Commit | Line | Data |
---|---|---|
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)) | |
44 | #define XWAY_STP_SPEED_MASK (0xf << 23) | |
45 | ||
46 | /* clock source for automatic update */ | |
47 | #define XWAY_STP_UPD_FPI BIT(31) | |
48 | #define XWAY_STP_UPD_MASK (BIT(31) | BIT(30)) | |
49 | ||
50 | /* let the adsl core drive the 2 LSBs */ | |
51 | #define XWAY_STP_ADSL_SHIFT 24 | |
52 | #define XWAY_STP_ADSL_MASK 0x3 | |
53 | ||
54 | /* 2 groups of 3 bits can be driven by the phys */ | |
08b085a0 | 55 | #define XWAY_STP_PHY_MASK 0x7 |
54f30066 JC |
56 | #define XWAY_STP_PHY1_SHIFT 27 |
57 | #define XWAY_STP_PHY2_SHIFT 15 | |
58 | ||
59 | /* STP has 3 groups of 8 bits */ | |
60 | #define XWAY_STP_GROUP0 BIT(0) | |
61 | #define XWAY_STP_GROUP1 BIT(1) | |
62 | #define XWAY_STP_GROUP2 BIT(2) | |
63 | #define XWAY_STP_GROUP_MASK (0x7) | |
64 | ||
65 | /* Edge configuration bits */ | |
66 | #define XWAY_STP_FALLING BIT(26) | |
67 | #define XWAY_STP_EDGE_MASK BIT(26) | |
68 | ||
69 | #define xway_stp_r32(m, reg) __raw_readl(m + reg) | |
70 | #define xway_stp_w32(m, val, reg) __raw_writel(val, m + reg) | |
71 | #define xway_stp_w32_mask(m, clear, set, reg) \ | |
c0ec7012 | 72 | xway_stp_w32(m, (xway_stp_r32(m, reg) & ~(clear)) | (set), reg) |
54f30066 JC |
73 | |
74 | struct xway_stp { | |
75 | struct gpio_chip gc; | |
76 | void __iomem *virt; | |
77 | u32 edge; /* rising or falling edge triggered shift register */ | |
c9e854cf | 78 | u32 shadow; /* shadow the shift registers state */ |
54f30066 JC |
79 | u8 groups; /* we can drive 1-3 groups of 8bit each */ |
80 | u8 dsl; /* the 2 LSBs can be driven by the dsl core */ | |
81 | u8 phy1; /* 3 bits can be driven by phy1 */ | |
82 | u8 phy2; /* 3 bits can be driven by phy2 */ | |
83 | u8 reserved; /* mask out the hw driven bits in gpio_request */ | |
84 | }; | |
85 | ||
5b9b2b52 MK |
86 | /** |
87 | * xway_stp_get() - gpio_chip->get - get gpios. | |
88 | * @gc: Pointer to gpio_chip device structure. | |
89 | * @gpio: GPIO signal number. | |
90 | * | |
91 | * Gets the shadow value. | |
92 | */ | |
93 | static int xway_stp_get(struct gpio_chip *gc, unsigned int gpio) | |
94 | { | |
95 | struct xway_stp *chip = gpiochip_get_data(gc); | |
96 | ||
97 | return (xway_stp_r32(chip->virt, XWAY_STP_CPU0) & BIT(gpio)); | |
98 | } | |
99 | ||
54f30066 JC |
100 | /** |
101 | * xway_stp_set() - gpio_chip->set - set gpios. | |
102 | * @gc: Pointer to gpio_chip device structure. | |
103 | * @gpio: GPIO signal number. | |
104 | * @val: Value to be written to specified signal. | |
105 | * | |
106 | * Set the shadow value and call ltq_ebu_apply. | |
107 | */ | |
108 | static void xway_stp_set(struct gpio_chip *gc, unsigned gpio, int val) | |
935c500c | 109 | { |
c63b30b0 | 110 | struct xway_stp *chip = gpiochip_get_data(gc); |
54f30066 JC |
111 | |
112 | if (val) | |
113 | chip->shadow |= BIT(gpio); | |
935c500c | 114 | else |
54f30066 JC |
115 | chip->shadow &= ~BIT(gpio); |
116 | xway_stp_w32(chip->virt, chip->shadow, XWAY_STP_CPU0); | |
117 | xway_stp_w32_mask(chip->virt, 0, XWAY_STP_CON_SWU, XWAY_STP_CON0); | |
935c500c JC |
118 | } |
119 | ||
54f30066 JC |
120 | /** |
121 | * xway_stp_dir_out() - gpio_chip->dir_out - set gpio direction. | |
122 | * @gc: Pointer to gpio_chip device structure. | |
123 | * @gpio: GPIO signal number. | |
124 | * @val: Value to be written to specified signal. | |
125 | * | |
126 | * Same as xway_stp_set, always returns 0. | |
127 | */ | |
