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[mirror_ubuntu-artful-kernel.git] / drivers / clk / clk-gemini.c
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1/*
2 * Cortina Gemini SoC Clock Controller driver
3 * Copyright (c) 2017 Linus Walleij <linus.walleij@linaro.org>
4 */
5
6#define pr_fmt(fmt) "clk-gemini: " fmt
7
8#include <linux/init.h>
9#include <linux/module.h>
10#include <linux/platform_device.h>
11#include <linux/slab.h>
12#include <linux/err.h>
13#include <linux/io.h>
14#include <linux/clk-provider.h>
15#include <linux/of.h>
16#include <linux/of_address.h>
17#include <linux/mfd/syscon.h>
18#include <linux/regmap.h>
19#include <linux/spinlock.h>
20#include <linux/reset-controller.h>
21#include <dt-bindings/reset/cortina,gemini-reset.h>
22#include <dt-bindings/clock/cortina,gemini-clock.h>
23
24/* Globally visible clocks */
25static DEFINE_SPINLOCK(gemini_clk_lock);
26
27#define GEMINI_GLOBAL_STATUS 0x04
28#define PLL_OSC_SEL BIT(30)
29#define AHBSPEED_SHIFT (15)
30#define AHBSPEED_MASK 0x07
31#define CPU_AHB_RATIO_SHIFT (18)
32#define CPU_AHB_RATIO_MASK 0x03
33
34#define GEMINI_GLOBAL_PLL_CONTROL 0x08
35
36#define GEMINI_GLOBAL_SOFT_RESET 0x0c
37
38#define GEMINI_GLOBAL_MISC_CONTROL 0x30
39#define PCI_CLK_66MHZ BIT(18)
40#define PCI_CLK_OE BIT(17)
41
42#define GEMINI_GLOBAL_CLOCK_CONTROL 0x34
43#define PCI_CLKRUN_EN BIT(16)
44#define TVC_HALFDIV_SHIFT (24)
45#define TVC_HALFDIV_MASK 0x1f
46#define SECURITY_CLK_SEL BIT(29)
47
48#define GEMINI_GLOBAL_PCI_DLL_CONTROL 0x44
49#define PCI_DLL_BYPASS BIT(31)
50#define PCI_DLL_TAP_SEL_MASK 0x1f
51
52/**
53 * struct gemini_data_data - Gemini gated clocks
54 * @bit_idx: the bit used to gate this clock in the clock register
55 * @name: the clock name
56 * @parent_name: the name of the parent clock
57 * @flags: standard clock framework flags
58 */
59struct gemini_gate_data {
60 u8 bit_idx;
61 const char *name;
62 const char *parent_name;
63 unsigned long flags;
64};
65
66/**
67 * struct clk_gemini_pci - Gemini PCI clock
68 * @hw: corresponding clock hardware entry
69 * @map: regmap to access the registers
70 * @rate: current rate
71 */
72struct clk_gemini_pci {
73 struct clk_hw hw;
74 struct regmap *map;
75 unsigned long rate;
76};
77
78/**
79 * struct gemini_reset - gemini reset controller
80 * @map: regmap to access the containing system controller
81 * @rcdev: reset controller device
82 */
83struct gemini_reset {
84 struct regmap *map;
85 struct reset_controller_dev rcdev;
86};
87
88/* Keeps track of all clocks */
89static struct clk_hw_onecell_data *gemini_clk_data;
90
91static const struct gemini_gate_data gemini_gates[] = {
92 { 1, "security-gate", "secdiv", 0 },
93 { 2, "gmac0-gate", "ahb", 0 },
94 { 3, "gmac1-gate", "ahb", 0 },
95 { 4, "sata0-gate", "ahb", 0 },
96 { 5, "sata1-gate", "ahb", 0 },
97 { 6, "usb0-gate", "ahb", 0 },
98 { 7, "usb1-gate", "ahb", 0 },
99 { 8, "ide-gate", "ahb", 0 },
100 { 9, "pci-gate", "ahb", 0 },
101 /*
102 * The DDR controller may never have a driver, but certainly must
103 * not be gated off.
104 */
105 { 10, "ddr-gate", "ahb", CLK_IS_CRITICAL },
106 /*
107 * The flash controller must be on to access NOR flash through the
108 * memory map.
