arch/arm/cpu/armv7/u8500/prcmu.c

   1 /*
   2  * Copyright (C) 2009 ST-Ericsson SA
   3  *
   4  * Adapted from the Linux version:
   5  * Author: Kumar Sanghvi <kumar.sanghvi@stericsson.com>
   6  *
   7  * SPDX-License-Identifier:     GPL-2.0+
   8  */
   9
  10 /*
  11  * NOTE: This currently does not support the I2C workaround access method.
  12  */
  13
  14 #include <common.h>
  15 #include <config.h>
  16 #include <asm/io.h>
  17 #include <asm/arch/hardware.h>
  18 #include <asm/types.h>
  19 #include <asm/io.h>
  20 #include <asm/errno.h>
  21 #include <asm/arch/prcmu.h>
  22
  23 /* CPU mailbox registers */
  24 #define PRCMU_I2C_WRITE(slave)  \
  25         (((slave) << 1) | I2CWRITE | (1 << 6))
  26 #define PRCMU_I2C_READ(slave) \
  27         (((slave) << 1) | I2CREAD | (1 << 6))
  28
  29 #define I2C_MBOX_BIT    (1 << 5)
  30
  31 static int prcmu_is_ready(void)
  32 {
  33         int ready = readb(PRCM_XP70_CUR_PWR_STATE) == AP_EXECUTE;
  34         if (!ready)
  35                 printf("PRCMU firmware not ready\n");
  36         return ready;
  37 }
  38
  39 static int wait_for_i2c_mbx_rdy(void)
  40 {
  41         int timeout = 10000;
  42
  43         if (readl(PRCM_ARM_IT1_VAL) & I2C_MBOX_BIT) {
  44                 printf("prcmu: warning i2c mailbox was not acked\n");
  45                 /* clear mailbox 5 ack irq */
  46                 writel(I2C_MBOX_BIT, PRCM_ARM_IT1_CLEAR);
  47         }
  48
  49         /* check any already on-going transaction */
  50         while ((readl(PRCM_MBOX_CPU_VAL) & I2C_MBOX_BIT) && timeout)
  51                 timeout--;
  52
  53         if (timeout == 0)
  54                 return -1;
  55
  56         return 0;
  57 }
  58
  59 static int wait_for_i2c_req_done(void)
  60 {
  61         int timeout = 10000;
  62
  63         /* Set an interrupt to XP70 */
  64         writel(I2C_MBOX_BIT, PRCM_MBOX_CPU_SET);
  65
  66         /* wait for mailbox 5 (i2c) ack */
  67         while (!(readl(PRCM_ARM_IT1_VAL) & I2C_MBOX_BIT) && timeout)
  68                 timeout--;
  69
  70         if (timeout == 0)
  71                 return -1;
  72
  73         return 0;
  74 }
  75
  76 /**
  77  * prcmu_i2c_read - PRCMU - 4500 communication using PRCMU I2C
  78  * @reg: - db8500 register bank to be accessed
  79  * @slave:  - db8500 register to be accessed
  80  * Returns: ACK_MB5  value containing the status
  81  */
  82 int prcmu_i2c_read(u8 reg, u16 slave)
  83 {
  84         uint8_t i2c_status;
  85         uint8_t i2c_val;
  86         int ret;
  87
  88         if (!prcmu_is_ready())
  89                 return -1;
  90
  91         debug("\nprcmu_4500_i2c_read:bank=%x;reg=%x;\n",
  92                         reg, slave);
  93
  94         ret = wait_for_i2c_mbx_rdy();
  95         if (ret) {
  96                 printf("prcmu_i2c_read: mailbox became not ready\n");
  97                 return ret;
  98         }
  99
 100         /* prepare the data for mailbox 5 */
 101         writeb(PRCMU_I2C_READ(reg), PRCM_REQ_MB5_I2COPTYPE_REG);
 102         writeb((1 << 3) | 0x0, PRCM_REQ_MB5_BIT_FIELDS);
 103         writeb(slave, PRCM_REQ_MB5_I2CSLAVE);
 104         writeb(0, PRCM_REQ_MB5_I2CVAL);
 105
 106         ret = wait_for_i2c_req_done();
 107         if (ret) {
 108                 printf("prcmu_i2c_read: mailbox request timed out\n");
 109                 return ret;
 110         }
 111
 112         /* retrieve values */
 113         debug("ack-mb5:transfer status = %x\n",
 114                         readb(PRCM_ACK_MB5_STATUS));
 115         debug("ack-mb5:reg bank = %x\n", readb(PRCM_ACK_MB5) >> 1);
 116         debug("ack-mb5:slave_add = %x\n",
