1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * (C) Copyright 2016 Google, Inc
4 */
5
6 #include <common.h>
7 #include <clk-uclass.h>
8 #include <dm.h>
9 #include <log.h>
10 #include <asm/global_data.h>
11 #include <asm/io.h>
12 #include <asm/arch/scu_ast2500.h>
13 #include <dm/lists.h>
14 #include <dt-bindings/clock/aspeed-clock.h>
15 #include <linux/delay.h>
16 #include <linux/err.h>
17
18 /*
19 * MAC Clock Delay settings, taken from Aspeed SDK
20 */
21 #define RGMII_TXCLK_ODLY 8
22 #define RMII_RXCLK_IDLY 2
23
24 /*
25 * TGMII Clock Duty constants, taken from Aspeed SDK
26 */
27 #define RGMII2_TXCK_DUTY 0x66
28 #define RGMII1_TXCK_DUTY 0x64
29
30 #define D2PLL_DEFAULT_RATE (250 * 1000 * 1000)
31
32 DECLARE_GLOBAL_DATA_PTR;
33
34 /*
35 * Clock divider/multiplier configuration struct.
36 * For H-PLL and M-PLL the formula is
37 * (Output Frequency) = CLKIN * ((M + 1) / (N + 1)) / (P + 1)
38 * M - Numerator
39 * N - Denumerator
40 * P - Post Divider
41 * They have the same layout in their control register.
42 *
43 * D-PLL and D2-PLL have extra divider (OD + 1), which is not
44 * yet needed and ignored by clock configurations.
45 */
46 struct ast2500_div_config {
47 unsigned int num;
48 unsigned int denum;
49 unsigned int post_div;
50 };
51
52 /*
53 * Get the rate of the M-PLL clock from input clock frequency and
54 * the value of the M-PLL Parameter Register.
55 */
ast2500_get_mpll_rate(ulong clkin,u32 mpll_reg)56 static ulong ast2500_get_mpll_rate(ulong clkin, u32 mpll_reg)
57 {
58 const ulong num = (mpll_reg & SCU_MPLL_NUM_MASK) >> SCU_MPLL_NUM_SHIFT;
59 const ulong denum = (mpll_reg & SCU_MPLL_DENUM_MASK)
60 >> SCU_MPLL_DENUM_SHIFT;
61 const ulong post_div = (mpll_reg & SCU_MPLL_POST_MASK)
62 >> SCU_MPLL_POST_SHIFT;
63
64 return (clkin * ((num + 1) / (denum + 1))) / (post_div + 1);
65 }
66
67 /*
68 * Get the rate of the H-PLL clock from input clock frequency and
69 * the value of the H-PLL Parameter Register.
70 */
ast2500_get_hpll_rate(ulong clkin,u32 hpll_reg)71 static ulong ast2500_get_hpll_rate(ulong clkin, u32 hpll_reg)
72 {
73 const ulong num = (hpll_reg & SCU_HPLL_NUM_MASK) >> SCU_HPLL_NUM_SHIFT;
74 const ulong denum = (hpll_reg & SCU_HPLL_DENUM_MASK)
75 >> SCU_HPLL_DENUM_SHIFT;
76 const ulong post_div = (hpll_reg & SCU_HPLL_POST_MASK)
77 >> SCU_HPLL_POST_SHIFT;
78
79 return (clkin * ((num + 1) / (denum + 1))) / (post_div + 1);
80 }
81
ast2500_get_clkin(struct ast2500_scu * scu)82 static ulong ast2500_get_clkin(struct ast2500_scu *scu)
83 {
84 return readl(&scu->hwstrap) & SCU_HWSTRAP_CLKIN_25MHZ
85 ? 25 * 1000 * 1000 : 24 * 1000 * 1000;
86 }
87
88 /**
89 * Get current rate or uart clock
90 *
91 * @scu SCU registers
92 * @uart_index UART index, 1-5
93 *
94 * @return current setting for uart clock rate
95 */
ast2500_get_uart_clk_rate(struct ast2500_scu * scu,int uart_index)96 static ulong ast2500_get_uart_clk_rate(struct ast2500_scu *scu, int uart_index)
97 {
98 /*
99 * ast2500 datasheet is very confusing when it comes to UART clocks,
100 * especially when CLKIN = 25 MHz. The settings are in
101 * different registers and it is unclear how they interact.
102 *
103 * This has only been tested with default settings and CLKIN = 24 MHz.
