Commit | Line | Data |
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d2912cb1 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
935c500c | 2 | /* |
935c500c | 3 | * |
baddc7ca | 4 | * Copyright (C) 2012 John Crispin <john@phrozen.org> |
935c500c JC |
5 | */ |
6 | ||
7 | #include <linux/slab.h> | |
8 | #include <linux/init.h> | |
54f30066 | 9 | #include <linux/module.h> |
935c500c | 10 | #include <linux/types.h> |
54f30066 | 11 | #include <linux/of_platform.h> |
935c500c | 12 | #include <linux/mutex.h> |
97a48fcd | 13 | #include <linux/gpio/driver.h> |
54f30066 | 14 | #include <linux/io.h> |
54f30066 JC |
15 | #include <linux/clk.h> |
16 | #include <linux/err.h> | |
935c500c | 17 | |
54f30066 JC |
18 | /* |
19 | * The Serial To Parallel (STP) is found on MIPS based Lantiq socs. It is a | |
20 | * peripheral controller used to drive external shift register cascades. At most | |
21 | * 3 groups of 8 bits can be driven. The hardware is able to allow the DSL modem | |
22 | * to drive the 2 LSBs of the cascade automatically. | |
23 | */ | |
24 | ||
25 | /* control register 0 */ | |
26 | #define XWAY_STP_CON0 0x00 | |
27 | /* control register 1 */ | |
28 | #define XWAY_STP_CON1 0x04 | |
29 | /* data register 0 */ | |
30 | #define XWAY_STP_CPU0 0x08 | |
31 | /* data register 1 */ | |
32 | #define XWAY_STP_CPU1 0x0C | |
33 | /* access register */ | |
34 | #define XWAY_STP_AR 0x10 | |
35 | ||
36 | /* software or hardware update select bit */ | |
37 | #define XWAY_STP_CON_SWU BIT(31) | |
38 | ||
39 | /* automatic update rates */ | |
40 | #define XWAY_STP_2HZ 0 | |
41 | #define XWAY_STP_4HZ BIT(23) | |
42 | #define XWAY_STP_8HZ BIT(24) | |
43 | #define XWAY_STP_10HZ (BIT(24) | BIT(23)) | |
329afb94 AJB |
44 | #define XWAY_STP_SPEED_MASK (BIT(23) | BIT(24) | BIT(25) | BIT(26) | BIT(27)) |
45 | ||
46 | #define XWAY_STP_FPIS_VALUE BIT(21) | |
47 | #define XWAY_STP_FPIS_MASK (BIT(20) | BIT(21)) | |
54f30066 JC |
48 | |
49 | /* clock source for automatic update */ | |
50 | #define XWAY_STP_UPD_FPI BIT(31) | |
51 | #define XWAY_STP_UPD_MASK (BIT(31) | BIT(30)) | |
52 | ||
53 | /* let the adsl core drive the 2 LSBs */ | |
54 | #define XWAY_STP_ADSL_SHIFT 24 | |
55 | #define XWAY_STP_ADSL_MASK 0x3 | |
56 | ||
57 | /* 2 groups of 3 bits can be driven by the phys */ | |
08b085a0 | 58 | #define XWAY_STP_PHY_MASK 0x7 |
54f30066 | 59 | #define XWAY_STP_PHY1_SHIFT 27 |
329afb94 AJB |
60 | #define XWAY_STP_PHY2_SHIFT 3 |
61 | #define XWAY_STP_PHY3_SHIFT 6 | |
62 | #define XWAY_STP_PHY4_SHIFT 15 | |
54f30066 JC |
63 | |
64 | /* STP has 3 groups of 8 bits */ | |
65 | #define XWAY_STP_GROUP0 BIT(0) | |
66 | #define XWAY_STP_GROUP1 BIT(1) | |
67 | #define XWAY_STP_GROUP2 BIT(2) | |
68 | #define XWAY_STP_GROUP_MASK (0x7) | |
69 | ||
70 | /* Edge configuration bits */ | |
