xref: /openbmc/linux/drivers/mfd/mxs-lradc.c (revision 7f6964c5)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Freescale MXS Low Resolution Analog-to-Digital Converter driver
4  *
5  * Copyright (c) 2012 DENX Software Engineering, GmbH.
6  * Copyright (c) 2017 Ksenija Stanojevic <ksenija.stanojevic@gmail.com>
7  *
8  * Authors:
9  *  Marek Vasut <marex@denx.de>
10  *  Ksenija Stanojevic <ksenija.stanojevic@gmail.com>
11  */
12 
13 #include <linux/clk.h>
14 #include <linux/device.h>
15 #include <linux/mfd/core.h>
16 #include <linux/mfd/mxs-lradc.h>
17 #include <linux/module.h>
18 #include <linux/of.h>
19 #include <linux/of_device.h>
20 #include <linux/platform_device.h>
21 #include <linux/slab.h>
22 
23 #define ADC_CELL		0
24 #define TSC_CELL		1
25 #define RES_MEM			0
26 
27 enum mx23_lradc_irqs {
28 	MX23_LRADC_TS_IRQ = 0,
29 	MX23_LRADC_CH0_IRQ,
30 	MX23_LRADC_CH1_IRQ,
31 	MX23_LRADC_CH2_IRQ,
32 	MX23_LRADC_CH3_IRQ,
33 	MX23_LRADC_CH4_IRQ,
34 	MX23_LRADC_CH5_IRQ,
35 	MX23_LRADC_CH6_IRQ,
36 	MX23_LRADC_CH7_IRQ,
37 };
38 
39 enum mx28_lradc_irqs {
40 	MX28_LRADC_TS_IRQ = 0,
41 	MX28_LRADC_TRESH0_IRQ,
42 	MX28_LRADC_TRESH1_IRQ,
43 	MX28_LRADC_CH0_IRQ,
44 	MX28_LRADC_CH1_IRQ,
45 	MX28_LRADC_CH2_IRQ,
46 	MX28_LRADC_CH3_IRQ,
47 	MX28_LRADC_CH4_IRQ,
48 	MX28_LRADC_CH5_IRQ,
49 	MX28_LRADC_CH6_IRQ,
50 	MX28_LRADC_CH7_IRQ,
51 	MX28_LRADC_BUTTON0_IRQ,
52 	MX28_LRADC_BUTTON1_IRQ,
53 };
54 
55 static struct resource mx23_adc_resources[] = {
56 	DEFINE_RES_MEM(0x0, 0x0),
57 	DEFINE_RES_IRQ_NAMED(MX23_LRADC_CH0_IRQ, "mxs-lradc-channel0"),
58 	DEFINE_RES_IRQ_NAMED(MX23_LRADC_CH1_IRQ, "mxs-lradc-channel1"),
59 	DEFINE_RES_IRQ_NAMED(MX23_LRADC_CH2_IRQ, "mxs-lradc-channel2"),
60 	DEFINE_RES_IRQ_NAMED(MX23_LRADC_CH3_IRQ, "mxs-lradc-channel3"),
61 	DEFINE_RES_IRQ_NAMED(MX23_LRADC_CH4_IRQ, "mxs-lradc-channel4"),
62 	DEFINE_RES_IRQ_NAMED(MX23_LRADC_CH5_IRQ, "mxs-lradc-channel5"),
63 };
64 
65 static struct resource mx23_touchscreen_resources[] = {
66 	DEFINE_RES_MEM(0x0, 0x0),
67 	DEFINE_RES_IRQ_NAMED(MX23_LRADC_TS_IRQ, "mxs-lradc-touchscreen"),
68 	DEFINE_RES_IRQ_NAMED(MX23_LRADC_CH6_IRQ, "mxs-lradc-channel6"),
69 	DEFINE_RES_IRQ_NAMED(MX23_LRADC_CH7_IRQ, "mxs-lradc-channel7"),
70 };
71 
72 static struct resource mx28_adc_resources[] = {
73 	DEFINE_RES_MEM(0x0, 0x0),
74 	DEFINE_RES_IRQ_NAMED(MX28_LRADC_TRESH0_IRQ, "mxs-lradc-thresh0"),
75 	DEFINE_RES_IRQ_NAMED(MX28_LRADC_TRESH1_IRQ, "mxs-lradc-thresh1"),
76 	DEFINE_RES_IRQ_NAMED(MX28_LRADC_CH0_IRQ, "mxs-lradc-channel0"),
77 	DEFINE_RES_IRQ_NAMED(MX28_LRADC_CH1_IRQ, "mxs-lradc-channel1"),
78 	DEFINE_RES_IRQ_NAMED(MX28_LRADC_CH2_IRQ, "mxs-lradc-channel2"),