104 */
105 ulong uart_clkin;
106
107 if (readl(&scu->misc_ctrl2) &
108 (1 << (uart_index - 1 + SCU_MISC2_UARTCLK_SHIFT)))
109 uart_clkin = 192 * 1000 * 1000;
110 else
111 uart_clkin = 24 * 1000 * 1000;
112
113 if (readl(&scu->misc_ctrl1) & SCU_MISC_UARTCLK_DIV13)
114 uart_clkin /= 13;
115
116 return uart_clkin;
117 }
118
ast2500_clk_get_rate(struct clk * clk)119 static ulong ast2500_clk_get_rate(struct clk *clk)
120 {
121 struct ast2500_clk_priv *priv = dev_get_priv(clk->dev);
122 ulong clkin = ast2500_get_clkin(priv->scu);
123 ulong rate;
124
125 switch (clk->id) {
126 case ASPEED_CLK_HPLL:
127 /*
128 * This ignores dynamic/static slowdown of ARMCLK and may
129 * be inaccurate.
130 */
131 rate = ast2500_get_hpll_rate(clkin,
132 readl(&priv->scu->h_pll_param));
133 break;
134 case ASPEED_CLK_MPLL:
135 rate = ast2500_get_mpll_rate(clkin,
136 readl(&priv->scu->m_pll_param));
137 break;
138 case ASPEED_CLK_APB:
139 {
140 ulong apb_div = 4 + 4 * ((readl(&priv->scu->clk_sel1)
141 & SCU_PCLK_DIV_MASK)
142 >> SCU_PCLK_DIV_SHIFT);
143 rate = ast2500_get_hpll_rate(clkin,
144 readl(&priv->
145 scu->h_pll_param));
146 rate = rate / apb_div;
147 }
148 break;
149 case ASPEED_CLK_SDIO:
150 {
151 ulong apb_div = 4 + 4 * ((readl(&priv->scu->clk_sel1)
152 & SCU_SDCLK_DIV_MASK)
153 >> SCU_SDCLK_DIV_SHIFT);
154 rate = ast2500_get_hpll_rate(clkin,
155 readl(&priv->
156 scu->h_pll_param));
157 rate = rate / apb_div;
158 }
159 break;
160 case ASPEED_CLK_GATE_UART1CLK:
161 rate = ast2500_get_uart_clk_rate(priv->scu, 1);
162 break;
163 case ASPEED_CLK_GATE_UART2CLK:
164 rate = ast2500_get_uart_clk_rate(priv->scu, 2);
165 break;
166 case ASPEED_CLK_GATE_UART3CLK:
167 rate = ast2500_get_uart_clk_rate(priv->scu, 3);
168 break;
169 case ASPEED_CLK_GATE_UART4CLK:
170 rate = ast2500_get_uart_clk_rate(priv->scu, 4);
171 break;
172 case ASPEED_CLK_GATE_UART5CLK:
173 rate = ast2500_get_uart_clk_rate(priv->scu, 5);
174 break;
175 default:
176 return -ENOENT;
177 }
178
179 return rate;
180 }
181
182 struct ast2500_clock_config {
183 ulong input_rate;
184 ulong rate;
185 struct ast2500_div_config cfg;
186 };
187
188 static const struct ast2500_clock_config ast2500_clock_config_defaults[] = {
189 { 24000000, 250000000, { .num = 124, .denum = 1, .post_div = 5 } },
190 };
191
ast2500_get_clock_config_default(ulong input_rate,ulong requested_rate,struct ast2500_div_config * cfg)192 static bool ast2500_get_clock_config_default(ulong input_rate,
193 ulong requested_rate,
194 struct ast2500_div_config *cfg)
195 {
196 int i;
197
198 for (i = 0; i < ARRAY_SIZE(ast2500_clock_config_defaults); i++) {
199 const struct ast2500_clock_config *default_cfg =
200 &ast2500_clock_config_defaults[i];
201 if (default_cfg->input_rate == input_rate &&
202 default_cfg->rate == requested_rate) {
203 *cfg = default_cfg->cfg;
204 return true;
205 }
206 }
207
208 return false;
209 }
210
211 /*
212 * @input_rate - the rate of input clock in Hz
213 * @requested_rate - desired output rate in Hz
214 * @div - this is an IN/OUT parameter, at input all fields of the config
215 * need to be set to their maximum allowed values.
216 * The result (the best config we could find), would also be returned
217 * in this structure.
218 *
219 * @return The clock rate, when the resulting div_config is used.
220 */
ast2500_calc_clock_config(ulong input_rate,ulong requested_rate,struct ast2500_div_config * cfg)221 static ulong ast2500_calc_clock_config(ulong input_rate, ulong requested_rate,
222 struct ast2500_div_config *cfg)
223 {
224 /*
225 * The assumption is that kHz precision is good enough and
226 * also enough to avoid overflow when multiplying.
