Nishanth Menon | 41d7ab1 | 2012-03-01 14:17:37 +0000 | [diff] [blame] | 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 | |
| 21 | /* |
| 22 | * Define Master code if there are multiple masters on the I2C_SR bus. |
| 23 | * Normally not required |
| 24 | */ |
| 25 | #ifndef CONFIG_OMAP_VC_I2C_HS_MCODE |
| 26 | #define CONFIG_OMAP_VC_I2C_HS_MCODE 0x0 |
| 27 | #endif |
| 28 | |
| 29 | /* Register defines and masks for VC IP Block */ |
| 30 | /* PRM_VC_CFG_I2C_MODE */ |
| 31 | #define PRM_VC_CFG_I2C_MODE_DFILTEREN_BIT (0x1 << 6) |
| 32 | #define PRM_VC_CFG_I2C_MODE_SRMODEEN_BIT (0x1 << 4) |
| 33 | #define PRM_VC_CFG_I2C_MODE_HSMODEEN_BIT (0x1 << 3) |
| 34 | #define PRM_VC_CFG_I2C_MODE_HSMCODE_SHIFT 0x0 |
| 35 | #define PRM_VC_CFG_I2C_MODE_HSMCODE_MASK 0x3 |
| 36 | |
| 37 | /* PRM_VC_CFG_I2C_CLK */ |
| 38 | #define PRM_VC_CFG_I2C_CLK_HSCLL_SHIFT 24 |
| 39 | #define PRM_VC_CFG_I2C_CLK_HSCLL_MASK 0xFF |
| 40 | #define PRM_VC_CFG_I2C_CLK_HSCLH_SHIFT 16 |
| 41 | #define PRM_VC_CFG_I2C_CLK_HSCLH_MASK 0xFF |
| 42 | #define PRM_VC_CFG_I2C_CLK_SCLH_SHIFT 0 |
| 43 | #define PRM_VC_CFG_I2C_CLK_SCLH_MASK 0xFF |
| 44 | #define PRM_VC_CFG_I2C_CLK_SCLL_SHIFT 8 |
| 45 | #define PRM_VC_CFG_I2C_CLK_SCLL_MASK (0xFF << 8) |
| 46 | |
| 47 | /* PRM_VC_VAL_BYPASS */ |
| 48 | #define PRM_VC_VAL_BYPASS_VALID_BIT (0x1 << 24) |
| 49 | #define PRM_VC_VAL_BYPASS_SLAVEADDR_SHIFT 0 |
| 50 | #define PRM_VC_VAL_BYPASS_SLAVEADDR_MASK 0x7F |
| 51 | #define PRM_VC_VAL_BYPASS_REGADDR_SHIFT 8 |
| 52 | #define PRM_VC_VAL_BYPASS_REGADDR_MASK 0xFF |
| 53 | #define PRM_VC_VAL_BYPASS_DATA_SHIFT 16 |
| 54 | #define PRM_VC_VAL_BYPASS_DATA_MASK 0xFF |
| 55 | |
| 56 | /** |
| 57 | * omap_vc_init() - Initialization for Voltage controller |
| 58 | * @speed_khz: I2C buspeed in KHz |
| 59 | */ |
| 60 | void omap_vc_init(u16 speed_khz) |
| 61 | { |
| 62 | u32 val; |
| 63 | u32 sys_clk_khz, cycles_hi, cycles_low; |
| 64 | |
| 65 | sys_clk_khz = get_sys_clk_freq() / 1000; |
| 66 | |
| 67 | if (speed_khz > 400) { |
| 68 | puts("higher speed requested - throttle to 400Khz\n"); |
| 69 | speed_khz = 400; |
| 70 | } |
| 71 | |
| 72 | /* |
| 73 | * Setup the dedicated I2C controller for Voltage Control |
| 74 | * I2C clk - high period 40% low period 60% |
| 75 | */ |
| 76 | speed_khz /= 10; |
| 77 | cycles_hi = sys_clk_khz * 4 / speed_khz; |
| 78 | cycles_low = sys_clk_khz * 6 / speed_khz; |
| 79 | /* values to be set in register - less by 5 & 7 respectively */ |
| 80 | cycles_hi -= 5; |
| 81 | cycles_low -= 7; |
| 82 | val = (cycles_hi << PRM_VC_CFG_I2C_CLK_SCLH_SHIFT) | |
| 83 | (cycles_low << PRM_VC_CFG_I2C_CLK_SCLL_SHIFT); |
| 84 | writel(val, &prcm->prm_vc_cfg_i2c_clk); |
| 85 | |
| 86 | val = CONFIG_OMAP_VC_I2C_HS_MCODE << |
| 87 | PRM_VC_CFG_I2C_MODE_HSMCODE_SHIFT; |
| 88 | /* No HS mode for now */ |
| 89 | val &= ~PRM_VC_CFG_I2C_MODE_HSMODEEN_BIT; |
| 90 | writel(val, &prcm->prm_vc_cfg_i2c_mode); |
| 91 | } |
| 92 | |
| 93 | /** |
| 94 | * omap_vc_bypass_send_value() - Send a data using VC Bypass command |
| 95 | * @sa: 7 bit I2C slave address of the PMIC |
| 96 | * @reg_addr: I2C register address(8 bit) address in PMIC |
| 97 | * @reg_data: what 8 bit data to write |
| 98 | */ |
| 99 | int omap_vc_bypass_send_value(u8 sa, u8 reg_addr, u8 reg_data) |
| 100 | { |
| 101 | /* |
| 102 | * Unfortunately we need to loop here instead of a defined time |
| 103 | * use arbitary large value |
| 104 | */ |
| 105 | u32 timeout = 0xFFFF; |
| 106 | u32 reg_val; |
| 107 | |
| 108 | sa &= PRM_VC_VAL_BYPASS_SLAVEADDR_MASK; |
| 109 | reg_addr &= PRM_VC_VAL_BYPASS_REGADDR_MASK; |
| 110 | reg_data &= PRM_VC_VAL_BYPASS_DATA_MASK; |
| 111 | |
| 112 | /* program VC to send data */ |
| 113 | reg_val = sa << PRM_VC_VAL_BYPASS_SLAVEADDR_SHIFT | |
| 114 | reg_addr << PRM_VC_VAL_BYPASS_REGADDR_SHIFT | |
| 115 | reg_data << PRM_VC_VAL_BYPASS_DATA_SHIFT; |
| 116 | writel(reg_val, &prcm->prm_vc_val_bypass); |
| 117 | |
| 118 | /* Signal VC to send data */ |
| 119 | writel(reg_val | PRM_VC_VAL_BYPASS_VALID_BIT, &prcm->prm_vc_val_bypass); |
| 120 | |
| 121 | /* Wait on VC to complete transmission */ |
| 122 | do { |
| 123 | reg_val = readl(&prcm->prm_vc_val_bypass) & |
| 124 | PRM_VC_VAL_BYPASS_VALID_BIT; |
| 125 | if (!reg_val) |
| 126 | break; |
| 127 | |
| 128 | sdelay(100); |
| 129 | } while (--timeout); |
| 130 | |
| 131 | /* Optional: cleanup PRM_IRQSTATUS_Ax */ |
| 132 | /* In case we can do something about it in future.. */ |
| 133 | if (!timeout) |
| 134 | return -1; |
| 135 | |
| 136 | /* All good.. */ |
| 137 | return 0; |
| 138 | } |