79 	DEFINE_RES_IRQ_NAMED(MX28_LRADC_CH3_IRQ, "mxs-lradc-channel3"),
80 	DEFINE_RES_IRQ_NAMED(MX28_LRADC_CH4_IRQ, "mxs-lradc-channel4"),
81 	DEFINE_RES_IRQ_NAMED(MX28_LRADC_CH5_IRQ, "mxs-lradc-channel5"),
82 	DEFINE_RES_IRQ_NAMED(MX28_LRADC_BUTTON0_IRQ, "mxs-lradc-button0"),
83 	DEFINE_RES_IRQ_NAMED(MX28_LRADC_BUTTON1_IRQ, "mxs-lradc-button1"),
84 };
85 
86 static struct resource mx28_touchscreen_resources[] = {
87 	DEFINE_RES_MEM(0x0, 0x0),
88 	DEFINE_RES_IRQ_NAMED(MX28_LRADC_TS_IRQ, "mxs-lradc-touchscreen"),
89 	DEFINE_RES_IRQ_NAMED(MX28_LRADC_CH6_IRQ, "mxs-lradc-channel6"),
90 	DEFINE_RES_IRQ_NAMED(MX28_LRADC_CH7_IRQ, "mxs-lradc-channel7"),
91 };
92 
93 static struct mfd_cell mx23_cells[] = {
94 	{
95 		.name = "mxs-lradc-adc",
96 		.resources = mx23_adc_resources,
97 		.num_resources = ARRAY_SIZE(mx23_adc_resources),
98 	},
99 	{
100 		.name = "mxs-lradc-ts",
101 		.resources = mx23_touchscreen_resources,
102 		.num_resources = ARRAY_SIZE(mx23_touchscreen_resources),
103 	},
104 };
105 
106 static struct mfd_cell mx28_cells[] = {
107 	{
108 		.name = "mxs-lradc-adc",
109 		.resources = mx28_adc_resources,
110 		.num_resources = ARRAY_SIZE(mx28_adc_resources),
111 	},
112 	{
113 		.name = "mxs-lradc-ts",
114 		.resources = mx28_touchscreen_resources,
115 		.num_resources = ARRAY_SIZE(mx28_touchscreen_resources),
116 	}
117 };
118 
119 static const struct of_device_id mxs_lradc_dt_ids[] = {
120 	{ .compatible = "fsl,imx23-lradc", .data = (void *)IMX23_LRADC, },
121 	{ .compatible = "fsl,imx28-lradc", .data = (void *)IMX28_LRADC, },
122 	{ /* sentinel */ }
123 };
124 MODULE_DEVICE_TABLE(of, mxs_lradc_dt_ids);
125 
126 static int mxs_lradc_probe(struct platform_device *pdev)
127 {
128 	const struct of_device_id *of_id;
129 	struct device *dev = &pdev->dev;
130 	struct device_node *node = dev->of_node;
131 	struct mxs_lradc *lradc;
132 	struct mfd_cell *cells = NULL;
133 	struct resource *res;
134 	int ret = 0;
135 	u32 ts_wires = 0;
136 
137 	lradc = devm_kzalloc(&pdev->dev, sizeof(*lradc), GFP_KERNEL);
138 	if (!lradc)
139 		return -ENOMEM;
140 
141 	of_id = of_match_device(mxs_lradc_dt_ids, &pdev->dev);
142 	if (!of_id)
143 		return -EINVAL;
144 
145 	lradc->soc = (enum mxs_lradc_id)of_id->data;
146 
147 	lradc->clk = devm_clk_get(&pdev->dev, NULL);
148 	if (IS_ERR(lradc->clk)) {
149 		dev_err(dev, "Failed to get the delay unit clock\n");
150 		return PTR_ERR(lradc->clk);
151 	}
152 
153 	ret = clk_prepare_enable(lradc->clk);
154 	if (ret) {
155 		dev_err(dev, "Failed to enable the delay unit clock\n");
156 		return ret;
157 	}
158 
159 	ret = of_property_read_u32(node, "fsl,lradc-touchscreen-wires",
