hc
2024-10-12 a5969cabbb4660eab42b6ef0412cbbd1200cf14d
kernel/drivers/i2c/busses/i2c-designware-baytrail.c
....@@ -1,142 +1,16 @@
11 // SPDX-License-Identifier: GPL-2.0
22 /*
3
- * Intel BayTrail PMIC I2C bus semaphore implementaion
3
+ * Intel BayTrail PMIC I2C bus semaphore implementation
44 * Copyright (c) 2014, Intel Corporation.
55 */
6
-#include <linux/delay.h>
76 #include <linux/device.h>
87 #include <linux/acpi.h>
98 #include <linux/i2c.h>
109 #include <linux/interrupt.h>
11
-#include <linux/pm_qos.h>
1210
1311 #include <asm/iosf_mbi.h>
1412
1513 #include "i2c-designware-core.h"
16
-
17
-#define SEMAPHORE_TIMEOUT 500
18
-#define PUNIT_SEMAPHORE 0x7
19
-#define PUNIT_SEMAPHORE_CHT 0x10e
20
-#define PUNIT_SEMAPHORE_BIT BIT(0)
21
-#define PUNIT_SEMAPHORE_ACQUIRE BIT(1)
22
-
23
-static unsigned long acquired;
24
-
25
-static u32 get_sem_addr(struct dw_i2c_dev *dev)
26
-{
27
- if (dev->flags & MODEL_CHERRYTRAIL)
28
- return PUNIT_SEMAPHORE_CHT;
29
- else
30
- return PUNIT_SEMAPHORE;
31
-}
32
-
33
-static int get_sem(struct dw_i2c_dev *dev, u32 *sem)
34
-{
35
- u32 addr = get_sem_addr(dev);
36
- u32 data;
37
- int ret;
38
-
39
- ret = iosf_mbi_read(BT_MBI_UNIT_PMC, MBI_REG_READ, addr, &data);
40
- if (ret) {
41
- dev_err(dev->dev, "iosf failed to read punit semaphore\n");
42
- return ret;
43
- }
44
-
45
- *sem = data & PUNIT_SEMAPHORE_BIT;
46
-
47
- return 0;
48
-}
49
-
50
-static void reset_semaphore(struct dw_i2c_dev *dev)
51
-{
52
- if (iosf_mbi_modify(BT_MBI_UNIT_PMC, MBI_REG_READ, get_sem_addr(dev),
53
- 0, PUNIT_SEMAPHORE_BIT))
54
- dev_err(dev->dev, "iosf failed to reset punit semaphore during write\n");
55
-
56
- pm_qos_update_request(&dev->pm_qos, PM_QOS_DEFAULT_VALUE);
57
-
58
- iosf_mbi_call_pmic_bus_access_notifier_chain(MBI_PMIC_BUS_ACCESS_END,
59
- NULL);
60
- iosf_mbi_punit_release();
61
-}
62
-
63
-static int baytrail_i2c_acquire(struct dw_i2c_dev *dev)
64
-{
65
- u32 addr;
66
- u32 sem = PUNIT_SEMAPHORE_ACQUIRE;
67
- int ret;
68
- unsigned long start, end;
69
-
70
- might_sleep();
71
-
72
- if (!dev || !dev->dev)
73
- return -ENODEV;
74
-
75
- if (!dev->release_lock)
76
- return 0;
77
-
78
- iosf_mbi_punit_acquire();
79
- iosf_mbi_call_pmic_bus_access_notifier_chain(MBI_PMIC_BUS_ACCESS_BEGIN,
80
- NULL);
81
-
82
- /*
83
- * Disallow the CPU to enter C6 or C7 state, entering these states
84
- * requires the punit to talk to the pmic and if this happens while
85
- * we're holding the semaphore, the SoC hangs.
86
- */
87
- pm_qos_update_request(&dev->pm_qos, 0);
88
-
89
- addr = get_sem_addr(dev);
90
-
91
- /* host driver writes to side band semaphore register */
92
- ret = iosf_mbi_write(BT_MBI_UNIT_PMC, MBI_REG_WRITE, addr, sem);
93
- if (ret) {
94
- dev_err(dev->dev, "iosf punit semaphore request failed\n");
95
- goto out;
96
- }
97
-
98
- /* host driver waits for bit 0 to be set in semaphore register */
99
- start = jiffies;
100
- end = start + msecs_to_jiffies(SEMAPHORE_TIMEOUT);
101
- do {
102
- ret = get_sem(dev, &sem);
103
- if (!ret && sem) {
104
- acquired = jiffies;
105
- dev_dbg(dev->dev, "punit semaphore acquired after %ums\n",
106
- jiffies_to_msecs(jiffies - start));
107
- return 0;
108
- }
109
-
110
- usleep_range(1000, 2000);
111
- } while (time_before(jiffies, end));
112
-
113
- dev_err(dev->dev, "punit semaphore timed out, resetting\n");
114
-out:
115
- reset_semaphore(dev);
116
-
117
- ret = iosf_mbi_read(BT_MBI_UNIT_PMC, MBI_REG_READ, addr, &sem);
118
- if (ret)
119
- dev_err(dev->dev, "iosf failed to read punit semaphore\n");
120
- else
121
- dev_err(dev->dev, "PUNIT SEM: %d\n", sem);
122
-
123
- WARN_ON(1);
124
-
125
- return -ETIMEDOUT;
126
-}
127
-
128
-static void baytrail_i2c_release(struct dw_i2c_dev *dev)
129
-{
130
- if (!dev || !dev->dev)
131
- return;
132
-
133
- if (!dev->acquire_lock)
134
- return;
135
-
136
- reset_semaphore(dev);
137
- dev_dbg(dev->dev, "punit semaphore held for %ums\n",
138
- jiffies_to_msecs(jiffies - acquired));
139
-}
14014
14115 int i2c_dw_probe_lock_support(struct dw_i2c_dev *dev)
14216 {
....@@ -162,18 +36,9 @@
16236 return -EPROBE_DEFER;
16337
16438 dev_info(dev->dev, "I2C bus managed by PUNIT\n");
165
- dev->acquire_lock = baytrail_i2c_acquire;
166
- dev->release_lock = baytrail_i2c_release;
167
- dev->pm_disabled = true;
168
-
169
- pm_qos_add_request(&dev->pm_qos, PM_QOS_CPU_DMA_LATENCY,
170
- PM_QOS_DEFAULT_VALUE);
39
+ dev->acquire_lock = iosf_mbi_block_punit_i2c_access;
40
+ dev->release_lock = iosf_mbi_unblock_punit_i2c_access;
41
+ dev->shared_with_punit = true;
17142
17243 return 0;
173
-}
174
-
175
-void i2c_dw_remove_lock_support(struct dw_i2c_dev *dev)
176
-{
177
- if (dev->acquire_lock)
178
- pm_qos_remove_request(&dev->pm_qos);
17944 }