1 // SPDX-License-Identifier: GPL-2.0
3 * (C) Copyright 2016 Google, Inc
7 #include <clk-uclass.h>
10 #include <asm/arch/scu_ast2500.h>
12 #include <dt-bindings/clock/ast2500-scu.h>
15 * MAC Clock Delay settings, taken from Aspeed SDK
17 #define RGMII_TXCLK_ODLY 8
18 #define RMII_RXCLK_IDLY 2
21 * TGMII Clock Duty constants, taken from Aspeed SDK
23 #define RGMII2_TXCK_DUTY 0x66
24 #define RGMII1_TXCK_DUTY 0x64
26 #define D2PLL_DEFAULT_RATE (250 * 1000 * 1000)
28 DECLARE_GLOBAL_DATA_PTR;
31 * Clock divider/multiplier configuration struct.
32 * For H-PLL and M-PLL the formula is
33 * (Output Frequency) = CLKIN * ((M + 1) / (N + 1)) / (P + 1)
37 * They have the same layout in their control register.
39 * D-PLL and D2-PLL have extra divider (OD + 1), which is not
40 * yet needed and ignored by clock configurations.
42 struct ast2500_div_config {
45 unsigned int post_div;
49 * Get the rate of the M-PLL clock from input clock frequency and
50 * the value of the M-PLL Parameter Register.
52 static ulong ast2500_get_mpll_rate(ulong clkin, u32 mpll_reg)
54 const ulong num = (mpll_reg & SCU_MPLL_NUM_MASK) >> SCU_MPLL_NUM_SHIFT;
55 const ulong denum = (mpll_reg & SCU_MPLL_DENUM_MASK)
56 >> SCU_MPLL_DENUM_SHIFT;
57 const ulong post_div = (mpll_reg & SCU_MPLL_POST_MASK)
58 >> SCU_MPLL_POST_SHIFT;
60 return (clkin * ((num + 1) / (denum + 1))) / (post_div + 1);
64 * Get the rate of the H-PLL clock from input clock frequency and
65 * the value of the H-PLL Parameter Register.
67 static ulong ast2500_get_hpll_rate(ulong clkin, u32 hpll_reg)
69 const ulong num = (hpll_reg & SCU_HPLL_NUM_MASK) >> SCU_HPLL_NUM_SHIFT;
70 const ulong denum = (hpll_reg & SCU_HPLL_DENUM_MASK)
71 >> SCU_HPLL_DENUM_SHIFT;
72 const ulong post_div = (hpll_reg & SCU_HPLL_POST_MASK)
73 >> SCU_HPLL_POST_SHIFT;
75 return (clkin * ((num + 1) / (denum + 1))) / (post_div + 1);
78 static ulong ast2500_get_clkin(struct ast2500_scu *scu)
80 return readl(&scu->hwstrap) & SCU_HWSTRAP_CLKIN_25MHZ
81 ? 25 * 1000 * 1000 : 24 * 1000 * 1000;
85 * Get current rate or uart clock
88 * @uart_index UART index, 1-5
90 * @return current setting for uart clock rate
92 static ulong ast2500_get_uart_clk_rate(struct ast2500_scu *scu, int uart_index)
95 * ast2500 datasheet is very confusing when it comes to UART clocks,
96 * especially when CLKIN = 25 MHz. The settings are in
97 * different registers and it is unclear how they interact.
99 * This has only been tested with default settings and CLKIN = 24 MHz.
103 if (readl(&scu->misc_ctrl2) &
104 (1 << (uart_index - 1 + SCU_MISC2_UARTCLK_SHIFT)))
105 uart_clkin = 192 * 1000 * 1000;
107 uart_clkin = 24 * 1000 * 1000;
109 if (readl(&scu->misc_ctrl1) & SCU_MISC_UARTCLK_DIV13)
115 static ulong ast2500_clk_get_rate(struct clk *clk)
117 struct ast2500_clk_priv *priv = dev_get_priv(clk->dev);
118 ulong clkin = ast2500_get_clkin(priv->scu);
125 * This ignores dynamic/static slowdown of ARMCLK and may
128 rate = ast2500_get_hpll_rate(clkin,
129 readl(&priv->scu->h_pll_param));
132 rate = ast2500_get_mpll_rate(clkin,
133 readl(&priv->scu->m_pll_param));
137 ulong apb_div = 4 + 4 * ((readl(&priv->scu->clk_sel1)
139 >> SCU_PCLK_DIV_SHIFT);
140 rate = ast2500_get_hpll_rate(clkin,
143 rate = rate / apb_div;
147 rate = ast2500_get_uart_clk_rate(priv->scu, 1);
150 rate = ast2500_get_uart_clk_rate(priv->scu, 2);
153 rate = ast2500_get_uart_clk_rate(priv->scu, 3);
156 rate = ast2500_get_uart_clk_rate(priv->scu, 4);
159 rate = ast2500_get_uart_clk_rate(priv->scu, 5);
169 * @input_rate - the rate of input clock in Hz
170 * @requested_rate - desired output rate in Hz
171 * @div - this is an IN/OUT parameter, at input all fields of the config
172 * need to be set to their maximum allowed values.
