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 /* ACPI _ADR value to match the child node */
35 #define MFD_ACPI_MATCH_GPIO	0ULL
36 #define MFD_ACPI_MATCH_I2C	1ULL
37 
38 /* The base GPIO number under GPIOLIB framework */
39 #define INTEL_QUARK_MFD_GPIO_BASE	8
40 
41 /* The default number of South-Cluster GPIO on Quark. */
42 #define INTEL_QUARK_MFD_NGPIO		8
43 
44 /* The DesignWare GPIO ports on Quark. */
45 #define INTEL_QUARK_GPIO_NPORTS	1
46 
47 #define INTEL_QUARK_IORES_MEM	0
48 #define INTEL_QUARK_IORES_IRQ	1
49 
50 #define INTEL_QUARK_I2C_CONTROLLER_CLK "i2c_designware.0"
51 
52 /* The Quark I2C controller source clock */
53 #define INTEL_QUARK_I2C_CLK_HZ	33000000
54 
55 struct intel_quark_mfd {
56 	struct pci_dev		*pdev;
57 	struct clk		*i2c_clk;
58 	struct clk_lookup	*i2c_clk_lookup;
59 };
60 
61 struct i2c_mode_info {
62 	const char *name;
63 	unsigned int i2c_scl_freq;
64 };
65 
66 static const struct i2c_mode_info platform_i2c_mode_info[] = {
67 	{
68 		.name = "Galileo",
69 		.i2c_scl_freq = 100000,
70 	},
71 	{
72 		.name = "GalileoGen2",
73 		.i2c_scl_freq = 400000,
74 	},
75 	{}
76 };
77 
78 static struct resource intel_quark_i2c_res[] = {
79 	[INTEL_QUARK_IORES_MEM] = {
80 		.flags = IORESOURCE_MEM,
81 	},
82 	[INTEL_QUARK_IORES_IRQ] = {
83 		.flags = IORESOURCE_IRQ,
84 	},
85 };
86 
87 static struct mfd_cell_acpi_match intel_quark_acpi_match_i2c = {
88 	.adr = MFD_ACPI_MATCH_I2C,
89 };
90 
91 static struct resource intel_quark_gpio_res[] = {
92 	[INTEL_QUARK_IORES_MEM] = {
93 		.flags = IORESOURCE_MEM,
94 	},
95 };
96 
97 static struct mfd_cell_acpi_match intel_quark_acpi_match_gpio = {
98 	.adr = MFD_ACPI_MATCH_GPIO,
99 };
100 
101 static struct mfd_cell intel_quark_mfd_cells[] = {
102 	{
103 		.id = MFD_GPIO_BAR,
104 		.name = "gpio-dwapb",
105 		.acpi_match = &intel_quark_acpi_match_gpio,
106 		.num_resources = ARRAY_SIZE(intel_quark_gpio_res),
107 		.resources = intel_quark_gpio_res,
108 		.ignore_resource_conflicts = true,
109 	},
110 	{
111 		.id = MFD_I2C_BAR,
112 		.name = "i2c_designware",
113 		.acpi_match = &intel_quark_acpi_match_i2c,
114 		.num_resources = ARRAY_SIZE(intel_quark_i2c_res),
115 		.resources = intel_quark_i2c_res,
116 		.ignore_resource_conflicts = true,
117 	},
118 };
119 
120 static const struct pci_device_id intel_quark_mfd_ids[] = {
121 	{ PCI_VDEVICE(INTEL, 0x0934), },
122 	{},
123 };
124 MODULE_DEVICE_TABLE(pci, intel_quark_mfd_ids);
125 
126 static int intel_quark_register_i2c_clk(struct intel_quark_mfd *quark_mfd)
127 {
128 	struct pci_dev *pdev = quark_mfd->pdev;
129 	struct clk *i2c_clk;
130 
131 	i2c_clk = clk_register_fixed_rate(&pdev->dev,
132 					  INTEL_QUARK_I2C_CONTROLLER_CLK, NULL,
133 					  CLK_IS_ROOT, INTEL_QUARK_I2C_CLK_HZ);
134 	if (IS_ERR(i2c_clk))
135 		return PTR_ERR(i2c_clk);
136 
137 	quark_mfd->i2c_clk = i2c_clk;
138 	quark_mfd->i2c_clk_lookup = clkdev_create(i2c_clk, NULL,
139 						INTEL_QUARK_I2C_CONTROLLER_CLK);
140 
141 	if (!quark_mfd->i2c_clk_lookup) {
142 		dev_err(&pdev->dev, "Fixed clk register failed\n");
143 		return -ENOMEM;
144 	}
145 
146 	return 0;
147 }
148 
149 static void intel_quark_unregister_i2c_clk(struct pci_dev *pdev)
150 {
151 	struct intel_quark_mfd *quark_mfd = dev_get_drvdata(&pdev->dev);
152 
153 	if (!quark_mfd->i2c_clk || !quark_mfd->i2c_clk_lookup)
154 		return;
155 
156 	clkdev_drop(quark_mfd->i2c_clk_lookup);
157 	clk_unregister(quark_mfd->i2c_clk);
158 }
159 
160 static int intel_quark_i2c_setup(struct pci_dev *pdev, struct mfd_cell *cell)
161 {
162 	const char *board_name = dmi_get_system_info(DMI_BOARD_NAME);
163 	const struct i2c_mode_info *info;
164 	struct dw_i2c_platform_data *pdata;
