.. | .. |
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1 | 1 | // SPDX-License-Identifier: GPL-2.0 |
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2 | 2 | /* |
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3 | | - * Intel BayTrail PMIC I2C bus semaphore implementaion |
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| 3 | + * Intel BayTrail PMIC I2C bus semaphore implementation |
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4 | 4 | * Copyright (c) 2014, Intel Corporation. |
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5 | 5 | */ |
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6 | | -#include <linux/delay.h> |
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7 | 6 | #include <linux/device.h> |
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8 | 7 | #include <linux/acpi.h> |
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9 | 8 | #include <linux/i2c.h> |
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10 | 9 | #include <linux/interrupt.h> |
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11 | | -#include <linux/pm_qos.h> |
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12 | 10 | |
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13 | 11 | #include <asm/iosf_mbi.h> |
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14 | 12 | |
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15 | 13 | #include "i2c-designware-core.h" |
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16 | | - |
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17 | | -#define SEMAPHORE_TIMEOUT 500 |
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18 | | -#define PUNIT_SEMAPHORE 0x7 |
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19 | | -#define PUNIT_SEMAPHORE_CHT 0x10e |
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20 | | -#define PUNIT_SEMAPHORE_BIT BIT(0) |
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21 | | -#define PUNIT_SEMAPHORE_ACQUIRE BIT(1) |
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22 | | - |
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23 | | -static unsigned long acquired; |
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24 | | - |
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25 | | -static u32 get_sem_addr(struct dw_i2c_dev *dev) |
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26 | | -{ |
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27 | | - if (dev->flags & MODEL_CHERRYTRAIL) |
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28 | | - return PUNIT_SEMAPHORE_CHT; |
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29 | | - else |
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30 | | - return PUNIT_SEMAPHORE; |
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31 | | -} |
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32 | | - |
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33 | | -static int get_sem(struct dw_i2c_dev *dev, u32 *sem) |
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34 | | -{ |
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35 | | - u32 addr = get_sem_addr(dev); |
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36 | | - u32 data; |
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37 | | - int ret; |
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38 | | - |
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39 | | - ret = iosf_mbi_read(BT_MBI_UNIT_PMC, MBI_REG_READ, addr, &data); |
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40 | | - if (ret) { |
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41 | | - dev_err(dev->dev, "iosf failed to read punit semaphore\n"); |
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42 | | - return ret; |
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43 | | - } |
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44 | | - |
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45 | | - *sem = data & PUNIT_SEMAPHORE_BIT; |
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46 | | - |
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47 | | - return 0; |
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48 | | -} |
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49 | | - |
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50 | | -static void reset_semaphore(struct dw_i2c_dev *dev) |
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51 | | -{ |
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52 | | - if (iosf_mbi_modify(BT_MBI_UNIT_PMC, MBI_REG_READ, get_sem_addr(dev), |
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53 | | - 0, PUNIT_SEMAPHORE_BIT)) |
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54 | | - dev_err(dev->dev, "iosf failed to reset punit semaphore during write\n"); |
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55 | | - |
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56 | | - pm_qos_update_request(&dev->pm_qos, PM_QOS_DEFAULT_VALUE); |
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57 | | - |
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58 | | - iosf_mbi_call_pmic_bus_access_notifier_chain(MBI_PMIC_BUS_ACCESS_END, |
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59 | | - NULL); |
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60 | | - iosf_mbi_punit_release(); |
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61 | | -} |
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62 | | - |
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63 | | -static int baytrail_i2c_acquire(struct dw_i2c_dev *dev) |
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64 | | -{ |
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65 | | - u32 addr; |
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66 | | - u32 sem = PUNIT_SEMAPHORE_ACQUIRE; |
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67 | | - int ret; |
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68 | | - unsigned long start, end; |
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69 | | - |
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70 | | - might_sleep(); |
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71 | | - |
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72 | | - if (!dev || !dev->dev) |
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73 | | - return -ENODEV; |
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74 | | - |
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75 | | - if (!dev->release_lock) |
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76 | | - return 0; |
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77 | | - |
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78 | | - iosf_mbi_punit_acquire(); |
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79 | | - iosf_mbi_call_pmic_bus_access_notifier_chain(MBI_PMIC_BUS_ACCESS_BEGIN, |
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80 | | - NULL); |
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81 | | - |
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82 | | - /* |
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83 | | - * Disallow the CPU to enter C6 or C7 state, entering these states |
