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_PR_MASK BIT(31) 18 #define PCG_PCS_SHIFT 24 19 #define PCG_PCS_MASK 0x7 20 #define PCG_CGC_SHIFT 30 21 #define PCG_FRAC_SHIFT 3 22 #define PCG_FRAC_WIDTH 1 23 #define PCG_PCD_SHIFT 0 24 #define PCG_PCD_WIDTH 3 25 26 #define SW_RST BIT(28) 27 28 static int pcc_gate_enable(struct clk_hw *hw) 29 { 30 struct clk_gate *gate = to_clk_gate(hw); 31 unsigned long flags; 32 u32 val; 33 int ret; 34 35 ret = clk_gate_ops.enable(hw); 36 if (ret) 37 return ret; 38 39 spin_lock_irqsave(gate->lock, flags); 40 /* 41 * release the sw reset for peripherals associated with 42 * with this pcc clock. 43 */ 44 val = readl(gate->reg); 45 val |= SW_RST; 46 writel(val, gate->reg); 47 48 spin_unlock_irqrestore(gate->lock, flags); 49 50 return 0; 51 } 52 53 static void pcc_gate_disable(struct clk_hw *hw) 54 { 55 clk_gate_ops.disable(hw); 56 } 57 58 static int pcc_gate_is_enabled(struct clk_hw *hw) 59 { 60 return clk_gate_ops.is_enabled(hw); 61 } 62 63 static const struct clk_ops pcc_gate_ops = { 64 .enable = pcc_gate_enable, 65 .disable = pcc_gate_disable, 66 .is_enabled = pcc_gate_is_enabled, 67 }; 68 69 static struct clk_hw *imx_ulp_clk_hw_composite(const char *name, 70 const char * const *parent_names, 71 int num_parents, bool mux_present, 72 bool rate_present, bool gate_present, 73 void __iomem *reg, bool has_swrst) 74 { 75 struct clk_hw *mux_hw = NULL, *fd_hw = NULL, *gate_hw = NULL; 76 struct clk_fractional_divider *fd = NULL; 77 struct clk_gate *gate = NULL; 78 struct clk_mux *mux = NULL; 79 struct clk_hw *hw; 80 u32 val; 81 82 val = readl(reg); 83 if (!(val & PCG_PR_MASK)) { 84 pr_info("PCC PR is 0 for clk:%s, bypass\n", name); 85 return NULL; 86 } 87 88 if (mux_present) { 89 mux = kzalloc(sizeof(*mux), GFP_KERNEL); 90 if (!mux) 91 return ERR_PTR(-ENOMEM); 92 mux_hw = &mux->hw; 93 mux->reg = reg; 94 mux->shift = PCG_PCS_SHIFT; 95 mux->mask = PCG_PCS_MASK; 96 if (has_swrst) 97 mux->lock = &imx_ccm_lock; 98 } 99 100 if (rate_present) { 101 fd = kzalloc(sizeof(*fd), GFP_KERNEL); 102 if (!fd) { 103 kfree(mux); 104 return ERR_PTR(-ENOMEM); 105 } 106 fd_hw = &fd->hw; 107 fd->reg = reg; 108 fd->mshift = PCG_FRAC_SHIFT; 109 fd->mwidth = PCG_FRAC_WIDTH; 110 fd->nshift = PCG_PCD_SHIFT; 111 fd->nwidth = PCG_PCD_WIDTH; 112 fd->flags = CLK_FRAC_DIVIDER_ZERO_BASED; 113 if (has_swrst) 114 fd->lock = &imx_ccm_lock; 115 } 116 117 if (gate_present) { 118 gate = kzalloc(sizeof(*gate), GFP_KERNEL); 119 if (!gate) { 120 kfree(mux); 121 kfree(fd); 122 return ERR_PTR(-ENOMEM); 123 } 124 gate_hw = &gate->hw; 125 gate->reg = reg; 126 gate->bit_idx = PCG_CGC_SHIFT; 127 if (has_swrst) 128 gate->lock = &imx_ccm_lock; 129 /* 130 * make sure clock is gated during clock tree initialization, 131 * the HW ONLY allow clock parent/rate changed with clock gated, 132 * during clock tree initialization, clocks could be enabled 133 * by bootloader, so the HW status will mismatch with clock tree 134 * prepare count, then clock core driver will allow parent/rate 135 * change since the prepare count is zero, but HW actually 136 * prevent the parent/rate change due to the clock is enabled. 137 */ 138 val = readl_relaxed(reg); 139 val &= ~(1 << PCG_CGC_SHIFT); 140 writel_relaxed(val, reg); 141 } 142 143 hw = clk_hw_register_composite(NULL, name, parent_names, num_parents, 144 mux_hw, &clk_mux_ops, fd_hw, 145 &clk_fractional_divider_ops, gate_hw, 146 has_swrst ? &pcc_gate_ops : &clk_gate_ops, CLK_SET_RATE_GATE | 147 CLK_SET_PARENT_GATE | CLK_SET_RATE_NO_REPARENT); 148 if (IS_ERR(hw)) { 149 kfree(mux); 150 kfree(fd); 151 kfree(gate); 152 } 153 154 return hw; 155 } 156 157 struct clk_hw *imx7ulp_clk_hw_composite(const char *name, const char * const *parent_names, 158 int num_parents, bool mux_present, bool rate_present, 159 bool gate_present, void __iomem *reg) 160 { 161 return imx_ulp_clk_hw_composite(name, parent_names, num_parents, mux_present, rate_present, 162 gate_present, reg, false); 163 } 164 165 struct clk_hw *imx8ulp_clk_hw_composite(const char *name, const char * const *parent_names, 166 int num_parents, bool mux_present, bool rate_present, 167 bool gate_present, void __iomem *reg, bool has_swrst) 168 { 169 return imx_ulp_clk_hw_composite(name, parent_names, num_parents, mux_present, rate_present, 170 gate_present, reg, has_swrst); 171 } 172 EXPORT_SYMBOL_GPL(imx8ulp_clk_hw_composite); 173