1 // SPDX-License-Identifier: GPL-2.0
3 * (C) Copyright 2016 Google, Inc
7 #include <clk-uclass.h>
11 #include <asm/arch/scu_ast2500.h>
13 #include <dt-bindings/clock/ast2500-scu.h>
14 #include <linux/err.h>
17 * MAC Clock Delay settings, taken from Aspeed SDK
19 #define RGMII_TXCLK_ODLY 8
20 #define RMII_RXCLK_IDLY 2
23 * TGMII Clock Duty constants, taken from Aspeed SDK
25 #define RGMII2_TXCK_DUTY 0x66
26 #define RGMII1_TXCK_DUTY 0x64
28 #define D2PLL_DEFAULT_RATE (250 * 1000 * 1000)
30 DECLARE_GLOBAL_DATA_PTR;
33 * Clock divider/multiplier configuration struct.
34 * For H-PLL and M-PLL the formula is
35 * (Output Frequency) = CLKIN * ((M + 1) / (N + 1)) / (P + 1)
39 * They have the same layout in their control register.
41 * D-PLL and D2-PLL have extra divider (OD + 1), which is not
42 * yet needed and ignored by clock configurations.
44 struct ast2500_div_config {
47 unsigned int post_div;
51 * Get the rate of the M-PLL clock from input clock frequency and
52 * the value of the M-PLL Parameter Register.
54 static ulong ast2500_get_mpll_rate(ulong clkin, u32 mpll_reg)
56 const ulong num = (mpll_reg & SCU_MPLL_NUM_MASK) >> SCU_MPLL_NUM_SHIFT;
57 const ulong denum = (mpll_reg & SCU_MPLL_DENUM_MASK)
58 >> SCU_MPLL_DENUM_SHIFT;
59 const ulong post_div = (mpll_reg & SCU_MPLL_POST_MASK)
60 >> SCU_MPLL_POST_SHIFT;
62 return (clkin * ((num + 1) / (denum + 1))) / (post_div + 1);
66 * Get the rate of the H-PLL clock from input clock frequency and
67 * the value of the H-PLL Parameter Register.
69 static ulong ast2500_get_hpll_rate(ulong clkin, u32 hpll_reg)
71 const ulong num = (hpll_reg & SCU_HPLL_NUM_MASK) >> SCU_HPLL_NUM_SHIFT;
72 const ulong denum = (hpll_reg & SCU_HPLL_DENUM_MASK)
73 >> SCU_HPLL_DENUM_SHIFT;
74 const ulong post_div = (hpll_reg & SCU_HPLL_POST_MASK)
75 >> SCU_HPLL_POST_SHIFT;
77 return (clkin * ((num + 1) / (denum + 1))) / (post_div + 1);
80 static ulong ast2500_get_clkin(struct ast2500_scu *scu)
82 return readl(&scu->hwstrap) & SCU_HWSTRAP_CLKIN_25MHZ
83 ? 25 * 1000 * 1000 : 24 * 1000 * 1000;
87 * Get current rate or uart clock
90 * @uart_index UART index, 1-5
92 * @return current setting for uart clock rate
94 static ulong ast2500_get_uart_clk_rate(struct ast2500_scu *scu, int uart_index)
97 * ast2500 datasheet is very confusing when it comes to UART clocks,
98 * especially when CLKIN = 25 MHz. The settings are in
99 * different registers and it is unclear how they interact.
101 * This has only been tested with default settings and CLKIN = 24 MHz.
