1 /*
2  * Copyright (c) 2010 Red Hat Inc.
3  * Author : Dave Airlie <airlied@redhat.com>
4  *
5  * Licensed under GPLv2
6  *
7  * ATPX support for both Intel/ATI
8  */
9 #include <linux/vga_switcheroo.h>
10 #include <linux/slab.h>
11 #include <acpi/acpi.h>
12 #include <acpi/acpi_bus.h>
13 #include <linux/pci.h>
14 
15 #define ATPX_VERSION 0
16 #define ATPX_GPU_PWR 2
17 #define ATPX_MUX_SELECT 3
18 #define ATPX_I2C_MUX_SELECT 4
19 #define ATPX_SWITCH_START 5
20 #define ATPX_SWITCH_END 6
21 
22 #define ATPX_INTEGRATED 0
23 #define ATPX_DISCRETE 1
24 
25 #define ATPX_MUX_IGD 0
26 #define ATPX_MUX_DISCRETE 1
27 
28 static struct radeon_atpx_priv {
29 	bool atpx_detected;
30 	/* handle for device - and atpx */
31 	acpi_handle dhandle;
32 	acpi_handle atpx_handle;
33 	acpi_handle atrm_handle;
34 } radeon_atpx_priv;
35 
36 /* retrieve the ROM in 4k blocks */
37 static int radeon_atrm_call(acpi_handle atrm_handle, uint8_t *bios,
38 			    int offset, int len)
39 {
40 	acpi_status status;
41 	union acpi_object atrm_arg_elements[2], *obj;
42 	struct acpi_object_list atrm_arg;
43 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL};
44 
45 	atrm_arg.count = 2;
46 	atrm_arg.pointer = &atrm_arg_elements[0];
47 
48 	atrm_arg_elements[0].type = ACPI_TYPE_INTEGER;
49 	atrm_arg_elements[0].integer.value = offset;
50 
51 	atrm_arg_elements[1].type = ACPI_TYPE_INTEGER;
52 	atrm_arg_elements[1].integer.value = len;
53 
54 	status = acpi_evaluate_object(atrm_handle, NULL, &atrm_arg, &buffer);
55 	if (ACPI_FAILURE(status)) {
56 		printk("failed to evaluate ATRM got %s\n", acpi_format_exception(status));
57 		return -ENODEV;
58 	}
59 
60 	obj = (union acpi_object *)buffer.pointer;
61 	memcpy(bios+offset, obj->buffer.pointer, len);
62 	kfree(buffer.pointer);
63 	return len;
64 }
65 
66 bool radeon_atrm_supported(struct pci_dev *pdev)
67 {
68 	/* get the discrete ROM only via ATRM */
69 	if (!radeon_atpx_priv.atpx_detected)
70 		return false;
71 
72 	if (radeon_atpx_priv.dhandle == DEVICE_ACPI_HANDLE(&pdev->dev))
73 		return false;
74 	return true;
75 }
76 
77 
78 int radeon_atrm_get_bios_chunk(uint8_t *bios, int offset, int len)
79 {
80 	return radeon_atrm_call(radeon_atpx_priv.atrm_handle, bios, offset, len);
81 }
82 
83 static int radeon_atpx_get_version(acpi_handle handle)
84 {
85 	acpi_status status;
86 	union acpi_object atpx_arg_elements[2], *obj;
87 	struct acpi_object_list atpx_arg;
88 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
89 
90 	atpx_arg.count = 2;
91 	atpx_arg.pointer = &atpx_arg_elements[0];
92 
93 	atpx_arg_elements[0].type = ACPI_TYPE_INTEGER;
94 	atpx_arg_elements[0].integer.value = ATPX_VERSION;
95 
96 	atpx_arg_elements[1].type = ACPI_TYPE_INTEGER;
97 	atpx_arg_elements[1].integer.value = ATPX_VERSION;
98 
99 	status = acpi_evaluate_object(handle, NULL, &atpx_arg, &buffer);
100 	if (ACPI_FAILURE(status)) {
101 		printk("%s: failed to call ATPX: %s\n", __func__, acpi_format_exception(status));
102 		return -ENOSYS;
103 	}
104 	obj = (union acpi_object *)buffer.pointer;
105 	if (obj && (obj->type == ACPI_TYPE_BUFFER))
106 		printk(KERN_INFO "radeon atpx: version is %d\n", *((u8 *)(obj->buffer.pointer) + 2));
107 	kfree(buffer.pointer);
108 	return 0;
109 }
110 
111 static int radeon_atpx_execute(acpi_handle handle, int cmd_id, u16 value)
112 {
113 	acpi_status status;
114 	union acpi_object atpx_arg_elements[2];
115 	struct acpi_object_list atpx_arg;
116 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
117 	uint8_t buf[4] = {0};
118 
119 	if (!handle)
120 		return -EINVAL;
121 
122 	atpx_arg.count = 2;
123 	atpx_arg.pointer = &atpx_arg_elements[0];
124 
125 	atpx_arg_elements[0].type = ACPI_TYPE_INTEGER;
126 	atpx_arg_elements[0].integer.value = cmd_id;
127 
128 	buf[2] = value & 0xff;
129 	buf[3] = (value >> 8) & 0xff;
130 
131 	atpx_arg_elements[1].type = ACPI_TYPE_BUFFER;
132 	atpx_arg_elements[1].buffer.length = 4;
133 	atpx_arg_elements[1].buffer.pointer = buf;
134 
135 	status = acpi_evaluate_object(handle, NULL, &atpx_arg, &buffer);
136 	if (ACPI_FAILURE(status)) {
137 		printk("%s: failed to call ATPX: %s\n", __func__, acpi_format_exception(status));
