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3bb16560 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
40eb4776 MK |
2 | /* |
3 | * Driver for NVIDIA Generic Memory Interface | |
4 | * | |
5 | * Copyright (C) 2016 Host Mobility AB. All rights reserved. | |
40eb4776 MK |
6 | */ |
7 | ||
8 | #include <linux/clk.h> | |
9 | #include <linux/delay.h> | |
10 | #include <linux/io.h> | |
11 | #include <linux/module.h> | |
1c5e9170 RH |
12 | #include <linux/of.h> |
13 | #include <linux/of_platform.h> | |
14 | #include <linux/platform_device.h> | |
59caf732 | 15 | #include <linux/pm_runtime.h> |
40eb4776 MK |
16 | #include <linux/reset.h> |
17 | ||
59caf732 DO |
18 | #include <soc/tegra/common.h> |
19 | ||
40eb4776 MK |
20 | #define TEGRA_GMI_CONFIG 0x00 |
21 | #define TEGRA_GMI_CONFIG_GO BIT(31) | |
22 | #define TEGRA_GMI_BUS_WIDTH_32BIT BIT(30) | |
23 | #define TEGRA_GMI_MUX_MODE BIT(28) | |
24 | #define TEGRA_GMI_RDY_BEFORE_DATA BIT(24) | |
25 | #define TEGRA_GMI_RDY_ACTIVE_HIGH BIT(23) | |
26 | #define TEGRA_GMI_ADV_ACTIVE_HIGH BIT(22) | |
27 | #define TEGRA_GMI_OE_ACTIVE_HIGH BIT(21) | |
28 | #define TEGRA_GMI_CS_ACTIVE_HIGH BIT(20) | |
29 | #define TEGRA_GMI_CS_SELECT(x) ((x & 0x7) << 4) | |
30 | ||
31 | #define TEGRA_GMI_TIMING0 0x10 | |
32 | #define TEGRA_GMI_MUXED_WIDTH(x) ((x & 0xf) << 12) | |
33 | #define TEGRA_GMI_HOLD_WIDTH(x) ((x & 0xf) << 8) | |
34 | #define TEGRA_GMI_ADV_WIDTH(x) ((x & 0xf) << 4) | |
35 | #define TEGRA_GMI_CE_WIDTH(x) (x & 0xf) | |
36 | ||
37 | #define TEGRA_GMI_TIMING1 0x14 | |
38 | #define TEGRA_GMI_WE_WIDTH(x) ((x & 0xff) << 16) | |
39 | #define TEGRA_GMI_OE_WIDTH(x) ((x & 0xff) << 8) | |
40 | #define TEGRA_GMI_WAIT_WIDTH(x) (x & 0xff) | |
41 | ||
42 | #define TEGRA_GMI_MAX_CHIP_SELECT 8 | |
43 | ||
44 | struct tegra_gmi { | |
45 | struct device *dev; | |
46 | void __iomem *base; | |
47 | struct clk *clk; | |
48 | struct reset_control *rst; | |
49 | ||
50 | u32 snor_config; | |
51 | u32 snor_timing0; | |
52 | u32 snor_timing1; | |
53 | }; | |
54 | ||
55 | static int tegra_gmi_enable(struct tegra_gmi *gmi) | |
56 | { | |
57 | int err; | |
58 | ||
59caf732 DO |
59 | pm_runtime_enable(gmi->dev); |
60 | err = pm_runtime_resume_and_get(gmi->dev); | |
61 | if (err) { | |
62 | pm_runtime_disable(gmi->dev); | |
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63 | return err; |
64 | } | |
65 | ||
66 | reset_control_assert(gmi->rst); | |
67 | usleep_range(2000, 4000); | |
68 | reset_control_deassert(gmi->rst); | |
69 | ||
70 | writel(gmi->snor_timing0, gmi->base + TEGRA_GMI_TIMING0); | |
71 | writel(gmi->snor_timing1, gmi->base + TEGRA_GMI_TIMING1); | |
72 | ||
73 | gmi->snor_config |= TEGRA_GMI_CONFIG_GO; | |
74 | writel(gmi->snor_config, gmi->base + TEGRA_GMI_CONFIG); | |
75 | ||
76 | return 0; | |
77 | } | |
78 | ||
79 | static void tegra_gmi_disable(struct tegra_gmi *gmi) | |
80 | { | |
81 | u32 config; | |
