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      1 /* $NetBSD: imx_ccm_pll.c,v 1.1 2020/12/23 14:42:38 skrll Exp $ */
      2 
      3 /*-
      4  * Copyright (c) 2020 Jared McNeill <jmcneill (at) invisible.ca>
      5  * All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  *
     16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
     21  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
     22  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
     23  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
     24  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     26  * SUCH DAMAGE.
     27  */
     28 
     29 #include <sys/cdefs.h>
     30 __KERNEL_RCSID(0, "$NetBSD: imx_ccm_pll.c,v 1.1 2020/12/23 14:42:38 skrll Exp $");
     31 
     32 #include <sys/param.h>
     33 #include <sys/bus.h>
     34 
     35 #include <dev/clk/clk_backend.h>
     36 
     37 #include <arm/nxp/imx_ccm.h>
     38 
     39 #include <dev/fdt/fdtvar.h>
     40 
     41 #define	PLL_POWERDOWN		__BIT(12)
     42 #define	PLL_POWERDOWN_ENET	__BIT(5)
     43 
     44 int
     45 imx_ccm_pll_enable(struct imx_ccm_softc *sc, struct imx_ccm_clk *clk,
     46     int enable)
     47 {
     48 	struct imx_ccm_pll *pll = &clk->u.pll;
     49 	uint32_t val, mask;
     50 
     51 	KASSERT(clk->type == IMX_CCM_PLL);
     52 
     53 	if ((pll->flags & IMX_PLL_ENET) != 0)
     54 		mask = PLL_POWERDOWN_ENET;
     55 	else
     56 		mask = PLL_POWERDOWN;
     57 
     58 	val = CCM_READ(sc, clk->regidx, pll->reg);
     59 	if (enable)
     60 		val &= ~mask;
     61 	else
     62 		val |= mask;
     63 	CCM_WRITE(sc, clk->regidx, pll->reg, val);
     64 
     65 	return 0;
     66 }
     67 
     68 u_int
     69 imx_ccm_pll_get_rate(struct imx_ccm_softc *sc,
     70     struct imx_ccm_clk *clk)
     71 {
     72 	struct imx_ccm_pll *pll= &clk->u.pll;
     73 	struct clk *clkp, *clkp_parent;
     74 
     75 	KASSERT(clk->type == IMX_CCM_PLL);
     76 
     77 	clkp = &clk->base;
     78 	clkp_parent = clk_get_parent(clkp);
     79 	if (clkp_parent == NULL)
     80 		return 0;
     81 
     82 	const u_int prate = clk_get_rate(clkp_parent);
     83 	if (prate == 0)
     84 		return 0;
     85 
     86 	if ((pll->flags & IMX_PLL_ENET) != 0) {
     87 		/* For ENET PLL, div_mask contains the fixed output rate */
     88 		return pll->div_mask;
     89 	}
     90 
     91 	const uint32_t val = CCM_READ(sc, clk->regidx, pll->reg);
     92 	const u_int div = __SHIFTOUT(val, pll->div_mask);
     93 
     94 	if ((pll->flags & IMX_PLL_ARM) != 0) {
     95 		return prate * div / 2;
     96 	}
     97 
     98 	if ((pll->flags & IMX_PLL_480M_528M) != 0) {
     99 		return div == 1 ? 528000000 : 480000000;
    100 	}
    101 
    102 	return 0;
    103 }
    104 
    105 const char *
    106 imx_ccm_pll_get_parent(struct imx_ccm_softc *sc,
    107     struct imx_ccm_clk *clk)
    108 {
    109 	struct imx_ccm_pll *pll = &clk->u.pll;
    110 
    111 	KASSERT(clk->type == IMX_CCM_PLL);
    112 
    113 	return pll->parent;
    114 }
    115