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