1 /*
2  * Synopsys HSDK SDP Generic PLL clock driver
3  *
4  * Copyright (C) 2017 Synopsys
5  * Author: Eugeniy Paltsev <Eugeniy.Paltsev@synopsys.com>
6  *
7  * This file is licensed under the terms of the GNU General Public
8  * License version 2. This program is licensed "as is" without any
9  * warranty of any kind, whether express or implied.
10  */
11 
12 #include <asm-generic/gpio.h>
13 #include <asm/io.h>
14 #include <common.h>
15 #include <dm.h>
16 #include <errno.h>
17 #include <linux/printk.h>
18 
19 #define DRV_NAME	"gpio_creg"
20 
21 struct hsdk_creg_gpio {
22 	u32	*regs;
23 	u8	shift;
24 	u8	activate;
25 	u8	deactivate;
26 	u8	bit_per_gpio;
27 };
28 
29 static int hsdk_creg_gpio_set_value(struct udevice *dev, unsigned oft, int val)
30 {
31 	struct hsdk_creg_gpio *hcg = dev_get_priv(dev);
32 	u8 reg_shift = oft * hcg->bit_per_gpio + hcg->shift;
33 	u32 reg = readl(hcg->regs);
34 
35 	reg &= ~(GENMASK(hcg->bit_per_gpio - 1, 0) << reg_shift);
36 	reg |=  ((val ? hcg->deactivate : hcg->activate) << reg_shift);
37 
38 	writel(reg, hcg->regs);
39 
40 	return 0;
41 }
42 
43 static int hsdk_creg_gpio_direction_output(struct udevice *dev, unsigned oft,
44 					   int val)
45 {
46 	hsdk_creg_gpio_set_value(dev, oft, val);
47 
48 	return 0;
49 }
50 
51 static int hsdk_creg_gpio_direction_input(struct udevice *dev, unsigned oft)
52 {
53 	struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
54 
55 	pr_err("%s can't be used as input!\n", uc_priv->bank_name);
56 
57 	return -ENOTSUPP;
58 }
59 
60 static int hsdk_creg_gpio_get_value(struct udevice *dev, unsigned int oft)
61 {
62 	struct hsdk_creg_gpio *hcg = dev_get_priv(dev);
63 	u32 val = readl(hcg->regs);
64 
65 	val >>= oft * hcg->bit_per_gpio + hcg->shift;
66 	val &= GENMASK(hcg->bit_per_gpio - 1, 0);
67 	return (val == hcg->deactivate) ? 1 : 0;
68 }
69 
70 static const struct dm_gpio_ops hsdk_creg_gpio_ops = {
71 	.direction_output	= hsdk_creg_gpio_direction_output,
72 	.direction_input	= hsdk_creg_gpio_direction_input,
73 	.set_value		= hsdk_creg_gpio_set_value,
74 	.get_value		= hsdk_creg_gpio_get_value,
75 };
76 
77 static int hsdk_creg_gpio_probe(struct udevice *dev)
78 {
79 	struct gpio_dev_priv *uc_priv = dev_get_uclass_priv(dev);
80 	struct hsdk_creg_gpio *hcg = dev_get_priv(dev);
81 	u32 shift, bit_per_gpio, activate, deactivate, gpio_count;
82 	const u8 *defaults;
83 
84 	hcg->regs = (u32 *)devfdt_get_addr_ptr(dev);
85 	gpio_count = dev_read_u32_default(dev, "gpio-count", 1);
86 	shift = dev_read_u32_default(dev, "gpio-first-shift", 0);
87 	bit_per_gpio = dev_read_u32_default(dev, "gpio-bit-per-line", 1);
88 	activate = dev_read_u32_default(dev, "gpio-activate-val", 1);
89 	deactivate = dev_read_u32_default(dev, "gpio-deactivate-val", 0);
90 	defaults = dev_read_u8_array_ptr(dev, "gpio-default-val", gpio_count);
91 
92 	uc_priv->bank_name = dev_read_string(dev, "gpio-bank-name");
93 	if (!uc_priv->bank_name)
94 		uc_priv->bank_name = dev_read_name(dev);
95 
96 	if (!bit_per_gpio) {
97 		pr_err("%s: 'gpio-bit-per-line' can't be 0\n",
98 		       uc_priv->bank_name);
99 
100 		return -EINVAL;
101 	}
102 
103 	if (!gpio_count) {
104 		pr_err("%s: 'gpio-count' can't be 0\n",
105 		       uc_priv->bank_name);
106 
107 		return -EINVAL;
108 	}
109 
110 	if ((gpio_count * bit_per_gpio + shift) > 32) {
111 		pr_err("%s: u32 io register overflow: try to use %u bits\n",
112 		       uc_priv->bank_name, gpio_count * bit_per_gpio + shift);
113 
114 		return -EINVAL;
115 	}
116 
117 	if (GENMASK(31, bit_per_gpio) & activate) {
118 		pr_err("%s: 'gpio-activate-val' can't be more than %lu\n",
119 		       uc_priv->bank_name, GENMASK(bit_per_gpio - 1, 0));
120 
121 		return -EINVAL;
122 	}
123 
124 	if (GENMASK(31, bit_per_gpio) & deactivate) {
125 		pr_err("%s: 'gpio-deactivate-val' can't be more than %lu\n",
126 		       uc_priv->bank_name, GENMASK(bit_per_gpio - 1, 0));
127 
128 		return -EINVAL;
129 	}
130 
131 	if (activate == deactivate) {
132 		pr_err("%s: 'gpio-deactivate-val' and 'gpio-activate-val' can't be equal\n",
133 		       uc_priv->bank_name);
134 
135 		return -EINVAL;
136 	}
137 
138 	hcg->shift = (u8)shift;
139 	hcg->bit_per_gpio = (u8)bit_per_gpio;
140 	hcg->activate = (u8)activate;
141 	hcg->deactivate = (u8)deactivate;
142 	uc_priv->gpio_count = gpio_count;
143 
144 	/* Setup default GPIO value if we have "gpio-default-val" array */
145 	if (defaults)
146 		for (u8 i = 0; i < gpio_count; i++)
147 			hsdk_creg_gpio_set_value(dev, i, defaults[i]);
148 
149 	pr_debug("%s GPIO [0x%p] controller with %d gpios probed\n",
150 		 uc_priv->bank_name, hcg->regs, uc_priv->gpio_count);
151 
152 	return 0;
153 }
154 
155 static const struct udevice_id hsdk_creg_gpio_ids[] = {
156 	{ .compatible = "snps,creg-gpio" },
157 	{ }
158 };
159 
160 U_BOOT_DRIVER(gpio_hsdk_creg) = {
161 	.name	= DRV_NAME,
162 	.id	= UCLASS_GPIO,
163 	.ops	= &hsdk_creg_gpio_ops,
164 	.probe	= hsdk_creg_gpio_probe,
165 	.of_match = hsdk_creg_gpio_ids,
166 	.platdata_auto_alloc_size = sizeof(struct hsdk_creg_gpio),
167 };
168