tests/qtest/qtest_aspeed.c

   1 /*
   2  * Aspeed i2c bus interface for reading from and writing to i2c device registers
   3  *
   4  * Copyright (c) 2023 IBM Corporation
   5  *
   6  * Authors:
   7  *   Stefan Berger <stefanb@linux.ibm.com>
   8  *
   9  * This work is licensed under the terms of the GNU GPL, version 2 or later.
  10  * See the COPYING file in the top-level directory.
  11  */
  12
  13 #include "qemu/osdep.h"
  14
  15 #include "qtest_aspeed.h"
  16 #include "hw/i2c/aspeed_i2c.h"
  17
  18 static void aspeed_i2c_startup(QTestState *s, uint32_t baseaddr,
  19                                uint8_t slave_addr, uint8_t reg)
  20 {
  21     uint32_t v;
  22     static int once;
  23
  24     if (!once) {
  25         /* one time: enable master */
  26        qtest_writel(s, baseaddr + A_I2CC_FUN_CTRL, 0);
  27        v = qtest_readl(s, baseaddr + A_I2CC_FUN_CTRL) | A_I2CD_MASTER_EN;
  28        qtest_writel(s, baseaddr + A_I2CC_FUN_CTRL, v);
  29        once = 1;
  30     }
  31
  32     /* select device */
  33     qtest_writel(s, baseaddr + A_I2CD_BYTE_BUF, slave_addr << 1);
  34     qtest_writel(s, baseaddr + A_I2CD_CMD,
  35                  A_I2CD_M_START_CMD | A_I2CD_M_RX_CMD);
  36
  37     /* select the register to write to */
  38     qtest_writel(s, baseaddr + A_I2CD_BYTE_BUF, reg);
  39     qtest_writel(s, baseaddr + A_I2CD_CMD, A_I2CD_M_TX_CMD);
  40 }
  41
  42 static uint32_t aspeed_i2c_read_n(QTestState *s,
  43                                   uint32_t baseaddr, uint8_t slave_addr,
  44                                   uint8_t reg, size_t nbytes)
  45 {
  46     uint32_t res = 0;
  47     uint32_t v;
  48     size_t i;
  49
  50     aspeed_i2c_startup(s, baseaddr, slave_addr, reg);
  51
  52     for (i = 0; i < nbytes; i++) {
  53         qtest_writel(s, baseaddr + A_I2CD_CMD, A_I2CD_M_RX_CMD);
  54         v = qtest_readl(s, baseaddr + A_I2CD_BYTE_BUF) >> 8;
  55         res |= (v & 0xff) << (i * 8);
  56     }
  57
  58     qtest_writel(s, baseaddr + A_I2CD_CMD, A_I2CD_M_STOP_CMD);
  59
  60     return res;
  61 }
  62
  63 uint32_t aspeed_i2c_readl(QTestState *s,
  64                           uint32_t baseaddr, uint8_t slave_addr, uint8_t reg)
  65 {
  66     return aspeed_i2c_read_n(s, baseaddr, slave_addr, reg, sizeof(uint32_t));
  67 }
  68
  69 uint16_t aspeed_i2c_readw(QTestState *s,
  70                           uint32_t baseaddr, uint8_t slave_addr, uint8_t reg)
  71 {
  72     return aspeed_i2c_read_n(s, baseaddr, slave_addr, reg, sizeof(uint16_t));
  73 }
  74
  75 uint8_t aspeed_i2c_readb(QTestState *s,
  76                          uint32_t baseaddr, uint8_t slave_addr, uint8_t reg)
  77 {
  78     return aspeed_i2c_read_n(s, baseaddr, slave_addr, reg, sizeof(uint8_t));
  79 }
  80
  81 static void aspeed_i2c_write_n(QTestState *s,
  82                                uint32_t baseaddr, uint8_t slave_addr,
  83                                uint8_t reg, uint32_t v, size_t nbytes)
  84 {
  85     size_t i;
  86
  87     aspeed_i2c_startup(s, baseaddr, slave_addr, reg);
  88
  89     for (i = 0; i < nbytes; i++) {
  90         qtest_writel(s, baseaddr + A_I2CD_BYTE_BUF, v & 0xff);
  91         v >>= 8;
  92         qtest_writel(s, baseaddr + A_I2CD_CMD, A_I2CD_M_TX_CMD);
  93     }
  94
  95     qtest_writel(s, baseaddr + A_I2CD_CMD, A_I2CD_M_STOP_CMD);
  96 }
  97
  98 void aspeed_i2c_writel(QTestState *s,
  99                        uint32_t baseaddr, uint8_t slave_addr,
 100                        uint8_t reg, uint32_t v)
 101 {
 102     aspeed_i2c_write_n(s, baseaddr, slave_addr, reg, v, sizeof(v));
 103 }
 104
 105 void aspeed_i2c_writew(QTestState *s,
 106                        uint32_t baseaddr, uint8_t slave_addr,
 107                        uint8_t reg, uint16_t v)
 108 {
 109     aspeed_i2c_write_n(s, baseaddr, slave_addr, reg, v, sizeof(v));
 110 }
 111
 112 void aspeed_i2c_writeb(QTestState *s,
 113                        uint32_t baseaddr, uint8_t slave_addr,
 114                        uint8_t reg, uint8_t v)
 115 {
 116     aspeed_i2c_write_n(s, baseaddr, slave_addr, reg, v, sizeof(v));
 117 }