 117                         readb(PRCM_ACK_MB5_SLAVE));
 118         debug("ack-mb5:reg_val = %d\n", readb(PRCM_ACK_MB5_VAL));
 119
 120         i2c_status = readb(PRCM_ACK_MB5_STATUS);
 121         i2c_val = readb(PRCM_ACK_MB5_VAL);
 122         /* clear mailbox 5 ack irq */
 123         writel(I2C_MBOX_BIT, PRCM_ARM_IT1_CLEAR);
 124
 125         if (i2c_status == I2C_RD_OK)
 126                 return i2c_val;
 127
 128         printf("prcmu_i2c_read:read return status= %d\n", i2c_status);
 129         return -1;
 130 }
 131
 132 /**
 133  * prcmu_i2c_write - PRCMU-db8500 communication using PRCMU I2C
 134  * @reg: - db8500 register bank to be accessed
 135  * @slave:  - db800 register to be written to
 136  * @reg_data: - the data to write
 137  * Returns: ACK_MB5 value containing the status
 138  */
 139 int prcmu_i2c_write(u8 reg, u16 slave, u8 reg_data)
 140 {
 141         uint8_t i2c_status;
 142         int ret;
 143
 144         if (!prcmu_is_ready())
 145                 return -1;
 146
 147         debug("\nprcmu_4500_i2c_write:bank=%x;reg=%x;\n",
 148                         reg, slave);
 149
 150         ret = wait_for_i2c_mbx_rdy();
 151         if (ret) {
 152                 printf("prcmu_i2c_write: mailbox became not ready\n");
 153                 return ret;
 154         }
 155
 156         /* prepare the data for mailbox 5 */
 157         writeb(PRCMU_I2C_WRITE(reg), PRCM_REQ_MB5_I2COPTYPE_REG);
 158         writeb((1 << 3) | 0x0, PRCM_REQ_MB5_BIT_FIELDS);
 159         writeb(slave, PRCM_REQ_MB5_I2CSLAVE);
 160         writeb(reg_data, PRCM_REQ_MB5_I2CVAL);
 161
 162         ret = wait_for_i2c_req_done();
 163         if (ret) {
 164                 printf("prcmu_i2c_write: mailbox request timed out\n");
 165                 return ret;
 166         }
 167
 168         /* retrieve values */
 169         debug("ack-mb5:transfer status = %x\n",
 170                         readb(PRCM_ACK_MB5_STATUS));
 171         debug("ack-mb5:reg bank = %x\n", readb(PRCM_ACK_MB5) >> 1);
 172         debug("ack-mb5:slave_add = %x\n",
 173                         readb(PRCM_ACK_MB5_SLAVE));
 174         debug("ack-mb5:reg_val = %d\n", readb(PRCM_ACK_MB5_VAL));
 175
 176         i2c_status = readb(PRCM_ACK_MB5_STATUS);
 177         debug("\ni2c_status = %x\n", i2c_status);
 178         /* clear mailbox 5 ack irq */
 179         writel(I2C_MBOX_BIT, PRCM_ARM_IT1_CLEAR);
 180
 181         if (i2c_status == I2C_WR_OK)
 182                 return 0;
 183
 184         printf("%s: i2c_status : 0x%x\n", __func__, i2c_status);
 185         return -1;
 186 }
 187
 188 void u8500_prcmu_enable(u32 *reg)
 189 {
 190         writel(readl(reg) | (1 << 8), reg);
 191 }
 192
 193 void db8500_prcmu_init(void)
 194 {
 195         /* Enable timers */
 196         writel(1 << 17, PRCM_TCR);
 197
 198         u8500_prcmu_enable((u32 *)PRCM_PER1CLK_MGT_REG);
 199         u8500_prcmu_enable((u32 *)PRCM_PER2CLK_MGT_REG);
 200         u8500_prcmu_enable((u32 *)PRCM_PER3CLK_MGT_REG);
 201         /* PER4CLK does not exist */
 202         u8500_prcmu_enable((u32 *)PRCM_PER5CLK_MGT_REG);
 203         u8500_prcmu_enable((u32 *)PRCM_PER6CLK_MGT_REG);
 204         /* Only exists in ED but is always ok to write to */
 205         u8500_prcmu_enable((u32 *)PRCM_PER7CLK_MGT_REG);
 206
 207         u8500_prcmu_enable((u32 *)PRCM_UARTCLK_MGT_REG);
 208         u8500_prcmu_enable((u32 *)PRCM_I2CCLK_MGT_REG);
 209
 210         u8500_prcmu_enable((u32 *)PRCM_SDMMCCLK_MGT_REG);
 211
 212         /* Clean up the mailbox interrupts after pre-u-boot code. */
 213         writel(I2C_MBOX_BIT, PRCM_ARM_IT1_CLEAR);
 214 }