diff options
Diffstat (limited to 'drivers/hwspinlock')
| -rw-r--r-- | drivers/hwspinlock/Kconfig | 9 | ||||
| -rw-r--r-- | drivers/hwspinlock/Makefile | 1 | ||||
| -rw-r--r-- | drivers/hwspinlock/sun6i_hwspinlock.c | 210 |
3 files changed, 220 insertions, 0 deletions
diff --git a/drivers/hwspinlock/Kconfig b/drivers/hwspinlock/Kconfig index 53e13476e831..3874d15b0e9b 100644 --- a/drivers/hwspinlock/Kconfig +++ b/drivers/hwspinlock/Kconfig @@ -44,6 +44,15 @@ config HWSPINLOCK_STM32 If unsure, say N. +config HWSPINLOCK_SUN6I + tristate "SUN6I Hardware Spinlock device" + depends on ARCH_SUNXI || COMPILE_TEST + help + Say y here to support the SUN6I Hardware Spinlock device which can be + found in most of the sun6i compatible Allwinner SoCs. + + If unsure, say N. + config HSEM_U8500 tristate "STE Hardware Semaphore functionality" depends on ARCH_U8500 || COMPILE_TEST diff --git a/drivers/hwspinlock/Makefile b/drivers/hwspinlock/Makefile index 1f8dd6f5814f..a0f16c9aaa82 100644 --- a/drivers/hwspinlock/Makefile +++ b/drivers/hwspinlock/Makefile @@ -8,4 +8,5 @@ obj-$(CONFIG_HWSPINLOCK_OMAP) += omap_hwspinlock.o obj-$(CONFIG_HWSPINLOCK_QCOM) += qcom_hwspinlock.o obj-$(CONFIG_HWSPINLOCK_SPRD) += sprd_hwspinlock.o obj-$(CONFIG_HWSPINLOCK_STM32) += stm32_hwspinlock.o +obj-$(CONFIG_HWSPINLOCK_SUN6I) += sun6i_hwspinlock.o obj-$(CONFIG_HSEM_U8500) += u8500_hsem.o diff --git a/drivers/hwspinlock/sun6i_hwspinlock.c b/drivers/hwspinlock/sun6i_hwspinlock.c new file mode 100644 index 000000000000..c2d314588046 --- /dev/null +++ b/drivers/hwspinlock/sun6i_hwspinlock.c @@ -0,0 +1,210 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * sun6i_hwspinlock.c - hardware spinlock driver for sun6i compatible Allwinner SoCs + * Copyright (C) 2020 Wilken Gottwalt <wilken.gottwalt@posteo.net> + */ + +#include <linux/clk.h> +#include <linux/debugfs.h> +#include <linux/errno.h> +#include <linux/hwspinlock.h> +#include <linux/io.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/platform_device.h> +#include <linux/reset.h> +#include <linux/slab.h> +#include <linux/spinlock.h> +#include <linux/types.h> + +#include "hwspinlock_internal.h" + +#define DRIVER_NAME "sun6i_hwspinlock" + +#define SPINLOCK_BASE_ID 0 /* there is only one hwspinlock device per SoC */ +#define SPINLOCK_SYSSTATUS_REG 0x0000 +#define SPINLOCK_LOCK_REGN 0x0100 +#define SPINLOCK_NOTTAKEN 0 + +struct sun6i_hwspinlock_data { + struct hwspinlock_device *bank; + struct reset_control *reset; + struct clk *ahb_clk; + struct dentry *debugfs; + int nlocks; +}; + +#ifdef CONFIG_DEBUG_FS + +static int hwlocks_supported_show(struct seq_file *seqf, void *unused) +{ + struct sun6i_hwspinlock_data *priv = seqf->private; + + seq_printf(seqf, "%d\n", priv->nlocks); + + return 0; +} +DEFINE_SHOW_ATTRIBUTE(hwlocks_supported); + +static void sun6i_hwspinlock_debugfs_init(struct sun6i_hwspinlock_data *priv) +{ + priv->debugfs = debugfs_create_dir(DRIVER_NAME, NULL); + debugfs_create_file("supported", 0444, priv->debugfs, priv, &hwlocks_supported_fops); +} + +#else + +static void sun6i_hwspinlock_debugfs_init(struct sun6i_hwspinlock_data *priv) +{ +} + +#endif + +static int sun6i_hwspinlock_trylock(struct hwspinlock *lock) +{ + void __iomem *lock_addr = lock->priv; + + return (readl(lock_addr) == SPINLOCK_NOTTAKEN); +} + +static void sun6i_hwspinlock_unlock(struct hwspinlock *lock) +{ + void __iomem *lock_addr = lock->priv; + + writel(SPINLOCK_NOTTAKEN, lock_addr); +} + +static const struct hwspinlock_ops sun6i_hwspinlock_ops = { + .trylock = sun6i_hwspinlock_trylock, + .unlock = sun6i_hwspinlock_unlock, +}; + +static void sun6i_hwspinlock_disable(void *data) +{ + struct sun6i_hwspinlock_data *priv = data; + + debugfs_remove_recursive(priv->debugfs); + clk_disable_unprepare(priv->ahb_clk); + reset_control_assert(priv->reset); +} + +static int sun6i_hwspinlock_probe(struct platform_device *pdev) +{ + struct sun6i_hwspinlock_data *priv; + struct hwspinlock *hwlock; + void __iomem *io_base; + u32 num_banks; + int err, i; + + io_base = devm_platform_ioremap_resource(pdev, SPINLOCK_BASE_ID); + if (IS_ERR(io_base)) + return PTR_ERR(io_base); + + priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + priv->ahb_clk = devm_clk_get(&pdev->dev, "ahb"); + if (IS_ERR(priv->ahb_clk)) { + err = PTR_ERR(priv->ahb_clk); + dev_err(&pdev->dev, "unable to get AHB clock (%d)\n", err); + return err; + } + + priv->reset = devm_reset_control_get(&pdev->dev, "ahb"); + if (IS_ERR(priv->reset)) + return dev_err_probe(&pdev->dev, PTR_ERR(priv->reset), + "unable to get reset control\n"); + + err = reset_control_deassert(priv->reset); + if (err) { + dev_err(&pdev->dev, "deassert reset control failure (%d)\n", err); + return err; + } + + err = clk_prepare_enable(priv->ahb_clk); + if (err) { + dev_err(&pdev->dev, "unable to prepare AHB clk (%d)\n", err); + goto clk_fail; + } + + /* + * bit 28 and 29 represents the hwspinlock setup + * + * every datasheet (A64, A80, A83T, H3, H5, H6 ...) says the default value is 0x1 and 0x1 + * to 0x4 represent 32, 64, 128 and 256 locks + * but later datasheets (H5, H6) say 00, 01, 10, 11 represent 32, 64, 128 and 256 locks, + * but that would mean H5 and H6 have 64 locks, while their datasheets talk about 32 locks + * all the time, not a single mentioning of 64 locks + * the 0x4 value is also not representable by 2 bits alone, so some datasheets are not + * correct + * one thing have all in common, default value of the sysstatus register is 0x10000000, + * which results in bit 28 being set + * this is the reason 0x1 is considered being 32 locks and bit 30 is taken into account + * verified on H2+ (datasheet 0x1 = 32 locks) and H5 (datasheet 01 = 64 locks) + */ + num_banks = readl(io_base + SPINLOCK_SYSSTATUS_REG) >> 28; + switch (num_banks) { + case 1 ... 4: + priv->nlocks = 1 << (4 + num_banks); + break; + default: + err = -EINVAL; + dev_err(&pdev->dev, "unsupported hwspinlock setup (%d)\n", num_banks); + goto bank_fail; + } + + priv->bank = devm_kzalloc(&pdev->dev, struct_size(priv->bank, lock, priv->nlocks), + GFP_KERNEL); + if (!priv->bank) { + err = -ENOMEM; + goto bank_fail; + } + + for (i = 0; i < priv->nlocks; ++i) { + hwlock = &priv->bank->lock[i]; + hwlock->priv = io_base + SPINLOCK_LOCK_REGN + sizeof(u32) * i; + } + + /* failure of debugfs is considered non-fatal */ + sun6i_hwspinlock_debugfs_init(priv); + if (IS_ERR(priv->debugfs)) + priv->debugfs = NULL; + + err = devm_add_action_or_reset(&pdev->dev, sun6i_hwspinlock_disable, priv); + if (err) { + dev_err(&pdev->dev, "failed to add hwspinlock disable action\n"); + goto bank_fail; + } + + platform_set_drvdata(pdev, priv); + + return devm_hwspin_lock_register(&pdev->dev, priv->bank, &sun6i_hwspinlock_ops, + SPINLOCK_BASE_ID, priv->nlocks); + +bank_fail: + clk_disable_unprepare(priv->ahb_clk); +clk_fail: + reset_control_assert(priv->reset); + + return err; +} + +static const struct of_device_id sun6i_hwspinlock_ids[] = { + { .compatible = "allwinner,sun6i-a31-hwspinlock", }, + {}, +}; +MODULE_DEVICE_TABLE(of, sun6i_hwspinlock_ids); + +static struct platform_driver sun6i_hwspinlock_driver = { + .probe = sun6i_hwspinlock_probe, + .driver = { + .name = DRIVER_NAME, + .of_match_table = sun6i_hwspinlock_ids, + }, +}; +module_platform_driver(sun6i_hwspinlock_driver); + +MODULE_LICENSE("GPL"); +MODULE_DESCRIPTION("SUN6I hardware spinlock driver"); +MODULE_AUTHOR("Wilken Gottwalt <wilken.gottwalt@posteo.net>"); |