xref: /openbmc/linux/drivers/gpu/drm/radeon/radeon_atpx_handler.c (revision df2634f43f5106947f3735a0b61a6527a4b278cd)
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 
19 #define ATPX_INTEGRATED 0
20 #define ATPX_DISCRETE 1
21 
22 #define ATPX_MUX_IGD 0
23 #define ATPX_MUX_DISCRETE 1
24 
25 static struct radeon_atpx_priv {
26 	bool atpx_detected;
27 	/* handle for device - and atpx */
28 	acpi_handle dhandle;
29 	acpi_handle atpx_handle;
30 	acpi_handle atrm_handle;
31 } radeon_atpx_priv;
32 
33 /* retrieve the ROM in 4k blocks */
34 static int radeon_atrm_call(acpi_handle atrm_handle, uint8_t *bios,
35 			    int offset, int len)
36 {
37 	acpi_status status;
38 	union acpi_object atrm_arg_elements[2], *obj;
39 	struct acpi_object_list atrm_arg;
40 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL};
41 
42 	atrm_arg.count = 2;
43 	atrm_arg.pointer = &atrm_arg_elements[0];
44 
45 	atrm_arg_elements[0].type = ACPI_TYPE_INTEGER;
46 	atrm_arg_elements[0].integer.value = offset;
47 
48 	atrm_arg_elements[1].type = ACPI_TYPE_INTEGER;
49 	atrm_arg_elements[1].integer.value = len;
50 
51 	status = acpi_evaluate_object(atrm_handle, NULL, &atrm_arg, &buffer);
52 	if (ACPI_FAILURE(status)) {
53 		printk("failed to evaluate ATRM got %s\n", acpi_format_exception(status));
54 		return -ENODEV;
55 	}
56 
57 	obj = (union acpi_object *)buffer.pointer;
58 	memcpy(bios+offset, obj->buffer.pointer, len);
59 	kfree(buffer.pointer);
60 	return len;
61 }
62 
63 bool radeon_atrm_supported(struct pci_dev *pdev)
64 {
65 	/* get the discrete ROM only via ATRM */
66 	if (!radeon_atpx_priv.atpx_detected)
67 		return false;
68 
69 	if (radeon_atpx_priv.dhandle == DEVICE_ACPI_HANDLE(&pdev->dev))
70 		return false;
71 	return true;
72 }
73 
74 
75 int radeon_atrm_get_bios_chunk(uint8_t *bios, int offset, int len)
76 {
77 	return radeon_atrm_call(radeon_atpx_priv.atrm_handle, bios, offset, len);
78 }
79 
80 static int radeon_atpx_get_version(acpi_handle handle)
81 {
82 	acpi_status status;
83 	union acpi_object atpx_arg_elements[2], *obj;
84 	struct acpi_object_list atpx_arg;
85 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
86 
87 	atpx_arg.count = 2;
88 	atpx_arg.pointer = &atpx_arg_elements[0];
89 
90 	atpx_arg_elements[0].type = ACPI_TYPE_INTEGER;
91 	atpx_arg_elements[0].integer.value = ATPX_VERSION;
92 
93 	atpx_arg_elements[1].type = ACPI_TYPE_INTEGER;
94 	atpx_arg_elements[1].integer.value = ATPX_VERSION;
95 
96 	status = acpi_evaluate_object(handle, NULL, &atpx_arg, &buffer);
97 	if (ACPI_FAILURE(status)) {
98 		printk("%s: failed to call ATPX: %s\n", __func__, acpi_format_exception(status));
99 		return -ENOSYS;
100 	}
101 	obj = (union acpi_object *)buffer.pointer;
102 	if (obj && (obj->type == ACPI_TYPE_BUFFER))
103 		printk(KERN_INFO "radeon atpx: version is %d\n", *((u8 *)(obj->buffer.pointer) + 2));
104 	kfree(buffer.pointer);
105 	return 0;
106 }
107 
108 static int radeon_atpx_execute(acpi_handle handle, int cmd_id, u16 value)
109 {
110 	acpi_status status;
111 	union acpi_object atpx_arg_elements[2];
112 	struct acpi_object_list atpx_arg;
113 	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
114 	uint8_t buf[4] = {0};
115 
116 	if (!handle)
117 		return -EINVAL;
118 
119 	atpx_arg.count = 2;
120 	atpx_arg.pointer = &atpx_arg_elements[0];
121 
122 	atpx_arg_elements[0].type = ACPI_TYPE_INTEGER;
123 	atpx_arg_elements[0].integer.value = cmd_id;
124 
125 	buf[2] = value & 0xff;
126 	buf[3] = (value >> 8) & 0xff;
127 
128 	atpx_arg_elements[1].type = ACPI_TYPE_BUFFER;
129 	atpx_arg_elements[1].buffer.length = 4;
130 	atpx_arg_elements[1].buffer.pointer = buf;