105 if (readl(&scu->misc_ctrl2) &
106 (1 << (uart_index - 1 + SCU_MISC2_UARTCLK_SHIFT)))
107 uart_clkin = 192 * 1000 * 1000;
109 uart_clkin = 24 * 1000 * 1000;
111 if (readl(&scu->misc_ctrl1) & SCU_MISC_UARTCLK_DIV13)
117 static ulong ast2500_clk_get_rate(struct clk *clk)
119 struct ast2500_clk_priv *priv = dev_get_priv(clk->dev);
120 ulong clkin = ast2500_get_clkin(priv->scu);
127 * This ignores dynamic/static slowdown of ARMCLK and may
130 rate = ast2500_get_hpll_rate(clkin,
131 readl(&priv->scu->h_pll_param));
134 rate = ast2500_get_mpll_rate(clkin,
135 readl(&priv->scu->m_pll_param));
139 ulong apb_div = 4 + 4 * ((readl(&priv->scu->clk_sel1)
141 >> SCU_PCLK_DIV_SHIFT);
142 rate = ast2500_get_hpll_rate(clkin,
145 rate = rate / apb_div;
150 ulong apb_div = 4 + 4 * ((readl(&priv->scu->clk_sel1)
151 & SCU_SDCLK_DIV_MASK)
152 >> SCU_SDCLK_DIV_SHIFT);
153 rate = ast2500_get_hpll_rate(clkin,
156 rate = rate / apb_div;
160 rate = ast2500_get_uart_clk_rate(priv->scu, 1);
163 rate = ast2500_get_uart_clk_rate(priv->scu, 2);
166 rate = ast2500_get_uart_clk_rate(priv->scu, 3);
169 rate = ast2500_get_uart_clk_rate(priv->scu, 4);
172 rate = ast2500_get_uart_clk_rate(priv->scu, 5);
181 struct ast2500_clock_config {
184 struct ast2500_div_config cfg;
187 static const struct ast2500_clock_config ast2500_clock_config_defaults[] = {
188 { 24000000, 250000000, { .num = 124, .denum = 1, .post_div = 5 } },
191 static bool ast2500_get_clock_config_default(ulong input_rate,
192 ulong requested_rate,
193 struct ast2500_div_config *cfg)
197 for (i = 0; i < ARRAY_SIZE(ast2500_clock_config_defaults); i++) {
198 const struct ast2500_clock_config *default_cfg =
199 &ast2500_clock_config_defaults[i];
200 if (default_cfg->input_rate == input_rate &&
201 default_cfg->rate == requested_rate) {
202 *cfg = default_cfg->cfg;
211 * @input_rate - the rate of input clock in Hz
212 * @requested_rate - desired output rate in Hz
213 * @div - this is an IN/OUT parameter, at input all fields of the config
214 * need to be set to their maximum allowed values.
215 * The result (the best config we could find), would also be returned
218 * @return The clock rate, when the resulting div_config is used.
220 static ulong ast2500_calc_clock_config(ulong input_rate, ulong requested_rate,
221 struct ast2500_div_config *cfg)
224 * The assumption is that kHz precision is good enough and
225 * also enough to avoid overflow when multiplying.
227 const ulong input_rate_khz = input_rate / 1000;
228 const ulong rate_khz = requested_rate / 1000;
229 const struct ast2500_div_config max_vals = *cfg;
230 struct ast2500_div_config it = { 0, 0, 0 };
231 ulong delta = rate_khz;
232 ulong new_rate_khz = 0;
235 * Look for a well known frequency first.
237 if (ast2500_get_clock_config_default(input_rate, requested_rate, cfg))
238 return requested_rate;
240 for (; it.denum <= max_vals.denum; ++it.denum) {
241 for (it.post_div = 0; it.post_div <= max_vals.post_div;
243 it.num = (rate_khz * (it.post_div + 1) / input_rate_khz)
245 if (it.num > max_vals.num)
248 new_rate_khz = (input_rate_khz
249 * ((it.num + 1) / (it.denum + 1)))
252 /* Keep the rate below requested one. */
253 if (new_rate_khz > rate_khz)
256 if (new_rate_khz - rate_khz < delta) {
257 delta = new_rate_khz - rate_khz;
260 return new_rate_khz * 1000;
