xref: /linux/drivers/mfd/intel_quark_i2c_gpio.c (revision b85d45947951d23cb22d90caecf4c1eb81342c96)
1 /*
2  * Intel Quark MFD PCI driver for I2C & GPIO
3  *
4  * Copyright(c) 2014 Intel Corporation.
5  *
6  * This program is free software; you can redistribute it and/or modify it
7  * under the terms and conditions of the GNU General Public License,
8  * version 2, as published by the Free Software Foundation.
9  *
10  * This program is distributed in the hope it will be useful, but WITHOUT
11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
13  * more details.
14  *
15  * Intel Quark PCI device for I2C and GPIO controller sharing the same
16  * PCI function. This PCI driver will split the 2 devices into their
17  * respective drivers.
18  */
19 
20 #include <linux/kernel.h>
21 #include <linux/module.h>
22 #include <linux/pci.h>
23 #include <linux/mfd/core.h>
24 #include <linux/clkdev.h>
25 #include <linux/clk-provider.h>
26 #include <linux/dmi.h>
27 #include <linux/platform_data/gpio-dwapb.h>
28 #include <linux/platform_data/i2c-designware.h>
29 
30 /* PCI BAR for register base address */
31 #define MFD_I2C_BAR		0
32 #define MFD_GPIO_BAR		1
33 
34 /* The base GPIO number under GPIOLIB framework */
35 #define INTEL_QUARK_MFD_GPIO_BASE	8
36 
37 /* The default number of South-Cluster GPIO on Quark. */
38 #define INTEL_QUARK_MFD_NGPIO		8
39 
40 /* The DesignWare GPIO ports on Quark. */
41 #define INTEL_QUARK_GPIO_NPORTS	1
42 
43 #define INTEL_QUARK_IORES_MEM	0
44 #define INTEL_QUARK_IORES_IRQ	1
45 
46 #define INTEL_QUARK_I2C_CONTROLLER_CLK "i2c_designware.0"
47 
48 /* The Quark I2C controller source clock */
49 #define INTEL_QUARK_I2C_CLK_HZ	33000000
50 
51 #define INTEL_QUARK_I2C_NCLK	1
52 
53 struct intel_quark_mfd {
54 	struct pci_dev		*pdev;
55 	struct clk		*i2c_clk;
56 	struct clk_lookup	*i2c_clk_lookup;
57 };
58 
59 struct i2c_mode_info {
60 	const char *name;
61 	unsigned int i2c_scl_freq;
62 };
63 
64 static const struct i2c_mode_info platform_i2c_mode_info[] = {
65 	{
66 		.name = "Galileo",
67 		.i2c_scl_freq = 100000,
68 	},
69 	{
70 		.name = "GalileoGen2",
71 		.i2c_scl_freq = 400000,
72 	},
73 	{}
74 };
75 
76 static struct resource intel_quark_i2c_res[] = {
77 	[INTEL_QUARK_IORES_MEM] = {
78 		.flags = IORESOURCE_MEM,
79 	},
80 	[INTEL_QUARK_IORES_IRQ] = {
81 		.flags = IORESOURCE_IRQ,
82 	},
83 };
84 
85 static struct resource intel_quark_gpio_res[] = {
86 	[INTEL_QUARK_IORES_MEM] = {
87 		.flags = IORESOURCE_MEM,
88 	},
89 };
90 
91 static struct mfd_cell intel_quark_mfd_cells[] = {
92 	{
93 		.id = MFD_I2C_BAR,
94 		.name = "i2c_designware",
95 		.num_resources = ARRAY_SIZE(intel_quark_i2c_res),
96 		.resources = intel_quark_i2c_res,
97 		.ignore_resource_conflicts = true,
98 	},
99 	{
100 		.id = MFD_GPIO_BAR,