131 
132 	status = acpi_evaluate_object(handle, NULL, &atpx_arg, &buffer);
133 	if (ACPI_FAILURE(status)) {
134 		printk("%s: failed to call ATPX: %s\n", __func__, acpi_format_exception(status));
135 		return -ENOSYS;
136 	}
137 	kfree(buffer.pointer);
138 
139 	return 0;
140 }
141 
142 static int radeon_atpx_set_discrete_state(acpi_handle handle, int state)
143 {
144 	return radeon_atpx_execute(handle, ATPX_GPU_PWR, state);
145 }
146 
147 static int radeon_atpx_switch_mux(acpi_handle handle, int mux_id)
148 {
149 	return radeon_atpx_execute(handle, ATPX_MUX_SELECT, mux_id);
150 }
151 
152 
153 static int radeon_atpx_switchto(enum vga_switcheroo_client_id id)
154 {
155 	if (id == VGA_SWITCHEROO_IGD)
156 		radeon_atpx_switch_mux(radeon_atpx_priv.atpx_handle, 0);
157 	else
158 		radeon_atpx_switch_mux(radeon_atpx_priv.atpx_handle, 1);
159 	return 0;
160 }
161 
162 static int radeon_atpx_power_state(enum vga_switcheroo_client_id id,
163 				   enum vga_switcheroo_state state)
164 {
165 	/* on w500 ACPI can't change intel gpu state */
166 	if (id == VGA_SWITCHEROO_IGD)
167 		return 0;
168 
169 	radeon_atpx_set_discrete_state(radeon_atpx_priv.atpx_handle, state);
170 	return 0;
171 }
172 
173 static bool radeon_atpx_pci_probe_handle(struct pci_dev *pdev)
174 {
175 	acpi_handle dhandle, atpx_handle, atrm_handle;
176 	acpi_status status;
177 
178 	dhandle = DEVICE_ACPI_HANDLE(&pdev->dev);
179 	if (!dhandle)
180 		return false;
181 
182 	status = acpi_get_handle(dhandle, "ATPX", &atpx_handle);
183 	if (ACPI_FAILURE(status))
184 		return false;
185 
186 	status = acpi_get_handle(dhandle, "ATRM", &atrm_handle);
187 	if (ACPI_FAILURE(status))
188 		return false;
189 
190 	radeon_atpx_priv.dhandle = dhandle;
191 	radeon_atpx_priv.atpx_handle = atpx_handle;
192 	radeon_atpx_priv.atrm_handle = atrm_handle;
193 	return true;
194 }
195 
196 static int radeon_atpx_init(void)
197 {
198 	/* set up the ATPX handle */
199 
200 	radeon_atpx_get_version(radeon_atpx_priv.atpx_handle);
201 	return 0;
202 }
203 
204 static int radeon_atpx_get_client_id(struct pci_dev *pdev)
205 {
206 	if (radeon_atpx_priv.dhandle == DEVICE_ACPI_HANDLE(&pdev->dev))
207 		return VGA_SWITCHEROO_IGD;
208 	else
209 		return VGA_SWITCHEROO_DIS;
210 }
211 
212 static struct vga_switcheroo_handler radeon_atpx_handler = {
213 	.switchto = radeon_atpx_switchto,
214 	.power_state = radeon_atpx_power_state,
215 	.init = radeon_atpx_init,
216 	.get_client_id = radeon_atpx_get_client_id,
217 };
218 
219 static bool radeon_atpx_detect(void)
220 {
221 	char acpi_method_name[255] = { 0 };
222 	struct acpi_buffer buffer = {sizeof(acpi_method_name), acpi_method_name};
223 	struct pci_dev *pdev = NULL;
224 	bool has_atpx = false;
225 	int vga_count = 0;
226 
227 	while ((pdev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, pdev)) != NULL) {
228 		vga_count++;
229 
230 		has_atpx |= (radeon_atpx_pci_probe_handle(pdev) == true);
231 	}
232 
233 	if (has_atpx && vga_count == 2) {
234 		acpi_get_name(radeon_atpx_priv.atpx_handle, ACPI_FULL_PATHNAME, &buffer);
235 		printk(KERN_INFO "VGA switcheroo: detected switching method %s handle\n",
236 		       acpi_method_name);
237 		radeon_atpx_priv.atpx_detected = true;
238 		return true;
239 	}
240 	return false;
241 }
242 
243 void radeon_register_atpx_handler(void)
244 {
245 	bool r;
246 
247 	/* detect if we have any ATPX + 2 VGA in the system */
248 	r = radeon_atpx_detect();
249 	if (!r)
250 		return;
251 
252 	vga_switcheroo_register_handler(&radeon_atpx_handler);
253 }
254 
255 void radeon_unregister_atpx_handler(void)
256 {
257 	vga_switcheroo_unregister_handler();
258 }
259