128 | static int xway_stp_dir_out(struct gpio_chip *gc, unsigned gpio, int val) | |
935c500c | 129 | { |
54f30066 | 130 | xway_stp_set(gc, gpio, val); |
935c500c JC |
131 | |
132 | return 0; | |
133 | } | |
134 | ||
54f30066 JC |
135 | /** |
136 | * xway_stp_request() - gpio_chip->request | |
137 | * @gc: Pointer to gpio_chip device structure. | |
138 | * @gpio: GPIO signal number. | |
139 | * | |
140 | * We mask out the HW driven pins | |
141 | */ | |
142 | static int xway_stp_request(struct gpio_chip *gc, unsigned gpio) | |
143 | { | |
c63b30b0 | 144 | struct xway_stp *chip = gpiochip_get_data(gc); |
54f30066 JC |
145 | |
146 | if ((gpio < 8) && (chip->reserved & BIT(gpio))) { | |
58383c78 | 147 | dev_err(gc->parent, "GPIO %d is driven by hardware\n", gpio); |
54f30066 JC |
148 | return -ENODEV; |
149 | } | |
935c500c | 150 | |
54f30066 JC |
151 | return 0; |
152 | } | |
153 | ||
154 | /** | |
155 | * xway_stp_hw_init() - Configure the STP unit and enable the clock gate | |
8a7b1797 | 156 | * @chip: Pointer to the xway_stp chip structure |
54f30066 | 157 | */ |
8a7b1797 | 158 | static void xway_stp_hw_init(struct xway_stp *chip) |
935c500c | 159 | { |
935c500c | 160 | /* sane defaults */ |
54f30066 JC |
161 | xway_stp_w32(chip->virt, 0, XWAY_STP_AR); |
162 | xway_stp_w32(chip->virt, 0, XWAY_STP_CPU0); | |
163 | xway_stp_w32(chip->virt, 0, XWAY_STP_CPU1); | |
164 | xway_stp_w32(chip->virt, XWAY_STP_CON_SWU, XWAY_STP_CON0); | |
165 | xway_stp_w32(chip->virt, 0, XWAY_STP_CON1); | |
935c500c | 166 | |
54f30066 JC |
167 | /* apply edge trigger settings for the shift register */ |
168 | xway_stp_w32_mask(chip->virt, XWAY_STP_EDGE_MASK, | |
169 | chip->edge, XWAY_STP_CON0); | |
935c500c | 170 | |
54f30066 JC |
171 | /* apply led group settings */ |
172 | xway_stp_w32_mask(chip->virt, XWAY_STP_GROUP_MASK, | |
173 | chip->groups, XWAY_STP_CON1); | |
935c500c | 174 | |
54f30066 JC |
175 | /* tell the hardware which pins are controlled by the dsl modem */ |
176 | xway_stp_w32_mask(chip->virt, | |
177 | XWAY_STP_ADSL_MASK << XWAY_STP_ADSL_SHIFT, | |
178 | chip->dsl << XWAY_STP_ADSL_SHIFT, | |
179 | XWAY_STP_CON0); | |
935c500c | 180 | |
54f30066 JC |
181 | /* tell the hardware which pins are controlled by the phys */ |
182 | xway_stp_w32_mask(chip->virt, | |
183 | XWAY_STP_PHY_MASK << XWAY_STP_PHY1_SHIFT, | |
184 | chip->phy1 << XWAY_STP_PHY1_SHIFT, | |
185 | XWAY_STP_CON0); | |
186 | xway_stp_w32_mask(chip->virt, | |
187 | XWAY_STP_PHY_MASK << XWAY_STP_PHY2_SHIFT, | |
188 | chip->phy2 << XWAY_STP_PHY2_SHIFT, | |
189 | XWAY_STP_CON1); | |
935c500c | 190 | |
54f30066 JC |
191 | /* mask out the hw driven bits in gpio_request */ |
192 | chip->reserved = (chip->phy2 << 5) | (chip->phy1 << 2) | chip->dsl; | |
193 | ||
194 | /* | |
195 | * if we have pins that are driven by hw, we need to tell the stp what | |
196 | * clock to use as a timer. | |
935c500c | 197 | */ |
54f30066 JC |
198 | if (chip->reserved) |
199 | xway_stp_w32_mask(chip->virt, XWAY_STP_UPD_MASK, | |
200 | XWAY_STP_UPD_FPI, XWAY_STP_CON1); | |
935c500c JC |
201 | } |
202 | ||
3836309d | 203 | static int xway_stp_probe(struct platform_device *pdev) |
935c500c | 204 | { |
50f09073 | 205 | u32 shadow, groups, dsl, phy; |
54f30066 JC |
206 | struct xway_stp *chip; |
207 | struct clk *clk; | |
935c500c JC |
208 | int ret = 0; |
209 | ||
54f30066 JC |
210 | chip = devm_kzalloc(&pdev->dev, sizeof(*chip), GFP_KERNEL); |
211 | if (!chip) | |
212 | return -ENOMEM; | |
213 | ||
