ics307_clk.c
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// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright 2010-2011 Freescale Semiconductor, Inc.
*/
#include <common.h>
#include <asm/io.h>
#include "ics307_clk.h"
#if defined(CONFIG_FSL_NGPIXIS)
#include "ngpixis.h"
#define fpga_reg pixis
#elif defined(CONFIG_FSL_QIXIS)
#include "qixis.h"
#define fpga_reg ((struct qixis *)QIXIS_BASE)
#else
#include "pixis.h"
#define fpga_reg pixis
#endif
/* define for SYS CLK or CLK1Frequency */
#define TTL 1
#define CLK2 0
#define CRYSTAL 0
#define MAX_VDW (511 + 8)
#define MAX_RDW (127 + 2)
#define MIN_VDW (4 + 8)
#define MIN_RDW (1 + 2)
#define NUM_OD_SETTING 8
/*
* These defines cover the industrial temperature range part,
* for commercial, change below to 400000 and 55000, respectively
*/
#define MAX_VCO 360000
#define MIN_VCO 60000
/* decode S[0-2] to Output Divider (OD) */
static u8 ics307_s_to_od[] = {
10, 2, 8, 4, 5, 7, 3, 6
};
/*
* Find one solution to generate required frequency for SYSCLK
* out_freq: KHz, required frequency to the SYSCLK
* the result will be retuned with component RDW, VDW, OD, TTL,
* CLK2 and crystal
*/
unsigned long ics307_sysclk_calculator(unsigned long out_freq)
{
const unsigned long input_freq = CONFIG_ICS307_REFCLK_HZ;
unsigned long vdw, rdw, odp, s_vdw = 0, s_rdw = 0, s_odp = 0, od;
unsigned long tmp_out, diff, result = 0;
int found = 0;
for (odp = 0; odp < NUM_OD_SETTING; odp++) {
od = ics307_s_to_od[odp];
if (od * out_freq < MIN_VCO || od * out_freq > MAX_VCO)
continue;
for (rdw = MIN_RDW; rdw <= MAX_RDW; rdw++) {
/* Calculate the VDW */
vdw = out_freq * 1000 * od * rdw / (input_freq * 2);
if (vdw > MAX_VDW)
vdw = MAX_VDW;
if (vdw < MIN_VDW)
continue;
/* Calculate the temp out frequency */
tmp_out = input_freq * 2 * vdw / (rdw * od * 1000);
diff = max(out_freq, tmp_out) - min(out_freq, tmp_out);
/*
* calculate the percent, the precision is 1/1000
* If greater than 1/1000, continue
* otherwise, we think the solution is we required
*/
if (diff * 1000 / out_freq > 1)
continue;
else {
s_vdw = vdw;
s_rdw = rdw;
s_odp = odp;
found = 1;
break;
}
}
}
if (found)
result = (s_rdw - 2) | (s_vdw - 8) << 7 | s_odp << 16 |
CLK2 << 19 | TTL << 21 | CRYSTAL << 22;
debug("ICS307-02: RDW: %ld, VDW: %ld, OD: %d\n", s_rdw - 2, s_vdw - 8,
ics307_s_to_od[s_odp]);
return result;
}
/*
* Calculate frequency being generated by ICS307-02 clock chip based upon
* the control bytes being programmed into it.
*/
static unsigned long ics307_clk_freq(u8 cw0, u8 cw1, u8 cw2)
{
const unsigned long input_freq = CONFIG_ICS307_REFCLK_HZ;
unsigned long vdw = ((cw1 << 1) & 0x1FE) + ((cw2 >> 7) & 1);
unsigned long rdw = cw2 & 0x7F;
unsigned long od = ics307_s_to_od[cw0 & 0x7];
unsigned long freq;
/*
* CLK1 Freq = Input Frequency * 2 * (VDW + 8) / ((RDW + 2) * OD)
*
* cw0: C1 C0 TTL F1 F0 S2 S1 S0
* cw1: V8 V7 V6 V5 V4 V3 V2 V1
* cw2: V0 R6 R5 R4 R3 R2 R1 R0
*
* R6:R0 = Reference Divider Word (RDW)
* V8:V0 = VCO Divider Word (VDW)
* S2:S0 = Output Divider Select (OD)
* F1:F0 = Function of CLK2 Output
* TTL = duty cycle
* C1:C0 = internal load capacitance for cyrstal
*
*/
freq = input_freq * 2 * (vdw + 8) / ((rdw + 2) * od);
debug("ICS307: CW[0-2]: %02X %02X %02X => %lu Hz\n", cw0, cw1, cw2,
freq);
return freq;
}
unsigned long get_board_sys_clk(void)
{
return ics307_clk_freq(
in_8(&fpga_reg->sclk[0]),
in_8(&fpga_reg->sclk[1]),
in_8(&fpga_reg->sclk[2]));
}
unsigned long get_board_ddr_clk(void)
{
return ics307_clk_freq(
in_8(&fpga_reg->dclk[0]),
in_8(&fpga_reg->dclk[1]),
in_8(&fpga_reg->dclk[2]));
}