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 static inline int is_pck(int id) 18 { 19 return (id >= 8) && (id <= 15); 20 } 21 22 static int at91_system_clk_enable(struct clk *clk) 23 { 24 struct pmc_platdata *plat = dev_get_platdata(clk->dev); 25 struct at91_pmc *pmc = plat->reg_base; 26 u32 mask; 27 28 if (clk->id > SYSTEM_MAX_ID) 29 return -EINVAL; 30 31 mask = BIT(clk->id); 32 33 writel(mask, &pmc->scer); 34 35 /** 36 * For the programmable clocks the Ready status in the PMC 37 * status register should be checked after enabling. 38 * For other clocks this is unnecessary. 39 */ 40 if (!is_pck(clk->id)) 41 return 0; 42 43 while (!(readl(&pmc->sr) & mask)) 44 ; 45 46 return 0; 47 } 48 49 static struct clk_ops at91_system_clk_ops = { 50 .enable = at91_system_clk_enable, 51 }; 52 53 static int at91_system_clk_bind(struct udevice *dev) 54 { 55 return at91_pmc_clk_node_bind(dev); 56 } 57 58 static int at91_system_clk_probe(struct udevice *dev) 59 { 60 return at91_pmc_core_probe(dev); 61 } 62 63 static const struct udevice_id at91_system_clk_match[] = { 64 { .compatible = "atmel,at91rm9200-clk-system" }, 65 {} 66 }; 67 68 U_BOOT_DRIVER(at91_system_clk) = { 69 .name = "at91-system-clk", 70 .id = UCLASS_CLK, 71 .of_match = at91_system_clk_match, 72 .bind = at91_system_clk_bind, 73 .probe = at91_system_clk_probe, 74 .platdata_auto_alloc_size = sizeof(struct pmc_platdata), 75 .ops = &at91_system_clk_ops, 76 }; 77