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 */
omap_vc_init(u16 speed_khz)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 */
omap_vc_bypass_send_value(u8 sa,u8 reg_addr,u8 reg_data)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
sri2c_init(void)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