71 | #define XWAY_STP_FALLING BIT(26) | |
72 | #define XWAY_STP_EDGE_MASK BIT(26) | |
73 | ||
74 | #define xway_stp_r32(m, reg) __raw_readl(m + reg) | |
75 | #define xway_stp_w32(m, val, reg) __raw_writel(val, m + reg) | |
76 | #define xway_stp_w32_mask(m, clear, set, reg) \ | |
c0ec7012 | 77 | xway_stp_w32(m, (xway_stp_r32(m, reg) & ~(clear)) | (set), reg) |
54f30066 JC |
78 | |
79 | struct xway_stp { | |
80 | struct gpio_chip gc; | |
81 | void __iomem *virt; | |
82 | u32 edge; /* rising or falling edge triggered shift register */ | |
c9e854cf | 83 | u32 shadow; /* shadow the shift registers state */ |
54f30066 JC |
84 | u8 groups; /* we can drive 1-3 groups of 8bit each */ |
85 | u8 dsl; /* the 2 LSBs can be driven by the dsl core */ | |
86 | u8 phy1; /* 3 bits can be driven by phy1 */ | |
87 | u8 phy2; /* 3 bits can be driven by phy2 */ | |
329afb94 AJB |
88 | u8 phy3; /* 3 bits can be driven by phy3 */ |
89 | u8 phy4; /* 3 bits can be driven by phy4 */ | |
54f30066 JC |
90 | u8 reserved; /* mask out the hw driven bits in gpio_request */ |
91 | }; | |
92 | ||
5b9b2b52 MK |
93 | /** |
94 | * xway_stp_get() - gpio_chip->get - get gpios. | |
95 | * @gc: Pointer to gpio_chip device structure. | |
96 | * @gpio: GPIO signal number. | |
97 | * | |
98 | * Gets the shadow value. | |
99 | */ | |
100 | static int xway_stp_get(struct gpio_chip *gc, unsigned int gpio) | |
101 | { | |
102 | struct xway_stp *chip = gpiochip_get_data(gc); | |
103 | ||
104 | return (xway_stp_r32(chip->virt, XWAY_STP_CPU0) & BIT(gpio)); | |
105 | } | |
106 | ||
54f30066 JC |
107 | /** |
108 | * xway_stp_set() - gpio_chip->set - set gpios. | |
109 | * @gc: Pointer to gpio_chip device structure. | |
110 | * @gpio: GPIO signal number. | |
111 | * @val: Value to be written to specified signal. | |
112 | * | |
113 | * Set the shadow value and call ltq_ebu_apply. | |
114 | */ | |
115 | static void xway_stp_set(struct gpio_chip *gc, unsigned gpio, int val) | |
935c500c | 116 | { |
c63b30b0 | 117 | struct xway_stp *chip = gpiochip_get_data(gc); |
54f30066 JC |
118 | |
119 | if (val) | |
120 | chip->shadow |= BIT(gpio); | |
935c500c | 121 | else |
54f30066 JC |
122 | chip->shadow &= ~BIT(gpio); |
123 | xway_stp_w32(chip->virt, chip->shadow, XWAY_STP_CPU0); | |
329afb94 AJB |
124 | if (!chip->reserved) |
125 | xway_stp_w32_mask(chip->virt, 0, XWAY_STP_CON_SWU, XWAY_STP_CON0); | |
935c500c JC |
126 | } |
127 | ||
54f30066 JC |
128 | /** |
129 | * xway_stp_dir_out() - gpio_chip->dir_out - set gpio direction. | |
130 | * @gc: Pointer to gpio_chip device structure. | |
131 | * @gpio: GPIO signal number. | |
132 | * @val: Value to be written to specified signal. | |
133 | * | |
134 | * Same as xway_stp_set, always returns 0. | |
135 | */ | |
136 | static int xway_stp_dir_out(struct gpio_chip *gc, unsigned gpio, int val) | |
