2 * Freescale i.MX23/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>
36 * The PLL frequency is 480MHz and XTAL frequency is 24MHz
37 * iMX23: datasheet section 4.2
38 * iMX28: datasheet section 10.2
40 #define PLL_FREQ_KHZ 480000
41 #define PLL_FREQ_COEF 18
42 #define XTAL_FREQ_KHZ 24000
44 #define PLL_FREQ_MHZ (PLL_FREQ_KHZ / 1000)
45 #define XTAL_FREQ_MHZ (XTAL_FREQ_KHZ / 1000)
47 #if defined(CONFIG_MX23)
48 #define MXC_SSPCLK_MAX MXC_SSPCLK0
49 #elif defined(CONFIG_MX28)
50 #define MXC_SSPCLK_MAX MXC_SSPCLK3
53 static uint32_t mxs_get_pclk(void)
55 struct mxs_clkctrl_regs *clkctrl_regs =
56 (struct mxs_clkctrl_regs *)MXS_CLKCTRL_BASE;
58 uint32_t clkctrl, clkseq, div;
59 uint8_t clkfrac, frac;
61 clkctrl = readl(&clkctrl_regs->hw_clkctrl_cpu);
63 /* No support of fractional divider calculation */
65 (CLKCTRL_CPU_DIV_XTAL_FRAC_EN | CLKCTRL_CPU_DIV_CPU_FRAC_EN)) {
69 clkseq = readl(&clkctrl_regs->hw_clkctrl_clkseq);
72 if (clkseq & CLKCTRL_CLKSEQ_BYPASS_CPU) {
73 div = (clkctrl & CLKCTRL_CPU_DIV_XTAL_MASK) >>
74 CLKCTRL_CPU_DIV_XTAL_OFFSET;
75 return XTAL_FREQ_MHZ / div;
79 clkfrac = readb(&clkctrl_regs->hw_clkctrl_frac0[CLKCTRL_FRAC0_CPU]);
80 frac = clkfrac & CLKCTRL_FRAC_FRAC_MASK;
81 div = clkctrl & CLKCTRL_CPU_DIV_CPU_MASK;
82 return (PLL_FREQ_MHZ * PLL_FREQ_COEF / frac) / div;
85 static uint32_t mxs_get_hclk(void)
87 struct mxs_clkctrl_regs *clkctrl_regs =
88 (struct mxs_clkctrl_regs *)MXS_CLKCTRL_BASE;
93 clkctrl = readl(&clkctrl_regs->hw_clkctrl_hbus);
95 /* No support of fractional divider calculation */
96 if (clkctrl & CLKCTRL_HBUS_DIV_FRAC_EN)
99 div = clkctrl & CLKCTRL_HBUS_DIV_MASK;
100 return mxs_get_pclk() / div;
103 static uint32_t mxs_get_emiclk(void)
105 struct mxs_clkctrl_regs *clkctrl_regs =
106 (struct mxs_clkctrl_regs *)MXS_CLKCTRL_BASE;
108 uint32_t clkctrl, clkseq, div;
109 uint8_t clkfrac, frac;
111 clkseq = readl(&clkctrl_regs->hw_clkctrl_clkseq);
112 clkctrl = readl(&clkctrl_regs->hw_clkctrl_emi);
115 if (clkseq & CLKCTRL_CLKSEQ_BYPASS_EMI) {
116 div = (clkctrl & CLKCTRL_EMI_DIV_XTAL_MASK) >>
117 CLKCTRL_EMI_DIV_XTAL_OFFSET;
118 return XTAL_FREQ_MHZ / div;
122 clkfrac = readb(&clkctrl_regs->hw_clkctrl_frac0[CLKCTRL_FRAC0_EMI]);
123 frac = clkfrac & CLKCTRL_FRAC_FRAC_MASK;
124 div = clkctrl & CLKCTRL_EMI_DIV_EMI_MASK;
125 return (PLL_FREQ_MHZ * PLL_FREQ_COEF / frac) / div;
128 static uint32_t mxs_get_gpmiclk(void)
130 struct mxs_clkctrl_regs *clkctrl_regs =
131 (struct mxs_clkctrl_regs *)MXS_CLKCTRL_BASE;
132 #if defined(CONFIG_MX23)
134 &clkctrl_regs->hw_clkctrl_frac0[CLKCTRL_FRAC0_CPU];
135 #elif defined(CONFIG_MX28)
137 &clkctrl_regs->hw_clkctrl_frac1[CLKCTRL_FRAC1_GPMI];
139 uint32_t clkctrl, clkseq, div;
140 uint8_t clkfrac, frac;
142 clkseq = readl(&clkctrl_regs->hw_clkctrl_clkseq);
143 clkctrl = readl(&clkctrl_regs->hw_clkctrl_gpmi);
146 if (clkseq & CLKCTRL_CLKSEQ_BYPASS_GPMI) {
147 div = clkctrl & CLKCTRL_GPMI_DIV_MASK;
148 return XTAL_FREQ_MHZ / div;
152 clkfrac = readb(reg);
153 frac = clkfrac & CLKCTRL_FRAC_FRAC_MASK;
154 div = clkctrl & CLKCTRL_GPMI_DIV_MASK;
155 return (PLL_FREQ_MHZ * PLL_FREQ_COEF / frac) / div;
159 * Set IO clock frequency, in kHz
161 void mxs_set_ioclk(enum mxs_ioclock io, uint32_t freq)
