1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Intel Quark MFD PCI driver for I2C & GPIO
4  *
5  * Copyright(c) 2014 Intel Corporation.
6  *
7  * Intel Quark PCI device for I2C and GPIO controller sharing the same
8  * PCI function. This PCI driver will split the 2 devices into their
9  * respective drivers.
10  */
11 
12 #include <linux/kernel.h>
13 #include <linux/module.h>
14 #include <linux/pci.h>
15 #include <linux/mfd/core.h>
16 #include <linux/clkdev.h>
17 #include <linux/clk-provider.h>
18 #include <linux/dmi.h>
19 #include <linux/i2c.h>
20 #include <linux/property.h>
21 
22 /* PCI BAR for register base address */
23 #define MFD_I2C_BAR		0
24 #define MFD_GPIO_BAR		1
25 
26 /* ACPI _ADR value to match the child node */
27 #define MFD_ACPI_MATCH_GPIO	0ULL
28 #define MFD_ACPI_MATCH_I2C	1ULL
29 
30 #define INTEL_QUARK_IORES_MEM	0
31 #define INTEL_QUARK_IORES_IRQ	1
32 
33 #define INTEL_QUARK_I2C_CONTROLLER_CLK "i2c_designware.0"
34 
35 /* The Quark I2C controller source clock */
36 #define INTEL_QUARK_I2C_CLK_HZ	33000000
37 
38 struct intel_quark_mfd {
39 	struct clk		*i2c_clk;
40 	struct clk_lookup	*i2c_clk_lookup;
41 };
42 
43 static const struct property_entry intel_quark_i2c_controller_standard_properties[] = {
44 	PROPERTY_ENTRY_U32("clock-frequency", I2C_MAX_STANDARD_MODE_FREQ),
45 	{ }
46 };
47 
48 static const struct software_node intel_quark_i2c_controller_standard_node = {
49 	.name = "intel-quark-i2c-controller",
50 	.properties = intel_quark_i2c_controller_standard_properties,
51 };
52 
53 static const struct property_entry intel_quark_i2c_controller_fast_properties[] = {
54 	PROPERTY_ENTRY_U32("clock-frequency", I2C_MAX_FAST_MODE_FREQ),
55 	{ }
56 };
57 
58 static const struct software_node intel_quark_i2c_controller_fast_node = {
59 	.name = "intel-quark-i2c-controller",
60 	.properties = intel_quark_i2c_controller_fast_properties,
61 };
62 
63 static const struct dmi_system_id dmi_platform_info[] = {
64 	{
65 		.matches = {
66 			DMI_EXACT_MATCH(DMI_BOARD_NAME, "Galileo"),
67 		},
68 		.driver_data = (void *)&intel_quark_i2c_controller_standard_node,
69 	},
70 	{
71 		.matches = {
72 			DMI_EXACT_MATCH(DMI_BOARD_NAME, "GalileoGen2"),
73 		},
74 		.driver_data = (void *)&intel_quark_i2c_controller_fast_node,
75 	},
76 	{
77 		.matches = {
78 			DMI_EXACT_MATCH(DMI_BOARD_NAME, "SIMATIC IOT2000"),
79 		},
80 		.driver_data = (void *)&intel_quark_i2c_controller_fast_node,
81 	},
82 	{}
83 };
84 
85 /* This is used as a place holder and will be modified at run-time */
86 static struct resource intel_quark_i2c_res[] = {
87 	[INTEL_QUARK_IORES_MEM] = {
88 		.flags = IORESOURCE_MEM,
89 	},
90 	[INTEL_QUARK_IORES_IRQ] = {
91 		.flags = IORESOURCE_IRQ,
92 	},
93 };
94 
95 static struct mfd_cell_acpi_match intel_quark_acpi_match_i2c = {
96 	.adr = MFD_ACPI_MATCH_I2C,
97 };
98 
99 /* This is used as a place holder and will be modified at run-time */
100 static struct resource intel_quark_gpio_res[] = {
101 	[INTEL_QUARK_IORES_MEM] = {
102 		.flags = IORESOURCE_MEM,
103 	},
104 	[INTEL_QUARK_IORES_IRQ] = {
105 		.flags = IORESOURCE_IRQ,
106 	},
107 };
108 
109 static struct mfd_cell_acpi_match intel_quark_acpi_match_gpio = {