935c500c | 137 | { |
54f30066 | 138 | xway_stp_set(gc, gpio, val); |
935c500c JC |
139 | |
140 | return 0; | |
141 | } | |
142 | ||
54f30066 JC |
143 | /** |
144 | * xway_stp_request() - gpio_chip->request | |
145 | * @gc: Pointer to gpio_chip device structure. | |
146 | * @gpio: GPIO signal number. | |
147 | * | |
148 | * We mask out the HW driven pins | |
149 | */ | |
150 | static int xway_stp_request(struct gpio_chip *gc, unsigned gpio) | |
151 | { | |
c63b30b0 | 152 | struct xway_stp *chip = gpiochip_get_data(gc); |
54f30066 JC |
153 | |
154 | if ((gpio < 8) && (chip->reserved & BIT(gpio))) { | |
58383c78 | 155 | dev_err(gc->parent, "GPIO %d is driven by hardware\n", gpio); |
54f30066 JC |
156 | return -ENODEV; |
157 | } | |
935c500c | 158 | |
54f30066 JC |
159 | return 0; |
160 | } | |
161 | ||
162 | /** | |
163 | * xway_stp_hw_init() - Configure the STP unit and enable the clock gate | |
8a7b1797 | 164 | * @chip: Pointer to the xway_stp chip structure |
54f30066 | 165 | */ |
8a7b1797 | 166 | static void xway_stp_hw_init(struct xway_stp *chip) |
935c500c | 167 | { |
935c500c | 168 | /* sane defaults */ |
54f30066 JC |
169 | xway_stp_w32(chip->virt, 0, XWAY_STP_AR); |
170 | xway_stp_w32(chip->virt, 0, XWAY_STP_CPU0); | |
171 | xway_stp_w32(chip->virt, 0, XWAY_STP_CPU1); | |
172 | xway_stp_w32(chip->virt, XWAY_STP_CON_SWU, XWAY_STP_CON0); | |
173 | xway_stp_w32(chip->virt, 0, XWAY_STP_CON1); | |
935c500c | 174 | |
54f30066 JC |
175 | /* apply edge trigger settings for the shift register */ |
176 | xway_stp_w32_mask(chip->virt, XWAY_STP_EDGE_MASK, | |
177 | chip->edge, XWAY_STP_CON0); | |
935c500c | 178 | |
54f30066 JC |
179 | /* apply led group settings */ |
180 | xway_stp_w32_mask(chip->virt, XWAY_STP_GROUP_MASK, | |
181 | chip->groups, XWAY_STP_CON1); | |
935c500c | 182 | |
54f30066 JC |
183 | /* tell the hardware which pins are controlled by the dsl modem */ |
184 | xway_stp_w32_mask(chip->virt, | |
185 | XWAY_STP_ADSL_MASK << XWAY_STP_ADSL_SHIFT, | |
186 | chip->dsl << XWAY_STP_ADSL_SHIFT, | |
187 | XWAY_STP_CON0); | |
935c500c | 188 | |
54f30066 JC |
189 | /* tell the hardware which pins are controlled by the phys */ |
190 | xway_stp_w32_mask(chip->virt, | |
191 | XWAY_STP_PHY_MASK << XWAY_STP_PHY1_SHIFT, | |
192 | chip->phy1 << XWAY_STP_PHY1_SHIFT, | |
193 | XWAY_STP_CON0); | |
194 | xway_stp_w32_mask(chip->virt, | |
195 | XWAY_STP_PHY_MASK << XWAY_STP_PHY2_SHIFT, | |
196 | chip->phy2 << XWAY_STP_PHY2_SHIFT, | |
197 | XWAY_STP_CON1); | |
935c500c | 198 | |
329afb94 AJB |
199 | if (of_machine_is_compatible("lantiq,grx390") |
200 | || of_machine_is_compatible("lantiq,ar10")) { | |
201 | xway_stp_w32_mask(chip->virt, | |
202 | XWAY_STP_PHY_MASK << XWAY_STP_PHY3_SHIFT, | |
203 | chip->phy3 << XWAY_STP_PHY3_SHIFT, | |