265 return new_rate_khz * 1000;
268 static ulong ast2500_configure_ddr(struct ast2500_scu *scu, ulong rate)
270 ulong clkin = ast2500_get_clkin(scu);
272 struct ast2500_div_config div_cfg = {
273 .num = (SCU_MPLL_NUM_MASK >> SCU_MPLL_NUM_SHIFT),
274 .denum = (SCU_MPLL_DENUM_MASK >> SCU_MPLL_DENUM_SHIFT),
275 .post_div = (SCU_MPLL_POST_MASK >> SCU_MPLL_POST_SHIFT),
278 ast2500_calc_clock_config(clkin, rate, &div_cfg);
280 mpll_reg = readl(&scu->m_pll_param);
281 mpll_reg &= ~(SCU_MPLL_POST_MASK | SCU_MPLL_NUM_MASK
282 | SCU_MPLL_DENUM_MASK);
283 mpll_reg |= (div_cfg.post_div << SCU_MPLL_POST_SHIFT)
284 | (div_cfg.num << SCU_MPLL_NUM_SHIFT)
285 | (div_cfg.denum << SCU_MPLL_DENUM_SHIFT);
288 writel(mpll_reg, &scu->m_pll_param);
291 return ast2500_get_mpll_rate(clkin, mpll_reg);
294 static ulong ast2500_configure_mac(struct ast2500_scu *scu, int index)
296 ulong clkin = ast2500_get_clkin(scu);
297 ulong hpll_rate = ast2500_get_hpll_rate(clkin,
298 readl(&scu->h_pll_param));
306 * According to data sheet, for 10/100 mode the MAC clock frequency
307 * should be at least 25MHz and for 1000 mode at least 100MHz
309 hwstrap = readl(&scu->hwstrap);
310 if (hwstrap & (SCU_HWSTRAP_MAC1_RGMII | SCU_HWSTRAP_MAC2_RGMII))
311 required_rate = 100 * 1000 * 1000;
313 required_rate = 25 * 1000 * 1000;
315 divisor = hpll_rate / required_rate;
318 /* Clock can't run fast enough, but let's try anyway */
319 debug("MAC clock too slow\n");
321 } else if (divisor > 16) {
322 /* Can't slow down the clock enough, but let's try anyway */
323 debug("MAC clock too fast\n");
329 reset_bit = SCU_SYSRESET_MAC1;
330 clkstop_bit = SCU_CLKSTOP_MAC1;
333 reset_bit = SCU_SYSRESET_MAC2;
334 clkstop_bit = SCU_CLKSTOP_MAC2;
341 clrsetbits_le32(&scu->clk_sel1, SCU_MACCLK_MASK,
342 ((divisor - 2) / 2) << SCU_MACCLK_SHIFT);
345 * Disable MAC, start its clock and re-enable it.
346 * The procedure and the delays (100us & 10ms) are
347 * specified in the datasheet.
349 setbits_le32(&scu->sysreset_ctrl1, reset_bit);
351 clrbits_le32(&scu->clk_stop_ctrl1, clkstop_bit);
353 clrbits_le32(&scu->sysreset_ctrl1, reset_bit);
355 writel((RGMII2_TXCK_DUTY << SCU_CLKDUTY_RGMII2TXCK_SHIFT)
356 | (RGMII1_TXCK_DUTY << SCU_CLKDUTY_RGMII1TXCK_SHIFT),
361 return required_rate;
364 static ulong ast2500_configure_d2pll(struct ast2500_scu *scu, ulong rate)
367 * The values and the meaning of the next three
368 * parameters are undocumented. Taken from Aspeed SDK.
370 * TODO(clg@kaod.org): the SIP and SIC values depend on the
373 const u32 d2_pll_ext_param = 0x2c;
374 const u32 d2_pll_sip = 0x11;
375 const u32 d2_pll_sic = 0x18;
376 u32 clk_delay_settings =
377 (RMII_RXCLK_IDLY << SCU_MICDS_MAC1RMII_RDLY_SHIFT)
378 | (RMII_RXCLK_IDLY << SCU_MICDS_MAC2RMII_RDLY_SHIFT)
379 | (RGMII_TXCLK_ODLY << SCU_MICDS_MAC1RGMII_TXDLY_SHIFT)
380 | (RGMII_TXCLK_ODLY << SCU_MICDS_MAC2RGMII_TXDLY_SHIFT);
381 struct ast2500_div_config div_cfg = {
382 .num = SCU_D2PLL_NUM_MASK >> SCU_D2PLL_NUM_SHIFT,
383 .denum = SCU_D2PLL_DENUM_MASK >> SCU_D2PLL_DENUM_SHIFT,
384 .post_div = SCU_D2PLL_POST_MASK >> SCU_D2PLL_POST_SHIFT,
386 ulong clkin = ast2500_get_clkin(scu);
390 writel((d2_pll_ext_param << SCU_D2PLL_EXT1_PARAM_SHIFT)
392 | SCU_D2PLL_EXT1_RESET, &scu->d2_pll_ext_param[0]);
395 * Select USB2.0 port1 PHY clock as a clock source for GCRT.