173 * The result (the best config we could find), would also be returned
176 * @return The clock rate, when the resulting div_config is used.
178 static ulong ast2500_calc_clock_config(ulong input_rate, ulong requested_rate,
179 struct ast2500_div_config *cfg)
182 * The assumption is that kHz precision is good enough and
183 * also enough to avoid overflow when multiplying.
185 const ulong input_rate_khz = input_rate / 1000;
186 const ulong rate_khz = requested_rate / 1000;
187 const struct ast2500_div_config max_vals = *cfg;
188 struct ast2500_div_config it = { 0, 0, 0 };
189 ulong delta = rate_khz;
190 ulong new_rate_khz = 0;
192 for (; it.denum <= max_vals.denum; ++it.denum) {
193 for (it.post_div = 0; it.post_div <= max_vals.post_div;
195 it.num = (rate_khz * (it.post_div + 1) / input_rate_khz)
197 if (it.num > max_vals.num)
200 new_rate_khz = (input_rate_khz
201 * ((it.num + 1) / (it.denum + 1)))
204 /* Keep the rate below requested one. */
205 if (new_rate_khz > rate_khz)
208 if (new_rate_khz - rate_khz < delta) {
209 delta = new_rate_khz - rate_khz;
212 return new_rate_khz * 1000;
217 return new_rate_khz * 1000;
220 static ulong ast2500_configure_ddr(struct ast2500_scu *scu, ulong rate)
222 ulong clkin = ast2500_get_clkin(scu);
224 struct ast2500_div_config div_cfg = {
225 .num = (SCU_MPLL_NUM_MASK >> SCU_MPLL_NUM_SHIFT),
226 .denum = (SCU_MPLL_DENUM_MASK >> SCU_MPLL_DENUM_SHIFT),
227 .post_div = (SCU_MPLL_POST_MASK >> SCU_MPLL_POST_SHIFT),
230 ast2500_calc_clock_config(clkin, rate, &div_cfg);
232 mpll_reg = readl(&scu->m_pll_param);
233 mpll_reg &= ~(SCU_MPLL_POST_MASK | SCU_MPLL_NUM_MASK
234 | SCU_MPLL_DENUM_MASK);
235 mpll_reg |= (div_cfg.post_div << SCU_MPLL_POST_SHIFT)
236 | (div_cfg.num << SCU_MPLL_NUM_SHIFT)
237 | (div_cfg.denum << SCU_MPLL_DENUM_SHIFT);
240 writel(mpll_reg, &scu->m_pll_param);
243 return ast2500_get_mpll_rate(clkin, mpll_reg);
246 static ulong ast2500_configure_mac(struct ast2500_scu *scu, int index)
248 ulong clkin = ast2500_get_clkin(scu);
249 ulong hpll_rate = ast2500_get_hpll_rate(clkin,
250 readl(&scu->h_pll_param));
258 * According to data sheet, for 10/100 mode the MAC clock frequency
259 * should be at least 25MHz and for 1000 mode at least 100MHz
261 hwstrap = readl(&scu->hwstrap);
262 if (hwstrap & (SCU_HWSTRAP_MAC1_RGMII | SCU_HWSTRAP_MAC2_RGMII))
263 required_rate = 100 * 1000 * 1000;
265 required_rate = 25 * 1000 * 1000;
267 divisor = hpll_rate / required_rate;
270 /* Clock can't run fast enough, but let's try anyway */
271 debug("MAC clock too slow\n");
273 } else if (divisor > 16) {
274 /* Can't slow down the clock enough, but let's try anyway */
275 debug("MAC clock too fast\n");
281 reset_bit = SCU_SYSRESET_MAC1;
282 clkstop_bit = SCU_CLKSTOP_MAC1;
285 reset_bit = SCU_SYSRESET_MAC2;
286 clkstop_bit = SCU_CLKSTOP_MAC2;
293 clrsetbits_le32(&scu->clk_sel1, SCU_MACCLK_MASK,
294 ((divisor - 2) / 2) << SCU_MACCLK_SHIFT);
297 * Disable MAC, start its clock and re-enable it.
298 * The procedure and the delays (100us & 10ms) are
299 * specified in the datasheet.
301 setbits_le32(&scu->sysreset_ctrl1, reset_bit);
303 clrbits_le32(&scu->clk_stop_ctrl1, clkstop_bit);
305 clrbits_le32(&scu->sysreset_ctrl1, reset_bit);
307 writel((RGMII2_TXCK_DUTY << SCU_CLKDUTY_RGMII2TXCK_SHIFT)
308 | (RGMII1_TXCK_DUTY << SCU_CLKDUTY_RGMII1TXCK_SHIFT),
313 return required_rate;
316 static ulong ast2500_configure_d2pll(struct ast2500_scu *scu, ulong rate)
319 * The values and the meaning of the next three
320 * parameters are undocumented. Taken from Aspeed SDK.