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84 | | - * requires the punit to talk to the pmic and if this happens while |
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85 | | - * we're holding the semaphore, the SoC hangs. |
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86 | | - */ |
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87 | | - pm_qos_update_request(&dev->pm_qos, 0); |
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88 | | - |
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89 | | - addr = get_sem_addr(dev); |
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90 | | - |
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91 | | - /* host driver writes to side band semaphore register */ |
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92 | | - ret = iosf_mbi_write(BT_MBI_UNIT_PMC, MBI_REG_WRITE, addr, sem); |
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93 | | - if (ret) { |
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94 | | - dev_err(dev->dev, "iosf punit semaphore request failed\n"); |
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95 | | - goto out; |
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96 | | - } |
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97 | | - |
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98 | | - /* host driver waits for bit 0 to be set in semaphore register */ |
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99 | | - start = jiffies; |
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100 | | - end = start + msecs_to_jiffies(SEMAPHORE_TIMEOUT); |
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101 | | - do { |
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102 | | - ret = get_sem(dev, &sem); |
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103 | | - if (!ret && sem) { |
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104 | | - acquired = jiffies; |
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105 | | - dev_dbg(dev->dev, "punit semaphore acquired after %ums\n", |
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106 | | - jiffies_to_msecs(jiffies - start)); |
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107 | | - return 0; |
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108 | | - } |
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109 | | - |
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110 | | - usleep_range(1000, 2000); |
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111 | | - } while (time_before(jiffies, end)); |
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112 | | - |
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113 | | - dev_err(dev->dev, "punit semaphore timed out, resetting\n"); |
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114 | | -out: |
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115 | | - reset_semaphore(dev); |
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116 | | - |
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117 | | - ret = iosf_mbi_read(BT_MBI_UNIT_PMC, MBI_REG_READ, addr, &sem); |
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118 | | - if (ret) |
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119 | | - dev_err(dev->dev, "iosf failed to read punit semaphore\n"); |
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120 | | - else |
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121 | | - dev_err(dev->dev, "PUNIT SEM: %d\n", sem); |
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122 | | - |
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123 | | - WARN_ON(1); |
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124 | | - |
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125 | | - return -ETIMEDOUT; |
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126 | | -} |
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127 | | - |
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128 | | -static void baytrail_i2c_release(struct dw_i2c_dev *dev) |
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129 | | -{ |
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130 | | - if (!dev || !dev->dev) |
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131 | | - return; |
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132 | | - |
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133 | | - if (!dev->acquire_lock) |
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134 | | - return; |
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135 | | - |
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136 | | - reset_semaphore(dev); |
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137 | | - dev_dbg(dev->dev, "punit semaphore held for %ums\n", |
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138 | | - jiffies_to_msecs(jiffies - acquired)); |
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139 | | -} |
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140 | 14 | |
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141 | 15 | int i2c_dw_probe_lock_support(struct dw_i2c_dev *dev) |
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142 | 16 | { |
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.. | .. |
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162 | 36 | return -EPROBE_DEFER; |
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163 | 37 | |
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164 | 38 | dev_info(dev->dev, "I2C bus managed by PUNIT\n"); |
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165 | | - dev->acquire_lock = baytrail_i2c_acquire; |
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166 | | - dev->release_lock = baytrail_i2c_release; |
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167 | | - dev->pm_disabled = true; |
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168 | | - |
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169 | | - pm_qos_add_request(&dev->pm_qos, PM_QOS_CPU_DMA_LATENCY, |
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170 | | - PM_QOS_DEFAULT_VALUE); |
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| 39 | + dev->acquire_lock = iosf_mbi_block_punit_i2c_access; |
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| 40 | + dev->release_lock = iosf_mbi_unblock_punit_i2c_access; |
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| 41 | + dev->shared_with_punit = true; |
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171 | 42 | |
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172 | 43 | return 0; |
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173 | | -} |
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174 | | - |
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175 | | -void i2c_dw_remove_lock_support(struct dw_i2c_dev *dev) |
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176 | | -{ |
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177 | | - if (dev->acquire_lock) |
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178 | | - pm_qos_remove_request(&dev->pm_qos); |
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179 | 44 | } |
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