drm/amdgpu: add uvd enc vm functions (v2)
[muen/linux.git] / drivers / memory / da8xx-ddrctl.c
1 /*
2  * TI da8xx DDR2/mDDR controller driver
3  *
4  * Copyright (C) 2016 BayLibre SAS
5  *
6  * Author:
7  *   Bartosz Golaszewski <bgolaszewski@baylibre.com>
8  *
9  * This program is free software; you can redistribute it and/or modify
10  * it under the terms of the GNU General Public License version 2 as
11  * published by the Free Software Foundation.
12  */
13
14 #include <linux/module.h>
15 #include <linux/of.h>
16 #include <linux/of_device.h>
17 #include <linux/platform_device.h>
18 #include <linux/io.h>
19
20 /*
21  * REVISIT: Linux doesn't have a good framework for the kind of performance
22  * knobs this driver controls. We can't use device tree properties as it deals
23  * with hardware configuration rather than description. We also don't want to
24  * commit to maintaining some random sysfs attributes.
25  *
26  * For now we just hardcode the register values for the boards that need
27  * some changes (as is the case for the LCD controller on da850-lcdk - the
28  * first board we support here). When linux gets an appropriate framework,
29  * we'll easily convert the driver to it.
30  */
31
32 struct da8xx_ddrctl_config_knob {
33         const char *name;
34         u32 reg;
35         u32 mask;
36         u32 shift;
37 };
38
39 static const struct da8xx_ddrctl_config_knob da8xx_ddrctl_knobs[] = {
40         {
41                 .name = "da850-pbbpr",
42                 .reg = 0x20,
43                 .mask = 0xffffff00,
44                 .shift = 0,
45         },
46 };
47
48 struct da8xx_ddrctl_setting {
49         const char *name;
50         u32 val;
51 };
52
53 struct da8xx_ddrctl_board_settings {
54         const char *board;
55         const struct da8xx_ddrctl_setting *settings;
56 };
57
58 static const struct da8xx_ddrctl_setting da850_lcdk_ddrctl_settings[] = {
59         {
60                 .name = "da850-pbbpr",
61                 .val = 0x20,
62         },
63         { }
64 };
65
66 static const struct da8xx_ddrctl_board_settings da8xx_ddrctl_board_confs[] = {
67         {
68                 .board = "ti,da850-lcdk",
69                 .settings = da850_lcdk_ddrctl_settings,
70         },
71 };
72
73 static const struct da8xx_ddrctl_config_knob *
74 da8xx_ddrctl_match_knob(const struct da8xx_ddrctl_setting *setting)
75 {
76         const struct da8xx_ddrctl_config_knob *knob;
77         int i;
78
79         for (i = 0; i < ARRAY_SIZE(da8xx_ddrctl_knobs); i++) {
80                 knob = &da8xx_ddrctl_knobs[i];
81
82                 if (strcmp(knob->name, setting->name) == 0)
83                         return knob;
84         }
85
86         return NULL;
87 }
88
89 static const struct da8xx_ddrctl_setting *da8xx_ddrctl_get_board_settings(void)
90 {
91         const struct da8xx_ddrctl_board_settings *board_settings;
92         int i;
93
94         for (i = 0; i < ARRAY_SIZE(da8xx_ddrctl_board_confs); i++) {
95                 board_settings = &da8xx_ddrctl_board_confs[i];
96
97                 if (of_machine_is_compatible(board_settings->board))
98                         return board_settings->settings;
99         }
100
101         return NULL;
102 }
103
104 static int da8xx_ddrctl_probe(struct platform_device *pdev)
105 {
106         const struct da8xx_ddrctl_config_knob *knob;
107         const struct da8xx_ddrctl_setting *setting;
108         struct device_node *node;
109         struct resource *res;
110         void __iomem *ddrctl;
111         struct device *dev;
112         u32 reg;
113
114         dev = &pdev->dev;
115         node = dev->of_node;
116
117         setting = da8xx_ddrctl_get_board_settings();
118         if (!setting) {
119                 dev_err(dev, "no settings defined for this board\n");
120                 return -EINVAL;
121         }
122
123         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
124         ddrctl = devm_ioremap_resource(dev, res);
125         if (IS_ERR(ddrctl)) {
126                 dev_err(dev, "unable to map memory controller registers\n");
127                 return PTR_ERR(ddrctl);
128         }
129
130         for (; setting->name; setting++) {
131                 knob = da8xx_ddrctl_match_knob(setting);
132                 if (!knob) {
133                         dev_warn(dev,
134                                  "no such config option: %s\n", setting->name);
135                         continue;
136                 }
137
138                 if (knob->reg + sizeof(u32) > resource_size(res)) {
139                         dev_warn(dev,
140                                  "register offset of '%s' exceeds mapped memory size\n",
141                                  knob->name);
142                         continue;
143                 }
144
145                 reg = readl(ddrctl + knob->reg);
146                 reg &= knob->mask;
147                 reg |= setting->val << knob->shift;
148
149                 dev_dbg(dev, "writing 0x%08x to %s\n", reg, setting->name);
150
151                 writel(reg, ddrctl + knob->reg);
152         }
153
154         return 0;
155 }
156
157 static const struct of_device_id da8xx_ddrctl_of_match[] = {
158         { .compatible = "ti,da850-ddr-controller", },
159         { },
160 };
161
162 static struct platform_driver da8xx_ddrctl_driver = {
163         .probe = da8xx_ddrctl_probe,
164         .driver = {
165                 .name = "da850-ddr-controller",
166                 .of_match_table = da8xx_ddrctl_of_match,
167         },
168 };
169 module_platform_driver(da8xx_ddrctl_driver);
170
171 MODULE_AUTHOR("Bartosz Golaszewski <bgolaszewski@baylibre.com>");
172 MODULE_DESCRIPTION("TI da8xx DDR2/mDDR controller driver");
173 MODULE_LICENSE("GPL v2");