138 		return -ENOSYS;
139 	}
140 	kfree(buffer.pointer);
141 
142 	return 0;
143 }
144 
145 static int radeon_atpx_set_discrete_state(acpi_handle handle, int state)
146 {
147 	return radeon_atpx_execute(handle, ATPX_GPU_PWR, state);
148 }
149 
150 static int radeon_atpx_switch_mux(acpi_handle handle, int mux_id)
151 {
152 	return radeon_atpx_execute(handle, ATPX_MUX_SELECT, mux_id);
153 }
154 
155 static int radeon_atpx_switch_i2c_mux(acpi_handle handle, int mux_id)
156 {
157 	return radeon_atpx_execute(handle, ATPX_I2C_MUX_SELECT, mux_id);
158 }
159 
160 static int radeon_atpx_switch_start(acpi_handle handle, int gpu_id)
161 {
162 	return radeon_atpx_execute(handle, ATPX_SWITCH_START, gpu_id);
163 }
164 
165 static int radeon_atpx_switch_end(acpi_handle handle, int gpu_id)
166 {
167 	return radeon_atpx_execute(handle, ATPX_SWITCH_END, gpu_id);
168 }
169 
170 static int radeon_atpx_switchto(enum vga_switcheroo_client_id id)
171 {
172 	int gpu_id;
173 
174 	if (id == VGA_SWITCHEROO_IGD)
175 		gpu_id = ATPX_INTEGRATED;
176 	else
177 		gpu_id = ATPX_DISCRETE;
178 
179 	radeon_atpx_switch_start(radeon_atpx_priv.atpx_handle, gpu_id);
180 	radeon_atpx_switch_mux(radeon_atpx_priv.atpx_handle, gpu_id);
181 	radeon_atpx_switch_i2c_mux(radeon_atpx_priv.atpx_handle, gpu_id);
182 	radeon_atpx_switch_end(radeon_atpx_priv.atpx_handle, gpu_id);
183 
184 	return 0;
185 }
186 
187 static int radeon_atpx_power_state(enum vga_switcheroo_client_id id,
188 				   enum vga_switcheroo_state state)
189 {
190 	/* on w500 ACPI can't change intel gpu state */
191 	if (id == VGA_SWITCHEROO_IGD)
192 		return 0;
193 
194 	radeon_atpx_set_discrete_state(radeon_atpx_priv.atpx_handle, state);
195 	return 0;
196 }
197 
198 static bool radeon_atpx_pci_probe_handle(struct pci_dev *pdev)
199 {
200 	acpi_handle dhandle, atpx_handle, atrm_handle;
201 	acpi_status status;
202 
203 	dhandle = DEVICE_ACPI_HANDLE(&pdev->dev);
204 	if (!dhandle)
205 		return false;
206 
207 	status = acpi_get_handle(dhandle, "ATPX", &atpx_handle);
208 	if (ACPI_FAILURE(status))
209 		return false;
210 
211 	status = acpi_get_handle(dhandle, "ATRM", &atrm_handle);
212 	if (ACPI_FAILURE(status))
213 		return false;
214 
215 	radeon_atpx_priv.dhandle = dhandle;
216 	radeon_atpx_priv.atpx_handle = atpx_handle;
217 	radeon_atpx_priv.atrm_handle = atrm_handle;
218 	return true;
219 }
220 
221 static int radeon_atpx_init(void)
222 {
223 	/* set up the ATPX handle */
224 
225 	radeon_atpx_get_version(radeon_atpx_priv.atpx_handle);
226 	return 0;
227 }
228 
229 static int radeon_atpx_get_client_id(struct pci_dev *pdev)
230 {
231 	if (radeon_atpx_priv.dhandle == DEVICE_ACPI_HANDLE(&pdev->dev))
232 		return VGA_SWITCHEROO_IGD;
233 	else
234 		return VGA_SWITCHEROO_DIS;
235 }
236 
237 static struct vga_switcheroo_handler radeon_atpx_handler = {
238 	.switchto = radeon_atpx_switchto,
239 	.power_state = radeon_atpx_power_state,
240 	.init = radeon_atpx_init,
241 	.get_client_id = radeon_atpx_get_client_id,
242 };
243 
244 static bool radeon_atpx_detect(void)
245 {
246 	char acpi_method_name[255] = { 0 };
247 	struct acpi_buffer buffer = {sizeof(acpi_method_name), acpi_method_name};
248 	struct pci_dev *pdev = NULL;
249 	bool has_atpx = false;
250 	int vga_count = 0;
251 
252 	while ((pdev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, pdev)) != NULL) {
253 		vga_count++;
254 
255 		has_atpx |= (radeon_atpx_pci_probe_handle(pdev) == true);
256 	}
257 
258 	if (has_atpx && vga_count == 2) {
259 		acpi_get_name(radeon_atpx_priv.atpx_handle, ACPI_FULL_PATHNAME, &buffer);
260 		printk(KERN_INFO "VGA switcheroo: detected switching method %s handle\n",
261 		       acpi_method_name);
262 		radeon_atpx_priv.atpx_detected = true;
263 		return true;
264 	}
265 	return false;
266 }
267 
268 void radeon_register_atpx_handler(void)
269 {
270 	bool r;
271 
272 	/* detect if we have any ATPX + 2 VGA in the system */
273 	r = radeon_atpx_detect();
274 	if (!r)
275 		return;
276 
277 	vga_switcheroo_register_handler(&radeon_atpx_handler);
278 }
279 
280 void radeon_unregister_atpx_handler(void)
281 {
282 	vga_switcheroo_unregister_handler();
283 }
284