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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * TI da8xx DDR2/mDDR controller driver
4 *
5 * Copyright (C) 2016 BayLibre SAS
6 *
7 * Author:
8 * Bartosz Golaszewski <bgolaszewski@baylibre.com>
9 */
10
11#include <linux/module.h>
12#include <linux/of.h>
13#include <linux/platform_device.h>
14#include <linux/io.h>
15
16/*
17 * REVISIT: Linux doesn't have a good framework for the kind of performance
18 * knobs this driver controls. We can't use device tree properties as it deals
19 * with hardware configuration rather than description. We also don't want to
20 * commit to maintaining some random sysfs attributes.
21 *
22 * For now we just hardcode the register values for the boards that need
23 * some changes (as is the case for the LCD controller on da850-lcdk - the
24 * first board we support here). When linux gets an appropriate framework,
25 * we'll easily convert the driver to it.
26 */
27
28struct da8xx_ddrctl_config_knob {
29 const char *name;
30 u32 reg;
31 u32 mask;
32 u32 shift;
33};
34
35static const struct da8xx_ddrctl_config_knob da8xx_ddrctl_knobs[] = {
36 {
37 .name = "da850-pbbpr",
38 .reg = 0x20,
39 .mask = 0xffffff00,
40 .shift = 0,
41 },
42};
43
44struct da8xx_ddrctl_setting {
45 const char *name;
46 u32 val;
47};
48
49struct da8xx_ddrctl_board_settings {
50 const char *board;
51 const struct da8xx_ddrctl_setting *settings;
52};
53
54static const struct da8xx_ddrctl_setting da850_lcdk_ddrctl_settings[] = {
55 {
56 .name = "da850-pbbpr",
57 .val = 0x20,
58 },
59 { }
60};
61
62static const struct da8xx_ddrctl_board_settings da8xx_ddrctl_board_confs[] = {
63 {
64 .board = "ti,da850-lcdk",
65 .settings = da850_lcdk_ddrctl_settings,
66 },
67};
68
69static const struct da8xx_ddrctl_config_knob *
70da8xx_ddrctl_match_knob(const struct da8xx_ddrctl_setting *setting)
71{
72 const struct da8xx_ddrctl_config_knob *knob;
73 int i;
74
75 for (i = 0; i < ARRAY_SIZE(da8xx_ddrctl_knobs); i++) {
76 knob = &da8xx_ddrctl_knobs[i];
77
78 if (strcmp(knob->name, setting->name) == 0)
79 return knob;
80 }
81
82 return NULL;
83}
84
85static const struct da8xx_ddrctl_setting *da8xx_ddrctl_get_board_settings(void)
86{
87 const struct da8xx_ddrctl_board_settings *board_settings;
88 int i;
89
90 for (i = 0; i < ARRAY_SIZE(da8xx_ddrctl_board_confs); i++) {
91 board_settings = &da8xx_ddrctl_board_confs[i];
92
93 if (of_machine_is_compatible(board_settings->board))
94 return board_settings->settings;
95 }
96
97 return NULL;
98}
99
100static int da8xx_ddrctl_probe(struct platform_device *pdev)
101{
102 const struct da8xx_ddrctl_config_knob *knob;
103 const struct da8xx_ddrctl_setting *setting;
104 struct resource *res;
105 void __iomem *ddrctl;
106 struct device *dev;
107 u32 reg;
108
109 dev = &pdev->dev;
110
111 setting = da8xx_ddrctl_get_board_settings();
112 if (!setting) {
113 dev_err(dev, "no settings defined for this board\n");
114 return -EINVAL;
115 }
116
117 ddrctl = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
118 if (IS_ERR(ddrctl)) {
119 dev_err(dev, "unable to map memory controller registers\n");
120 return PTR_ERR(ddrctl);
121 }
122
123 for (; setting->name; setting++) {
124 knob = da8xx_ddrctl_match_knob(setting);
125 if (!knob) {
126 dev_warn(dev,
127 "no such config option: %s\n", setting->name);
128 continue;
129 }
130
131 if (knob->reg + sizeof(u32) > resource_size(res)) {
132 dev_warn(dev,
133 "register offset of '%s' exceeds mapped memory size\n",
134 knob->name);
135 continue;
136 }
137
138 reg = readl(ddrctl + knob->reg);
139 reg &= knob->mask;
140 reg |= setting->val << knob->shift;
141
142 dev_dbg(dev, "writing 0x%08x to %s\n", reg, setting->name);
143
144 writel(reg, ddrctl + knob->reg);
145 }
146
147 return 0;
148}
149
150static const struct of_device_id da8xx_ddrctl_of_match[] = {
151 { .compatible = "ti,da850-ddr-controller", },
152 { },
153};
154
155static struct platform_driver da8xx_ddrctl_driver = {
156 .probe = da8xx_ddrctl_probe,
157 .driver = {
158 .name = "da850-ddr-controller",
159 .of_match_table = da8xx_ddrctl_of_match,
160 },
161};
162module_platform_driver(da8xx_ddrctl_driver);
163
164MODULE_AUTHOR("Bartosz Golaszewski <bgolaszewski@baylibre.com>");
165MODULE_DESCRIPTION("TI da8xx DDR2/mDDR controller driver");
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
32struct da8xx_ddrctl_config_knob {
33 const char *name;
34 u32 reg;
35 u32 mask;
36 u32 shift;
37};
38
39static 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
48struct da8xx_ddrctl_setting {
49 const char *name;
50 u32 val;
51};
52
53struct da8xx_ddrctl_board_settings {
54 const char *board;
55 const struct da8xx_ddrctl_setting *settings;
56};
57
58static const struct da8xx_ddrctl_setting da850_lcdk_ddrctl_settings[] = {
59 {
60 .name = "da850-pbbpr",
61 .val = 0x20,
62 },
63 { }
64};
65
66static 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
73static const struct da8xx_ddrctl_config_knob *
74da8xx_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
89static 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
104static 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
157static const struct of_device_id da8xx_ddrctl_of_match[] = {
158 { .compatible = "ti,da850-ddr-controller", },
159 { },
160};
161
162static 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};
169module_platform_driver(da8xx_ddrctl_driver);
170
171MODULE_AUTHOR("Bartosz Golaszewski <bgolaszewski@baylibre.com>");
172MODULE_DESCRIPTION("TI da8xx DDR2/mDDR controller driver");
173MODULE_LICENSE("GPL v2");