227 */
228 const ulong input_rate_khz = input_rate / 1000;
229 const ulong rate_khz = requested_rate / 1000;
230 const struct ast2500_div_config max_vals = *cfg;
231 struct ast2500_div_config it = { 0, 0, 0 };
232 ulong delta = rate_khz;
233 ulong new_rate_khz = 0;
234
235 /*
236 * Look for a well known frequency first.
237 */
238 if (ast2500_get_clock_config_default(input_rate, requested_rate, cfg))
239 return requested_rate;
240
241 for (; it.denum <= max_vals.denum; ++it.denum) {
242 for (it.post_div = 0; it.post_div <= max_vals.post_div;
243 ++it.post_div) {
244 it.num = (rate_khz * (it.post_div + 1) / input_rate_khz)
245 * (it.denum + 1);
246 if (it.num > max_vals.num)
247 continue;
248
249 new_rate_khz = (input_rate_khz
250 * ((it.num + 1) / (it.denum + 1)))
251 / (it.post_div + 1);
252
253 /* Keep the rate below requested one. */
254 if (new_rate_khz > rate_khz)
255 continue;
256
257 if (new_rate_khz - rate_khz < delta) {
258 delta = new_rate_khz - rate_khz;
259 *cfg = it;
260 if (delta == 0)
261 return new_rate_khz * 1000;
262 }
263 }
264 }
265
266 return new_rate_khz * 1000;
267 }
268
ast2500_configure_ddr(struct ast2500_scu * scu,ulong rate)269 static ulong ast2500_configure_ddr(struct ast2500_scu *scu, ulong rate)
270 {
271 ulong clkin = ast2500_get_clkin(scu);
272 u32 mpll_reg;
273 struct ast2500_div_config div_cfg = {
274 .num = (SCU_MPLL_NUM_MASK >> SCU_MPLL_NUM_SHIFT),
275 .denum = (SCU_MPLL_DENUM_MASK >> SCU_MPLL_DENUM_SHIFT),
276 .post_div = (SCU_MPLL_POST_MASK >> SCU_MPLL_POST_SHIFT),
277 };
278
279 ast2500_calc_clock_config(clkin, rate, &div_cfg);
280
281 mpll_reg = readl(&scu->m_pll_param);
282 mpll_reg &= ~(SCU_MPLL_POST_MASK | SCU_MPLL_NUM_MASK
283 | SCU_MPLL_DENUM_MASK);
284 mpll_reg |= (div_cfg.post_div << SCU_MPLL_POST_SHIFT)
285 | (div_cfg.num << SCU_MPLL_NUM_SHIFT)
286 | (div_cfg.denum << SCU_MPLL_DENUM_SHIFT);
287
288 ast_scu_unlock(scu);
289 writel(mpll_reg, &scu->m_pll_param);
290 ast_scu_lock(scu);
291
292 return ast2500_get_mpll_rate(clkin, mpll_reg);
293 }
294
ast2500_configure_mac(struct ast2500_scu * scu,int index)295 static ulong ast2500_configure_mac(struct ast2500_scu *scu, int index)
296 {
297 ulong clkin = ast2500_get_clkin(scu);
298 ulong hpll_rate = ast2500_get_hpll_rate(clkin,
299 readl(&scu->h_pll_param));
300 ulong required_rate;
301 u32 hwstrap;
302 u32 divisor;
303 u32 reset_bit;
304 u32 clkstop_bit;
305
306 /*
307 * According to data sheet, for 10/100 mode the MAC clock frequency
308 * should be at least 25MHz and for 1000 mode at least 100MHz
309 */
310 hwstrap = readl(&scu->hwstrap);
311 if (hwstrap & (SCU_HWSTRAP_MAC1_RGMII | SCU_HWSTRAP_MAC2_RGMII))
312 required_rate = 100 * 1000 * 1000;
313 else
314 required_rate = 25 * 1000 * 1000;
315
316 divisor = hpll_rate / required_rate;
317
318 if (divisor < 4) {
319 /* Clock can't run fast enough, but let's try anyway */
320 debug("MAC clock too slow\n");
321 divisor = 4;
322 } else if (divisor > 16) {
323 /* Can't slow down the clock enough, but let's try anyway */
324 debug("MAC clock too fast\n");
325 divisor = 16;
326 }
327
328 switch (index) {
329 case 1:
330 reset_bit = SCU_SYSRESET_MAC1;
331 clkstop_bit = SCU_CLKSTOP_MAC1;
332 break;
333 case 2:
334 reset_bit = SCU_SYSRESET_MAC2;
335 clkstop_bit = SCU_CLKSTOP_MAC2;
336 break;
337 default:
338 return -EINVAL;
339 }
340
341 ast_scu_unlock(scu);
342 clrsetbits_le32(&scu->clk_sel1, SCU_MACCLK_MASK,
343 ((divisor - 2) / 2) << SCU_MACCLK_SHIFT);
344
345 /*
346 * Disable MAC, start its clock and re-enable it.