82 | ||
83 | /* stop GMI operation */ | |
84 | config = readl(gmi->base + TEGRA_GMI_CONFIG); | |
85 | config &= ~TEGRA_GMI_CONFIG_GO; | |
86 | writel(config, gmi->base + TEGRA_GMI_CONFIG); | |
87 | ||
88 | reset_control_assert(gmi->rst); | |
59caf732 DO |
89 | |
90 | pm_runtime_put_sync_suspend(gmi->dev); | |
91 | pm_runtime_force_suspend(gmi->dev); | |
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92 | } |
93 | ||
94 | static int tegra_gmi_parse_dt(struct tegra_gmi *gmi) | |
95 | { | |
96 | struct device_node *child; | |
97 | u32 property, ranges[4]; | |
98 | int err; | |
99 | ||
100 | child = of_get_next_available_child(gmi->dev->of_node, NULL); | |
101 | if (!child) { | |
102 | dev_err(gmi->dev, "no child nodes found\n"); | |
103 | return -ENODEV; | |
104 | } | |
105 | ||
106 | /* | |
107 | * We currently only support one child device due to lack of | |
108 | * chip-select address decoding. Which means that we only have one | |
109 | * chip-select line from the GMI controller. | |
110 | */ | |
111 | if (of_get_child_count(gmi->dev->of_node) > 1) | |
112 | dev_warn(gmi->dev, "only one child device is supported."); | |
113 | ||
114 | if (of_property_read_bool(child, "nvidia,snor-data-width-32bit")) | |
115 | gmi->snor_config |= TEGRA_GMI_BUS_WIDTH_32BIT; | |
116 | ||
117 | if (of_property_read_bool(child, "nvidia,snor-mux-mode")) | |
118 | gmi->snor_config |= TEGRA_GMI_MUX_MODE; | |
119 | ||
120 | if (of_property_read_bool(child, "nvidia,snor-rdy-active-before-data")) | |
121 | gmi->snor_config |= TEGRA_GMI_RDY_BEFORE_DATA; | |
122 | ||
123 | if (of_property_read_bool(child, "nvidia,snor-rdy-active-high")) | |
124 | gmi->snor_config |= TEGRA_GMI_RDY_ACTIVE_HIGH; | |
125 | ||
126 | if (of_property_read_bool(child, "nvidia,snor-adv-active-high")) | |
127 | gmi->snor_config |= TEGRA_GMI_ADV_ACTIVE_HIGH; | |
128 | ||
129 | if (of_property_read_bool(child, "nvidia,snor-oe-active-high")) | |
130 | gmi->snor_config |= TEGRA_GMI_OE_ACTIVE_HIGH; | |
131 | ||
132 | if (of_property_read_bool(child, "nvidia,snor-cs-active-high")) | |
133 | gmi->snor_config |= TEGRA_GMI_CS_ACTIVE_HIGH; | |
134 | ||
135 | /* Decode the CS# */ | |
136 | err = of_property_read_u32_array(child, "ranges", ranges, 4); | |
137 | if (err < 0) { | |
138 | /* Invalid binding */ | |
139 | if (err == -EOVERFLOW) { | |
140 | dev_err(gmi->dev, | |
141 | "failed to decode CS: invalid ranges length\n"); | |
142 | goto error_cs; | |
143 | } | |
144 | ||
145 | /* | |
146 | * If we reach here it means that the child node has an empty | |
147 | * ranges or it does not exist at all. Attempt to decode the | |
148 | * CS# from the reg property instead. | |
149 | */ | |
150 | err = of_property_read_u32(child, "reg", &property); | |
151 | if (err < 0) { | |
152 | dev_err(gmi->dev, | |
153 | "failed to decode CS: no reg property found\n"); | |
154 | goto error_cs; | |
155 | } | |
156 | } else { | |
