gate_flags = 0;
142	struct ti_clk_gate *gate;
143
144	gate = setup->data;
145
146	if (gate->flags & CLKF_INTERFACE)
147		return ti_clk_register_interface(setup);
148
149	reg_setup = (struct clk_omap_reg *)&reg;
150
151	if (gate->flags & CLKF_SET_RATE_PARENT)
152		flags |= CLK_SET_RATE_PARENT;
153
154	if (gate->flags & CLKF_SET_BIT_TO_DISABLE)
155		clk_gate_flags |= INVERT_ENABLE;
156
157	if (gate->flags & CLKF_HSDIV) {
158		ops = &omap_gate_clk_hsdiv_restore_ops;
159		hw_ops = &clkhwops_wait;
160	}
161
162	if (gate->flags & CLKF_DSS)
163		hw_ops = &clkhwops_omap3430es2_dss_usbhost_wait;
164
165	if (gate->flags & CLKF_WAIT)
166		hw_ops = &clkhwops_wait;
167
168	if (gate->flags & CLKF_CLKDM)
169		ops = &omap_gate_clkdm_clk_ops;
170
171	if (gate->flags & CLKF_AM35XX)
172		hw_ops = &clkhwops_am35xx_ipss_module_wait;
173
174	reg_setup->index = gate->module;
175	reg_setup->offset = gate->reg;
176
177	return _register_gate(NULL, setup->name, gate->parent, flags,
178			      (void __iomem *)reg, gate->bit_shift,
179			      clk_gate_flags, ops, hw_ops);
180}
181
182struct clk_hw *ti_clk_build_component_gate(struct ti_clk_gate *setup)
183{
184	struct clk_hw_omap *gate;
185	struct clk_omap_reg *reg;
186	const struct clk_hw_omap_ops *ops = &clkhwops_wait;
187
188	if (!setup)
189		return NULL;
190
191	gate = kzalloc(sizeof(*gate), GFP_KERNEL);
192	if (!gate)
193		return ERR_PTR(-ENOMEM);
194
195	reg = (struct clk_omap_reg *)&gate->enable_reg;
196	reg->index = setup->module;
197	reg->offset = setup->reg;
198
199	gate->enable_bit = setup->bit_shift;
200
201	if (setup->flags & CLKF_NO_WAIT)
202		ops = NULL;
203
204	if (setup->flags & CLKF_INTERFACE)
205		ops = &clkhwops_iclk_wait;
206
207	gate->ops = ops;
208	gate->flags = MEMMAP_ADDRESSING;
209
210	return &gate->hw;
211}
212#endif
213
214static void __init _of_ti_gate_clk_setup(struct device_node *node,
215					 const struct clk_ops *ops,
216					 const struct clk_hw_omap_ops *hw_ops)
217{
218	struct clk *clk;
219	const char *parent_name;
220	void __iomem *reg = NULL;
221	u8 enable_bit = 0;
222	u32 val;
223	u32 flags = 0;
224	u8 clk_gate_flags = 0;
225
226	if (ops != &omap_gate_clkdm_clk_ops) {
227		reg = ti_clk_get_reg_addr(node, 0);
228		if (IS_ERR(reg))
229			return;
230
231		if (!of_property_read_u32(node, "ti,bit-shift", &val))
232			enable_bit = val;
233	}
234
235	if (of_clk_get_parent_count(node) != 1) {
236		pr_err("%s must have 1 parent\n", node->name);
237		return;
238	}
239
240	parent_name = of_clk_get_parent_name(node, 0);
241
242	if (of_property_read_bool(node, "ti,set-rate-parent"))
243		flags |= CLK_SET_RATE_PARENT;
244
245	if (of_property_read_bool(node, "ti,set-bit-to-disable"))
246		clk_gate_flags |= INVERT_ENABLE;
247
248	clk = _register_gate(NULL, node->name, parent_name, flags, reg,
249			     enable_bit, clk_gate_flags, ops, hw_ops);
250
251	if (!IS_ERR(clk))
252		of_clk_add_provider(node, of_clk_src_simple_get, clk);
253}
254
255static void __init
256_of_ti_composite_gate_clk_setup(struct device_node *node,
257				const struct clk_hw_omap_ops *hw_ops)