165 	struct resource *res = (struct resource *)cell->resources;
166 	struct device *dev = &pdev->dev;
167 
168 	res[INTEL_QUARK_IORES_MEM].start =
169 		pci_resource_start(pdev, MFD_I2C_BAR);
170 	res[INTEL_QUARK_IORES_MEM].end =
171 		pci_resource_end(pdev, MFD_I2C_BAR);
172 
173 	res[INTEL_QUARK_IORES_IRQ].start = pdev->irq;
174 	res[INTEL_QUARK_IORES_IRQ].end = pdev->irq;
175 
176 	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
177 	if (!pdata)
178 		return -ENOMEM;
179 
180 	/* Normal mode by default */
181 	pdata->i2c_scl_freq = 100000;
182 
183 	if (board_name) {
184 		for (info = platform_i2c_mode_info; info->name; info++) {
185 			if (!strcmp(board_name, info->name)) {
186 				pdata->i2c_scl_freq = info->i2c_scl_freq;
187 				break;
188 			}
189 		}
190 	}
191 
192 	cell->platform_data = pdata;
193 	cell->pdata_size = sizeof(*pdata);
194 
195 	return 0;
196 }
197 
198 static int intel_quark_gpio_setup(struct pci_dev *pdev, struct mfd_cell *cell)
199 {
200 	struct dwapb_platform_data *pdata;
201 	struct resource *res = (struct resource *)cell->resources;
202 	struct device *dev = &pdev->dev;
203 
204 	res[INTEL_QUARK_IORES_MEM].start =
205 		pci_resource_start(pdev, MFD_GPIO_BAR);
206 	res[INTEL_QUARK_IORES_MEM].end =
207 		pci_resource_end(pdev, MFD_GPIO_BAR);
208 
209 	pdata = devm_kzalloc(dev, sizeof(*pdata), GFP_KERNEL);
210 	if (!pdata)
211 		return -ENOMEM;
212 
213 	/* For intel quark x1000, it has only one port: portA */
214 	pdata->nports = INTEL_QUARK_GPIO_NPORTS;
215 	pdata->properties = devm_kcalloc(dev, pdata->nports,
216 					 sizeof(*pdata->properties),
217 					 GFP_KERNEL);
218 	if (!pdata->properties)
219 		return -ENOMEM;
220 
221 	/* Set the properties for portA */
222 	pdata->properties->node		= NULL;
223 	pdata->properties->name		= "intel-quark-x1000-gpio-portA";
224 	pdata->properties->idx		= 0;
225 	pdata->properties->ngpio	= INTEL_QUARK_MFD_NGPIO;
226 	pdata->properties->gpio_base	= INTEL_QUARK_MFD_GPIO_BASE;
227 	pdata->properties->irq		= pdev->irq;
228 	pdata->properties->irq_shared	= true;
229 
230 	cell->platform_data = pdata;
231 	cell->pdata_size = sizeof(*pdata);
232 
233 	return 0;
234 }
235 
236 static int intel_quark_mfd_probe(struct pci_dev *pdev,
237 				 const struct pci_device_id *id)
238 {
239 	struct intel_quark_mfd *quark_mfd;
240 	int ret;
241 
242 	ret = pcim_enable_device(pdev);
243 	if (ret)
244 		return ret;
245 
246 	quark_mfd = devm_kzalloc(&pdev->dev, sizeof(*quark_mfd), GFP_KERNEL);
247 	if (!quark_mfd)
248 		return -ENOMEM;
249 	quark_mfd->pdev = pdev;
250 
251 	ret = intel_quark_register_i2c_clk(quark_mfd);
252 	if (ret)
253 		return ret;
254 
255 	dev_set_drvdata(&pdev->dev, quark_mfd);
256 
257 	ret = intel_quark_i2c_setup(pdev, &intel_quark_mfd_cells[1]);
258 	if (ret)
259 		return ret;
260 
261 	ret = intel_quark_gpio_setup(pdev, &intel_quark_mfd_cells[0]);
262 	if (ret)
263 		return ret;
264 
265 	return mfd_add_devices(&pdev->dev, 0, intel_quark_mfd_cells,
266 			       ARRAY_SIZE(intel_quark_mfd_cells), NULL, 0,
267 			       NULL);
268 }
269 
270 static void intel_quark_mfd_remove(struct pci_dev *pdev)
271 {
272 	intel_quark_unregister_i2c_clk(pdev);
273 	mfd_remove_devices(&pdev->dev);
274 }
275 
276 static struct pci_driver intel_quark_mfd_driver = {
277 	.name		= "intel_quark_mfd_i2c_gpio",
278 	.id_table	= intel_quark_mfd_ids,
279 	.probe		= intel_quark_mfd_probe,
280 	.remove		= intel_quark_mfd_remove,
281 };
282 
283 module_pci_driver(intel_quark_mfd_driver);
284 
285 MODULE_AUTHOR("Raymond Tan <raymond.tan@intel.com>");
286 MODULE_DESCRIPTION("Intel Quark MFD PCI driver for I2C & GPIO");
287 MODULE_LICENSE("GPL v2");
288