147 lines
3.3 KiB
C
147 lines
3.3 KiB
C
/*
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* Copyright (C) 2018 Microhip / Atmel Corporation
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* Wenyou.Yang <wenyou.yang@microchip.com>
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*
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* SPDX-License-Identifier: GPL-2.0+
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*/
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#include <common.h>
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#include <clk-uclass.h>
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#include <dm/device.h>
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#include <linux/io.h>
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#include <mach/at91_pmc.h>
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#include "pmc.h"
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DECLARE_GLOBAL_DATA_PTR;
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#define AT91_USB_CLK_SOURCE_MAX 2
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#define AT91_USB_CLK_MAX_DIV 15
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struct at91_usb_clk_priv {
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u32 num_clksource;
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};
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static ulong at91_usb_clk_get_rate(struct clk *clk)
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{
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struct pmc_platdata *plat = dev_get_platdata(clk->dev);
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struct at91_pmc *pmc = plat->reg_base;
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struct clk source;
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u32 tmp, usbdiv;
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u8 source_index;
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int ret;
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tmp = readl(&pmc->pcr);
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source_index = (tmp >> AT91_PMC_USB_USBS_OFFSET) &
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AT91_PMC_USB_USBS_MASK;
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usbdiv = (tmp >> AT91_PMC_USB_DIV_OFFSET) & AT91_PMC_USB_DIV_MASK;
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ret = clk_get_by_index(clk->dev, source_index, &source);
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if (ret)
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return 0;
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return clk_get_rate(&source) / (usbdiv + 1);
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}
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static ulong at91_usb_clk_set_rate(struct clk *clk, ulong rate)
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{
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struct pmc_platdata *plat = dev_get_platdata(clk->dev);
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struct at91_pmc *pmc = plat->reg_base;
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struct at91_usb_clk_priv *priv = dev_get_priv(clk->dev);
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struct clk source, best_source;
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ulong tmp_rate, best_rate = rate, source_rate;
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int tmp_diff, best_diff = -1;
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u32 div, best_div = 0;
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u8 best_source_index = 0;
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u8 i;
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u32 tmp;
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int ret;
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for (i = 0; i < priv->num_clksource; i++) {
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ret = clk_get_by_index(clk->dev, i, &source);
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if (ret)
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return ret;
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source_rate = clk_get_rate(&source);
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if (IS_ERR_VALUE(source_rate))
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return source_rate;
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for (div = 1; div < AT91_USB_CLK_MAX_DIV + 2; div++) {
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tmp_rate = DIV_ROUND_CLOSEST(source_rate, div);
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tmp_diff = abs(rate - tmp_rate);
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if (best_diff < 0 || best_diff > tmp_diff) {
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best_rate = tmp_rate;
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best_diff = tmp_diff;
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best_div = div - 1;
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best_source = source;
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best_source_index = i;
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}
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if (!best_diff || tmp_rate < rate)
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break;
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}
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if (!best_diff)
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break;
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}
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debug("AT91 USB: best sourc: %s, best_rate = %ld, best_div = %d\n",
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best_source.dev->name, best_rate, best_div);
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ret = clk_enable(&best_source);
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if (ret)
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return ret;
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tmp = AT91_PMC_USB_USBS_(best_source_index) |
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AT91_PMC_USB_DIV_(best_div);
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writel(tmp, &pmc->usb);
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return 0;
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}
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static struct clk_ops at91_usb_clk_ops = {
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.get_rate = at91_usb_clk_get_rate,
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.set_rate = at91_usb_clk_set_rate,
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};
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static int at91_usb_clk_ofdata_to_platdata(struct udevice *dev)
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{
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struct at91_usb_clk_priv *priv = dev_get_priv(dev);
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u32 cells[AT91_USB_CLK_SOURCE_MAX];
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u32 num_clksource;
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num_clksource = fdtdec_get_int_array_count(gd->fdt_blob,
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dev_of_offset(dev),
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"clocks", cells,
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AT91_USB_CLK_SOURCE_MAX);
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if (!num_clksource)
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return -1;
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priv->num_clksource = num_clksource;
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return 0;
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}
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static int at91_usb_clk_probe(struct udevice *dev)
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{
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return at91_pmc_core_probe(dev);
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}
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static const struct udevice_id at91_usb_clk_match[] = {
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{ .compatible = "atmel,at91sam9x5-clk-usb" },
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{}
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};
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U_BOOT_DRIVER(at91_usb_clk) = {
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.name = "at91-usb-clk",
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.id = UCLASS_CLK,
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.of_match = at91_usb_clk_match,
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.probe = at91_usb_clk_probe,
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.ofdata_to_platdata = at91_usb_clk_ofdata_to_platdata,
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.priv_auto_alloc_size = sizeof(struct at91_usb_clk_priv),
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.platdata_auto_alloc_size = sizeof(struct pmc_platdata),
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.ops = &at91_usb_clk_ops,
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};
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