1 /* 2 * Voltage Controller implementation for OMAP 3 * 4 * Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.com/ 5 * Nishanth Menon 6 * 7 * This program is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License version 2 as 9 * published by the Free Software Foundation. 10 * 11 * This program is distributed "as is" WITHOUT ANY WARRANTY of any 12 * kind, whether express or implied; without even the implied warranty 13 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 */ 16 17 #include <common.h> 18 #include <asm/omap_common.h> 19 #include <asm/arch/sys_proto.h> 20 #include <asm/arch/clock.h> 21 22 /* Register defines and masks for VC IP Block */ 23 /* PRM_VC_CFG_I2C_MODE */ 24 #define PRM_VC_CFG_I2C_MODE_DFILTEREN_BIT (0x1 << 6) 25 #define PRM_VC_CFG_I2C_MODE_SRMODEEN_BIT (0x1 << 4) 26 #define PRM_VC_CFG_I2C_MODE_HSMODEEN_BIT (0x1 << 3) 27 #define PRM_VC_CFG_I2C_MODE_HSMCODE_SHIFT 0x0 28 #define PRM_VC_CFG_I2C_MODE_HSMCODE_MASK 0x3 29 30 /* PRM_VC_CFG_I2C_CLK */ 31 #define PRM_VC_CFG_I2C_CLK_HSCLL_SHIFT 24 32 #define PRM_VC_CFG_I2C_CLK_HSCLL_MASK 0xFF 33 #define PRM_VC_CFG_I2C_CLK_HSCLH_SHIFT 16 34 #define PRM_VC_CFG_I2C_CLK_HSCLH_MASK 0xFF 35 #define PRM_VC_CFG_I2C_CLK_SCLH_SHIFT 0 36 #define PRM_VC_CFG_I2C_CLK_SCLH_MASK 0xFF 37 #define PRM_VC_CFG_I2C_CLK_SCLL_SHIFT 8 38 #define PRM_VC_CFG_I2C_CLK_SCLL_MASK (0xFF << 8) 39 40 /* PRM_VC_VAL_BYPASS */ 41 #define PRM_VC_VAL_BYPASS_VALID_BIT (0x1 << 24) 42 #define PRM_VC_VAL_BYPASS_SLAVEADDR_SHIFT 0 43 #define PRM_VC_VAL_BYPASS_SLAVEADDR_MASK 0x7F 44 #define PRM_VC_VAL_BYPASS_REGADDR_SHIFT 8 45 #define PRM_VC_VAL_BYPASS_REGADDR_MASK 0xFF 46 #define PRM_VC_VAL_BYPASS_DATA_SHIFT 16 47 #define PRM_VC_VAL_BYPASS_DATA_MASK 0xFF 48 49 /** 50 * omap_vc_init() - Initialization for Voltage controller 51 * @speed_khz: I2C buspeed in KHz 52 */ 53 static void omap_vc_init(u16 speed_khz) 54 { 55 u32 val; 56 u32 sys_clk_khz, cycles_hi, cycles_low; 57 58 sys_clk_khz = get_sys_clk_freq() / 1000; 59 60 if (speed_khz > 400) { 61 puts("higher speed requested - throttle to 400Khz\n"); 62 speed_khz = 400; 63 } 64 65 /* 66 * Setup the dedicated I2C controller for Voltage Control 67 * I2C clk - high period 40% low period 60% 68 */ 69 speed_khz /= 10; 70 cycles_hi = sys_clk_khz * 4 / speed_khz; 71 cycles_low = sys_clk_khz * 6 / speed_khz; 72 /* values to be set in register - less by 5 & 7 respectively */ 73 cycles_hi -= 5; 74 cycles_low -= 7; 75 val = (cycles_hi << PRM_VC_CFG_I2C_CLK_SCLH_SHIFT) | 76 (cycles_low << PRM_VC_CFG_I2C_CLK_SCLL_SHIFT); 77 writel(val, (*prcm)->prm_vc_cfg_i2c_clk); 78 79 /* 80 * Master code if there are multiple masters on the I2C_SR bus. 81 */ 82 val = 0x0 << PRM_VC_CFG_I2C_MODE_HSMCODE_SHIFT; 83 /* No HS mode for now */ 84 val &= ~PRM_VC_CFG_I2C_MODE_HSMODEEN_BIT; 85 writel(val, (*prcm)->prm_vc_cfg_i2c_mode); 86 } 87 88 /** 89 * omap_vc_bypass_send_value() - Send a data using VC Bypass command 90 * @sa: 7 bit I2C slave address of the PMIC 91 * @reg_addr: I2C register address(8 bit) address in PMIC 92 * @reg_data: what 8 bit data to write 93 */ 94 int omap_vc_bypass_send_value(u8 sa, u8 reg_addr, u8 reg_data) 95 { 96 /* 97 * Unfortunately we need to loop here instead of a defined time 98 * use arbitary large value 99 */ 100 u32 timeout = 0xFFFF; 101 u32 reg_val; 102 103 sa &= PRM_VC_VAL_BYPASS_SLAVEADDR_MASK; 104 reg_addr &= PRM_VC_VAL_BYPASS_REGADDR_MASK; 105 reg_data &= PRM_VC_VAL_BYPASS_DATA_MASK; 106 107 /* program VC to send data */ 108 reg_val = sa << PRM_VC_VAL_BYPASS_SLAVEADDR_SHIFT | 109 reg_addr << PRM_VC_VAL_BYPASS_REGADDR_SHIFT | 110 reg_data << PRM_VC_VAL_BYPASS_DATA_SHIFT; 111 writel(reg_val, (*prcm)->prm_vc_val_bypass); 112 113 /* Signal VC to send data */ 114 writel(reg_val | PRM_VC_VAL_BYPASS_VALID_BIT, 115 (*prcm)->prm_vc_val_bypass); 116 117 /* Wait on VC to complete transmission */ 118 do { 119 reg_val = readl((*prcm)->prm_vc_val_bypass) & 120 PRM_VC_VAL_BYPASS_VALID_BIT; 121 if (!reg_val) 122 break; 123 124 sdelay(100); 125 } while (--timeout); 126 127 /* Optional: cleanup PRM_IRQSTATUS_Ax */ 128 /* In case we can do something about it in future.. */ 129 if (!timeout) 130 return -1; 131 132 /* All good.. */ 133 return 0; 134 } 135 136 void sri2c_init(void) 137 { 138 static int sri2c = 1; 139 140 if (sri2c) { 141 omap_vc_init(PRM_VC_I2C_CHANNEL_FREQ_KHZ); 142 sri2c = 0; 143 } 144 return; 145 } 146