1 /* 2 * Copyright (C) 2016 Atmel Corporation 3 * Wenyou.Yang <wenyou.yang@atmel.com> 4 * 5 * SPDX-License-Identifier: GPL-2.0+ 6 */ 7 8 #include <common.h> 9 #include <clk-uclass.h> 10 #include <dm/device.h> 11 #include <linux/io.h> 12 #include <mach/at91_pmc.h> 13 #include "pmc.h" 14 15 #define SYSTEM_MAX_ID 31 16 17 /** 18 * at91_system_clk_bind() - for the system clock driver 19 * Recursively bind its children as clk devices. 20 * 21 * @return: 0 on success, or negative error code on failure 22 */ 23 static int at91_system_clk_bind(struct udevice *dev) 24 { 25 return at91_clk_sub_device_bind(dev, "system-clk"); 26 } 27 28 static const struct udevice_id at91_system_clk_match[] = { 29 { .compatible = "atmel,at91rm9200-clk-system" }, 30 {} 31 }; 32 33 U_BOOT_DRIVER(at91_system_clk) = { 34 .name = "at91-system-clk", 35 .id = UCLASS_MISC, 36 .of_match = at91_system_clk_match, 37 .bind = at91_system_clk_bind, 38 }; 39 40 /*----------------------------------------------------------*/ 41 42 static inline int is_pck(int id) 43 { 44 return (id >= 8) && (id <= 15); 45 } 46 47 static int system_clk_enable(struct clk *clk) 48 { 49 struct pmc_platdata *plat = dev_get_platdata(clk->dev); 50 struct at91_pmc *pmc = plat->reg_base; 51 u32 mask; 52 53 if (clk->id > SYSTEM_MAX_ID) 54 return -EINVAL; 55 56 mask = BIT(clk->id); 57 58 writel(mask, &pmc->scer); 59 60 /** 61 * For the programmable clocks the Ready status in the PMC 62 * status register should be checked after enabling. 63 * For other clocks this is unnecessary. 64 */ 65 if (!is_pck(clk->id)) 66 return 0; 67 68 while (!(readl(&pmc->sr) & mask)) 69 ; 70 71 return 0; 72 } 73 74 static struct clk_ops system_clk_ops = { 75 .of_xlate = at91_clk_of_xlate, 76 .enable = system_clk_enable, 77 }; 78 79 U_BOOT_DRIVER(system_clk) = { 80 .name = "system-clk", 81 .id = UCLASS_CLK, 82 .probe = at91_clk_probe, 83 .platdata_auto_alloc_size = sizeof(struct pmc_platdata), 84 .ops = &system_clk_ops, 85 }; 86