101 		.name = "gpio-dwapb",
102 		.num_resources = ARRAY_SIZE(intel_quark_gpio_res),
103 		.resources = intel_quark_gpio_res,
104 		.ignore_resource_conflicts = true,
105 	},
106 };
107 
108 static const struct pci_device_id intel_quark_mfd_ids[] = {
109 	{ PCI_VDEVICE(INTEL, 0x0934), },
110 	{},
111 };
112 MODULE_DEVICE_TABLE(pci, intel_quark_mfd_ids);
113 
114 static int intel_quark_register_i2c_clk(struct intel_quark_mfd *quark_mfd)
115 {
116 	struct pci_dev *pdev = quark_mfd->pdev;
117 	struct clk_lookup *i2c_clk_lookup;
118 	struct clk *i2c_clk;
119 	int ret;
120 
121 	i2c_clk_lookup = devm_kcalloc(&pdev->dev, INTEL_QUARK_I2C_NCLK,
122 				      sizeof(*i2c_clk_lookup), GFP_KERNEL);
123 	if (!i2c_clk_lookup)
124 		return -ENOMEM;
125 
126 	i2c_clk_lookup[0].dev_id = INTEL_QUARK_I2C_CONTROLLER_CLK;
127 
128 	i2c_clk = clk_register_fixed_rate(&pdev->dev,
129 					  INTEL_QUARK_I2C_CONTROLLER_CLK, NULL,
130 					  CLK_IS_ROOT, INTEL_QUARK_I2C_CLK_HZ);
131 
132 	quark_mfd->i2c_clk_lookup = i2c_clk_lookup;
133 	quark_mfd->i2c_clk = i2c_clk;
134 
135 	ret = clk_register_clkdevs(i2c_clk, i2c_clk_lookup,
136 				   INTEL_QUARK_I2C_NCLK);
137 	if (ret)
138 		dev_err(&pdev->dev, "Fixed clk register failed: %d\n", ret);
139 
140 	return ret;
141 }
142 
143 static void intel_quark_unregister_i2c_clk(struct pci_dev *pdev)
144 {
145 	struct intel_quark_mfd *quark_mfd = dev_get_drvdata(&pdev->dev);
146 
147 	if (!quark_mfd->i2c_clk || !quark_mfd->i2c_clk_lookup)
148 		return;
149 
150 	clkdev_drop(quark_mfd->i2c_clk_lookup);
151 	clk_unregister(quark_mfd->i2c_clk);
152 }
153 
154 static int intel_quark_i2c_setup(struct pci_dev *pdev, struct mfd_cell *cell)
155 {
156 	const char *board_name = dmi_get_system_info(DMI_BOARD_NAME);
157 	const struct i2c_mode_info *info;
158 	struct dw_i2c_platform_data *pdata;
159 	struct resource *res = (struct resource *)cell->resources;
160 	struct device *dev = &pdev->dev;
161 
162 	res[INTEL_QUARK_IORES_MEM].start =
163 		pci_resource_start(pdev, MFD_I2C_BAR);
164 	res[INTEL_QUARK_IORES_MEM].end =
165 		pci_resource_end(pdev, MFD_I2C_BAR);
166 
167 	res[INTEL_QUARK_IORES_IRQ].start = pdev->irq;
168 	res[INTEL_QUARK_IORES_IRQ].end = pdev->irq;
169 
170 	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
171 	if (!pdata)
172 		return -ENOMEM;
173 
174 	/* Normal mode by default */
175 	pdata->i2c_scl_freq = 100000;
176 
177 	if (board_name) {
178 		for (info = platform_i2c_mode_info; info->name; info++) {
179 			if (!strcmp(board_name, info->name)) {
180 				pdata->i2c_scl_freq = info->i2c_scl_freq;
181 				break;
182 			}
183 		}
184 	}
185 
186 	cell->platform_data = pdata;
187 	cell->pdata_size = sizeof(*pdata);
188 
189 	return 0;
190 }
191 
