Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
Merge tag 'hwlock-v7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/remoteproc/linux
Pull hwspinlock updates from Bjorn Andersson:
"Remove the unused u8500 hardware spinlock driver, and clean out the
hwspinlock_pdata struct as this was the last user of the struct"
* tag 'hwlock-v7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/remoteproc/linux:
hwspinlock: remove now unused pdata from header file
hwspinlock: u8500: delete driver
-196
-1
MAINTAINERS
-1
MAINTAINERS
···
3153
3153
F: drivers/dma/ste_dma40*
3154
3154
F: drivers/pmdomain/st/ste-ux500-pm-domain.c
3155
3155
F: drivers/gpio/gpio-nomadik.c
3156
-
F: drivers/hwspinlock/u8500_hsem.c
3157
3156
F: drivers/i2c/busses/i2c-nomadik.c
3158
3157
F: drivers/iio/adc/ab8500-gpadc.c
3159
3158
F: drivers/mfd/ab8500*
-1
arch/arm/configs/u8500_defconfig
-1
arch/arm/configs/u8500_defconfig
-10
drivers/hwspinlock/Kconfig
-10
drivers/hwspinlock/Kconfig
···
53
53
54
54
If unsure, say N.
55
55
56
-
config HSEM_U8500
57
-
tristate "STE Hardware Semaphore functionality"
58
-
depends on ARCH_U8500 || COMPILE_TEST
59
-
help
60
-
Say y here to support the STE Hardware Semaphore functionality, which
61
-
provides a synchronisation mechanism for the various processor on the
62
-
SoC.
63
-
64
-
If unsure, say N.
65
-
66
56
endif # HWSPINLOCK
-1
drivers/hwspinlock/Makefile
-1
drivers/hwspinlock/Makefile
-155
drivers/hwspinlock/u8500_hsem.c
-155
drivers/hwspinlock/u8500_hsem.c
···
1
-
// SPDX-License-Identifier: GPL-2.0
2
-
/*
3
-
* u8500 HWSEM driver
4
-
*
5
-
* Copyright (C) 2010-2011 ST-Ericsson
6
-
*
7
-
* Implements u8500 semaphore handling for protocol 1, no interrupts.
8
-
*
9
-
* Author: Mathieu Poirier <mathieu.poirier@linaro.org>
10
-
* Heavily borrowed from the work of :
11
-
* Simon Que <sque@ti.com>
12
-
* Hari Kanigeri <h-kanigeri2@ti.com>
13
-
* Ohad Ben-Cohen <ohad@wizery.com>
14
-
*/
15
-
16
-
#include <linux/module.h>
17
-
#include <linux/delay.h>
18
-
#include <linux/io.h>
19
-
#include <linux/slab.h>
20
-
#include <linux/spinlock.h>
21
-
#include <linux/hwspinlock.h>
22
-
#include <linux/platform_device.h>
23
-
24
-
#include "hwspinlock_internal.h"
25
-
26
-
/*
27
-
* Implementation of STE's HSem protocol 1 without interrutps.
28
-
* The only masterID we allow is '0x01' to force people to use
29
-
* HSems for synchronisation between processors rather than processes
30
-
* on the ARM core.
31
-
*/
32
-
33
-
#define U8500_MAX_SEMAPHORE 32 /* a total of 32 semaphore */
34
-
#define RESET_SEMAPHORE (0) /* free */
35
-
36
-
/*
37
-
* CPU ID for master running u8500 kernel.
38
-
* Hswpinlocks should only be used to synchonise operations
39
-
* between the Cortex A9 core and the other CPUs. Hence
40
-
* forcing the masterID to a preset value.
41
-
*/
42
-
#define HSEM_MASTER_ID 0x01
43
-
44
-
#define HSEM_REGISTER_OFFSET 0x08
45
-
46
-
#define HSEM_CTRL_REG 0x00
47
-
#define HSEM_ICRALL 0x90
48
-
#define HSEM_PROTOCOL_1 0x01
49
-
50
-
static int u8500_hsem_trylock(struct hwspinlock *lock)
51
-
{
52
-
void __iomem *lock_addr = lock->priv;
53
-
54
-
writel(HSEM_MASTER_ID, lock_addr);
55
-
56
-
/* get only first 4 bit and compare to masterID.
57
-
* if equal, we have the semaphore, otherwise
58
-
* someone else has it.
59
-
*/
60
-
return (HSEM_MASTER_ID == (0x0F & readl(lock_addr)));
61
-
}
62
-
63
-
static void u8500_hsem_unlock(struct hwspinlock *lock)
64
-
{
65
-
void __iomem *lock_addr = lock->priv;
66
-
67
-
/* release the lock by writing 0 to it */
68
-
writel(RESET_SEMAPHORE, lock_addr);
69
-
}
70
-
71
-
/*
72
-
* u8500: what value is recommended here ?