396 * This would disconnect it from D2-PLL.
398 clrsetbits_le32(&scu->misc_ctrl1, SCU_MISC_D2PLL_OFF,
399 SCU_MISC_GCRT_USB20CLK);
401 new_rate = ast2500_calc_clock_config(clkin, rate, &div_cfg);
402 writel((d2_pll_sip << SCU_D2PLL_SIP_SHIFT)
403 | (d2_pll_sic << SCU_D2PLL_SIC_SHIFT)
404 | (div_cfg.num << SCU_D2PLL_NUM_SHIFT)
405 | (div_cfg.denum << SCU_D2PLL_DENUM_SHIFT)
406 | (div_cfg.post_div << SCU_D2PLL_POST_SHIFT),
409 clrbits_le32(&scu->d2_pll_ext_param[0],
410 SCU_D2PLL_EXT1_OFF | SCU_D2PLL_EXT1_RESET);
412 clrsetbits_le32(&scu->misc_ctrl2,
413 SCU_MISC2_RGMII_HPLL | SCU_MISC2_RMII_MPLL
414 | SCU_MISC2_RGMII_CLKDIV_MASK |
415 SCU_MISC2_RMII_CLKDIV_MASK,
416 (4 << SCU_MISC2_RMII_CLKDIV_SHIFT));
418 writel(clk_delay_settings | SCU_MICDS_RGMIIPLL, &scu->mac_clk_delay);
419 writel(clk_delay_settings, &scu->mac_clk_delay_100M);
420 writel(clk_delay_settings, &scu->mac_clk_delay_10M);
427 static ulong ast2500_clk_set_rate(struct clk *clk, ulong rate)
429 struct ast2500_clk_priv *priv = dev_get_priv(clk->dev);
435 new_rate = ast2500_configure_ddr(priv->scu, rate);
438 new_rate = ast2500_configure_d2pll(priv->scu, rate);
447 static int ast2500_clk_enable(struct clk *clk)
449 struct ast2500_clk_priv *priv = dev_get_priv(clk->dev);
453 if (readl(&priv->scu->clk_stop_ctrl1) & SCU_CLKSTOP_SDCLK) {
454 ast_scu_unlock(priv->scu);
456 setbits_le32(&priv->scu->sysreset_ctrl1,
459 clrbits_le32(&priv->scu->clk_stop_ctrl1,
462 clrbits_le32(&priv->scu->sysreset_ctrl1,
465 ast_scu_lock(priv->scu);
469 * For MAC clocks the clock rate is
470 * configured based on whether RGMII or RMII mode has been selected
471 * through hardware strapping.
474 ast2500_configure_mac(priv->scu, 1);
477 ast2500_configure_mac(priv->scu, 2);
480 ast2500_configure_d2pll(priv->scu, D2PLL_DEFAULT_RATE);
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,
495 static int ast2500_clk_ofdata_to_platdata(struct udevice *dev)
497 struct ast2500_clk_priv *priv = dev_get_priv(dev);
499 priv->scu = devfdt_get_addr_ptr(dev);
500 if (IS_ERR(priv->scu))
501 return PTR_ERR(priv->scu);
506 static int ast2500_clk_bind(struct udevice *dev)
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);
513 debug("Warning: No reset driver: ret=%d\n", ret);
518 static const struct udevice_id ast2500_clk_ids[] = {
519 { .compatible = "aspeed,ast2500-scu" },
523 U_BOOT_DRIVER(aspeed_ast2500_scu) = {
524 .name = "aspeed_ast2500_scu",
526 .of_match = ast2500_clk_ids,
527 .priv_auto_alloc_size = sizeof(struct ast2500_clk_priv),
528 .ops = &ast2500_clk_ops,
529 .bind = ast2500_clk_bind,
530 .ofdata_to_platdata = ast2500_clk_ofdata_to_platdata,