clk/at91/clk-slow.c

0001 // SPDX-License-Identifier: GPL-2.0-or-later
0002 /*
0003  * drivers/clk/at91/clk-slow.c
0004  *
0005  *  Copyright (C) 2013 Boris BREZILLON <b.brezillon@overkiz.com>
0006  */
0007
0008 #include <linux/clk-provider.h>
0009 #include <linux/clkdev.h>
0010 #include <linux/clk/at91_pmc.h>
0011 #include <linux/of.h>
0012 #include <linux/mfd/syscon.h>
0013 #include <linux/regmap.h>
0014
0015 #include "pmc.h"
0016
0017 struct clk_sam9260_slow {
0018     struct clk_hw hw;
0019     struct regmap *regmap;
0020 };
0021
0022 #define to_clk_sam9260_slow(hw) container_of(hw, struct clk_sam9260_slow, hw)
0023
0024 static u8 clk_sam9260_slow_get_parent(struct clk_hw *hw)
0025 {
0026     struct clk_sam9260_slow *slowck = to_clk_sam9260_slow(hw);
0027     unsigned int status;
0028
0029     regmap_read(slowck->regmap, AT91_PMC_SR, &status);
0030
0031     return status & AT91_PMC_OSCSEL ? 1 : 0;
0032 }
0033
0034 static const struct clk_ops sam9260_slow_ops = {
0035     .get_parent = clk_sam9260_slow_get_parent,
0036 };
0037
0038 struct clk_hw * __init
0039 at91_clk_register_sam9260_slow(struct regmap *regmap,
0040                    const char *name,
0041                    const char **parent_names,
0042                    int num_parents)
0043 {
0044     struct clk_sam9260_slow *slowck;
0045     struct clk_hw *hw;
0046     struct clk_init_data init;
0047     int ret;
0048
0049     if (!name)
0050         return ERR_PTR(-EINVAL);
0051
0052     if (!parent_names || !num_parents)
0053         return ERR_PTR(-EINVAL);
0054
0055     slowck = kzalloc(sizeof(*slowck), GFP_KERNEL);
0056     if (!slowck)
0057         return ERR_PTR(-ENOMEM);
0058
0059     init.name = name;
0060     init.ops = &sam9260_slow_ops;
0061     init.parent_names = parent_names;
0062     init.num_parents = num_parents;
0063     init.flags = 0;
0064
0065     slowck->hw.init = &init;
0066     slowck->regmap = regmap;
0067
0068     hw = &slowck->hw;
0069     ret = clk_hw_register(NULL, &slowck->hw);
0070     if (ret) {
0071         kfree(slowck);
0072         hw = ERR_PTR(ret);
0073     }
0074
0075     return hw;
0076 }