192 static int intel_quark_gpio_setup(struct pci_dev *pdev, struct mfd_cell *cell)
193 {
194 	struct dwapb_platform_data *pdata;
195 	struct resource *res = (struct resource *)cell->resources;
196 	struct device *dev = &pdev->dev;
197 
198 	res[INTEL_QUARK_IORES_MEM].start =
199 		pci_resource_start(pdev, MFD_GPIO_BAR);
200 	res[INTEL_QUARK_IORES_MEM].end =
201 		pci_resource_end(pdev, MFD_GPIO_BAR);
202 
203 	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
204 	if (!pdata)
205 		return -ENOMEM;
206 
207 	/* For intel quark x1000, it has only one port: portA */
208 	pdata->nports = INTEL_QUARK_GPIO_NPORTS;
209 	pdata->properties = devm_kcalloc(dev, pdata->nports,
210 					 sizeof(*pdata->properties),
211 					 GFP_KERNEL);
212 	if (!pdata->properties)
213 		return -ENOMEM;
214 
215 	/* Set the properties for portA */
216 	pdata->properties->node		= NULL;
217 	pdata->properties->name		= "intel-quark-x1000-gpio-portA";
218 	pdata->properties->idx		= 0;
219 	pdata->properties->ngpio	= INTEL_QUARK_MFD_NGPIO;
220 	pdata->properties->gpio_base	= INTEL_QUARK_MFD_GPIO_BASE;
221 	pdata->properties->irq		= pdev->irq;
222 	pdata->properties->irq_shared	= true;
223 
224 	cell->platform_data = pdata;
225 	cell->pdata_size = sizeof(*pdata);
226 
227 	return 0;
228 }
229 
230 static int intel_quark_mfd_probe(struct pci_dev *pdev,
231 				 const struct pci_device_id *id)
232 {
233 	struct intel_quark_mfd *quark_mfd;
234 	int ret;
235 
236 	ret = pcim_enable_device(pdev);
237 	if (ret)
238 		return ret;
239 
240 	quark_mfd = devm_kzalloc(&pdev->dev, sizeof(*quark_mfd), GFP_KERNEL);
241 	if (!quark_mfd)
242 		return -ENOMEM;
243 	quark_mfd->pdev = pdev;
244 
245 	ret = intel_quark_register_i2c_clk(quark_mfd);
246 	if (ret)
247 		return ret;
248 
249 	dev_set_drvdata(&pdev->dev, quark_mfd);
250 
251 	ret = intel_quark_i2c_setup(pdev, &intel_quark_mfd_cells[MFD_I2C_BAR]);
252 	if (ret)
253 		return ret;
254 
255 	ret = intel_quark_gpio_setup(pdev,
256 				     &intel_quark_mfd_cells[MFD_GPIO_BAR]);
257 	if (ret)
258 		return ret;
259 
260 	return mfd_add_devices(&pdev->dev, 0, intel_quark_mfd_cells,
261 			       ARRAY_SIZE(intel_quark_mfd_cells), NULL, 0,
262 			       NULL);
263 }
264 
265 static void intel_quark_mfd_remove(struct pci_dev *pdev)
266 {
267 	intel_quark_unregister_i2c_clk(pdev);
268 	mfd_remove_devices(&pdev->dev);
269 }
270 
271 static struct pci_driver intel_quark_mfd_driver = {
272 	.name		= "intel_quark_mfd_i2c_gpio",
273 	.id_table	= intel_quark_mfd_ids,
274 	.probe		= intel_quark_mfd_probe,
275 	.remove		= intel_quark_mfd_remove,
276 };
277 
278 module_pci_driver(intel_quark_mfd_driver);
279 
280 MODULE_AUTHOR("Raymond Tan <raymond.tan@intel.com>");
281 MODULE_DESCRIPTION("Intel Quark MFD PCI driver for I2C & GPIO");
282 MODULE_LICENSE("GPL v2");
283