xref: /linux/drivers/mfd/mxs-lradc.c (revision 9a379e77033f02c4a071891afdf0f0a01eff8ccb)
1 /*
2  * Freescale MXS Low Resolution Analog-to-Digital Converter driver
3  *
4  * Copyright (c) 2012 DENX Software Engineering, GmbH.
5  * Copyright (c) 2017 Ksenija Stanojevic <ksenija.stanojevic@gmail.com>
6  *
7  * Authors:
8  *  Marek Vasut <marex@denx.de>
9  *  Ksenija Stanojevic <ksenija.stanojevic@gmail.com>
10  *
11  * This program is free software; you can redistribute it and/or modify
12  * it under the terms of the GNU General Public License as published by
13  * the Free Software Foundation; either version 2 of the License, or
14  * (at your option) any later version.
15  *
16  * This program is distributed in the hope that it will be useful,
17  * but WITHOUT ANY WARRANTY; without even the implied warranty of
18  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19  * GNU General Public License for more details.
20  */
21 
22 #include <linux/clk.h>
23 #include <linux/device.h>
24 #include <linux/mfd/core.h>
25 #include <linux/mfd/mxs-lradc.h>
26 #include <linux/module.h>
27 #include <linux/of.h>
28 #include <linux/of_device.h>
29 #include <linux/platform_device.h>
30 #include <linux/slab.h>
31 
32 #define ADC_CELL		0
33 #define TSC_CELL		1
34 #define RES_MEM			0
35 
36 enum mx23_lradc_irqs {
37 	MX23_LRADC_TS_IRQ = 0,
38 	MX23_LRADC_CH0_IRQ,
39 	MX23_LRADC_CH1_IRQ,
40 	MX23_LRADC_CH2_IRQ,
41 	MX23_LRADC_CH3_IRQ,
42 	MX23_LRADC_CH4_IRQ,
43 	MX23_LRADC_CH5_IRQ,
44 	MX23_LRADC_CH6_IRQ,
45 	MX23_LRADC_CH7_IRQ,
46 };
47 
48 enum mx28_lradc_irqs {
49 	MX28_LRADC_TS_IRQ = 0,
50 	MX28_LRADC_TRESH0_IRQ,
51 	MX28_LRADC_TRESH1_IRQ,
52 	MX28_LRADC_CH0_IRQ,
53 	MX28_LRADC_CH1_IRQ,
54 	MX28_LRADC_CH2_IRQ,
55 	MX28_LRADC_CH3_IRQ,
56 	MX28_LRADC_CH4_IRQ,
57 	MX28_LRADC_CH5_IRQ,
58 	MX28_LRADC_CH6_IRQ,
59 	MX28_LRADC_CH7_IRQ,
60 	MX28_LRADC_BUTTON0_IRQ,
61 	MX28_LRADC_BUTTON1_IRQ,
62 };
63 
64 static struct resource mx23_adc_resources[] = {
65 	DEFINE_RES_MEM(0x0, 0x0),
66 	DEFINE_RES_IRQ_NAMED(MX23_LRADC_CH0_IRQ, "mxs-lradc-channel0"),
67 	DEFINE_RES_IRQ_NAMED(MX23_LRADC_CH1_IRQ, "mxs-lradc-channel1"),
68 	DEFINE_RES_IRQ_NAMED(MX23_LRADC_CH2_IRQ, "mxs-lradc-channel2"),
69 	DEFINE_RES_IRQ_NAMED(MX23_LRADC_CH3_IRQ, "mxs-lradc-channel3"),
70 	DEFINE_RES_IRQ_NAMED(MX23_LRADC_CH4_IRQ, "mxs-lradc-channel4"),
71 	DEFINE_RES_IRQ_NAMED(MX23_LRADC_CH5_IRQ, "mxs-lradc-channel5"),
72 };
73 
74 static struct resource mx23_touchscreen_resources[] = {
75 	DEFINE_RES_MEM(0x0, 0x0),
76 	DEFINE_RES_IRQ_NAMED(MX23_LRADC_TS_IRQ, "mxs-lradc-touchscreen"),
77 	DEFINE_RES_IRQ_NAMED(MX23_LRADC_CH6_IRQ, "mxs-lradc-channel6"),
78 	DEFINE_RES_IRQ_NAMED(MX23_LRADC_CH7_IRQ, "mxs-lradc-channel7"),
79 };
80 
81 static struct resource mx28_adc_resources[] = {
82 	DEFINE_RES_MEM(0x0, 0x0),
