xref: /linux/drivers/pinctrl/meson/pinctrl-meson-axg-pmx.c (revision 55d0969c451159cff86949b38c39171cab962069)
1 // SPDX-License-Identifier: (GPL-2.0+ OR MIT)
2 /*
3  * Second generation of pinmux driver for Amlogic Meson-AXG SoC.
4  *
5  * Copyright (c) 2017 Baylibre SAS.
6  * Author:  Jerome Brunet  <jbrunet@baylibre.com>
7  *
8  * Copyright (c) 2017 Amlogic, Inc. All rights reserved.
9  * Author: Xingyu Chen <xingyu.chen@amlogic.com>
10  */
11 
12 /*
13  * This new generation of pinctrl IP is mainly adopted by the
14  * Meson-AXG SoC and later series, which use 4-width continuous
15  * register bit to select the function for each pin.
16  *
17  * The value 0 is always selecting the GPIO mode, while other
18  * values (start from 1) for selecting the function mode.
19  */
20 #include <linux/device.h>
21 #include <linux/regmap.h>
22 #include <linux/pinctrl/pinctrl.h>
23 #include <linux/pinctrl/pinmux.h>
24 
25 #include "pinctrl-meson.h"
26 #include "pinctrl-meson-axg-pmx.h"
27 
28 static int meson_axg_pmx_get_bank(struct meson_pinctrl *pc,
29 			unsigned int pin,
30 			const struct meson_pmx_bank **bank)
31 {
32 	int i;
33 	const struct meson_axg_pmx_data *pmx = pc->data->pmx_data;
34 
35 	for (i = 0; i < pmx->num_pmx_banks; i++)
36 		if (pin >= pmx->pmx_banks[i].first &&
37 				pin <= pmx->pmx_banks[i].last) {
38 			*bank = &pmx->pmx_banks[i];
39 			return 0;
40 		}
41 
42 	return -EINVAL;
43 }
44 
45 static int meson_pmx_calc_reg_and_offset(const struct meson_pmx_bank *bank,
46 			unsigned int pin, unsigned int *reg,
47 			unsigned int *offset)
48 {
49 	int shift;
50 
51 	shift = pin - bank->first;
52 
53 	*reg = bank->reg + (bank->offset + (shift << 2)) / 32;
54 	*offset = (bank->offset + (shift << 2)) % 32;
55 
56 	return 0;
57 }
58 
59 static int meson_axg_pmx_update_function(struct meson_pinctrl *pc,
60 			unsigned int pin, unsigned int func)
61 {
62 	const struct meson_pmx_bank *bank;
63 	int ret;
64 	int reg;
65 	int offset;
66 
67 	ret = meson_axg_pmx_get_bank(pc, pin, &bank);
68 	if (ret)
69 		return ret;
70 
71 	meson_pmx_calc_reg_and_offset(bank, pin, &reg, &offset);
72 
73 	ret = regmap_update_bits(pc->reg_mux, reg << 2,
74 		0xf << offset, (func & 0xf) << offset);
75 
76 	return ret;
77 }
78 
79 static int meson_axg_pmx_set_mux(struct pinctrl_dev *pcdev,
80 			unsigned int func_num, unsigned int group_num)
81 {
82 	int i;
83 	int ret;
84 	struct meson_pinctrl *pc = pinctrl_dev_get_drvdata(pcdev);
85 	const struct meson_pmx_func *func = &pc->data->funcs[func_num];
86 	const struct meson_pmx_group *group = &pc->data->groups[group_num];
87 	struct meson_pmx_axg_data *pmx_data =
88 		(struct meson_pmx_axg_data *)group->data;
89 
90 	dev_dbg(pc->dev, "enable function %s, group %s\n", func->name,
91 		group->name);
92 
93 	for (i = 0; i < group->num_pins; i++) {
94 		ret = meson_axg_pmx_update_function(pc, group->pins[i],
95 			pmx_data->func);
96 		if (ret)
97 			return ret;
98 	}
99 
100 	return 0;
101 }
102 
103 static int meson_axg_pmx_request_gpio(struct pinctrl_dev *pcdev,
104 			struct pinctrl_gpio_range *range, unsigned int offset)
105 {
106 	struct meson_pinctrl *pc = pinctrl_dev_get_drvdata(pcdev);
107 
108 	return meson_axg_pmx_update_function(pc, offset, 0);
109 }
110 
111 const struct pinmux_ops meson_axg_pmx_ops = {
112 	.set_mux = meson_axg_pmx_set_mux,
113 	.get_functions_count = meson_pmx_get_funcs_count,
114 	.get_function_name = meson_pmx_get_func_name,
115 	.get_function_groups = meson_pmx_get_groups,
116 	.gpio_request_enable = meson_axg_pmx_request_gpio,
117 };
118 EXPORT_SYMBOL_GPL(meson_axg_pmx_ops);
119 
120 MODULE_DESCRIPTION("Amlogic Meson AXG second generation pinmux driver");
121 MODULE_LICENSE("Dual BSD/GPL");
122