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Release 4.11 drivers/clk/bcm/clk-iproc-armpll.c

Directory: drivers/clk/bcm
/*
 * Copyright (C) 2014 Broadcom Corporation
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation version 2.
 *
 * This program is distributed "as is" WITHOUT ANY WARRANTY of any
 * kind, whether express or implied; without even the implied warranty
 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

#include <linux/kernel.h>
#include <linux/slab.h>
#include <linux/err.h>
#include <linux/clk-provider.h>
#include <linux/io.h>
#include <linux/of.h>
#include <linux/clkdev.h>
#include <linux/of_address.h>

#include "clk-iproc.h"


#define IPROC_CLK_MAX_FREQ_POLICY                    0x3

#define IPROC_CLK_POLICY_FREQ_OFFSET                 0x008

#define IPROC_CLK_POLICY_FREQ_POLICY_FREQ_SHIFT      8

#define IPROC_CLK_POLICY_FREQ_POLICY_FREQ_MASK       0x7


#define IPROC_CLK_PLLARMA_OFFSET                     0xc00

#define IPROC_CLK_PLLARMA_LOCK_SHIFT                 28

#define IPROC_CLK_PLLARMA_PDIV_SHIFT                 24

#define IPROC_CLK_PLLARMA_PDIV_MASK                  0xf

#define IPROC_CLK_PLLARMA_NDIV_INT_SHIFT             8

#define IPROC_CLK_PLLARMA_NDIV_INT_MASK              0x3ff


#define IPROC_CLK_PLLARMB_OFFSET                     0xc04

#define IPROC_CLK_PLLARMB_NDIV_FRAC_MASK             0xfffff


#define IPROC_CLK_PLLARMC_OFFSET                     0xc08

#define IPROC_CLK_PLLARMC_BYPCLK_EN_SHIFT            8

#define IPROC_CLK_PLLARMC_MDIV_MASK                  0xff


#define IPROC_CLK_PLLARMCTL5_OFFSET                  0xc20

#define IPROC_CLK_PLLARMCTL5_H_MDIV_MASK             0xff


#define IPROC_CLK_PLLARM_OFFSET_OFFSET               0xc24

#define IPROC_CLK_PLLARM_SW_CTL_SHIFT                29

#define IPROC_CLK_PLLARM_NDIV_INT_OFFSET_SHIFT       20

#define IPROC_CLK_PLLARM_NDIV_INT_OFFSET_MASK        0xff

#define IPROC_CLK_PLLARM_NDIV_FRAC_OFFSET_MASK       0xfffff


#define IPROC_CLK_ARM_DIV_OFFSET                     0xe00

#define IPROC_CLK_ARM_DIV_PLL_SELECT_OVERRIDE_SHIFT  4

#define IPROC_CLK_ARM_DIV_ARM_PLL_SELECT_MASK        0xf


#define IPROC_CLK_POLICY_DBG_OFFSET                  0xec0

#define IPROC_CLK_POLICY_DBG_ACT_FREQ_SHIFT          12

#define IPROC_CLK_POLICY_DBG_ACT_FREQ_MASK           0x7


enum iproc_arm_pll_fid {
	
ARM_PLL_FID_CRYSTAL_CLK   = 0,
	
ARM_PLL_FID_SYS_CLK       = 2,
	
ARM_PLL_FID_CH0_SLOW_CLK  = 6,
	
ARM_PLL_FID_CH1_FAST_CLK  = 7
};


struct iproc_arm_pll {
	
struct clk_hw hw;
	
void __iomem *base;
	
unsigned long rate;
};


#define to_iproc_arm_pll(hw) container_of(hw, struct iproc_arm_pll, hw)


static unsigned int __get_fid(struct iproc_arm_pll *pll) { u32 val; unsigned int policy, fid, active_fid; val = readl(pll->base + IPROC_CLK_ARM_DIV_OFFSET); if (val & (1 << IPROC_CLK_ARM_DIV_PLL_SELECT_OVERRIDE_SHIFT)) policy = val & IPROC_CLK_ARM_DIV_ARM_PLL_SELECT_MASK; else policy = 0; /* something is seriously wrong */ BUG_ON(policy > IPROC_CLK_MAX_FREQ_POLICY); val = readl(pll->base + IPROC_CLK_POLICY_FREQ_OFFSET); fid = (val >> (IPROC_CLK_POLICY_FREQ_POLICY_FREQ_SHIFT * policy)) & IPROC_CLK_POLICY_FREQ_POLICY_FREQ_MASK; val = readl(pll->base + IPROC_CLK_POLICY_DBG_OFFSET); active_fid = IPROC_CLK_POLICY_DBG_ACT_FREQ_MASK & (val >> IPROC_CLK_POLICY_DBG_ACT_FREQ_SHIFT); if (fid != active_fid) { pr_debug("%s: fid override %u->%u\n", __func__, fid, active_fid); fid = active_fid; } pr_debug("%s: active fid: %u\n", __func__, fid); return fid; }