109 */
110 { 11, "flash-gate", "ahb", CLK_IGNORE_UNUSED },
111 { 12, "tvc-gate", "ahb", 0 },
112 { 13, "boot-gate", "apb", 0 },
113};
114
115#define to_pciclk(_hw) container_of(_hw, struct clk_gemini_pci, hw)
116
117#define to_gemini_reset(p) container_of((p), struct gemini_reset, rcdev)
118
119static unsigned long gemini_pci_recalc_rate(struct clk_hw *hw,
120 unsigned long parent_rate)
121{
122 struct clk_gemini_pci *pciclk = to_pciclk(hw);
123 u32 val;
124
125 regmap_read(pciclk->map, GEMINI_GLOBAL_MISC_CONTROL, &val);
126 if (val & PCI_CLK_66MHZ)
127 return 66000000;
128 return 33000000;
129}
130
131static long gemini_pci_round_rate(struct clk_hw *hw, unsigned long rate,
132 unsigned long *prate)
133{
134 /* We support 33 and 66 MHz */
135 if (rate < 48000000)
136 return 33000000;
137 return 66000000;
138}
139
140static int gemini_pci_set_rate(struct clk_hw *hw, unsigned long rate,
141 unsigned long parent_rate)
142{
143 struct clk_gemini_pci *pciclk = to_pciclk(hw);
144
145 if (rate == 33000000)
146 return regmap_update_bits(pciclk->map,
147 GEMINI_GLOBAL_MISC_CONTROL,
148 PCI_CLK_66MHZ, 0);
149 if (rate == 66000000)
150 return regmap_update_bits(pciclk->map,
151 GEMINI_GLOBAL_MISC_CONTROL,
152 0, PCI_CLK_66MHZ);
153 return -EINVAL;
154}
155
156static int gemini_pci_enable(struct clk_hw *hw)
157{
158 struct clk_gemini_pci *pciclk = to_pciclk(hw);
159
160 regmap_update_bits(pciclk->map, GEMINI_GLOBAL_CLOCK_CONTROL,
161 0, PCI_CLKRUN_EN);
162 regmap_update_bits(pciclk->map,
163 GEMINI_GLOBAL_MISC_CONTROL,
164 0, PCI_CLK_OE);
165 return 0;
166}
167
168static void gemini_pci_disable(struct clk_hw *hw)
169{
170 struct clk_gemini_pci *pciclk = to_pciclk(hw);
171
172 regmap_update_bits(pciclk->map,
173 GEMINI_GLOBAL_MISC_CONTROL,
174 PCI_CLK_OE, 0);
175 regmap_update_bits(pciclk->map, GEMINI_GLOBAL_CLOCK_CONTROL,
176 PCI_CLKRUN_EN, 0);
177}
178
179static int gemini_pci_is_enabled(struct clk_hw *hw)
180{
181 struct clk_gemini_pci *pciclk = to_pciclk(hw);
182 unsigned int val;
183
184 regmap_read(pciclk->map, GEMINI_GLOBAL_CLOCK_CONTROL, &val);
185 return !!(val & PCI_CLKRUN_EN);
186}
187
188static const struct clk_ops gemini_pci_clk_ops = {
189 .recalc_rate = gemini_pci_recalc_rate,
190 .round_rate = gemini_pci_round_rate,
191 .set_rate = gemini_pci_set_rate,
192 .enable = gemini_pci_enable,
193 .disable = gemini_pci_disable,
194 .is_enabled = gemini_pci_is_enabled,
195};
196
197static struct clk_hw *gemini_pci_clk_setup(const char *name,
198 const char *parent_name,
199 struct regmap *map)
200{
201 struct clk_gemini_pci *pciclk;
202 struct clk_init_data init;
203 int ret;
204
205 pciclk = kzalloc(sizeof(*pciclk), GFP_KERNEL);
206 if (!pciclk)
207 return ERR_PTR(-ENOMEM);
208
209 init.name = name;
210 init.ops = &gemini_pci_clk_ops;
211 init.flags = 0;
212 init.parent_names = &parent_name;
213 init.num_parents = 1;
214 pciclk->map = map;
215 pciclk->hw.init = &init;
216
217 ret = clk_hw_register(NULL, &pciclk->hw);
218 if (ret) {
219 kfree(pciclk);
220 return ERR_PTR(ret);
221 }
222
223 return &pciclk->hw;
224}
225
226/*
227 * This is a self-deasserting reset controller.
