1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
|
/*
* TI da8xx DDR2/mDDR controller driver
*
* Copyright (C) 2016 BayLibre SAS
*
* Author:
* Bartosz Golaszewski <bgolaszewski@baylibre.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/of_fdt.h>
#include <linux/platform_device.h>
#include <linux/io.h>
/*
* REVISIT: Linux doesn't have a good framework for the kind of performance
* knobs this driver controls. We can't use device tree properties as it deals
* with hardware configuration rather than description. We also don't want to
* commit to maintaining some random sysfs attributes.
*
* For now we just hardcode the register values for the boards that need
* some changes (as is the case for the LCD controller on da850-lcdk - the
* first board we support here). When linux gets an appropriate framework,
* we'll easily convert the driver to it.
*/
struct da8xx_ddrctl_config_knob {
const char *name;
u32 reg;
u32 mask;
u32 shift;
};
static const struct da8xx_ddrctl_config_knob da8xx_ddrctl_knobs[] = {
{
.name = "da850-pbbpr",
.reg = 0x20,
.mask = 0xffffff00,
.shift = 0,
},
};
struct da8xx_ddrctl_setting {
const char *name;
u32 val;
};
struct da8xx_ddrctl_board_settings {
const char *board;
const struct da8xx_ddrctl_setting *settings;
};
static const struct da8xx_ddrctl_setting da850_lcdk_ddrctl_settings[] = {
{
.name = "da850-pbbpr",
.val = 0x20,
},
{ }
};
static const struct da8xx_ddrctl_board_settings da8xx_ddrctl_board_confs[] = {
{
.board = "ti,da850-lcdk",
.settings = da850_lcdk_ddrctl_settings,
},
};
static const struct da8xx_ddrctl_config_knob *
da8xx_ddrctl_match_knob(const struct da8xx_ddrctl_setting *setting)
{
const struct da8xx_ddrctl_config_knob *knob;
int i;
for (i = 0; i < ARRAY_SIZE(da8xx_ddrctl_knobs); i++) {
knob = &da8xx_ddrctl_knobs[i];
if (strcmp(knob->name, setting->name) == 0)
return knob;
}
return NULL;
}
static const struct da8xx_ddrctl_setting *da8xx_ddrctl_get_board_settings(void)
{
const struct da8xx_ddrctl_board_settings *board_settings;
int i;
for (i = 0; i < ARRAY_SIZE(da8xx_ddrctl_board_confs); i++) {
board_settings = &da8xx_ddrctl_board_confs[i];
if (of_machine_is_compatible(board_settings->board))
return board_settings->settings;
}
return NULL;
}
static int da8xx_ddrctl_probe(struct platform_device *pdev)
{
const struct da8xx_ddrctl_config_knob *knob;
const struct da8xx_ddrctl_setting *setting;
struct device_node *node;
struct resource *res;
void __iomem *ddrctl;
struct device *dev;
u32 reg;
dev = &pdev->dev;
node = dev->of_node;
setting = da8xx_ddrctl_get_board_settings();
if (!setting) {
dev_err(dev, "no settings for board '%s'\n",
of_flat_dt_get_machine_name());
return -EINVAL;
}
res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
ddrctl = devm_ioremap_resource(dev, res);
if (IS_ERR(ddrctl)) {
dev_err(dev, "unable to map memory controller registers\n");
return PTR_ERR(ddrctl);
}
for (; setting->name; setting++) {
knob = da8xx_ddrctl_match_knob(setting);
if (!knob) {
dev_warn(dev,
"no such config option: %s\n", setting->name);
continue;
}
if (knob->reg + sizeof(u32) > resource_size(res)) {
dev_warn(dev,
"register offset of '%s' exceeds mapped memory size\n",
knob->name);
continue;
}
reg = readl(ddrctl + knob->reg);
reg &= knob->mask;
reg |= setting->val << knob->shift;
dev_dbg(dev, "writing 0x%08x to %s\n", reg, setting->name);
writel(reg, ddrctl + knob->reg);
}
return 0;
}
static const struct of_device_id da8xx_ddrctl_of_match[] = {
{ .compatible = "ti,da850-ddr-controller", },
{ },
};
static struct platform_driver da8xx_ddrctl_driver = {
.probe = da8xx_ddrctl_probe,
.driver = {
.name = "da850-ddr-controller",
.of_match_table = da8xx_ddrctl_of_match,
},
};
module_platform_driver(da8xx_ddrctl_driver);
MODULE_AUTHOR("Bartosz Golaszewski <bgolaszewski@baylibre.com>");
MODULE_DESCRIPTION("TI da8xx DDR2/mDDR controller driver");
MODULE_LICENSE("GPL v2");
|
