2 * Freescale i.MX28 clock setup code
4 * Copyright (C) 2011 Marek Vasut <marek.vasut@gmail.com>
5 * on behalf of DENX Software Engineering GmbH
7 * Based on code from LTIB:
8 * Copyright (C) 2010 Freescale Semiconductor, Inc.
10 * See file CREDITS for list of people who contributed to this
13 * This program is free software; you can redistribute it and/or
14 * modify it under the terms of the GNU General Public License as
15 * published by the Free Software Foundation; either version 2 of
16 * the License, or (at your option) any later version.
18 * This program is distributed in the hope that it will be useful,
19 * but WITHOUT ANY WARRANTY; without even the implied warranty of
20 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
21 * GNU General Public License for more details.
23 * You should have received a copy of the GNU General Public License
24 * along with this program; if not, write to the Free Software
25 * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
30 #include <asm/errno.h>
32 #include <asm/arch/clock.h>
33 #include <asm/arch/imx-regs.h>
35 /* The PLL frequency is always 480MHz, see section 10.2 in iMX28 datasheet. */
36 #define PLL_FREQ_KHZ 480000
37 #define PLL_FREQ_COEF 18
38 /* The XTAL frequency is always 24MHz, see section 10.2 in iMX28 datasheet. */
39 #define XTAL_FREQ_KHZ 24000
41 #define PLL_FREQ_MHZ (PLL_FREQ_KHZ / 1000)
42 #define XTAL_FREQ_MHZ (XTAL_FREQ_KHZ / 1000)
44 static struct mxs_clkctrl_regs *clkctrl_regs = (void *)MXS_CLKCTRL_BASE;
46 static uint32_t get_frac_clk(uint32_t refclk, uint32_t div, uint32_t _mask)
48 uint32_t mask = (_mask + 1) >> 1;
65 return refclk * mult / period;
68 static uint32_t mx28_get_pclk(void)
70 uint32_t clkctrl, clkseq, div;
71 uint8_t clkfrac, frac;
73 clkctrl = readl(&clkctrl_regs->hw_clkctrl_cpu);
75 div = clkctrl & CLKCTRL_CPU_DIV_CPU_MASK;
76 clkfrac = readb(&clkctrl_regs->hw_clkctrl_frac0[CLKCTRL_FRAC0_CPU]);
77 frac = clkfrac & CLKCTRL_FRAC_FRAC_MASK;
78 clkseq = readl(&clkctrl_regs->hw_clkctrl_clkseq);
81 (CLKCTRL_CPU_DIV_XTAL_FRAC_EN | CLKCTRL_CPU_DIV_CPU_FRAC_EN)) {
82 uint32_t refclk, mask;
84 if (clkseq & CLKCTRL_CLKSEQ_BYPASS_CPU) {
85 refclk = XTAL_FREQ_MHZ;
86 mask = CLKCTRL_CPU_DIV_XTAL_MASK >>
87 CLKCTRL_CPU_DIV_XTAL_OFFSET;
88 div = (clkctrl & CLKCTRL_CPU_DIV_XTAL_MASK) >>
89 CLKCTRL_CPU_DIV_XTAL_OFFSET;
91 refclk = PLL_FREQ_MHZ * PLL_FREQ_COEF / frac;
92 mask = CLKCTRL_CPU_DIV_CPU_MASK;
94 return get_frac_clk(refclk, div, mask);
98 if (clkseq & CLKCTRL_CLKSEQ_BYPASS_CPU) {
99 div = (clkctrl & CLKCTRL_CPU_DIV_XTAL_MASK) >>
100 CLKCTRL_CPU_DIV_XTAL_OFFSET;
101 return XTAL_FREQ_MHZ / div;
105 return (PLL_FREQ_MHZ * PLL_FREQ_COEF / frac) / div;
108 static uint32_t mx28_get_hclk(void)