110 	.adr = MFD_ACPI_MATCH_GPIO,
111 };
112 
113 static const struct software_node intel_quark_gpio_controller_node = {
114 	.name = "intel-quark-gpio-controller",
115 };
116 
117 static const struct property_entry intel_quark_gpio_portA_properties[] = {
118 	PROPERTY_ENTRY_U32("reg", 0),
119 	PROPERTY_ENTRY_U32("snps,nr-gpios", 8),
120 	PROPERTY_ENTRY_U32("gpio-base", 8),
121 	{ }
122 };
123 
124 static const struct software_node intel_quark_gpio_portA_node = {
125 	.name = "portA",
126 	.parent = &intel_quark_gpio_controller_node,
127 	.properties = intel_quark_gpio_portA_properties,
128 };
129 
130 static const struct software_node *intel_quark_gpio_node_group[] = {
131 	&intel_quark_gpio_controller_node,
132 	&intel_quark_gpio_portA_node,
133 	NULL
134 };
135 
136 static struct mfd_cell intel_quark_mfd_cells[] = {
137 	[MFD_I2C_BAR] = {
138 		.id = MFD_I2C_BAR,
139 		.name = "i2c_designware",
140 		.acpi_match = &intel_quark_acpi_match_i2c,
141 		.num_resources = ARRAY_SIZE(intel_quark_i2c_res),
142 		.resources = intel_quark_i2c_res,
143 		.ignore_resource_conflicts = true,
144 	},
145 	[MFD_GPIO_BAR] = {
146 		.id = MFD_GPIO_BAR,
147 		.name = "gpio-dwapb",
148 		.acpi_match = &intel_quark_acpi_match_gpio,
149 		.num_resources = ARRAY_SIZE(intel_quark_gpio_res),
150 		.resources = intel_quark_gpio_res,
151 		.ignore_resource_conflicts = true,
152 	},
153 };
154 
155 static const struct pci_device_id intel_quark_mfd_ids[] = {
156 	{ PCI_VDEVICE(INTEL, 0x0934), },
157 	{},
158 };
159 MODULE_DEVICE_TABLE(pci, intel_quark_mfd_ids);
160 
intel_quark_register_i2c_clk(struct device * dev)161 static int intel_quark_register_i2c_clk(struct device *dev)
162 {
163 	struct intel_quark_mfd *quark_mfd = dev_get_drvdata(dev);
164 	struct clk *i2c_clk;
165 
166 	i2c_clk = clk_register_fixed_rate(dev,
167 					  INTEL_QUARK_I2C_CONTROLLER_CLK, NULL,
168 					  0, INTEL_QUARK_I2C_CLK_HZ);
169 	if (IS_ERR(i2c_clk))
170 		return PTR_ERR(i2c_clk);
171 
172 	quark_mfd->i2c_clk = i2c_clk;
173 	quark_mfd->i2c_clk_lookup = clkdev_create(i2c_clk, NULL,
174 						INTEL_QUARK_I2C_CONTROLLER_CLK);
175 
176 	if (!quark_mfd->i2c_clk_lookup) {
177 		clk_unregister(quark_mfd->i2c_clk);
178 		dev_err(dev, "Fixed clk register failed\n");
179 		return -ENOMEM;
180 	}
181 
182 	return 0;
183 }
184 
intel_quark_unregister_i2c_clk(struct device * dev)185 static void intel_quark_unregister_i2c_clk(struct device *dev)
186 {
187 	struct intel_quark_mfd *quark_mfd = dev_get_drvdata(dev);
188 
189 	if (!quark_mfd->i2c_clk_lookup)
190 		return;
191 
192 	clkdev_drop(quark_mfd->i2c_clk_lookup);
193 	clk_unregister(quark_mfd->i2c_clk);
194 }
195 
intel_quark_i2c_setup(struct pci_dev * pdev)196 static int intel_quark_i2c_setup(struct pci_dev *pdev)
197 {
198 	struct mfd_cell *cell = &intel_quark_mfd_cells[MFD_I2C_BAR];
199 	struct resource *res = intel_quark_i2c_res;
200 	const struct dmi_system_id *dmi_id;
201 
202 	res[INTEL_QUARK_IORES_MEM].start = pci_resource_start(pdev, MFD_I2C_BAR);
203 	res[INTEL_QUARK_IORES_MEM].end = pci_resource_end(pdev, MFD_I2C_BAR);
204 
205 	res[INTEL_QUARK_IORES_IRQ].start = pci_irq_vector(pdev, 0);
206 	res[INTEL_QUARK_IORES_IRQ].end = pci_irq_vector(pdev, 0);
207 