347 * The procedure and the delays (100us & 10ms) are
348 * specified in the datasheet.
349 */
350 setbits_le32(&scu->sysreset_ctrl1, reset_bit);
351 udelay(100);
352 clrbits_le32(&scu->clk_stop_ctrl1, clkstop_bit);
353 mdelay(10);
354 clrbits_le32(&scu->sysreset_ctrl1, reset_bit);
355
356 writel((RGMII2_TXCK_DUTY << SCU_CLKDUTY_RGMII2TXCK_SHIFT)
357 | (RGMII1_TXCK_DUTY << SCU_CLKDUTY_RGMII1TXCK_SHIFT),
358 &scu->clk_duty_sel);
359
360 ast_scu_lock(scu);
361
362 return required_rate;
363 }
364
ast2500_configure_d2pll(struct ast2500_scu * scu,ulong rate)365 static ulong ast2500_configure_d2pll(struct ast2500_scu *scu, ulong rate)
366 {
367 /*
368 * The values and the meaning of the next three
369 * parameters are undocumented. Taken from Aspeed SDK.
370 *
371 * TODO(clg@kaod.org): the SIP and SIC values depend on the
372 * Numerator value
373 */
374 const u32 d2_pll_ext_param = 0x2c;
375 const u32 d2_pll_sip = 0x11;
376 const u32 d2_pll_sic = 0x18;
377 u32 clk_delay_settings =
378 (RMII_RXCLK_IDLY << SCU_MICDS_MAC1RMII_RDLY_SHIFT)
379 | (RMII_RXCLK_IDLY << SCU_MICDS_MAC2RMII_RDLY_SHIFT)
380 | (RGMII_TXCLK_ODLY << SCU_MICDS_MAC1RGMII_TXDLY_SHIFT)
381 | (RGMII_TXCLK_ODLY << SCU_MICDS_MAC2RGMII_TXDLY_SHIFT);
382 struct ast2500_div_config div_cfg = {
383 .num = SCU_D2PLL_NUM_MASK >> SCU_D2PLL_NUM_SHIFT,
384 .denum = SCU_D2PLL_DENUM_MASK >> SCU_D2PLL_DENUM_SHIFT,
385 .post_div = SCU_D2PLL_POST_MASK >> SCU_D2PLL_POST_SHIFT,
386 };
387 ulong clkin = ast2500_get_clkin(scu);
388 ulong new_rate;
389
390 ast_scu_unlock(scu);
391 writel((d2_pll_ext_param << SCU_D2PLL_EXT1_PARAM_SHIFT)
392 | SCU_D2PLL_EXT1_OFF
393 | SCU_D2PLL_EXT1_RESET, &scu->d2_pll_ext_param[0]);
394
395 /*
396 * Select USB2.0 port1 PHY clock as a clock source for GCRT.
397 * This would disconnect it from D2-PLL.