157 | property = ranges[1]; | |
158 | } | |
159 | ||
160 | /* Valid chip selects are CS0-CS7 */ | |
161 | if (property >= TEGRA_GMI_MAX_CHIP_SELECT) { | |
162 | dev_err(gmi->dev, "invalid chip select: %d", property); | |
163 | err = -EINVAL; | |
164 | goto error_cs; | |
165 | } | |
166 | ||
167 | gmi->snor_config |= TEGRA_GMI_CS_SELECT(property); | |
168 | ||
169 | /* The default values that are provided below are reset values */ | |
170 | if (!of_property_read_u32(child, "nvidia,snor-muxed-width", &property)) | |
171 | gmi->snor_timing0 |= TEGRA_GMI_MUXED_WIDTH(property); | |
172 | else | |
173 | gmi->snor_timing0 |= TEGRA_GMI_MUXED_WIDTH(1); | |
174 | ||
175 | if (!of_property_read_u32(child, "nvidia,snor-hold-width", &property)) | |
176 | gmi->snor_timing0 |= TEGRA_GMI_HOLD_WIDTH(property); | |
177 | else | |
178 | gmi->snor_timing0 |= TEGRA_GMI_HOLD_WIDTH(1); | |
179 | ||
180 | if (!of_property_read_u32(child, "nvidia,snor-adv-width", &property)) | |
181 | gmi->snor_timing0 |= TEGRA_GMI_ADV_WIDTH(property); | |
182 | else | |
183 | gmi->snor_timing0 |= TEGRA_GMI_ADV_WIDTH(1); | |
184 | ||
185 | if (!of_property_read_u32(child, "nvidia,snor-ce-width", &property)) | |
186 | gmi->snor_timing0 |= TEGRA_GMI_CE_WIDTH(property); | |
187 | else | |
188 | gmi->snor_timing0 |= TEGRA_GMI_CE_WIDTH(4); | |
189 | ||
190 | if (!of_property_read_u32(child, "nvidia,snor-we-width", &property)) | |
191 | gmi->snor_timing1 |= TEGRA_GMI_WE_WIDTH(property); | |
192 | else | |
193 | gmi->snor_timing1 |= TEGRA_GMI_WE_WIDTH(1); | |
194 | ||
195 | if (!of_property_read_u32(child, "nvidia,snor-oe-width", &property)) | |
196 | gmi->snor_timing1 |= TEGRA_GMI_OE_WIDTH(property); | |
197 | else | |
198 | gmi->snor_timing1 |= TEGRA_GMI_OE_WIDTH(1); | |
199 | ||
200 | if (!of_property_read_u32(child, "nvidia,snor-wait-width", &property)) | |
201 | gmi->snor_timing1 |= TEGRA_GMI_WAIT_WIDTH(property); | |
202 | else | |
203 | gmi->snor_timing1 |= TEGRA_GMI_WAIT_WIDTH(3); | |
204 | ||
205 | error_cs: | |
206 | of_node_put(child); | |
207 | return err; | |
208 | } | |
209 | ||
210 | static int tegra_gmi_probe(struct platform_device *pdev) | |
211 | { | |
212 | struct device *dev = &pdev->dev; | |
213 | struct tegra_gmi *gmi; | |
40eb4776 MK |
214 | int err; |
215 | ||
216 | gmi = devm_kzalloc(dev, sizeof(*gmi), GFP_KERNEL); | |
217 | if (!gmi) | |
218 | return -ENOMEM; | |
219 | ||
59caf732 | 220 | platform_set_drvdata(pdev, gmi); |
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221 | gmi->dev = dev; |
222 | ||
df823d21 | 223 | gmi->base = devm_platform_ioremap_resource(pdev, 0); |
40eb4776 MK |
224 | if (IS_ERR(gmi->base)) |
225 | return PTR_ERR(gmi->base); | |
226 | ||
227 | gmi->clk = devm_clk_get(dev, "gmi"); | |
228 | if (IS_ERR(gmi->clk)) { | |
229 | dev_err(dev, "can not get clock\n"); | |
230 | return PTR_ERR(gmi->clk); | |
231 | } | |
232 | ||