208 	/* Normal mode by default */
209 	cell->swnode = &intel_quark_i2c_controller_standard_node;
210 
211 	dmi_id = dmi_first_match(dmi_platform_info);
212 	if (dmi_id)
213 		cell->swnode = (struct software_node *)dmi_id->driver_data;
214 
215 	return 0;
216 }
217 
intel_quark_gpio_setup(struct pci_dev * pdev)218 static int intel_quark_gpio_setup(struct pci_dev *pdev)
219 {
220 	struct mfd_cell *cell = &intel_quark_mfd_cells[MFD_GPIO_BAR];
221 	struct resource *res = intel_quark_gpio_res;
222 	int ret;
223 
224 	res[INTEL_QUARK_IORES_MEM].start = pci_resource_start(pdev, MFD_GPIO_BAR);
225 	res[INTEL_QUARK_IORES_MEM].end = pci_resource_end(pdev, MFD_GPIO_BAR);
226 
227 	res[INTEL_QUARK_IORES_IRQ].start = pci_irq_vector(pdev, 0);
228 	res[INTEL_QUARK_IORES_IRQ].end = pci_irq_vector(pdev, 0);
229 
230 	ret = software_node_register_node_group(intel_quark_gpio_node_group);
231 	if (ret)
232 		return ret;
233 
234 	cell->swnode = &intel_quark_gpio_controller_node;
235 	return 0;
236 }
237 
intel_quark_mfd_probe(struct pci_dev * pdev,const struct pci_device_id * id)238 static int intel_quark_mfd_probe(struct pci_dev *pdev,
239 				 const struct pci_device_id *id)
240 {
241 	struct intel_quark_mfd *quark_mfd;
242 	int ret;
243 
244 	ret = pcim_enable_device(pdev);
245 	if (ret)
246 		return ret;
247 
248 	quark_mfd = devm_kzalloc(&pdev->dev, sizeof(*quark_mfd), GFP_KERNEL);
249 	if (!quark_mfd)
250 		return -ENOMEM;
251 
252 	dev_set_drvdata(&pdev->dev, quark_mfd);
253 
254 	ret = intel_quark_register_i2c_clk(&pdev->dev);
255 	if (ret)
256 		return ret;
257 
258 	pci_set_master(pdev);
259 
260 	/* This driver only requires 1 IRQ vector */
261 	ret = pci_alloc_irq_vectors(pdev, 1, 1, PCI_IRQ_ALL_TYPES);
262 	if (ret < 0)
263 		goto err_unregister_i2c_clk;
264 
265 	ret = intel_quark_i2c_setup(pdev);
266 	if (ret)
267 		goto err_free_irq_vectors;
268 
269 	ret = intel_quark_gpio_setup(pdev);
270 	if (ret)
271 		goto err_free_irq_vectors;
272 
273 	ret = mfd_add_devices(&pdev->dev, 0, intel_quark_mfd_cells,
274 			      ARRAY_SIZE(intel_quark_mfd_cells), NULL, 0,
275 			      NULL);
276 	if (ret)
277 		goto err_unregister_gpio_node_group;
278 
279 	return 0;
280 
281 err_unregister_gpio_node_group:
282 	software_node_unregister_node_group(intel_quark_gpio_node_group);
283 err_free_irq_vectors:
284 	pci_free_irq_vectors(pdev);
285 err_unregister_i2c_clk:
286 	intel_quark_unregister_i2c_clk(&pdev->dev);
287 	return ret;
288 }
289 
intel_quark_mfd_remove(struct pci_dev * pdev)290 static void intel_quark_mfd_remove(struct pci_dev *pdev)
291 {
292 	mfd_remove_devices(&pdev->dev);
293 	software_node_unregister_node_group(intel_quark_gpio_node_group);
294 	pci_free_irq_vectors(pdev);
295 	intel_quark_unregister_i2c_clk(&pdev->dev);
296 }
297 
298 static struct pci_driver intel_quark_mfd_driver = {
299 	.name		= "intel_quark_mfd_i2c_gpio",
300 	.id_table	= intel_quark_mfd_ids,
301 	.probe		= intel_quark_mfd_probe,
302 	.remove		= intel_quark_mfd_remove,
303 };
304 
305 module_pci_driver(intel_quark_mfd_driver);
306 
307 MODULE_AUTHOR("Raymond Tan <raymond.tan@intel.com>");
308 MODULE_DESCRIPTION("Intel Quark MFD PCI driver for I2C & GPIO");
309 MODULE_LICENSE("GPL v2");
310