204 | XWAY_STP_CON1); | |
205 | } | |
206 | ||
207 | if (of_machine_is_compatible("lantiq,grx390")) { | |
208 | xway_stp_w32_mask(chip->virt, | |
209 | XWAY_STP_PHY_MASK << XWAY_STP_PHY4_SHIFT, | |
210 | chip->phy4 << XWAY_STP_PHY4_SHIFT, | |
211 | XWAY_STP_CON1); | |
212 | } | |
213 | ||
54f30066 | 214 | /* mask out the hw driven bits in gpio_request */ |
329afb94 AJB |
215 | chip->reserved = (chip->phy4 << 11) | (chip->phy3 << 8) | (chip->phy2 << 5) |
216 | | (chip->phy1 << 2) | chip->dsl; | |
54f30066 JC |
217 | |
218 | /* | |
219 | * if we have pins that are driven by hw, we need to tell the stp what | |
220 | * clock to use as a timer. | |
935c500c | 221 | */ |
329afb94 | 222 | if (chip->reserved) { |
54f30066 JC |
223 | xway_stp_w32_mask(chip->virt, XWAY_STP_UPD_MASK, |
224 | XWAY_STP_UPD_FPI, XWAY_STP_CON1); | |
329afb94 AJB |
225 | xway_stp_w32_mask(chip->virt, XWAY_STP_SPEED_MASK, |
226 | XWAY_STP_10HZ, XWAY_STP_CON1); | |
227 | xway_stp_w32_mask(chip->virt, XWAY_STP_FPIS_MASK, | |
228 | XWAY_STP_FPIS_VALUE, XWAY_STP_CON1); | |
229 | } | |
935c500c JC |
230 | } |
231 | ||
3836309d | 232 | static int xway_stp_probe(struct platform_device *pdev) |
935c500c | 233 | { |
50f09073 | 234 | u32 shadow, groups, dsl, phy; |
54f30066 JC |
235 | struct xway_stp *chip; |
236 | struct clk *clk; | |
935c500c JC |
237 | int ret = 0; |
238 | ||
54f30066 JC |
239 | chip = devm_kzalloc(&pdev->dev, sizeof(*chip), GFP_KERNEL); |
240 | if (!chip) | |
241 | return -ENOMEM; | |
242 | ||
6ba7c53b | 243 | chip->virt = devm_platform_ioremap_resource(pdev, 0); |
641d0342 TR |
244 | if (IS_ERR(chip->virt)) |
245 | return PTR_ERR(chip->virt); | |
8ab2a6d2 | 246 | |
58383c78 | 247 | chip->gc.parent = &pdev->dev; |
54f30066 JC |
248 | chip->gc.label = "stp-xway"; |
249 | chip->gc.direction_output = xway_stp_dir_out; | |
5b9b2b52 | 250 | chip->gc.get = xway_stp_get; |
54f30066 JC |
251 | chip->gc.set = xway_stp_set; |
252 | chip->gc.request = xway_stp_request; | |
253 | chip->gc.base = -1; | |
254 | chip->gc.owner = THIS_MODULE; | |
255 | ||
256 | /* store the shadow value if one was passed by the devicetree */ | |
50f09073 MB |
257 | if (!of_property_read_u32(pdev->dev.of_node, "lantiq,shadow", &shadow)) |
258 | chip->shadow = shadow; | |
54f30066 JC |
259 | |
260 | /* find out which gpio groups should be enabled */ | |
50f09073 MB |
261 | if (!of_property_read_u32(pdev->dev.of_node, "lantiq,groups", &groups)) |
262 | chip->groups = groups & XWAY_STP_GROUP_MASK; | |
54f30066 JC |
263 | else |
264 | chip->groups = XWAY_STP_GROUP0; | |
265 | chip->gc.ngpio = fls(chip->groups) * 8; | |
266 | ||
267 | /* find out which gpios are controlled by the dsl core */ | |
50f09073 MB |
268 | if (!of_property_read_u32(pdev->dev.of_node, "lantiq,dsl", &dsl)) |
269 | chip->dsl = dsl & XWAY_STP_ADSL_MASK; | |