83 	DEFINE_RES_IRQ_NAMED(MX28_LRADC_TRESH0_IRQ, "mxs-lradc-thresh0"),
84 	DEFINE_RES_IRQ_NAMED(MX28_LRADC_TRESH1_IRQ, "mxs-lradc-thresh1"),
85 	DEFINE_RES_IRQ_NAMED(MX28_LRADC_CH0_IRQ, "mxs-lradc-channel0"),
86 	DEFINE_RES_IRQ_NAMED(MX28_LRADC_CH1_IRQ, "mxs-lradc-channel1"),
87 	DEFINE_RES_IRQ_NAMED(MX28_LRADC_CH2_IRQ, "mxs-lradc-channel2"),
88 	DEFINE_RES_IRQ_NAMED(MX28_LRADC_CH3_IRQ, "mxs-lradc-channel3"),
89 	DEFINE_RES_IRQ_NAMED(MX28_LRADC_CH4_IRQ, "mxs-lradc-channel4"),
90 	DEFINE_RES_IRQ_NAMED(MX28_LRADC_CH5_IRQ, "mxs-lradc-channel5"),
91 	DEFINE_RES_IRQ_NAMED(MX28_LRADC_BUTTON0_IRQ, "mxs-lradc-button0"),
92 	DEFINE_RES_IRQ_NAMED(MX28_LRADC_BUTTON1_IRQ, "mxs-lradc-button1"),
93 };
94 
95 static struct resource mx28_touchscreen_resources[] = {
96 	DEFINE_RES_MEM(0x0, 0x0),
97 	DEFINE_RES_IRQ_NAMED(MX28_LRADC_TS_IRQ, "mxs-lradc-touchscreen"),
98 	DEFINE_RES_IRQ_NAMED(MX28_LRADC_CH6_IRQ, "mxs-lradc-channel6"),
99 	DEFINE_RES_IRQ_NAMED(MX28_LRADC_CH7_IRQ, "mxs-lradc-channel7"),
100 };
101 
102 static struct mfd_cell mx23_cells[] = {
103 	{
104 		.name = "mxs-lradc-adc",
105 		.resources = mx23_adc_resources,
106 		.num_resources = ARRAY_SIZE(mx23_adc_resources),
107 	},
108 	{
109 		.name = "mxs-lradc-ts",
110 		.resources = mx23_touchscreen_resources,
111 		.num_resources = ARRAY_SIZE(mx23_touchscreen_resources),
112 	},
113 };
114 
115 static struct mfd_cell mx28_cells[] = {
116 	{
117 		.name = "mxs-lradc-adc",
118 		.resources = mx28_adc_resources,
119 		.num_resources = ARRAY_SIZE(mx28_adc_resources),
120 	},
121 	{
122 		.name = "mxs-lradc-ts",
123 		.resources = mx28_touchscreen_resources,
124 		.num_resources = ARRAY_SIZE(mx28_touchscreen_resources),
125 	}
126 };
127 
128 static const struct of_device_id mxs_lradc_dt_ids[] = {
129 	{ .compatible = "fsl,imx23-lradc", .data = (void *)IMX23_LRADC, },
130 	{ .compatible = "fsl,imx28-lradc", .data = (void *)IMX28_LRADC, },
131 	{ /* sentinel */ }
132 };
133 MODULE_DEVICE_TABLE(of, mxs_lradc_dt_ids);
134 
135 static int mxs_lradc_probe(struct platform_device *pdev)
136 {
137 	const struct of_device_id *of_id;
138 	struct device *dev = &pdev->dev;
139 	struct device_node *node = dev->of_node;
140 	struct mxs_lradc *lradc;
141 	struct mfd_cell *cells = NULL;
142 	struct resource *res;
143 	int ret = 0;
144 	u32 ts_wires = 0;
145 
146 	lradc = devm_kzalloc(&pdev->dev, sizeof(*lradc), GFP_KERNEL);
147 	if (!lradc)
148 		return -ENOMEM;
149 
150 	of_id = of_match_device(mxs_lradc_dt_ids, &pdev->dev);
151 	if (!of_id)
152 		return -EINVAL;
153 
154 	lradc->soc = (enum mxs_lradc_id)of_id->data;
155 
156 	lradc->clk = devm_clk_get(&pdev->dev, NULL);
157 	if (IS_ERR(lradc->clk)) {
158 		dev_err(dev, "Failed to get the delay unit clock\n");
159 		return PTR_ERR(lradc->clk);
160 	}
161 