322 const u32 d2_pll_ext_param = 0x2c;
323 const u32 d2_pll_sip = 0x11;
324 const u32 d2_pll_sic = 0x18;
325 u32 clk_delay_settings =
326 (RMII_RXCLK_IDLY << SCU_MICDS_MAC1RMII_RDLY_SHIFT)
327 | (RMII_RXCLK_IDLY << SCU_MICDS_MAC2RMII_RDLY_SHIFT)
328 | (RGMII_TXCLK_ODLY << SCU_MICDS_MAC1RGMII_TXDLY_SHIFT)
329 | (RGMII_TXCLK_ODLY << SCU_MICDS_MAC2RGMII_TXDLY_SHIFT);
330 struct ast2500_div_config div_cfg = {
331 .num = SCU_D2PLL_NUM_MASK >> SCU_D2PLL_NUM_SHIFT,
332 .denum = SCU_D2PLL_DENUM_MASK >> SCU_D2PLL_DENUM_SHIFT,
333 .post_div = SCU_D2PLL_POST_MASK >> SCU_D2PLL_POST_SHIFT,
335 ulong clkin = ast2500_get_clkin(scu);
339 writel((d2_pll_ext_param << SCU_D2PLL_EXT1_PARAM_SHIFT)
341 | SCU_D2PLL_EXT1_RESET, &scu->d2_pll_ext_param[0]);
344 * Select USB2.0 port1 PHY clock as a clock source for GCRT.
345 * This would disconnect it from D2-PLL.
347 clrsetbits_le32(&scu->misc_ctrl1, SCU_MISC_D2PLL_OFF,
348 SCU_MISC_GCRT_USB20CLK);
350 new_rate = ast2500_calc_clock_config(clkin, rate, &div_cfg);
351 writel((d2_pll_sip << SCU_D2PLL_SIP_SHIFT)
352 | (d2_pll_sic << SCU_D2PLL_SIC_SHIFT)
353 | (div_cfg.num << SCU_D2PLL_NUM_SHIFT)
354 | (div_cfg.denum << SCU_D2PLL_DENUM_SHIFT)
355 | (div_cfg.post_div << SCU_D2PLL_POST_SHIFT),
358 clrbits_le32(&scu->d2_pll_ext_param[0],
359 SCU_D2PLL_EXT1_OFF | SCU_D2PLL_EXT1_RESET);
361 clrsetbits_le32(&scu->misc_ctrl2,
362 SCU_MISC2_RGMII_HPLL | SCU_MISC2_RMII_MPLL
363 | SCU_MISC2_RGMII_CLKDIV_MASK |
364 SCU_MISC2_RMII_CLKDIV_MASK,
365 (4 << SCU_MISC2_RMII_CLKDIV_SHIFT));
367 writel(clk_delay_settings | SCU_MICDS_RGMIIPLL, &scu->mac_clk_delay);
368 writel(clk_delay_settings, &scu->mac_clk_delay_100M);
369 writel(clk_delay_settings, &scu->mac_clk_delay_10M);
376 static ulong ast2500_clk_set_rate(struct clk *clk, ulong rate)
378 struct ast2500_clk_priv *priv = dev_get_priv(clk->dev);
384 new_rate = ast2500_configure_ddr(priv->scu, rate);
387 new_rate = ast2500_configure_d2pll(priv->scu, rate);
396 static int ast2500_clk_enable(struct clk *clk)
398 struct ast2500_clk_priv *priv = dev_get_priv(clk->dev);
402 * For MAC clocks the clock rate is
403 * configured based on whether RGMII or RMII mode has been selected
404 * through hardware strapping.
407 ast2500_configure_mac(priv->scu, 1);
410 ast2500_configure_mac(priv->scu, 2);
413 ast2500_configure_d2pll(priv->scu, D2PLL_DEFAULT_RATE);
421 struct clk_ops ast2500_clk_ops = {
422 .get_rate = ast2500_clk_get_rate,
423 .set_rate = ast2500_clk_set_rate,
424 .enable = ast2500_clk_enable,
427 static int ast2500_clk_probe(struct udevice *dev)
429 struct ast2500_clk_priv *priv = dev_get_priv(dev);
431 priv->scu = devfdt_get_addr_ptr(dev);
432 if (IS_ERR(priv->scu))
433 return PTR_ERR(priv->scu);
438 static int ast2500_clk_bind(struct udevice *dev)
442 /* The reset driver does not have a device node, so bind it here */
443 ret = device_bind_driver(gd->dm_root, "ast_sysreset", "reset", &dev);
445 debug("Warning: No reset driver: ret=%d\n", ret);
450 static const struct udevice_id ast2500_clk_ids[] = {
451 { .compatible = "aspeed,ast2500-scu" },
455 U_BOOT_DRIVER(aspeed_ast2500_scu) = {
456 .name = "aspeed_ast2500_scu",
458 .of_match = ast2500_clk_ids,
459 .priv_auto_alloc_size = sizeof(struct ast2500_clk_priv),
460 .ops = &ast2500_clk_ops,
461 .bind = ast2500_clk_bind,
462 .probe = ast2500_clk_probe,