398 */
399 clrsetbits_le32(&scu->misc_ctrl1, SCU_MISC_D2PLL_OFF,
400 SCU_MISC_GCRT_USB20CLK);
401
402 new_rate = ast2500_calc_clock_config(clkin, rate, &div_cfg);
403 writel((d2_pll_sip << SCU_D2PLL_SIP_SHIFT)
404 | (d2_pll_sic << SCU_D2PLL_SIC_SHIFT)
405 | (div_cfg.num << SCU_D2PLL_NUM_SHIFT)
406 | (div_cfg.denum << SCU_D2PLL_DENUM_SHIFT)
407 | (div_cfg.post_div << SCU_D2PLL_POST_SHIFT),
408 &scu->d2_pll_param);
409
410 clrbits_le32(&scu->d2_pll_ext_param[0],
411 SCU_D2PLL_EXT1_OFF | SCU_D2PLL_EXT1_RESET);
412
413 clrsetbits_le32(&scu->misc_ctrl2,
414 SCU_MISC2_RGMII_HPLL | SCU_MISC2_RMII_MPLL
415 | SCU_MISC2_RGMII_CLKDIV_MASK |
416 SCU_MISC2_RMII_CLKDIV_MASK,
417 (4 << SCU_MISC2_RMII_CLKDIV_SHIFT));
418
419 writel(clk_delay_settings | SCU_MICDS_RGMIIPLL, &scu->mac_clk_delay);
420 writel(clk_delay_settings, &scu->mac_clk_delay_100M);
421 writel(clk_delay_settings, &scu->mac_clk_delay_10M);
422
423 ast_scu_lock(scu);
424
425 return new_rate;
426 }
427
ast2500_clk_set_rate(struct clk * clk,ulong rate)428 static ulong ast2500_clk_set_rate(struct clk *clk, ulong rate)
429 {
430 struct ast2500_clk_priv *priv = dev_get_priv(clk->dev);
431
432 ulong new_rate;
433 switch (clk->id) {
434 case ASPEED_CLK_MPLL:
435 new_rate = ast2500_configure_ddr(priv->scu, rate);
436 break;
437 case ASPEED_CLK_D2PLL:
438 new_rate = ast2500_configure_d2pll(priv->scu, rate);
439 break;
440 default:
441 return -ENOENT;
442 }
443
444 return new_rate;
445 }
446
ast2500_clk_enable(struct clk * clk)447 static int ast2500_clk_enable(struct clk *clk)
448 {
449 struct ast2500_clk_priv *priv = dev_get_priv(clk->dev);
450
451 switch (clk->id) {
452 case ASPEED_CLK_SDIO:
453 if (readl(&priv->scu->clk_stop_ctrl1) & SCU_CLKSTOP_SDCLK) {
454 ast_scu_unlock(priv->scu);
455
456 setbits_le32(&priv->scu->sysreset_ctrl1,
457 SCU_SYSRESET_SDIO);
458 udelay(100);
459 clrbits_le32(&priv->scu->clk_stop_ctrl1,
460 SCU_CLKSTOP_SDCLK);
461 mdelay(10);
462 clrbits_le32(&priv->scu->sysreset_ctrl1,
463 SCU_SYSRESET_SDIO);
464
465 ast_scu_lock(priv->scu);
466 }
467 break;
468 /*
469 * For MAC clocks the clock rate is
470 * configured based on whether RGMII or RMII mode has been selected
471 * through hardware strapping.
472 */
473 case ASPEED_CLK_GATE_MAC1CLK:
474 ast2500_configure_mac(priv->scu, 1);
475 break;
476 case ASPEED_CLK_GATE_MAC2CLK:
477 ast2500_configure_mac(priv->scu, 2);
478 break;
479 case ASPEED_CLK_D2PLL:
480 ast2500_configure_d2pll(priv->scu, D2PLL_DEFAULT_RATE);
481 break;
482 default:
483 return -ENOENT;
484 }
485
486 return 0;
487 }
488
489 struct clk_ops ast2500_clk_ops = {
490 .get_rate = ast2500_clk_get_rate,
491 .set_rate = ast2500_clk_set_rate,
492 .enable = ast2500_clk_enable,
493 };
494
ast2500_clk_of_to_plat(struct udevice * dev)495 static int ast2500_clk_of_to_plat(struct udevice *dev)
496 {
497 struct ast2500_clk_priv *priv = dev_get_priv(dev);
498
499 priv->scu = devfdt_get_addr_ptr(dev);
500 if (IS_ERR(priv->scu))
501 return PTR_ERR(priv->scu);
502
503 return 0;
504 }
505
ast2500_clk_bind(struct udevice * dev)506 static int ast2500_clk_bind(struct udevice *dev)
507 {
508 int ret;
509
510 /* The reset driver does not have a device node, so bind it here */
511 ret = device_bind_driver(gd->dm_root, "ast_sysreset", "reset", &dev);
512 if (ret)
513 debug("Warning: No reset driver: ret=%d\n", ret);
514
515 return 0;
516 }
517
518 static const struct udevice_id ast2500_clk_ids[] = {
519 { .compatible = "aspeed,ast2500-scu" },
520 { }
521 };
522
523 U_BOOT_DRIVER(aspeed_ast2500_scu) = {
524 .name = "aspeed_ast2500_scu",
525 .id = UCLASS_CLK,
526 .of_match = ast2500_clk_ids,
527 .priv_auto = sizeof(struct ast2500_clk_priv),
528 .ops = &ast2500_clk_ops,
529 .bind = ast2500_clk_bind,
530 .of_to_plat = ast2500_clk_of_to_plat,
531 };
532