1 // SPDX-License-Identifier: GPL-2.0+
3 * Copyright 2010-2011 Freescale Semiconductor, Inc.
7 #include <clock_legacy.h>
11 #include "ics307_clk.h"
13 #if defined(CONFIG_FSL_NGPIXIS)
15 #define fpga_reg pixis
16 #elif defined(CONFIG_FSL_QIXIS)
18 #define fpga_reg ((struct qixis *)QIXIS_BASE)
21 #define fpga_reg pixis
24 /* define for SYS CLK or CLK1Frequency */
28 #define MAX_VDW (511 + 8)
29 #define MAX_RDW (127 + 2)
30 #define MIN_VDW (4 + 8)
31 #define MIN_RDW (1 + 2)
32 #define NUM_OD_SETTING 8
34 * These defines cover the industrial temperature range part,
35 * for commercial, change below to 400000 and 55000, respectively
37 #define MAX_VCO 360000
40 /* decode S[0-2] to Output Divider (OD) */
41 static u8 ics307_s_to_od[] = {
42 10, 2, 8, 4, 5, 7, 3, 6
46 * Find one solution to generate required frequency for SYSCLK
47 * out_freq: KHz, required frequency to the SYSCLK
48 * the result will be retuned with component RDW, VDW, OD, TTL,
51 unsigned long ics307_sysclk_calculator(unsigned long out_freq)
53 const unsigned long input_freq = CFG_ICS307_REFCLK_HZ;
54 unsigned long vdw, rdw, odp, s_vdw = 0, s_rdw = 0, s_odp = 0, od;
55 unsigned long tmp_out, diff, result = 0;
58 for (odp = 0; odp < NUM_OD_SETTING; odp++) {
59 od = ics307_s_to_od[odp];
60 if (od * out_freq < MIN_VCO || od * out_freq > MAX_VCO)
62 for (rdw = MIN_RDW; rdw <= MAX_RDW; rdw++) {
63 /* Calculate the VDW */
64 vdw = out_freq * 1000 * od * rdw / (input_freq * 2);
69 /* Calculate the temp out frequency */
70 tmp_out = input_freq * 2 * vdw / (rdw * od * 1000);
71 diff = max(out_freq, tmp_out) - min(out_freq, tmp_out);
73 * calculate the percent, the precision is 1/1000
74 * If greater than 1/1000, continue
75 * otherwise, we think the solution is we required
77 if (diff * 1000 / out_freq > 1)
90 result = (s_rdw - 2) | (s_vdw - 8) << 7 | s_odp << 16 |
91 CLK2 << 19 | TTL << 21 | CRYSTAL << 22;
93 debug("ICS307-02: RDW: %ld, VDW: %ld, OD: %d\n", s_rdw - 2, s_vdw - 8,
94 ics307_s_to_od[s_odp]);
99 * Calculate frequency being generated by ICS307-02 clock chip based upon
100 * the control bytes being programmed into it.
102 static unsigned long ics307_clk_freq(u8 cw0, u8 cw1, u8 cw2)
104 const unsigned long input_freq = CFG_ICS307_REFCLK_HZ;
105 unsigned long vdw = ((cw1 << 1) & 0x1FE) + ((cw2 >> 7) & 1);
106 unsigned long rdw = cw2 & 0x7F;
107 unsigned long od = ics307_s_to_od[cw0 & 0x7];
111 * CLK1 Freq = Input Frequency * 2 * (VDW + 8) / ((RDW + 2) * OD)
113 * cw0: C1 C0 TTL F1 F0 S2 S1 S0
114 * cw1: V8 V7 V6 V5 V4 V3 V2 V1
115 * cw2: V0 R6 R5 R4 R3 R2 R1 R0
117 * R6:R0 = Reference Divider Word (RDW)
118 * V8:V0 = VCO Divider Word (VDW)
119 * S2:S0 = Output Divider Select (OD)
120 * F1:F0 = Function of CLK2 Output
122 * C1:C0 = internal load capacitance for cyrstal
126 freq = input_freq * 2 * (vdw + 8) / ((rdw + 2) * od);
128 debug("ICS307: CW[0-2]: %02X %02X %02X => %lu Hz\n", cw0, cw1, cw2,
133 unsigned long get_board_sys_clk(void)
135 return ics307_clk_freq(
136 in_8(&fpga_reg->sclk[0]),
137 in_8(&fpga_reg->sclk[1]),
138 in_8(&fpga_reg->sclk[2]));
141 #ifdef CONFIG_DYNAMIC_DDR_CLK_FREQ
142 unsigned long get_board_ddr_clk(void)
144 return ics307_clk_freq(
145 in_8(&fpga_reg->dclk[0]),
146 in_8(&fpga_reg->dclk[1]),
147 in_8(&fpga_reg->dclk[2]));