1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * Copyright (C) 2016 Freescale Semiconductor, Inc.
4 * Copyright 2017~2018 NXP
5 *
6 */
7
8#include <linux/bits.h>
9#include <linux/clk-provider.h>
10#include <linux/err.h>
11#include <linux/io.h>
12#include <linux/slab.h>
13
14#include "../clk-fractional-divider.h"
15#include "clk.h"
16
17#define PCG_PCS_SHIFT 24
18#define PCG_PCS_MASK 0x7
19#define PCG_CGC_SHIFT 30
20#define PCG_FRAC_SHIFT 3
21#define PCG_FRAC_WIDTH 1
22#define PCG_PCD_SHIFT 0
23#define PCG_PCD_WIDTH 3
24
25#define SW_RST BIT(28)
26
27static int pcc_gate_enable(struct clk_hw *hw)
28{
29 struct clk_gate *gate = to_clk_gate(hw);
30 unsigned long flags;
31 u32 val;
32 int ret;
33
34 ret = clk_gate_ops.enable(hw);
35 if (ret)
36 return ret;
37
38 spin_lock_irqsave(gate->lock, flags);
39 /*
40 * release the sw reset for peripherals associated with
41 * with this pcc clock.
42 */
43 val = readl(addr: gate->reg);
44 val |= SW_RST;
45 writel(val, addr: gate->reg);
46
47 spin_unlock_irqrestore(lock: gate->lock, flags);
48
49 return 0;
50}
51
52static void pcc_gate_disable(struct clk_hw *hw)
53{
54 clk_gate_ops.disable(hw);
55}
56
57static int pcc_gate_is_enabled(struct clk_hw *hw)
58{
59 return clk_gate_ops.is_enabled(hw);
60}
61
62static const struct clk_ops pcc_gate_ops = {
63 .enable = pcc_gate_enable,
64 .disable = pcc_gate_disable,
65 .is_enabled = pcc_gate_is_enabled,
66};
67
68static struct clk_hw *imx_ulp_clk_hw_composite(const char *name,
69 const char * const *parent_names,
70 int num_parents, bool mux_present,
71 bool rate_present, bool gate_present,
72 void __iomem *reg, bool has_swrst)
73{
74 struct clk_hw *mux_hw = NULL, *fd_hw = NULL, *gate_hw = NULL;
75 struct clk_fractional_divider *fd = NULL;
76 struct clk_gate *gate = NULL;
77 struct clk_mux *mux = NULL;
78 struct clk_hw *hw;
79 u32 val;
80
81 if (mux_present) {
82 mux = kzalloc(size: sizeof(*mux), GFP_KERNEL);
83 if (!mux)
84 return ERR_PTR(error: -ENOMEM);
85 mux_hw = &mux->hw;
86 mux->reg = reg;
87 mux->shift = PCG_PCS_SHIFT;
88 mux->mask = PCG_PCS_MASK;
89 if (has_swrst)
90 mux->lock = &imx_ccm_lock;
91 }
92
93 if (rate_present) {
94 fd = kzalloc(size: sizeof(*fd), GFP_KERNEL);
95 if (!fd) {
96 kfree(objp: mux);
97 return ERR_PTR(error: -ENOMEM);
98 }
99 fd_hw = &fd->hw;
100 fd->reg = reg;
101 fd->mshift = PCG_FRAC_SHIFT;
102 fd->mwidth = PCG_FRAC_WIDTH;
103 fd->nshift = PCG_PCD_SHIFT;
104 fd->nwidth = PCG_PCD_WIDTH;
105 fd->flags = CLK_FRAC_DIVIDER_ZERO_BASED;
106 if (has_swrst)
107 fd->lock = &imx_ccm_lock;
108 }
109
110 if (gate_present) {
111 gate = kzalloc(size: sizeof(*gate), GFP_KERNEL);
112 if (!gate) {
113 kfree(objp: mux);
114 kfree(objp: fd);
115 return ERR_PTR(error: -ENOMEM);
116 }
117 gate_hw = &gate->hw;
118 gate->reg = reg;
119 gate->bit_idx = PCG_CGC_SHIFT;
120 if (has_swrst)
121 gate->lock = &imx_ccm_lock;
122 /*
123 * make sure clock is gated during clock tree initialization,
124 * the HW ONLY allow clock parent/rate changed with clock gated,
125 * during clock tree initialization, clocks could be enabled
126 * by bootloader, so the HW status will mismatch with clock tree
127 * prepare count, then clock core driver will allow parent/rate
128 * change since the prepare count is zero, but HW actually
129 * prevent the parent/rate change due to the clock is enabled.
130 */
131 val = readl_relaxed(reg);
132 val &= ~(1 << PCG_CGC_SHIFT);
133 writel_relaxed(val, reg);
134 }
135
136 hw = clk_hw_register_composite(NULL, name, parent_names, num_parents,
137 mux_hw, mux_ops: &clk_mux_ops, rate_hw: fd_hw,
138 rate_ops: &clk_fractional_divider_ops, gate_hw,
139 gate_ops: has_swrst ? &pcc_gate_ops : &clk_gate_ops, CLK_SET_RATE_GATE |
140 CLK_SET_PARENT_GATE | CLK_SET_RATE_NO_REPARENT);
141 if (IS_ERR(ptr: hw)) {
142 kfree(objp: mux);
143 kfree(objp: fd);
144 kfree(objp: gate);
145 }
146
147 return hw;
148}
149
150struct clk_hw *imx7ulp_clk_hw_composite(const char *name, const char * const *parent_names,
151 int num_parents, bool mux_present, bool rate_present,
152 bool gate_present, void __iomem *reg)
153{
154 return imx_ulp_clk_hw_composite(name, parent_names, num_parents, mux_present, rate_present,
155 gate_present, reg, has_swrst: false);
156}
157
158struct clk_hw *imx8ulp_clk_hw_composite(const char *name, const char * const *parent_names,
159 int num_parents, bool mux_present, bool rate_present,
160 bool gate_present, void __iomem *reg, bool has_swrst)
161{
162 return imx_ulp_clk_hw_composite(name, parent_names, num_parents, mux_present, rate_present,
163 gate_present, reg, has_swrst);
164}
165EXPORT_SYMBOL_GPL(imx8ulp_clk_hw_composite);
166

source code of linux/drivers/clk/imx/clk-composite-7ulp.c