112 uint32_t refclk = mx28_get_pclk();
114 clkctrl = readl(&clkctrl_regs->hw_clkctrl_hbus);
115 div = clkctrl & CLKCTRL_HBUS_DIV_MASK;
117 if (clkctrl & CLKCTRL_HBUS_DIV_FRAC_EN)
118 return get_frac_clk(refclk, div, CLKCTRL_HBUS_DIV_MASK);
123 static uint32_t mx28_get_emiclk(void)
125 uint32_t clkctrl, clkseq, div;
126 uint8_t clkfrac, frac;
128 clkseq = readl(&clkctrl_regs->hw_clkctrl_clkseq);
129 clkctrl = readl(&clkctrl_regs->hw_clkctrl_emi);
132 if (clkseq & CLKCTRL_CLKSEQ_BYPASS_EMI) {
133 div = (clkctrl & CLKCTRL_EMI_DIV_XTAL_MASK) >>
134 CLKCTRL_EMI_DIV_XTAL_OFFSET;
135 return XTAL_FREQ_MHZ / div;
139 clkfrac = readb(&clkctrl_regs->hw_clkctrl_frac0[CLKCTRL_FRAC0_EMI]);
140 frac = clkfrac & CLKCTRL_FRAC_FRAC_MASK;
141 div = clkctrl & CLKCTRL_EMI_DIV_EMI_MASK;
142 return (PLL_FREQ_MHZ * PLL_FREQ_COEF / frac) / div;
145 static uint32_t mx28_get_gpmiclk(void)
147 uint32_t clkctrl, clkseq, div;
148 uint8_t clkfrac, frac;
150 clkseq = readl(&clkctrl_regs->hw_clkctrl_clkseq);
151 clkctrl = readl(&clkctrl_regs->hw_clkctrl_gpmi);
154 if (clkseq & CLKCTRL_CLKSEQ_BYPASS_GPMI) {
155 div = clkctrl & CLKCTRL_GPMI_DIV_MASK;
156 return XTAL_FREQ_MHZ / div;
160 clkfrac = readb(&clkctrl_regs->hw_clkctrl_frac1[CLKCTRL_FRAC1_GPMI]);
161 frac = clkfrac & CLKCTRL_FRAC_FRAC_MASK;
162 div = clkctrl & CLKCTRL_GPMI_DIV_MASK;
163 return (PLL_FREQ_MHZ * PLL_FREQ_COEF / frac) / div;
167 * Set IO clock frequency, in kHz
169 void mx28_set_ioclk(enum mxs_ioclock io, uint32_t freq)
177 if ((io < MXC_IOCLK0) || (io > MXC_IOCLK1))
180 div = (PLL_FREQ_KHZ * PLL_FREQ_COEF) / freq;
188 io_reg = CLKCTRL_FRAC0_IO0 - io; /* Register order is reversed */
189 writeb(CLKCTRL_FRAC_CLKGATE,
190 &clkctrl_regs->hw_clkctrl_frac0_set[io_reg]);
191 writeb(CLKCTRL_FRAC_CLKGATE | (div & CLKCTRL_FRAC_FRAC_MASK),
192 &clkctrl_regs->hw_clkctrl_frac0[io_reg]);
193 writeb(CLKCTRL_FRAC_CLKGATE,
194 &clkctrl_regs->hw_clkctrl_frac0_clr[io_reg]);
198 * Get IO clock, returns IO clock in kHz
200 static uint32_t mx28_get_ioclk(enum mxs_ioclock io)
205 if ((io < MXC_IOCLK0) || (io > MXC_IOCLK1)) {
206 printf("%s: IO clock selector %u out of range %u..%u\n",
207 __func__, io, MXC_IOCLK0, MXC_IOCLK1);
210 io_reg = CLKCTRL_FRAC0_IO0 - io; /* Register order is reversed */
212 ret = readb(&clkctrl_regs->hw_clkctrl_frac0[io_reg]) &
213 CLKCTRL_FRAC_FRAC_MASK;
215 return (PLL_FREQ_KHZ * PLL_FREQ_COEF) / ret;
219 * Configure SSP clock frequency, in kHz
221 void mx28_set_sspclk(enum mxs_sspclock ssp, uint32_t freq, int xtal)
223 uint32_t clk, clkreg;
225 if (ssp > MXC_SSPCLK3)
228 clkreg = (uint32_t)(&clkctrl_regs->hw_clkctrl_ssp0) +
229 (ssp * sizeof(struct mxs_register_32));
231 clrbits_le32(clkreg, CLKCTRL_SSP_CLKGATE);
232 while (readl(clkreg) & CLKCTRL_SSP_CLKGATE)