6ba7c53b | 214 | chip->virt = devm_platform_ioremap_resource(pdev, 0); |
641d0342 TR |
215 | if (IS_ERR(chip->virt)) |
216 | return PTR_ERR(chip->virt); | |
8ab2a6d2 | 217 | |
58383c78 | 218 | chip->gc.parent = &pdev->dev; |
54f30066 JC |
219 | chip->gc.label = "stp-xway"; |
220 | chip->gc.direction_output = xway_stp_dir_out; | |
5b9b2b52 | 221 | chip->gc.get = xway_stp_get; |
54f30066 JC |
222 | chip->gc.set = xway_stp_set; |
223 | chip->gc.request = xway_stp_request; | |
224 | chip->gc.base = -1; | |
225 | chip->gc.owner = THIS_MODULE; | |
226 | ||
227 | /* store the shadow value if one was passed by the devicetree */ | |
50f09073 MB |
228 | if (!of_property_read_u32(pdev->dev.of_node, "lantiq,shadow", &shadow)) |
229 | chip->shadow = shadow; | |
54f30066 JC |
230 | |
231 | /* find out which gpio groups should be enabled */ | |
50f09073 MB |
232 | if (!of_property_read_u32(pdev->dev.of_node, "lantiq,groups", &groups)) |
233 | chip->groups = groups & XWAY_STP_GROUP_MASK; | |
54f30066 JC |
234 | else |
235 | chip->groups = XWAY_STP_GROUP0; | |
236 | chip->gc.ngpio = fls(chip->groups) * 8; | |
237 | ||
238 | /* find out which gpios are controlled by the dsl core */ | |
50f09073 MB |
239 | if (!of_property_read_u32(pdev->dev.of_node, "lantiq,dsl", &dsl)) |
240 | chip->dsl = dsl & XWAY_STP_ADSL_MASK; | |
54f30066 JC |
241 | |
242 | /* find out which gpios are controlled by the phys */ | |
243 | if (of_machine_is_compatible("lantiq,ar9") || | |
244 | of_machine_is_compatible("lantiq,gr9") || | |
245 | of_machine_is_compatible("lantiq,vr9")) { | |
50f09073 MB |
246 | if (!of_property_read_u32(pdev->dev.of_node, "lantiq,phy1", &phy)) |
247 | chip->phy1 = phy & XWAY_STP_PHY_MASK; | |
248 | if (!of_property_read_u32(pdev->dev.of_node, "lantiq,phy2", &phy)) | |
249 | chip->phy2 = phy & XWAY_STP_PHY_MASK; | |
54f30066 JC |
250 | } |
251 | ||
252 | /* check which edge trigger we should use, default to a falling edge */ | |
253 | if (!of_find_property(pdev->dev.of_node, "lantiq,rising", NULL)) | |
254 | chip->edge = XWAY_STP_FALLING; | |
255 | ||
bd791c48 | 256 | clk = devm_clk_get(&pdev->dev, NULL); |
54f30066 JC |
257 | if (IS_ERR(clk)) { |
258 | dev_err(&pdev->dev, "Failed to get clock\n"); | |
259 | return PTR_ERR(clk); | |
260 | } | |
54f30066 | 261 | |
bd791c48 MB |
262 | ret = clk_prepare_enable(clk); |
263 | if (ret) | |
264 | return ret; | |
54f30066 | 265 | |
8a7b1797 | 266 | xway_stp_hw_init(chip); |
935c500c | 267 | |
8a7b1797 | 268 | ret = devm_gpiochip_add_data(&pdev->dev, &chip->gc, chip); |
bd791c48 MB |
269 | if (ret) { |
270 | clk_disable_unprepare(clk); | |
8a7b1797 | 271 | return ret; |
bd791c48 | 272 | } |
935c500c | 273 | |
8a7b1797 MB |
274 | dev_info(&pdev->dev, "Init done\n"); |
275 | ||
276 | return 0; | |
935c500c JC |
277 | } |
278 | ||
54f30066 JC |
279 | static const struct of_device_id xway_stp_match[] = { |
280 | { .compatible = "lantiq,gpio-stp-xway" }, | |
281 | {}, | |
282 | }; | |
283 | MODULE_DEVICE_TABLE(of, xway_stp_match); | |
284 | ||
285 | static struct platform_driver xway_stp_driver = { | |
286 | .probe = xway_stp_probe, | |
935c500c | 287 | .driver = { |
54f30066 | 288 | .name = "gpio-stp-xway", |
54f30066 | 289 | .of_match_table = xway_stp_match, |
935c500c JC |
290 | }, |
291 | }; | |
292 | ||
afdadc06 | 293 | static int __init xway_stp_init(void) |
935c500c | 294 | { |
54f30066 | 295 | return platform_driver_register(&xway_stp_driver); |
935c500c JC |
296 | } |
297 | ||
54f30066 | 298 | subsys_initcall(xway_stp_init); |