233 | gmi->rst = devm_reset_control_get(dev, "gmi"); | |
234 | if (IS_ERR(gmi->rst)) { | |
235 | dev_err(dev, "can not get reset\n"); | |
236 | return PTR_ERR(gmi->rst); | |
237 | } | |
238 | ||
59caf732 DO |
239 | err = devm_tegra_core_dev_init_opp_table_common(&pdev->dev); |
240 | if (err) | |
241 | return err; | |
242 | ||
40eb4776 MK |
243 | err = tegra_gmi_parse_dt(gmi); |
244 | if (err) | |
245 | return err; | |
246 | ||
247 | err = tegra_gmi_enable(gmi); | |
248 | if (err < 0) | |
249 | return err; | |
250 | ||
251 | err = of_platform_default_populate(dev->of_node, NULL, dev); | |
252 | if (err < 0) { | |
253 | dev_err(dev, "fail to create devices.\n"); | |
254 | tegra_gmi_disable(gmi); | |
255 | return err; | |
256 | } | |
257 | ||
40eb4776 MK |
258 | return 0; |
259 | } | |
260 | ||
812c0c38 | 261 | static void tegra_gmi_remove(struct platform_device *pdev) |
40eb4776 MK |
262 | { |
263 | struct tegra_gmi *gmi = platform_get_drvdata(pdev); | |
264 | ||
265 | of_platform_depopulate(gmi->dev); | |
266 | tegra_gmi_disable(gmi); | |
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267 | } |
268 | ||
59caf732 DO |
269 | static int __maybe_unused tegra_gmi_runtime_resume(struct device *dev) |
270 | { | |
271 | struct tegra_gmi *gmi = dev_get_drvdata(dev); | |
272 | int err; | |
273 | ||
274 | err = clk_prepare_enable(gmi->clk); | |
275 | if (err < 0) { | |
276 | dev_err(gmi->dev, "failed to enable clock: %d\n", err); | |
277 | return err; | |
278 | } | |
279 | ||
280 | return 0; | |
281 | } | |
282 | ||
283 | static int __maybe_unused tegra_gmi_runtime_suspend(struct device *dev) | |
284 | { | |
285 | struct tegra_gmi *gmi = dev_get_drvdata(dev); | |
286 | ||
287 | clk_disable_unprepare(gmi->clk); | |
288 | ||
289 | return 0; | |
290 | } | |
291 | ||
292 | static const struct dev_pm_ops tegra_gmi_pm = { | |
293 | SET_RUNTIME_PM_OPS(tegra_gmi_runtime_suspend, tegra_gmi_runtime_resume, | |
294 | NULL) | |
295 | }; | |
296 | ||
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297 | static const struct of_device_id tegra_gmi_id_table[] = { |
298 | { .compatible = "nvidia,tegra20-gmi", }, | |
299 | { .compatible = "nvidia,tegra30-gmi", }, | |
300 | { } | |
301 | }; | |
302 | MODULE_DEVICE_TABLE(of, tegra_gmi_id_table); | |
303 | ||
304 | static struct platform_driver tegra_gmi_driver = { | |
305 | .probe = tegra_gmi_probe, | |
812c0c38 | 306 | .remove_new = tegra_gmi_remove, |
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307 | .driver = { |
308 | .name = "tegra-gmi", | |
309 | .of_match_table = tegra_gmi_id_table, | |
59caf732 | 310 | .pm = &tegra_gmi_pm, |
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311 | }, |
312 | }; | |
313 | module_platform_driver(tegra_gmi_driver); | |
314 | ||
315 | MODULE_AUTHOR("Mirza Krak <mirza.krak@gmail.com"); | |
316 | MODULE_DESCRIPTION("NVIDIA Tegra GMI Bus Driver"); | |
317 | MODULE_LICENSE("GPL v2"); |