163 struct mxs_clkctrl_regs *clkctrl_regs =
164 (struct mxs_clkctrl_regs *)MXS_CLKCTRL_BASE;
171 if ((io < MXC_IOCLK0) || (io > MXC_IOCLK1))
174 div = (PLL_FREQ_KHZ * PLL_FREQ_COEF) / freq;
182 io_reg = CLKCTRL_FRAC0_IO0 - io; /* Register order is reversed */
183 writeb(CLKCTRL_FRAC_CLKGATE,
184 &clkctrl_regs->hw_clkctrl_frac0_set[io_reg]);
185 writeb(CLKCTRL_FRAC_CLKGATE | (div & CLKCTRL_FRAC_FRAC_MASK),
186 &clkctrl_regs->hw_clkctrl_frac0[io_reg]);
187 writeb(CLKCTRL_FRAC_CLKGATE,
188 &clkctrl_regs->hw_clkctrl_frac0_clr[io_reg]);
192 * Get IO clock, returns IO clock in kHz
194 static uint32_t mxs_get_ioclk(enum mxs_ioclock io)
196 struct mxs_clkctrl_regs *clkctrl_regs =
197 (struct mxs_clkctrl_regs *)MXS_CLKCTRL_BASE;
201 if ((io < MXC_IOCLK0) || (io > MXC_IOCLK1))
204 io_reg = CLKCTRL_FRAC0_IO0 - io; /* Register order is reversed */
206 ret = readb(&clkctrl_regs->hw_clkctrl_frac0[io_reg]) &
207 CLKCTRL_FRAC_FRAC_MASK;
209 return (PLL_FREQ_KHZ * PLL_FREQ_COEF) / ret;
213 * Configure SSP clock frequency, in kHz
215 void mxs_set_sspclk(enum mxs_sspclock ssp, uint32_t freq, int xtal)
217 struct mxs_clkctrl_regs *clkctrl_regs =
218 (struct mxs_clkctrl_regs *)MXS_CLKCTRL_BASE;
219 uint32_t clk, clkreg;
221 if (ssp > MXC_SSPCLK_MAX)
224 clkreg = (uint32_t)(&clkctrl_regs->hw_clkctrl_ssp0) +
225 (ssp * sizeof(struct mxs_register_32));
227 clrbits_le32(clkreg, CLKCTRL_SSP_CLKGATE);
228 while (readl(clkreg) & CLKCTRL_SSP_CLKGATE)
234 clk = mxs_get_ioclk(ssp >> 1);
239 /* Calculate the divider and cap it if necessary */
241 if (clk > CLKCTRL_SSP_DIV_MASK)
242 clk = CLKCTRL_SSP_DIV_MASK;
244 clrsetbits_le32(clkreg, CLKCTRL_SSP_DIV_MASK, clk);
245 while (readl(clkreg) & CLKCTRL_SSP_BUSY)
249 writel(CLKCTRL_CLKSEQ_BYPASS_SSP0 << ssp,
250 &clkctrl_regs->hw_clkctrl_clkseq_set);
252 writel(CLKCTRL_CLKSEQ_BYPASS_SSP0 << ssp,
253 &clkctrl_regs->hw_clkctrl_clkseq_clr);
257 * Return SSP frequency, in kHz
259 static uint32_t mxs_get_sspclk(enum mxs_sspclock ssp)
261 struct mxs_clkctrl_regs *clkctrl_regs =
262 (struct mxs_clkctrl_regs *)MXS_CLKCTRL_BASE;
266 if (ssp > MXC_SSPCLK_MAX)
269 tmp = readl(&clkctrl_regs->hw_clkctrl_clkseq);
270 if (tmp & (CLKCTRL_CLKSEQ_BYPASS_SSP0 << ssp))
271 return XTAL_FREQ_KHZ;
273 clkreg = (uint32_t)(&clkctrl_regs->hw_clkctrl_ssp0) +
274 (ssp * sizeof(struct mxs_register_32));
276 tmp = readl(clkreg) & CLKCTRL_SSP_DIV_MASK;
281 clk = mxs_get_ioclk(ssp >> 1);
287 * Set SSP/MMC bus frequency, in kHz)
289 void mxs_set_ssp_busclock(unsigned int bus, uint32_t freq)
291 struct mxs_ssp_regs *ssp_regs;
292 const uint32_t sspclk = mxs_get_sspclk(bus);
294 uint32_t divide, rate, tgtclk;
296 ssp_regs = mxs_ssp_regs_by_bus(bus);
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 uint32_t mxc_get_clock(enum mxc_clock clk)
331 return mxs_get_pclk() * 1000000;
333 return mxs_get_gpmiclk() * 1000000;
336 return mxs_get_hclk() * 1000000;
338 return mxs_get_emiclk();
340 return mxs_get_ioclk(MXC_IOCLK0);
342 return mxs_get_ioclk(MXC_IOCLK1);
344 return XTAL_FREQ_KHZ * 1000;
346 return mxs_get_sspclk(MXC_SSPCLK0);
349 return mxs_get_sspclk(MXC_SSPCLK1);
351 return mxs_get_sspclk(MXC_SSPCLK2);
353 return mxs_get_sspclk(MXC_SSPCLK3);