160 					 &ts_wires);
161 
162 	if (!ret) {
163 		lradc->buffer_vchans = BUFFER_VCHANS_LIMITED;
164 
165 		switch (ts_wires) {
166 		case 4:
167 			lradc->touchscreen_wire = MXS_LRADC_TOUCHSCREEN_4WIRE;
168 			break;
169 		case 5:
170 			if (lradc->soc == IMX28_LRADC) {
171 				lradc->touchscreen_wire =
172 					MXS_LRADC_TOUCHSCREEN_5WIRE;
173 				break;
174 			}
175 			/* fall through - to an error message for i.MX23 */
176 		default:
177 			dev_err(&pdev->dev,
178 				"Unsupported number of touchscreen wires (%d)\n"
179 				, ts_wires);
180 			ret = -EINVAL;
181 			goto err_clk;
182 		}
183 	} else {
184 		lradc->buffer_vchans = BUFFER_VCHANS_ALL;
185 	}
186 
187 	platform_set_drvdata(pdev, lradc);
188 
189 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
190 	if (!res) {
191 		ret = -ENOMEM;
192 		goto err_clk;
193 	}
194 
195 	switch (lradc->soc) {
196 	case IMX23_LRADC:
197 		mx23_adc_resources[RES_MEM] = *res;
198 		mx23_touchscreen_resources[RES_MEM] = *res;
199 		cells = mx23_cells;
200 		break;
201 	case IMX28_LRADC:
202 		mx28_adc_resources[RES_MEM] = *res;
203 		mx28_touchscreen_resources[RES_MEM] = *res;
204 		cells = mx28_cells;
205 		break;
206 	default:
207 		dev_err(dev, "Unsupported SoC\n");
208 		ret = -ENODEV;
209 		goto err_clk;
210 	}
211 
212 	ret = devm_mfd_add_devices(&pdev->dev, PLATFORM_DEVID_NONE,
213 				   &cells[ADC_CELL], 1, NULL, 0, NULL);
214 	if (ret) {
215 		dev_err(&pdev->dev, "Failed to add the ADC subdevice\n");
216 		goto err_clk;
217 	}
218 
219 	if (!lradc->touchscreen_wire)
220 		return 0;
221 
222 	ret = devm_mfd_add_devices(&pdev->dev, PLATFORM_DEVID_NONE,
223 				   &cells[TSC_CELL], 1, NULL, 0, NULL);
224 	if (ret) {
225 		dev_err(&pdev->dev,
226 			"Failed to add the touchscreen subdevice\n");
227 		goto err_clk;
228 	}
229 
230 	return 0;
231 
232 err_clk:
233 	clk_disable_unprepare(lradc->clk);
234 
235 	return ret;
236 }
237 
238 static int mxs_lradc_remove(struct platform_device *pdev)
239 {
240 	struct mxs_lradc *lradc = platform_get_drvdata(pdev);
241 
242 	clk_disable_unprepare(lradc->clk);
243 
244 	return 0;
245 }
246 
247 static struct platform_driver mxs_lradc_driver = {
248 	.driver = {
249 		.name = "mxs-lradc",
250 		.of_match_table = mxs_lradc_dt_ids,
251 	},
252 	.probe = mxs_lradc_probe,
253 	.remove = mxs_lradc_remove,
254 };
255 module_platform_driver(mxs_lradc_driver);
256 
257 MODULE_AUTHOR("Ksenija Stanojevic <ksenija.stanojevic@gmail.com>");
258 MODULE_DESCRIPTION("Freescale i.MX23/i.MX28 LRADC driver");
259 MODULE_LICENSE("GPL");
260 MODULE_ALIAS("platform:mxs-lradc");
261