2 * Copyright (C) 2018 Microhip / Atmel Corporation
3 * Wenyou.Yang <wenyou.yang@microchip.com>
5 * SPDX-License-Identifier: GPL-2.0+
9 #include <clk-uclass.h>
10 #include <dm/device.h>
12 #include <mach/at91_pmc.h>
15 DECLARE_GLOBAL_DATA_PTR;
17 #define AT91_USB_CLK_SOURCE_MAX 2
18 #define AT91_USB_CLK_MAX_DIV 15
20 struct at91_usb_clk_priv {
24 static ulong at91_usb_clk_get_rate(struct clk *clk)
26 struct pmc_platdata *plat = dev_get_platdata(clk->dev);
27 struct at91_pmc *pmc = plat->reg_base;
33 tmp = readl(&pmc->pcr);
34 source_index = (tmp >> AT91_PMC_USB_USBS_OFFSET) &
35 AT91_PMC_USB_USBS_MASK;
36 usbdiv = (tmp >> AT91_PMC_USB_DIV_OFFSET) & AT91_PMC_USB_DIV_MASK;
38 ret = clk_get_by_index(clk->dev, source_index, &source);
42 return clk_get_rate(&source) / (usbdiv + 1);
45 static ulong at91_usb_clk_set_rate(struct clk *clk, ulong rate)
47 struct pmc_platdata *plat = dev_get_platdata(clk->dev);
48 struct at91_pmc *pmc = plat->reg_base;
49 struct at91_usb_clk_priv *priv = dev_get_priv(clk->dev);
50 struct clk source, best_source;
51 ulong tmp_rate, best_rate = rate, source_rate;
52 int tmp_diff, best_diff = -1;
53 u32 div, best_div = 0;
54 u8 best_source_index = 0;
59 for (i = 0; i < priv->num_clksource; i++) {
60 ret = clk_get_by_index(clk->dev, i, &source);
64 source_rate = clk_get_rate(&source);
65 if (IS_ERR_VALUE(source_rate))
68 for (div = 1; div < AT91_USB_CLK_MAX_DIV + 2; div++) {
69 tmp_rate = DIV_ROUND_CLOSEST(source_rate, div);
70 tmp_diff = abs(rate - tmp_rate);
72 if (best_diff < 0 || best_diff > tmp_diff) {
78 best_source_index = i;
81 if (!best_diff || tmp_rate < rate)
89 debug("AT91 USB: best sourc: %s, best_rate = %ld, best_div = %d\n",
90 best_source.dev->name, best_rate, best_div);
92 ret = clk_enable(&best_source);
96 tmp = AT91_PMC_USB_USBS_(best_source_index) |
97 AT91_PMC_USB_DIV_(best_div);
98 writel(tmp, &pmc->usb);
103 static struct clk_ops at91_usb_clk_ops = {
104 .get_rate = at91_usb_clk_get_rate,
105 .set_rate = at91_usb_clk_set_rate,
108 static int at91_usb_clk_ofdata_to_platdata(struct udevice *dev)
110 struct at91_usb_clk_priv *priv = dev_get_priv(dev);
111 u32 cells[AT91_USB_CLK_SOURCE_MAX];
114 num_clksource = fdtdec_get_int_array_count(gd->fdt_blob,
117 AT91_USB_CLK_SOURCE_MAX);
122 priv->num_clksource = num_clksource;
127 static int at91_usb_clk_probe(struct udevice *dev)
129 return at91_pmc_core_probe(dev);
132 static const struct udevice_id at91_usb_clk_match[] = {
133 { .compatible = "atmel,at91sam9x5-clk-usb" },
137 U_BOOT_DRIVER(at91_usb_clk) = {
138 .name = "at91-usb-clk",
140 .of_match = at91_usb_clk_match,
141 .probe = at91_usb_clk_probe,
142 .ofdata_to_platdata = at91_usb_clk_ofdata_to_platdata,
143 .priv_auto_alloc_size = sizeof(struct at91_usb_clk_priv),
144 .platdata_auto_alloc_size = sizeof(struct pmc_platdata),
145 .ops = &at91_usb_clk_ops,