1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * clkgen-mux.c: ST GEN-MUX Clock driver 4 * 5 * Copyright (C) 2014 STMicroelectronics (R&D) Limited 6 * 7 * Authors: Stephen Gallimore <stephen.gallimore@st.com> 8 * Pankaj Dev <pankaj.dev@st.com> 9 */ 10 11 #include <linux/slab.h> 12 #include <linux/io.h> 13 #include <linux/of_address.h> 14 #include <linux/clk.h> 15 #include <linux/clk-provider.h> 16 #include "clkgen.h" 17 18 static const char ** __init clkgen_mux_get_parents(struct device_node *np, 19 int *num_parents) 20 { 21 const char **parents; 22 unsigned int nparents; 23 24 nparents = of_clk_get_parent_count(np); 25 if (WARN_ON(!nparents)) 26 return ERR_PTR(-EINVAL); 27 28 parents = kcalloc(nparents, sizeof(const char *), GFP_KERNEL); 29 if (!parents) 30 return ERR_PTR(-ENOMEM); 31 32 *num_parents = of_clk_parent_fill(np, parents, nparents); 33 return parents; 34 } 35 36 struct clkgen_mux_data { 37 u32 offset; 38 u8 shift; 39 u8 width; 40 spinlock_t *lock; 41 unsigned long clk_flags; 42 u8 mux_flags; 43 }; 44 45 static struct clkgen_mux_data stih407_a9_mux_data = { 46 .offset = 0x1a4, 47 .shift = 0, 48 .width = 2, 49 .lock = &clkgen_a9_lock, 50 }; 51 52 static void __init st_of_clkgen_mux_setup(struct device_node *np, 53 struct clkgen_mux_data *data) 54 { 55 struct clk *clk; 56 void __iomem *reg; 57 const char **parents; 58 int num_parents = 0; 59 60 /* 61 * First check for reg property within the node to keep backward 62 * compatibility, then if reg doesn't exist look at the parent node 63 */ 64 reg = of_iomap(np, 0); 65 if (!reg) { 66 reg = of_iomap(of_get_parent(np), 0); 67 if (!reg) { 68 pr_err("%s: Failed to get base address\n", __func__); 69 return; 70 } 71 } 72 73 parents = clkgen_mux_get_parents(np, &num_parents); 74 if (IS_ERR(parents)) { 75 pr_err("%s: Failed to get parents (%ld)\n", 76 __func__, PTR_ERR(parents)); 77 goto err_parents; 78 } 79 80 clk = clk_register_mux(NULL, np->name, parents, num_parents, 81 data->clk_flags | CLK_SET_RATE_PARENT, 82 reg + data->offset, 83 data->shift, data->width, data->mux_flags, 84 data->lock); 85 if (IS_ERR(clk)) 86 goto err; 87 88 pr_debug("%s: parent %s rate %u\n", 89 __clk_get_name(clk), 90 __clk_get_name(clk_get_parent(clk)), 91 (unsigned int)clk_get_rate(clk)); 92 93 kfree(parents); 94 of_clk_add_provider(np, of_clk_src_simple_get, clk); 95 return; 96 97 err: 98 kfree(parents); 99 err_parents: 100 iounmap(reg); 101 } 102 103 static void __init st_of_clkgen_a9_mux_setup(struct device_node *np) 104 { 105 st_of_clkgen_mux_setup(np, &stih407_a9_mux_data); 106 } 107 CLK_OF_DECLARE(clkgen_a9mux, "st,stih407-clkgen-a9-mux", 108 st_of_clkgen_a9_mux_setup); 109