73
-
*/
74
-
static void u8500_hsem_relax(struct hwspinlock *lock)
75
-
{
76
-
ndelay(50);
77
-
}
78
-
79
-
static const struct hwspinlock_ops u8500_hwspinlock_ops = {
80
-
.trylock = u8500_hsem_trylock,
81
-
.unlock = u8500_hsem_unlock,
82
-
.relax = u8500_hsem_relax,
83
-
};
84
-
85
-
static int u8500_hsem_probe(struct platform_device *pdev)
86
-
{
87
-
struct hwspinlock_pdata *pdata = pdev->dev.platform_data;
88
-
struct hwspinlock_device *bank;
89
-
struct hwspinlock *hwlock;
90
-
void __iomem *io_base;
91
-
int i, num_locks = U8500_MAX_SEMAPHORE;
92
-
ulong val;
93
-
94
-
if (!pdata)
95
-
return -ENODEV;
96
-
97
-
io_base = devm_platform_ioremap_resource(pdev, 0);
98
-
if (IS_ERR(io_base))
99
-
return PTR_ERR(io_base);
100
-
101
-
/* make sure protocol 1 is selected */
102
-
val = readl(io_base + HSEM_CTRL_REG);
103
-
writel((val & ~HSEM_PROTOCOL_1), io_base + HSEM_CTRL_REG);
104
-
105
-
/* clear all interrupts */
106
-
writel(0xFFFF, io_base + HSEM_ICRALL);
107
-
108
-
bank = devm_kzalloc(&pdev->dev, struct_size(bank, lock, num_locks),
109
-
GFP_KERNEL);
110
-
if (!bank)
111
-
return -ENOMEM;
112
-
113
-
platform_set_drvdata(pdev, bank);
114
-
115
-
for (i = 0, hwlock = &bank->lock[0]; i < num_locks; i++, hwlock++)
116
-
hwlock->priv = io_base + HSEM_REGISTER_OFFSET + sizeof(u32) * i;
117
-
118
-
return devm_hwspin_lock_register(&pdev->dev, bank,
119
-
&u8500_hwspinlock_ops,
120
-
pdata->base_id, num_locks);
121
-
}
122
-
123
-
static void u8500_hsem_remove(struct platform_device *pdev)
124
-
{
125
-
struct hwspinlock_device *bank = platform_get_drvdata(pdev);
126
-
void __iomem *io_base = bank->lock[0].priv - HSEM_REGISTER_OFFSET;
127
-
128
-
/* clear all interrupts */
129
-
writel(0xFFFF, io_base + HSEM_ICRALL);
130
-
}
131
-
132
-
static struct platform_driver u8500_hsem_driver = {
133
-
.probe = u8500_hsem_probe,
134
-
.remove = u8500_hsem_remove,
135
-
.driver = {
136
-
.name = "u8500_hsem",
137
-
},
138
-
};
139
-
140
-
static int __init u8500_hsem_init(void)
141
-
{
142
-
return platform_driver_register(&u8500_hsem_driver);
143
-
}
144
-
/* board init code might need to reserve hwspinlocks for predefined purposes */
145
-
postcore_initcall(u8500_hsem_init);
146
-
147
-
static void __exit u8500_hsem_exit(void)
148
-
{
149
-
platform_driver_unregister(&u8500_hsem_driver);
150
-
}
151
-
module_exit(u8500_hsem_exit);
152
-
153
-
MODULE_LICENSE("GPL v2");
154
-
MODULE_DESCRIPTION("Hardware Spinlock driver for u8500");
155
-
MODULE_AUTHOR("Mathieu Poirier <mathieu.poirier@linaro.org>");
-28
include/linux/hwspinlock.h
-28
include/linux/hwspinlock.h
···
25
25
struct hwspinlock_device;
26
26
struct hwspinlock_ops;
27
27
28
-
/**
29
-
* struct hwspinlock_pdata - platform data for hwspinlock drivers
30
-
* @base_id: base id for this hwspinlock device
31
-
*
32
-
* hwspinlock devices provide system-wide hardware locks that are used
33
-
* by remote processors that have no other way to achieve synchronization.
34
-
*
35
-
* To achieve that, each physical lock must have a system-wide id number
36
-
* that is agreed upon, otherwise remote processors can't possibly assume
37
-
* they're using the same hardware lock.
38
-
*
39
-
* Usually boards have a single hwspinlock device, which provides several
40
-
* hwspinlocks, and in this case, they can be trivially numbered 0 to
41
-
* (num-of-locks - 1).
42
-
*
43
-
* In case boards have several hwspinlocks devices, a different base id
44
-
* should be used for each hwspinlock device (they can't all use 0 as
45
-
* a starting id!).
46
-
*
47
-
* This platform data structure should be used to provide the base id
48
-
* for each device (which is trivially 0 when only a single hwspinlock
49
-
* device exists). It can be shared between different platforms, hence
50
-
* its location.
51
-
*/
52
-
struct hwspinlock_pdata {
53
-
int base_id;
54
-
};
55
-
56
28
#ifdef CONFIG_HWSPINLOCK
57
29
58
30
int hwspin_lock_register(struct hwspinlock_device *bank, struct device *dev,