228 */
229static int gemini_reset(struct reset_controller_dev *rcdev,
230 unsigned long id)
231{
232 struct gemini_reset *gr = to_gemini_reset(rcdev);
233
234 /* Manual says to always set BIT 30 (CPU1) to 1 */
235 return regmap_write(gr->map,
236 GEMINI_GLOBAL_SOFT_RESET,
237 BIT(GEMINI_RESET_CPU1) | BIT(id));
238}
239
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240static int gemini_reset_assert(struct reset_controller_dev *rcdev,
241 unsigned long id)
242{
243 return 0;
244}
245
246static int gemini_reset_deassert(struct reset_controller_dev *rcdev,
247 unsigned long id)
248{
249 return 0;
250}
251
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252static int gemini_reset_status(struct reset_controller_dev *rcdev,
253 unsigned long id)
254{
255 struct gemini_reset *gr = to_gemini_reset(rcdev);
256 u32 val;
257 int ret;
258
259 ret = regmap_read(gr->map, GEMINI_GLOBAL_SOFT_RESET, &val);
260 if (ret)
261 return ret;
262
263 return !!(val & BIT(id));
264}
265
266static const struct reset_control_ops gemini_reset_ops = {
267 .reset = gemini_reset,
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268 .assert = gemini_reset_assert,
269 .deassert = gemini_reset_deassert,
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270 .status = gemini_reset_status,
271};
272
273static int gemini_clk_probe(struct platform_device *pdev)
274{
275 /* Gives the fracions 1x, 1.5x, 1.85x and 2x */
276 unsigned int cpu_ahb_mult[4] = { 1, 3, 24, 2 };
277 unsigned int cpu_ahb_div[4] = { 1, 2, 13, 1 };
278 void __iomem *base;
279 struct gemini_reset *gr;
280 struct regmap *map;
281 struct clk_hw *hw;
282 struct device *dev = &pdev->dev;
283 struct device_node *np = dev->of_node;
284 unsigned int mult, div;
285 struct resource *res;
286 u32 val;
287 int ret;
288 int i;
289
290 gr = devm_kzalloc(dev, sizeof(*gr), GFP_KERNEL);
291 if (!gr)
292 return -ENOMEM;
293
294 /* Remap the system controller for the exclusive register */
295 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
296 base = devm_ioremap_resource(dev, res);
297 if (IS_ERR(base))
298 return PTR_ERR(base);
299
300 map = syscon_node_to_regmap(np);
301 if (IS_ERR(map)) {
302 dev_err(dev, "no syscon regmap\n");
303 return PTR_ERR(map);
304 }
305
306 gr->map = map;
307 gr->rcdev.owner = THIS_MODULE;
308 gr->rcdev.nr_resets = 32;
309 gr->rcdev.ops = &gemini_reset_ops;
310 gr->rcdev.of_node = np;
311
312 ret = devm_reset_controller_register(dev, &gr->rcdev);
313 if (ret) {
314 dev_err(dev, "could not register reset controller\n");
315 return ret;
316 }
317
318 /* RTC clock 32768 Hz */
319 hw = clk_hw_register_fixed_rate(NULL, "rtc", NULL, 0, 32768);
320 gemini_clk_data->hws[GEMINI_CLK_RTC] = hw;
321
322 /* CPU clock derived as a fixed ratio from the AHB clock */
785b6216 323 regmap_read(map, GEMINI_GLOBAL_STATUS, &val);
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324 val >>= CPU_AHB_RATIO_SHIFT;
325 val &= CPU_AHB_RATIO_MASK;
326 hw = clk_hw_register_fixed_factor(NULL, "cpu", "ahb", 0,
327 cpu_ahb_mult[val],
328 cpu_ahb_div[val]);
329 gemini_clk_data->hws[GEMINI_CLK_CPU] = hw;
330
331 /* Security clock is 1:1 or 0.75 of APB */
332 regmap_read(map, GEMINI_GLOBAL_CLOCK_CONTROL, &val);
333 if (val & SECURITY_CLK_SEL) {
334 mult = 1;
335 div = 1;
336 } else {
337 mult = 3;
338 div = 4;
339 }
340 hw = clk_hw_register_fixed_factor(NULL, "secdiv", "ahb", 0, mult, div);
341
342 /*
343 * These are the leaf gates, at boot no clocks are gated.
344 */
345 for (i = 0; i < ARRAY_SIZE(gemini_gates); i++) {
346 const struct gemini_gate_data *gd;
347
348 gd = &gemini_gates[i];
349 gemini_clk_data->hws[GEMINI_CLK_GATES + i] =
350 clk_hw_register_gate(NULL, gd->name,
351 gd->parent_name,
352 gd->flags,
353 base + GEMINI_GLOBAL_CLOCK_CONTROL,
354 gd->bit_idx,
355 CLK_GATE_SET_TO_DISABLE,
356 &gemini_clk_lock);
357 }
358
359 /*
360 * The TV Interface Controller has a 5-bit half divider register.
