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at91pmc.c revision 1.2.4.2 
      1 /*	$Id: at91pmc.c,v 1.2.4.2 2008/09/18 04:33:19 wrstuden Exp $	*/
      2 /*	$NetBSD: at91pmc.c,v 1.2.4.2 2008/09/18 04:33:19 wrstuden Exp $	*/
      3 
      4 /*
      5  * Copyright (c) 2007 Embedtronics Oy
      6  * All rights reserved.
      7  *
      8  * Redistribution and use in source and binary forms, with or without
      9  * modification, are permitted provided that the following conditions
     10  * are met:
     11  * 1. Redistributions of source code must retain the above copyright
     12  *    notice, this list of conditions and the following disclaimer.
     13  * 2. Redistributions in binary form must reproduce the above copyright
     14  *    notice, this list of conditions and the following disclaimer in the
     15  *    documentation and/or other materials provided with the distribution.
     16  * 3. All advertising materials mentioning features or use of this software
     17  *    must display the following acknowledgement:
     18  *	This product includes software developed by the NetBSD
     19  *	Foundation, Inc. and its contributors.
     20  * 4. Neither the name of The NetBSD Foundation nor the names of its
     21  *    contributors may be used to endorse or promote products derived
     22  *    from this software without specific prior written permission.
     23  *
     24  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     25  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     26  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     27  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     28  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     29  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     30  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     31  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     32  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     33  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     34  * POSSIBILITY OF SUCH DAMAGE.
     35  */
     36 
     37 #include <sys/cdefs.h>
     38 __KERNEL_RCSID(0, "$NetBSD");
     39 
     40 #include <sys/types.h>
     41 #include <sys/param.h>
     42 #include <sys/systm.h>
     43 #include <sys/kernel.h>
     44 #include <sys/time.h>
     45 #include <sys/device.h>
     46 
     47 #include <machine/bus.h>
     48 #include <machine/intr.h>
     49 
     50 #include <arm/cpufunc.h>
     51 
     52 #include <arm/at91/at91reg.h>
     53 #include <arm/at91/at91var.h>
     54 #include <arm/at91/at91pmcreg.h>
     55 #include <arm/at91/at91pmcvar.h>
     56 
     57 #define	SLOW_CLOCK	32768LU
     58 
     59 void
     60 at91pmc_get_clocks(struct at91bus_clocks *clocks)
     61 {
     62 	u_int64_t		mclk, pllaclk, pllbclk, pclk, mstclk;
     63 	u_int32_t		reg;
     64 
     65 	if (!((reg = PMCREG(PMC_MOR)) & PMC_MOR_MOSCEN))
     66 		panic("%s: main oscillator not enabled (MOR=0x%#X)", __FUNCTION__, reg);
     67 
     68 	if (!((reg = PMCREG(PMC_MCFR)) & PMC_MCFR_MAINRDY))
     69 		panic("%s: main oscillator not ready (MCFR=0x%#X)", __FUNCTION__, reg);
     70 
     71 	mclk  = ((reg & PMC_MCFR_MAINF) * SLOW_CLOCK) / 16U;
     72 
     73 	// try to guess some nice MHz value
     74 	if (((mclk / 1000) % 1000) >= 990) {
     75 	  mclk += 1000000U - (mclk % 1000000U);
     76 	} else if (((mclk / 1000) % 1000) <= 10) {
     77 	  mclk -= (mclk % 1000000U);
     78 	}
     79 
     80 	reg = PMCREG(PMC_PLLAR); pllaclk = 0;
     81 	if (reg & PMC_PLL_DIV) {
     82 		pllaclk = mclk * (((reg & PMC_PLL_MUL) >> PMC_PLL_MUL_SHIFT) + 1);
     83 		pllaclk /= (reg & PMC_PLL_DIV) >> PMC_PLL_DIV_SHIFT;
     84 	}
     85 
     86 	reg = PMCREG(PMC_PLLBR); pllbclk = 0;
     87 	if (reg & PMC_PLL_DIV) {
     88 		pllbclk = mclk * (((reg & PMC_PLL_MUL) >> PMC_PLL_MUL_SHIFT) + 1);
     89 		pllbclk /= (reg & PMC_PLL_DIV) >> PMC_PLL_DIV_SHIFT;
     90 		if (reg & PMC_PLLBR_USB_96M) {
     91 			pllbclk /= 2;
     92 		}
     93 	}
     94 
     95 	reg = PMCREG(PMC_MCKR);
     96 	switch ((reg & PMC_MCKR_CSS)) {
     97 	case PMC_MCKR_CSS_SLOW_CLK:
     98 	  pclk = SLOW_CLOCK;
     99 	  break;
    100 	default:
    101 	case PMC_MCKR_CSS_MAIN_CLK:
    102 	  pclk = mclk;
    103 	  break;
    104 	case PMC_MCKR_CSS_PLLA:
    105 	  pclk = pllaclk;
    106 	  break;
    107 	case PMC_MCKR_CSS_PLLB:
    108 	  pclk = pllbclk;
    109 	  break;
    110 	}
    111 	pclk >>= (reg & PMC_MCKR_PRES) >> PMC_MCKR_PRES_SHIFT;
    112 	mstclk = pclk / (((reg & PMC_MCKR_MDIV) >> PMC_MCKR_MDIV_SHIFT) + 1);
    113 
    114 	clocks->slow = SLOW_CLOCK;
    115 	clocks->main = mclk;
    116 	clocks->cpu = pclk;
    117 	clocks->master = mstclk;
    118 	clocks->plla = pllaclk;
    119 	clocks->pllb = pllbclk;
    120 }
    121 
    122 
    123 #define	PID_COUNT	32
    124 static int pid_enable_count[PID_COUNT] = {0};
    125 
    126 void
    127 at91pmc_peripheral_clock(int pid, int enable)
    128 {
    129 	int s;
    130 
    131 	if (pid < 0 || pid >= PID_COUNT)
    132 		panic("%s: pid %d out of range", __FUNCTION__, pid);
    133 
    134 	s = splhigh();
    135 
    136 	if (enable) {
    137 		pid_enable_count[pid]++;
    138 		PMCREG(PMC_PCER) = (1U << pid);
    139 	} else {
    140 		if (--pid_enable_count[pid] < 0)
    141 			panic("%s: pid %d enable count got negative (%d)",
    142 			      __FUNCTION__, pid, pid_enable_count[pid]);
    143 		if (pid_enable_count[pid] == 0)
    144 			PMCREG(PMC_PCDR) = (1U << pid);
    145 	}
    146 
    147 	splx(s);
    148 
    149 	if (enable) {
    150 		int c;
    151 		for (c = 0; c < 10000; c++) {
    152 		  __insn_barrier();
    153 		}
    154 	}
    155 }
    156