diff options
Diffstat (limited to 'drivers/hwspinlock/sprd_hwspinlock.c')
| -rw-r--r-- | drivers/hwspinlock/sprd_hwspinlock.c | 183 |
1 files changed, 183 insertions, 0 deletions
diff --git a/drivers/hwspinlock/sprd_hwspinlock.c b/drivers/hwspinlock/sprd_hwspinlock.c new file mode 100644 index 000000000000..638e64ac18f5 --- /dev/null +++ b/drivers/hwspinlock/sprd_hwspinlock.c @@ -0,0 +1,183 @@ +/* + * Spreadtrum hardware spinlock driver + * Copyright (C) 2017 Spreadtrum - http://www.spreadtrum.com + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * version 2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + */ + +#include <linux/bitops.h> +#include <linux/clk.h> +#include <linux/delay.h> +#include <linux/device.h> +#include <linux/hwspinlock.h> +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/of_device.h> +#include <linux/platform_device.h> +#include <linux/pm_runtime.h> +#include <linux/slab.h> + +#include "hwspinlock_internal.h" + +/* hwspinlock registers definition */ +#define HWSPINLOCK_RECCTRL 0x4 +#define HWSPINLOCK_MASTERID(_X_) (0x80 + 0x4 * (_X_)) +#define HWSPINLOCK_TOKEN(_X_) (0x800 + 0x4 * (_X_)) + +/* unlocked value */ +#define HWSPINLOCK_NOTTAKEN 0x55aa10c5 +/* bits definition of RECCTRL reg */ +#define HWSPINLOCK_USER_BITS 0x1 + +/* hwspinlock number */ +#define SPRD_HWLOCKS_NUM 32 + +struct sprd_hwspinlock_dev { + void __iomem *base; + struct clk *clk; + struct hwspinlock_device bank; +}; + +/* try to lock the hardware spinlock */ +static int sprd_hwspinlock_trylock(struct hwspinlock *lock) +{ + struct sprd_hwspinlock_dev *sprd_hwlock = + dev_get_drvdata(lock->bank->dev); + void __iomem *addr = lock->priv; + int user_id, lock_id; + + if (!readl(addr)) + return 1; + + lock_id = hwlock_to_id(lock); + /* get the hardware spinlock master/user id */ + user_id = readl(sprd_hwlock->base + HWSPINLOCK_MASTERID(lock_id)); + dev_warn(sprd_hwlock->bank.dev, + "hwspinlock [%d] lock failed and master/user id = %d!\n", + lock_id, user_id); + return 0; +} + +/* unlock the hardware spinlock */ +static void sprd_hwspinlock_unlock(struct hwspinlock *lock) +{ + void __iomem *lock_addr = lock->priv; + + writel(HWSPINLOCK_NOTTAKEN, lock_addr); +} + +/* The specs recommended below number as the retry delay time */ +static void sprd_hwspinlock_relax(struct hwspinlock *lock) +{ + ndelay(10); +} + +static const struct hwspinlock_ops sprd_hwspinlock_ops = { + .trylock = sprd_hwspinlock_trylock, + .unlock = sprd_hwspinlock_unlock, + .relax = sprd_hwspinlock_relax, +}; + +static int sprd_hwspinlock_probe(struct platform_device *pdev) +{ + struct sprd_hwspinlock_dev *sprd_hwlock; + struct hwspinlock *lock; + struct resource *res; + int i, ret; + + if (!pdev->dev.of_node) + return -ENODEV; + + sprd_hwlock = devm_kzalloc(&pdev->dev, + sizeof(struct sprd_hwspinlock_dev) + + SPRD_HWLOCKS_NUM * sizeof(*lock), + GFP_KERNEL); + if (!sprd_hwlock) + return -ENOMEM; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + sprd_hwlock->base = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(sprd_hwlock->base)) + return PTR_ERR(sprd_hwlock->base); + + sprd_hwlock->clk = devm_clk_get(&pdev->dev, "enable"); + if (IS_ERR(sprd_hwlock->clk)) { + dev_err(&pdev->dev, "get hwspinlock clock failed!\n"); + return PTR_ERR(sprd_hwlock->clk); + } + + clk_prepare_enable(sprd_hwlock->clk); + + /* set the hwspinlock to record user id to identify subsystems */ + writel(HWSPINLOCK_USER_BITS, sprd_hwlock->base + HWSPINLOCK_RECCTRL); + + for (i = 0; i < SPRD_HWLOCKS_NUM; i++) { + lock = &sprd_hwlock->bank.lock[i]; + lock->priv = sprd_hwlock->base + HWSPINLOCK_TOKEN(i); + } + + platform_set_drvdata(pdev, sprd_hwlock); + pm_runtime_enable(&pdev->dev); + + ret = hwspin_lock_register(&sprd_hwlock->bank, &pdev->dev, + &sprd_hwspinlock_ops, 0, SPRD_HWLOCKS_NUM); + if (ret) { + pm_runtime_disable(&pdev->dev); + clk_disable_unprepare(sprd_hwlock->clk); + return ret; + } + + return 0; +} + +static int sprd_hwspinlock_remove(struct platform_device *pdev) +{ + struct sprd_hwspinlock_dev *sprd_hwlock = platform_get_drvdata(pdev); + + hwspin_lock_unregister(&sprd_hwlock->bank); + pm_runtime_disable(&pdev->dev); + clk_disable_unprepare(sprd_hwlock->clk); + return 0; +} + +static const struct of_device_id sprd_hwspinlock_of_match[] = { + { .compatible = "sprd,hwspinlock-r3p0", }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, sprd_hwspinlock_of_match); + +static struct platform_driver sprd_hwspinlock_driver = { + .probe = sprd_hwspinlock_probe, + .remove = sprd_hwspinlock_remove, + .driver = { + .name = "sprd_hwspinlock", + .of_match_table = of_match_ptr(sprd_hwspinlock_of_match), + }, +}; + +static int __init sprd_hwspinlock_init(void) +{ + return platform_driver_register(&sprd_hwspinlock_driver); +} +postcore_initcall(sprd_hwspinlock_init); + +static void __exit sprd_hwspinlock_exit(void) +{ + platform_driver_unregister(&sprd_hwspinlock_driver); +} +module_exit(sprd_hwspinlock_exit); + +MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION("Hardware spinlock driver for Spreadtrum"); +MODULE_AUTHOR("Baolin Wang <baolin.wang@spreadtrum.com>"); +MODULE_AUTHOR("Lanqing Liu <lanqing.liu@spreadtrum.com>"); +MODULE_AUTHOR("Long Cheng <aiden.cheng@spreadtrum.com>"); |