361 * This clock is supposed to be 27MHz as this is an exact multiple
362 * of PAL and NTSC frequencies. The register is undocumented :(
363 * FIXME: figure out the parent and how the divider works.
364 */
365 mult = 1;
366 div = ((val >> TVC_HALFDIV_SHIFT) & TVC_HALFDIV_MASK);
367 dev_dbg(dev, "TVC half divider value = %d\n", div);
368 div += 1;
369 hw = clk_hw_register_fixed_rate(NULL, "tvcdiv", "xtal", 0, 27000000);
370 gemini_clk_data->hws[GEMINI_CLK_TVC] = hw;
371
372 /* FIXME: very unclear what the parent is */
373 hw = gemini_pci_clk_setup("PCI", "xtal", map);
374 gemini_clk_data->hws[GEMINI_CLK_PCI] = hw;
375
376 /* FIXME: very unclear what the parent is */
377 hw = clk_hw_register_fixed_rate(NULL, "uart", "xtal", 0, 48000000);
378 gemini_clk_data->hws[GEMINI_CLK_UART] = hw;
379
380 return 0;
381}
382
383static const struct of_device_id gemini_clk_dt_ids[] = {
384 { .compatible = "cortina,gemini-syscon", },
385 { /* sentinel */ },
386};
387
388static struct platform_driver gemini_clk_driver = {
389 .probe = gemini_clk_probe,
390 .driver = {
391 .name = "gemini-clk",
392 .of_match_table = gemini_clk_dt_ids,
393 .suppress_bind_attrs = true,
394 },
395};
396builtin_platform_driver(gemini_clk_driver);
397
398static void __init gemini_cc_init(struct device_node *np)
399{
400 struct regmap *map;
401 struct clk_hw *hw;
402 unsigned long freq;
403 unsigned int mult, div;
404 u32 val;
405 int ret;
406 int i;
407
408 gemini_clk_data = kzalloc(sizeof(*gemini_clk_data) +
409 sizeof(*gemini_clk_data->hws) * GEMINI_NUM_CLKS,
410 GFP_KERNEL);
411 if (!gemini_clk_data)
412 return;
413
414 /*
415 * This way all clock fetched before the platform device probes,
416 * except those we assign here for early use, will be deferred.
417 */
418 for (i = 0; i < GEMINI_NUM_CLKS; i++)
419 gemini_clk_data->hws[i] = ERR_PTR(-EPROBE_DEFER);
420
421 map = syscon_node_to_regmap(np);
422 if (IS_ERR(map)) {
423 pr_err("no syscon regmap\n");
424 return;
425 }
426 /*
427 * We check that the regmap works on this very first access,
428 * but as this is an MMIO-backed regmap, subsequent regmap
429 * access is not going to fail and we skip error checks from
430 * this point.
431 */
432 ret = regmap_read(map, GEMINI_GLOBAL_STATUS, &val);
433 if (ret) {
434 pr_err("failed to read global status register\n");
435 return;
436 }
437
438 /*
439 * XTAL is the crystal oscillator, 60 or 30 MHz selected from
440 * strap pin E6
441 */
442 if (val & PLL_OSC_SEL)
443 freq = 30000000;
444 else
445 freq = 60000000;
446 hw = clk_hw_register_fixed_rate(NULL, "xtal", NULL, 0, freq);
447 pr_debug("main crystal @%lu MHz\n", freq / 1000000);
448
449 /* VCO clock derived from the crystal */
450 mult = 13 + ((val >> AHBSPEED_SHIFT) & AHBSPEED_MASK);
451 div = 2;
452 /* If we run on 30 MHz crystal we have to multiply with two */
453 if (val & PLL_OSC_SEL)
454 mult *= 2;
455 hw = clk_hw_register_fixed_factor(NULL, "vco", "xtal", 0, mult, div);
456
457 /* The AHB clock is always 1/3 of the VCO */
458 hw = clk_hw_register_fixed_factor(NULL, "ahb", "vco", 0, 1, 3);
459 gemini_clk_data->hws[GEMINI_CLK_AHB] = hw;
460
461 /* The APB clock is always 1/6 of the AHB */
462 hw = clk_hw_register_fixed_factor(NULL, "apb", "ahb", 0, 1, 6);
463 gemini_clk_data->hws[GEMINI_CLK_APB] = hw;
464
465 /* Register the clocks to be accessed by the device tree */
466 gemini_clk_data->num = GEMINI_NUM_CLKS;
467 of_clk_add_hw_provider(np, of_clk_hw_onecell_get, gemini_clk_data);
468}
469CLK_OF_DECLARE_DRIVER(gemini_cc, "cortina,gemini-syscon", gemini_cc_init);