1 /*
2  * (C) Copyright 2017, Fuzhou Rockchip Electronics Co., Ltd
3  *
4  * SPDX-License-Identifier:	GPL-2.0+
5  *
6  * Rockchip SARADC driver for U-Boot
7  */
8 
9 #include <common.h>
10 #include <adc.h>
11 #include <clk.h>
12 #include <dm.h>
13 #include <errno.h>
14 #include <asm/io.h>
15 
16 #define SARADC_CTRL_CHN_MASK		GENMASK(2, 0)
17 #define SARADC_CTRL_POWER_CTRL		BIT(3)
18 #define SARADC_CTRL_IRQ_ENABLE		BIT(5)
19 #define SARADC_CTRL_IRQ_STATUS		BIT(6)
20 
21 #define SARADC_TIMEOUT			(100 * 1000)
22 
23 struct rockchip_saradc_regs {
24 	unsigned int data;
25 	unsigned int stas;
26 	unsigned int ctrl;
27 	unsigned int dly_pu_soc;
28 };
29 
30 struct rockchip_saradc_data {
31 	int				num_bits;
32 	int				num_channels;
33 	unsigned long			clk_rate;
34 };
35 
36 struct rockchip_saradc_priv {
37 	struct rockchip_saradc_regs		*regs;
38 	int					active_channel;
39 	const struct rockchip_saradc_data	*data;
40 };
41 
42 int rockchip_saradc_channel_data(struct udevice *dev, int channel,
43 				 unsigned int *data)
44 {
45 	struct rockchip_saradc_priv *priv = dev_get_priv(dev);
46 	struct adc_uclass_platdata *uc_pdata = dev_get_uclass_platdata(dev);
47 
48 	if (channel != priv->active_channel) {
49 		pr_err("Requested channel is not active!");
50 		return -EINVAL;
51 	}
52 
53 	if ((readl(&priv->regs->ctrl) & SARADC_CTRL_IRQ_STATUS) !=
54 	    SARADC_CTRL_IRQ_STATUS)
55 		return -EBUSY;
56 
57 	/* Read value */
58 	*data = readl(&priv->regs->data);
59 	*data &= uc_pdata->data_mask;
60 
61 	/* Power down adc */
62 	writel(0, &priv->regs->ctrl);
63 
64 	return 0;
65 }
66 
67 int rockchip_saradc_start_channel(struct udevice *dev, int channel)
68 {
69 	struct rockchip_saradc_priv *priv = dev_get_priv(dev);
70 
71 	if (channel < 0 || channel >= priv->data->num_channels) {
72 		pr_err("Requested channel is invalid!");
73 		return -EINVAL;
74 	}
75 
76 	/* 8 clock periods as delay between power up and start cmd */
77 	writel(8, &priv->regs->dly_pu_soc);
78 
79 	/* Select the channel to be used and trigger conversion */
80 	writel(SARADC_CTRL_POWER_CTRL | (channel & SARADC_CTRL_CHN_MASK) |
81 	       SARADC_CTRL_IRQ_ENABLE, &priv->regs->ctrl);
82 
83 	priv->active_channel = channel;
84 
85 	return 0;
86 }
87 
88 int rockchip_saradc_stop(struct udevice *dev)
89 {
90 	struct rockchip_saradc_priv *priv = dev_get_priv(dev);
91 
92 	/* Power down adc */
93 	writel(0, &priv->regs->ctrl);
94 
95 	priv->active_channel = -1;
96 
97 	return 0;
98 }
99 
100 int rockchip_saradc_probe(struct udevice *dev)
101 {
102 	struct rockchip_saradc_priv *priv = dev_get_priv(dev);
103 	struct clk clk;
104 	int ret;
105 
106 	ret = clk_get_by_index(dev, 0, &clk);
107 	if (ret)
108 		return ret;
109 
110 	ret = clk_set_rate(&clk, priv->data->clk_rate);
111 	if (IS_ERR_VALUE(ret))
112 		return ret;
113 
114 	priv->active_channel = -1;
115 
116 	return 0;
117 }
118 
119 int rockchip_saradc_ofdata_to_platdata(struct udevice *dev)
120 {
121 	struct adc_uclass_platdata *uc_pdata = dev_get_uclass_platdata(dev);
122 	struct rockchip_saradc_priv *priv = dev_get_priv(dev);
123 	struct rockchip_saradc_data *data;
124 
125 	data = (struct rockchip_saradc_data *)dev_get_driver_data(dev);
126 	priv->regs = (struct rockchip_saradc_regs *)dev_read_addr(dev);
127 	if (priv->regs == (struct rockchip_saradc_regs *)FDT_ADDR_T_NONE) {
128 		pr_err("Dev: %s - can't get address!", dev->name);
129 		return -ENODATA;
130 	}
131 
132 	priv->data = data;
133 	uc_pdata->data_mask = (1 << priv->data->num_bits) - 1;;
134 	uc_pdata->data_format = ADC_DATA_FORMAT_BIN;
135 	uc_pdata->data_timeout_us = SARADC_TIMEOUT / 5;
136 	uc_pdata->channel_mask = (1 << priv->data->num_channels) - 1;
137 
138 	return 0;
139 }
140 
141 static const struct adc_ops rockchip_saradc_ops = {
142 	.start_channel = rockchip_saradc_start_channel,
143 	.channel_data = rockchip_saradc_channel_data,
144 	.stop = rockchip_saradc_stop,
145 };
146 
147 static const struct rockchip_saradc_data saradc_data = {
148 	.num_bits = 10,
149 	.num_channels = 3,
150 	.clk_rate = 1000000,
151 };
152 
153 static const struct rockchip_saradc_data rk3066_tsadc_data = {
154 	.num_bits = 12,
155 	.num_channels = 2,
156 	.clk_rate = 50000,
157 };
158 
159 static const struct rockchip_saradc_data rk3399_saradc_data = {
160 	.num_bits = 10,
161 	.num_channels = 6,
162 	.clk_rate = 1000000,
163 };
164 
165 static const struct udevice_id rockchip_saradc_ids[] = {
166 	{ .compatible = "rockchip,saradc",
167 	  .data = (ulong)&saradc_data },
168 	{ .compatible = "rockchip,rk3066-tsadc",
169 	  .data = (ulong)&rk3066_tsadc_data },
170 	{ .compatible = "rockchip,rk3399-saradc",
171 	  .data = (ulong)&rk3399_saradc_data },
172 	{ }
173 };
174 
175 U_BOOT_DRIVER(rockchip_saradc) = {
176 	.name		= "rockchip_saradc",
177 	.id		= UCLASS_ADC,
178 	.of_match	= rockchip_saradc_ids,
179 	.ops		= &rockchip_saradc_ops,
180 	.probe		= rockchip_saradc_probe,
181 	.ofdata_to_platdata = rockchip_saradc_ofdata_to_platdata,
182 	.priv_auto_alloc_size = sizeof(struct rockchip_saradc_priv),
183 };
184