238 clk = mx28_get_ioclk(ssp >> 1);
243 /* Calculate the divider and cap it if necessary */
245 if (clk > CLKCTRL_SSP_DIV_MASK)
246 clk = CLKCTRL_SSP_DIV_MASK;
248 clrsetbits_le32(clkreg, CLKCTRL_SSP_DIV_MASK, clk);
249 while (readl(clkreg) & CLKCTRL_SSP_BUSY)
253 writel(CLKCTRL_CLKSEQ_BYPASS_SSP0 << ssp,
254 &clkctrl_regs->hw_clkctrl_clkseq_set);
256 writel(CLKCTRL_CLKSEQ_BYPASS_SSP0 << ssp,
257 &clkctrl_regs->hw_clkctrl_clkseq_clr);
261 * Return SSP frequency, in kHz
263 static uint32_t mx28_get_sspclk(enum mxs_sspclock ssp)
268 if (ssp > MXC_SSPCLK3)
271 tmp = readl(&clkctrl_regs->hw_clkctrl_clkseq);
272 if (tmp & (CLKCTRL_CLKSEQ_BYPASS_SSP0 << ssp))
273 return XTAL_FREQ_KHZ;
275 clkreg = &clkctrl_regs->hw_clkctrl_ssp0 +
276 ssp * sizeof(struct mxs_register_32);
278 tmp = readl(clkreg) & CLKCTRL_SSP_DIV_MASK;
282 clk = mx28_get_ioclk(ssp >> 1);
287 * Set SSP/MMC bus frequency, in kHz)
289 void mx28_set_ssp_busclock(unsigned int bus, uint32_t freq)
291 struct mxs_ssp_regs *ssp_regs;
292 const uint32_t sspclk = mx28_get_sspclk(bus);
294 uint32_t divide, rate, tgtclk;
296 ssp_regs = (struct mxs_ssp_regs *)(MXS_SSP0_BASE + (bus * 0x2000));
299 * SSP bit rate = SSPCLK / (CLOCK_DIVIDE * (1 + CLOCK_RATE)),
300 * CLOCK_DIVIDE has to be an even value from 2 to 254, and
301 * CLOCK_RATE could be any integer from 0 to 255.
303 for (divide = 2; divide < 254; divide += 2) {
304 rate = sspclk / freq / divide;
309 tgtclk = sspclk / divide / rate;
310 while (tgtclk > freq) {
312 tgtclk = sspclk / divide / rate;
317 /* Always set timeout the maximum */
318 reg = SSP_TIMING_TIMEOUT_MASK |
319 (divide << SSP_TIMING_CLOCK_DIVIDE_OFFSET) |
320 ((rate - 1) << SSP_TIMING_CLOCK_RATE_OFFSET);
321 writel(reg, &ssp_regs->hw_ssp_timing);
323 debug("SPI%d: Set freq rate to %d KHz (requested %d KHz)\n",
327 static uint32_t mx28_get_xbus_clk(void)
329 struct mxs_clkctrl_regs *clkctrl_regs =
330 (struct mxs_clkctrl_regs *)MXS_CLKCTRL_BASE;
333 uint32_t refclk = mx28_get_pclk();
335 clkctrl = readl(&clkctrl_regs->hw_clkctrl_xbus);
336 div = clkctrl & CLKCTRL_XBUS_DIV_MASK;
338 if (clkctrl & CLKCTRL_XBUS_DIV_FRAC_EN)
339 return get_frac_clk(refclk, div, CLKCTRL_XBUS_DIV_MASK);
344 uint32_t mxc_get_clock(enum mxc_clock clk)
348 return mx28_get_pclk() * 1000000;
350 return mx28_get_gpmiclk() * 1000000;
353 return mx28_get_hclk() * 1000000;
355 return mx28_get_emiclk();
357 return mx28_get_ioclk(MXC_IOCLK0);
359 return mx28_get_ioclk(MXC_IOCLK1);
361 return mx28_get_sspclk(MXC_SSPCLK0);
363 return mx28_get_sspclk(MXC_SSPCLK1);
365 return mx28_get_sspclk(MXC_SSPCLK2);
367 return mx28_get_sspclk(MXC_SSPCLK3);
369 return XTAL_FREQ_KHZ * 1000;
371 return mx28_get_xbus_clk() * 1000000;
373 printf("Invalid clock selector %u\n", clk);