xref: /openbmc/linux/drivers/mfd/mxs-lradc.c (revision 00af6729b52ede86a08173c8d5f2c8cd9fa3390d)
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  			fallthrough;	/* 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