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/* * Determine the mdiv (post divider) based on the frequency ID being used. * There are 4 sources that can be used to derive the output clock rate: * - 25 MHz Crystal * - System clock * - PLL channel 0 (slow clock) * - PLL channel 1 (fast clock) */
static int __get_mdiv(struct iproc_arm_pll *pll) { unsigned int fid; int mdiv; u32 val; fid = __get_fid(pll); switch (fid) { case ARM_PLL_FID_CRYSTAL_CLK: case ARM_PLL_FID_SYS_CLK: mdiv = 1; break; case ARM_PLL_FID_CH0_SLOW_CLK: val = readl(pll->base + IPROC_CLK_PLLARMC_OFFSET); mdiv = val & IPROC_CLK_PLLARMC_MDIV_MASK; if (mdiv == 0) mdiv = 256; break; case ARM_PLL_FID_CH1_FAST_CLK: val = readl(pll->base + IPROC_CLK_PLLARMCTL5_OFFSET); mdiv = val & IPROC_CLK_PLLARMCTL5_H_MDIV_MASK; if (mdiv == 0) mdiv = 256; break; default: mdiv = -EFAULT; } return mdiv; }

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static unsigned int __get_ndiv(struct iproc_arm_pll *pll) { u32 val; unsigned int ndiv_int, ndiv_frac, ndiv; val = readl(pll->base + IPROC_CLK_PLLARM_OFFSET_OFFSET); if (val & (1 << IPROC_CLK_PLLARM_SW_CTL_SHIFT)) { /* * offset mode is active. Read the ndiv from the PLLARM OFFSET * register */ ndiv_int = (val >> IPROC_CLK_PLLARM_NDIV_INT_OFFSET_SHIFT) & IPROC_CLK_PLLARM_NDIV_INT_OFFSET_MASK; if (ndiv_int == 0) ndiv_int = 256; ndiv_frac = val & IPROC_CLK_PLLARM_NDIV_FRAC_OFFSET_MASK; } else { /* offset mode not active */ val = readl(pll->base + IPROC_CLK_PLLARMA_OFFSET); ndiv_int = (val >> IPROC_CLK_PLLARMA_NDIV_INT_SHIFT) & IPROC_CLK_PLLARMA_NDIV_INT_MASK; if (ndiv_int == 0) ndiv_int = 1024; val = readl(pll->base + IPROC_CLK_PLLARMB_OFFSET); ndiv_frac = val & IPROC_CLK_PLLARMB_NDIV_FRAC_MASK; } ndiv = (ndiv_int << 20) | ndiv_frac; return ndiv; }

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/* * The output frequency of the ARM PLL is calculated based on the ARM PLL * divider values: * pdiv = ARM PLL pre-divider * ndiv = ARM PLL multiplier * mdiv = ARM PLL post divider * * The frequency is calculated by: * ((ndiv * parent clock rate) / pdiv) / mdiv */
static unsigned long iproc_arm_pll_recalc_rate(struct clk_hw *hw, unsigned long parent_rate) { struct iproc_arm_pll *pll = to_iproc_arm_pll(hw); u32 val; int mdiv; u64 ndiv; unsigned int pdiv; /* in bypass mode, use parent rate */ val = readl(pll->base + IPROC_CLK_PLLARMC_OFFSET); if (val & (1 << IPROC_CLK_PLLARMC_BYPCLK_EN_SHIFT)) { pll->rate = parent_rate; return pll->rate; } /* PLL needs to be locked */ val = readl(pll->base + IPROC_CLK_PLLARMA_OFFSET); if (!(val & (1 << IPROC_CLK_PLLARMA_LOCK_SHIFT))) { pll->rate = 0; return 0; } pdiv = (val >> IPROC_CLK_PLLARMA_PDIV_SHIFT) & IPROC_CLK_PLLARMA_PDIV_MASK; if (pdiv == 0) pdiv = 16; ndiv = __get_ndiv(pll); mdiv = __get_mdiv(pll); if (mdiv <= 0) { pll->rate = 0; return 0; } pll->rate = (ndiv * parent_rate) >> 20; pll->rate = (pll->rate / pdiv) / mdiv; pr_debug("%s: ARM PLL rate: %lu. parent rate: %lu\n", __func__, pll->rate, parent_rate); pr_debug("%s: ndiv_int: %u, pdiv: %u, mdiv: %d\n", __func__, (unsigned int)(ndiv >> 20), pdiv, mdiv); return pll->rate; }

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static const struct clk_ops iproc_arm_pll_ops = { .recalc_rate = iproc_arm_pll_recalc_rate, };
void __init iproc_armpll_setup(struct device_node *node) { int ret; struct iproc_arm_pll *pll; struct clk_init_data init; const char *parent_name; pll = kzalloc(sizeof(*pll), GFP_KERNEL); if (WARN_ON(!pll)) return; pll->base = of_iomap(node, 0); if (WARN_ON(!pll->base)) goto err_free_pll; init.name = node->name; init.ops = &iproc_arm_pll_ops; init.flags = 0; parent_name = of_clk_get_parent_name(node, 0); init.parent_names = (parent_name ? &parent_name : NULL); init.num_parents = (parent_name ? 1 : 0); pll->hw.init = &init; ret = clk_hw_register(NULL, &pll->hw); if (WARN_ON(ret)) goto err_iounmap; ret = of_clk_add_hw_provider(node, of_clk_hw_simple_get, &pll->hw); if (WARN_ON(ret)) goto err_clk_unregister; return; err_clk_unregister: clk_hw_unregister(&pll->hw); err_iounmap: iounmap(pll->base); err_free_pll: kfree(pll); }

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Directory: drivers/clk/bcm
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