1/* 2 * OMAP3517/3505-specific clock framework functions 3 * 4 * Copyright (C) 2010 Texas Instruments, Inc. 5 * Copyright (C) 2010 Nokia Corporation 6 * 7 * Ranjith Lohithakshan 8 * Paul Walmsley 9 * 10 * Parts of this code are based on code written by 11 * Richard Woodruff, Tony Lindgren, Tuukka Tikkanen, Karthik Dasu, 12 * Russell King 13 * 14 * This program is free software; you can redistribute it and/or modify 15 * it under the terms of the GNU General Public License version 2 as 16 * published by the Free Software Foundation. 17 */ 18#undef DEBUG 19 20#include <linux/kernel.h> 21#include <linux/clk.h> 22#include <linux/io.h> 23 24#include <plat/clock.h> 25 26#include "clock.h" 27#include "clock3517.h" 28#include "cm.h" 29#include "cm-regbits-34xx.h" 30 31/* 32 * In AM35xx IPSS, the {ICK,FCK} enable bits for modules are exported 33 * in the same register at a bit offset of 0x8. The EN_ACK for ICK is 34 * at an offset of 4 from ICK enable bit. 35 */ 36#define AM35XX_IPSS_ICK_MASK 0xF 37#define AM35XX_IPSS_ICK_EN_ACK_OFFSET 0x4 38#define AM35XX_IPSS_ICK_FCK_OFFSET 0x8 39#define AM35XX_IPSS_CLK_IDLEST_VAL 0 40 41/** 42 * am35xx_clk_find_idlest - return clock ACK info for AM35XX IPSS 43 * @clk: struct clk * being enabled 44 * @idlest_reg: void __iomem ** to store CM_IDLEST reg address into 45 * @idlest_bit: pointer to a u8 to store the CM_IDLEST bit shift into 46 * @idlest_val: pointer to a u8 to store the CM_IDLEST indicator 47 * 48 * The interface clocks on AM35xx IPSS reflects the clock idle status 49 * in the enable register itsel at a bit offset of 4 from the enable 50 * bit. A value of 1 indicates that clock is enabled. 51 */ 52static void am35xx_clk_find_idlest(struct clk *clk, 53 void __iomem **idlest_reg, 54 u8 *idlest_bit, 55 u8 *idlest_val) 56{ 57 *idlest_reg = (__force void __iomem *)(clk->enable_reg); 58 *idlest_bit = clk->enable_bit + AM35XX_IPSS_ICK_EN_ACK_OFFSET; 59 *idlest_val = AM35XX_IPSS_CLK_IDLEST_VAL; 60} 61 62/** 63 * am35xx_clk_find_companion - find companion clock to @clk 64 * @clk: struct clk * to find the companion clock of 65 * @other_reg: void __iomem ** to return the companion clock CM_*CLKEN va in 66 * @other_bit: u8 ** to return the companion clock bit shift in 67 * 68 * Some clocks don't have companion clocks. For example, modules with 69 * only an interface clock (such as HECC) don't have a companion 70 * clock. Right now, this code relies on the hardware exporting a bit 71 * in the correct companion register that indicates that the 72 * nonexistent 'companion clock' is active. Future patches will 73 * associate this type of code with per-module data structures to 74 * avoid this issue, and remove the casts. No return value. 75 */ 76static void am35xx_clk_find_companion(struct clk *clk, void __iomem **other_reg, 77 u8 *other_bit) 78{ 79 *other_reg = (__force void __iomem *)(clk->enable_reg); 80 if (clk->enable_bit & AM35XX_IPSS_ICK_MASK) 81 *other_bit = clk->enable_bit + AM35XX_IPSS_ICK_FCK_OFFSET; 82 else 83 *other_bit = clk->enable_bit - AM35XX_IPSS_ICK_FCK_OFFSET; 84} 85 86const struct clkops clkops_am35xx_ipss_module_wait = { 87 .enable = omap2_dflt_clk_enable, 88 .disable = omap2_dflt_clk_disable, 89 .find_idlest = am35xx_clk_find_idlest, 90 .find_companion = am35xx_clk_find_companion, 91}; 92 93/** 94 * am35xx_clk_ipss_find_idlest - return CM_IDLEST info for IPSS 95 * @clk: struct clk * being enabled 96 * @idlest_reg: void __iomem ** to store CM_IDLEST reg address into 97 * @idlest_bit: pointer to a u8 to store the CM_IDLEST bit shift into 98 * @idlest_val: pointer to a u8 to store the CM_IDLEST indicator 99 * 100 * The IPSS target CM_IDLEST bit is at a different shift from the 101 * CM_{I,F}CLKEN bit. Pass back the correct info via @idlest_reg 102 * and @idlest_bit. No return value. 103 */ 104static void am35xx_clk_ipss_find_idlest(struct clk *clk, 105 void __iomem **idlest_reg, 106 u8 *idlest_bit, 107 u8 *idlest_val) 108{ 109 u32 r; 110 111 r = (((__force u32)clk->enable_reg & ~0xf0) | 0x20); 112 *idlest_reg = (__force void __iomem *)r; 113 *idlest_bit = AM35XX_ST_IPSS_SHIFT; 114 *idlest_val = OMAP34XX_CM_IDLEST_VAL; 115} 116 117const struct clkops clkops_am35xx_ipss_wait = { 118 .enable = omap2_dflt_clk_enable, 119 .disable = omap2_dflt_clk_disable, 120 .find_idlest = am35xx_clk_ipss_find_idlest, 121 .find_companion = omap2_clk_dflt_find_companion, 122}; 123