162 	ret = clk_prepare_enable(lradc->clk);
163 	if (ret) {
164 		dev_err(dev, "Failed to enable the delay unit clock\n");
165 		return ret;
166 	}
167 
168 	ret = of_property_read_u32(node, "fsl,lradc-touchscreen-wires",
169 					 &ts_wires);
170 
171 	if (!ret) {
172 		lradc->buffer_vchans = BUFFER_VCHANS_LIMITED;
173 
174 		switch (ts_wires) {
175 		case 4:
176 			lradc->touchscreen_wire = MXS_LRADC_TOUCHSCREEN_4WIRE;
177 			break;
178 		case 5:
179 			if (lradc->soc == IMX28_LRADC) {
180 				lradc->touchscreen_wire =
181 					MXS_LRADC_TOUCHSCREEN_5WIRE;
182 				break;
183 			}
184 			/* fall through to an error message for i.MX23 */
185 		default:
186 			dev_err(&pdev->dev,
187 				"Unsupported number of touchscreen wires (%d)\n"
188 				, ts_wires);
189 			ret = -EINVAL;
190 			goto err_clk;
191 		}
192 	} else {
193 		lradc->buffer_vchans = BUFFER_VCHANS_ALL;
194 	}
195 
196 	platform_set_drvdata(pdev, lradc);
197 
198 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
199 	if (!res) {
200 		ret = -ENOMEM;
201 		goto err_clk;
202 	}
203 
204 	switch (lradc->soc) {
205 	case IMX23_LRADC:
206 		mx23_adc_resources[RES_MEM] = *res;
207 		mx23_touchscreen_resources[RES_MEM] = *res;
208 		cells = mx23_cells;
209 		break;
210 	case IMX28_LRADC:
211 		mx28_adc_resources[RES_MEM] = *res;
212 		mx28_touchscreen_resources[RES_MEM] = *res;
213 		cells = mx28_cells;
214 		break;
215 	default:
216 		dev_err(dev, "Unsupported SoC\n");
217 		ret = -ENODEV;
218 		goto err_clk;
219 	}
220 
221 	ret = devm_mfd_add_devices(&pdev->dev, PLATFORM_DEVID_NONE,
222 				   &cells[ADC_CELL], 1, NULL, 0, NULL);
223 	if (ret) {
224 		dev_err(&pdev->dev, "Failed to add the ADC subdevice\n");
225 		goto err_clk;
226 	}
227 
228 	if (!lradc->touchscreen_wire)
229 		return 0;
230 
231 	ret = devm_mfd_add_devices(&pdev->dev, PLATFORM_DEVID_NONE,
232 				   &cells[TSC_CELL], 1, NULL, 0, NULL);
233 	if (ret) {
234 		dev_err(&pdev->dev,
235 			"Failed to add the touchscreen subdevice\n");
236 		goto err_clk;
237 	}
238 
239 	return 0;
240 
241 err_clk:
242 	clk_disable_unprepare(lradc->clk);
243 
244 	return ret;
245 }
246 
247 static int mxs_lradc_remove(struct platform_device *pdev)
248 {
249 	struct mxs_lradc *lradc = platform_get_drvdata(pdev);
250 
251 	clk_disable_unprepare(lradc->clk);
252 
253 	return 0;
254 }
255 
256 static struct platform_driver mxs_lradc_driver = {
257 	.driver = {
258 		.name = "mxs-lradc",
259 		.of_match_table = mxs_lradc_dt_ids,
260 	},
261 	.probe = mxs_lradc_probe,
262 	.remove = mxs_lradc_remove,
263 };
264 module_platform_driver(mxs_lradc_driver);
265 
266 MODULE_AUTHOR("Ksenija Stanojevic <ksenija.stanojevic@gmail.com>");
267 MODULE_DESCRIPTION("Freescale i.MX23/i.MX28 LRADC driver");
268 MODULE_LICENSE("GPL");
269 MODULE_ALIAS("platform:mxs-lradc");
270