54f30066 JC |
270 | |
271 | /* find out which gpios are controlled by the phys */ | |
272 | if (of_machine_is_compatible("lantiq,ar9") || | |
273 | of_machine_is_compatible("lantiq,gr9") || | |
329afb94 AJB |
274 | of_machine_is_compatible("lantiq,vr9") || |
275 | of_machine_is_compatible("lantiq,ar10") || | |
276 | of_machine_is_compatible("lantiq,grx390")) { | |
50f09073 MB |
277 | if (!of_property_read_u32(pdev->dev.of_node, "lantiq,phy1", &phy)) |
278 | chip->phy1 = phy & XWAY_STP_PHY_MASK; | |
279 | if (!of_property_read_u32(pdev->dev.of_node, "lantiq,phy2", &phy)) | |
280 | chip->phy2 = phy & XWAY_STP_PHY_MASK; | |
329afb94 AJB |
281 | } |
282 | ||
283 | if (of_machine_is_compatible("lantiq,ar10") || | |
284 | of_machine_is_compatible("lantiq,grx390")) { | |
285 | if (!of_property_read_u32(pdev->dev.of_node, "lantiq,phy3", &phy)) | |
286 | chip->phy3 = phy & XWAY_STP_PHY_MASK; | |
287 | } | |
288 | ||
289 | if (of_machine_is_compatible("lantiq,grx390")) { | |
290 | if (!of_property_read_u32(pdev->dev.of_node, "lantiq,phy4", &phy)) | |
291 | chip->phy4 = phy & XWAY_STP_PHY_MASK; | |
54f30066 JC |
292 | } |
293 | ||
294 | /* check which edge trigger we should use, default to a falling edge */ | |
295 | if (!of_find_property(pdev->dev.of_node, "lantiq,rising", NULL)) | |
296 | chip->edge = XWAY_STP_FALLING; | |
297 | ||
bd791c48 | 298 | clk = devm_clk_get(&pdev->dev, NULL); |
54f30066 JC |
299 | if (IS_ERR(clk)) { |
300 | dev_err(&pdev->dev, "Failed to get clock\n"); | |
301 | return PTR_ERR(clk); | |
302 | } | |
54f30066 | 303 | |
bd791c48 MB |
304 | ret = clk_prepare_enable(clk); |
305 | if (ret) | |
306 | return ret; | |
54f30066 | 307 | |
8a7b1797 | 308 | xway_stp_hw_init(chip); |
935c500c | 309 | |
8a7b1797 | 310 | ret = devm_gpiochip_add_data(&pdev->dev, &chip->gc, chip); |
bd791c48 MB |
311 | if (ret) { |
312 | clk_disable_unprepare(clk); | |
8a7b1797 | 313 | return ret; |
bd791c48 | 314 | } |
935c500c | 315 | |
8a7b1797 MB |
316 | dev_info(&pdev->dev, "Init done\n"); |
317 | ||
318 | return 0; | |
935c500c JC |
319 | } |
320 | ||
54f30066 JC |
321 | static const struct of_device_id xway_stp_match[] = { |
322 | { .compatible = "lantiq,gpio-stp-xway" }, | |
323 | {}, | |
324 | }; | |
325 | MODULE_DEVICE_TABLE(of, xway_stp_match); | |
326 | ||
327 | static struct platform_driver xway_stp_driver = { | |
328 | .probe = xway_stp_probe, | |
935c500c | 329 | .driver = { |
54f30066 | 330 | .name = "gpio-stp-xway", |
54f30066 | 331 | .of_match_table = xway_stp_match, |
935c500c JC |
332 | }, |
333 | }; | |
334 | ||
afdadc06 | 335 | static int __init xway_stp_init(void) |
935c500c | 336 | { |
54f30066 | 337 | return platform_driver_register(&xway_stp_driver); |
935c500c JC |
338 | } |
339 | ||
54f30066 | 340 | subsys_initcall(xway_stp_init); |