258{
259	struct clk_hw_omap *gate;
260	u32 val = 0;
261
262	gate = kzalloc(sizeof(*gate), GFP_KERNEL);
263	if (!gate)
264		return;
265
266	gate->enable_reg = ti_clk_get_reg_addr(node, 0);
267	if (IS_ERR(gate->enable_reg))
268		goto cleanup;
269
270	of_property_read_u32(node, "ti,bit-shift", &val);
271
272	gate->enable_bit = val;
273	gate->ops = hw_ops;
274	gate->flags = MEMMAP_ADDRESSING;
275
276	if (!ti_clk_add_component(node, &gate->hw, CLK_COMPONENT_TYPE_GATE))
277		return;
278
279cleanup:
280	kfree(gate);
281}
282
283static void __init
284of_ti_composite_no_wait_gate_clk_setup(struct device_node *node)
285{
286	_of_ti_composite_gate_clk_setup(node, NULL);
287}
288CLK_OF_DECLARE(ti_composite_no_wait_gate_clk, "ti,composite-no-wait-gate-clock",
289	       of_ti_composite_no_wait_gate_clk_setup);
290
291#if defined(CONFIG_ARCH_OMAP2) || defined(CONFIG_ARCH_OMAP3)
292static void __init of_ti_composite_interface_clk_setup(struct device_node *node)
293{
294	_of_ti_composite_gate_clk_setup(node, &clkhwops_iclk_wait);
295}
296CLK_OF_DECLARE(ti_composite_interface_clk, "ti,composite-interface-clock",
297	       of_ti_composite_interface_clk_setup);
298#endif
299
300static void __init of_ti_composite_gate_clk_setup(struct device_node *node)
301{
302	_of_ti_composite_gate_clk_setup(node, &clkhwops_wait);
303}
304CLK_OF_DECLARE(ti_composite_gate_clk, "ti,composite-gate-clock",
305	       of_ti_composite_gate_clk_setup);
306
307
308static void __init of_ti_clkdm_gate_clk_setup(struct device_node *node)
309{
310	_of_ti_gate_clk_setup(node, &omap_gate_clkdm_clk_ops, NULL);
311}
312CLK_OF_DECLARE(ti_clkdm_gate_clk, "ti,clkdm-gate-clock",
313	       of_ti_clkdm_gate_clk_setup);
314
315static void __init of_ti_hsdiv_gate_clk_setup(struct device_node *node)
316{
317	_of_ti_gate_clk_setup(node, &omap_gate_clk_hsdiv_restore_ops,
318			      &clkhwops_wait);
319}
320CLK_OF_DECLARE(ti_hsdiv_gate_clk, "ti,hsdiv-gate-clock",
321	       of_ti_hsdiv_gate_clk_setup);
322
323static void __init of_ti_gate_clk_setup(struct device_node *node)
324{
325	_of_ti_gate_clk_setup(node, &omap_gate_clk_ops, NULL);
326}
327CLK_OF_DECLARE(ti_gate_clk, "ti,gate-clock", of_ti_gate_clk_setup);
328
329static void __init of_ti_wait_gate_clk_setup(struct device_node *node)
330{
331	_of_ti_gate_clk_setup(node, &omap_gate_clk_ops, &clkhwops_wait);
332}
333CLK_OF_DECLARE(ti_wait_gate_clk, "ti,wait-gate-clock",
334	       of_ti_wait_gate_clk_setup);
335
336#ifdef CONFIG_ARCH_OMAP3
337static void __init of_ti_am35xx_gate_clk_setup(struct device_node *node)
338{
339	_of_ti_gate_clk_setup(node, &omap_gate_clk_ops,
340			      &clkhwops_am35xx_ipss_module_wait);
341}
342CLK_OF_DECLARE(ti_am35xx_gate_clk, "ti,am35xx-gate-clock",
343	       of_ti_am35xx_gate_clk_setup);
344
345static void __init of_ti_dss_gate_clk_setup(struct device_node *node)
346{
347	_of_ti_gate_clk_setup(node, &omap_gate_clk_ops,
348			      &clkhwops_omap3430es2_dss_usbhost_wait);
349}
350CLK_OF_DECLARE(ti_dss_gate_clk, "ti,dss-gate-clock",
351	       of_ti_dss_gate_clk_setup);
352#endif
353