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a9c0688fde
This patch adds at91 smd (Soft Modem) clock implementation using common clk framework. Not used by any driver right now. Signed-off-by: Boris BREZILLON <b.brezillon@overkiz.com> Acked-by: Mike Turquette <mturquette@linaro.org> Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
172 lines
4.1 KiB
C
172 lines
4.1 KiB
C
/*
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* Copyright (C) 2013 Boris BREZILLON <b.brezillon@overkiz.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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*/
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#include <linux/clk-provider.h>
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#include <linux/clkdev.h>
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#include <linux/clk/at91_pmc.h>
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#include <linux/of.h>
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#include <linux/of_address.h>
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#include <linux/io.h>
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#include "pmc.h"
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#define SMD_SOURCE_MAX 2
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#define SMD_DIV_SHIFT 8
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#define SMD_MAX_DIV 0xf
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struct at91sam9x5_clk_smd {
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struct clk_hw hw;
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struct at91_pmc *pmc;
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};
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#define to_at91sam9x5_clk_smd(hw) \
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container_of(hw, struct at91sam9x5_clk_smd, hw)
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static unsigned long at91sam9x5_clk_smd_recalc_rate(struct clk_hw *hw,
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unsigned long parent_rate)
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{
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u32 tmp;
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u8 smddiv;
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struct at91sam9x5_clk_smd *smd = to_at91sam9x5_clk_smd(hw);
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struct at91_pmc *pmc = smd->pmc;
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tmp = pmc_read(pmc, AT91_PMC_SMD);
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smddiv = (tmp & AT91_PMC_SMD_DIV) >> SMD_DIV_SHIFT;
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return parent_rate / (smddiv + 1);
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}
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static long at91sam9x5_clk_smd_round_rate(struct clk_hw *hw, unsigned long rate,
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unsigned long *parent_rate)
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{
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unsigned long div;
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unsigned long bestrate;
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unsigned long tmp;
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if (rate >= *parent_rate)
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return *parent_rate;
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div = *parent_rate / rate;
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if (div > SMD_MAX_DIV)
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return *parent_rate / (SMD_MAX_DIV + 1);
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bestrate = *parent_rate / div;
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tmp = *parent_rate / (div + 1);
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if (bestrate - rate > rate - tmp)
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bestrate = tmp;
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return bestrate;
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}
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static int at91sam9x5_clk_smd_set_parent(struct clk_hw *hw, u8 index)
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{
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u32 tmp;
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struct at91sam9x5_clk_smd *smd = to_at91sam9x5_clk_smd(hw);
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struct at91_pmc *pmc = smd->pmc;
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if (index > 1)
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return -EINVAL;
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tmp = pmc_read(pmc, AT91_PMC_SMD) & ~AT91_PMC_SMDS;
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if (index)
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tmp |= AT91_PMC_SMDS;
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pmc_write(pmc, AT91_PMC_SMD, tmp);
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return 0;
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}
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static u8 at91sam9x5_clk_smd_get_parent(struct clk_hw *hw)
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{
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struct at91sam9x5_clk_smd *smd = to_at91sam9x5_clk_smd(hw);
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struct at91_pmc *pmc = smd->pmc;
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return pmc_read(pmc, AT91_PMC_SMD) & AT91_PMC_SMDS;
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}
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static int at91sam9x5_clk_smd_set_rate(struct clk_hw *hw, unsigned long rate,
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unsigned long parent_rate)
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{
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u32 tmp;
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struct at91sam9x5_clk_smd *smd = to_at91sam9x5_clk_smd(hw);
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struct at91_pmc *pmc = smd->pmc;
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unsigned long div = parent_rate / rate;
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if (parent_rate % rate || div < 1 || div > (SMD_MAX_DIV + 1))
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return -EINVAL;
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tmp = pmc_read(pmc, AT91_PMC_SMD) & ~AT91_PMC_SMD_DIV;
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tmp |= (div - 1) << SMD_DIV_SHIFT;
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pmc_write(pmc, AT91_PMC_SMD, tmp);
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return 0;
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}
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static const struct clk_ops at91sam9x5_smd_ops = {
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.recalc_rate = at91sam9x5_clk_smd_recalc_rate,
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.round_rate = at91sam9x5_clk_smd_round_rate,
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.get_parent = at91sam9x5_clk_smd_get_parent,
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.set_parent = at91sam9x5_clk_smd_set_parent,
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.set_rate = at91sam9x5_clk_smd_set_rate,
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};
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static struct clk * __init
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at91sam9x5_clk_register_smd(struct at91_pmc *pmc, const char *name,
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const char **parent_names, u8 num_parents)
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{
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struct at91sam9x5_clk_smd *smd;
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struct clk *clk = NULL;
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struct clk_init_data init;
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smd = kzalloc(sizeof(*smd), GFP_KERNEL);
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if (!smd)
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return ERR_PTR(-ENOMEM);
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init.name = name;
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init.ops = &at91sam9x5_smd_ops;
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init.parent_names = parent_names;
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init.num_parents = num_parents;
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init.flags = CLK_SET_RATE_GATE | CLK_SET_PARENT_GATE;
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smd->hw.init = &init;
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smd->pmc = pmc;
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clk = clk_register(NULL, &smd->hw);
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if (IS_ERR(clk))
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kfree(smd);
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return clk;
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}
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void __init of_at91sam9x5_clk_smd_setup(struct device_node *np,
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struct at91_pmc *pmc)
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{
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struct clk *clk;
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int i;
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int num_parents;
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const char *parent_names[SMD_SOURCE_MAX];
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const char *name = np->name;
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num_parents = of_count_phandle_with_args(np, "clocks", "#clock-cells");
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if (num_parents <= 0 || num_parents > SMD_SOURCE_MAX)
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return;
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for (i = 0; i < num_parents; i++) {
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parent_names[i] = of_clk_get_parent_name(np, i);
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if (!parent_names[i])
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return;
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}
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of_property_read_string(np, "clock-output-names", &name);
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clk = at91sam9x5_clk_register_smd(pmc, name, parent_names,
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num_parents);
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if (IS_ERR(clk))
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return;
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of_clk_add_provider(np, of_clk_src_simple_get, clk);
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}
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