diff options
author | Antoine Ténart <antoine.tenart@free-electrons.com> | 2014-09-03 07:48:20 (GMT) |
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committer | Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com> | 2014-10-20 14:51:56 (GMT) |
commit | bd13251f71fc86f06b344810835bc4e5e77edef7 (patch) | |
tree | 549c2849901c660bfbb25e17e6b7c33fc0c839ee /drivers | |
parent | f114040e3ea6e07372334ade75d1ee0775c355e1 (diff) | |
download | linux-bd13251f71fc86f06b344810835bc4e5e77edef7.tar.xz |
reset: add the Berlin reset controller driver
Add a reset controller for Marvell Berlin SoCs which is used by the
USB PHYs drivers (for now).
Signed-off-by: Antoine Ténart <antoine.tenart@free-electrons.com>
Acked-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/reset/Makefile | 1 | ||||
-rw-r--r-- | drivers/reset/reset-berlin.c | 131 |
2 files changed, 132 insertions, 0 deletions
diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile index 60fed3d..157d421 100644 --- a/drivers/reset/Makefile +++ b/drivers/reset/Makefile @@ -1,4 +1,5 @@ obj-$(CONFIG_RESET_CONTROLLER) += core.o obj-$(CONFIG_ARCH_SOCFPGA) += reset-socfpga.o +obj-$(CONFIG_ARCH_BERLIN) += reset-berlin.o obj-$(CONFIG_ARCH_SUNXI) += reset-sunxi.o obj-$(CONFIG_ARCH_STI) += sti/ diff --git a/drivers/reset/reset-berlin.c b/drivers/reset/reset-berlin.c new file mode 100644 index 0000000..f8b48a1 --- /dev/null +++ b/drivers/reset/reset-berlin.c @@ -0,0 +1,131 @@ +/* + * Copyright (C) 2014 Marvell Technology Group Ltd. + * + * Antoine Tenart <antoine.tenart@free-electrons.com> + * Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com> + * + * This file is licensed under the terms of the GNU General Public + * License version 2. This program is licensed "as is" without any + * warranty of any kind, whether express or implied. + */ + +#include <linux/delay.h> +#include <linux/io.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/platform_device.h> +#include <linux/reset-controller.h> +#include <linux/slab.h> +#include <linux/types.h> + +#define BERLIN_MAX_RESETS 32 + +#define to_berlin_reset_priv(p) \ + container_of((p), struct berlin_reset_priv, rcdev) + +struct berlin_reset_priv { + void __iomem *base; + unsigned int size; + struct reset_controller_dev rcdev; +}; + +static int berlin_reset_reset(struct reset_controller_dev *rcdev, + unsigned long id) +{ + struct berlin_reset_priv *priv = to_berlin_reset_priv(rcdev); + int offset = id >> 8; + int mask = BIT(id & 0x1f); + + writel(mask, priv->base + offset); + + /* let the reset be effective */ + udelay(10); + + return 0; +} + +static struct reset_control_ops berlin_reset_ops = { + .reset = berlin_reset_reset, +}; + +static int berlin_reset_xlate(struct reset_controller_dev *rcdev, + const struct of_phandle_args *reset_spec) +{ + struct berlin_reset_priv *priv = to_berlin_reset_priv(rcdev); + unsigned offset, bit; + + if (WARN_ON(reset_spec->args_count != rcdev->of_reset_n_cells)) + return -EINVAL; + + offset = reset_spec->args[0]; + bit = reset_spec->args[1]; + + if (offset >= priv->size) + return -EINVAL; + + if (bit >= BERLIN_MAX_RESETS) + return -EINVAL; + + return (offset << 8) | bit; +} + +static int __berlin_reset_init(struct device_node *np) +{ + struct berlin_reset_priv *priv; + struct resource res; + resource_size_t size; + int ret; + + priv = kzalloc(sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + ret = of_address_to_resource(np, 0, &res); + if (ret) + goto err; + + size = resource_size(&res); + priv->base = ioremap(res.start, size); + if (!priv->base) { + ret = -ENOMEM; + goto err; + } + priv->size = size; + + priv->rcdev.owner = THIS_MODULE; + priv->rcdev.ops = &berlin_reset_ops; + priv->rcdev.of_node = np; + priv->rcdev.of_reset_n_cells = 2; + priv->rcdev.of_xlate = berlin_reset_xlate; + + reset_controller_register(&priv->rcdev); + + return 0; + +err: + kfree(priv); + return ret; +} + +static const struct of_device_id berlin_reset_of_match[] __initconst = { + { .compatible = "marvell,berlin2-chip-ctrl" }, + { .compatible = "marvell,berlin2cd-chip-ctrl" }, + { .compatible = "marvell,berlin2q-chip-ctrl" }, + { }, +}; + +static int __init berlin_reset_init(void) +{ + struct device_node *np; + int ret; + + for_each_matching_node(np, berlin_reset_of_match) { + ret = __berlin_reset_init(np); + if (ret) + return ret; + } + + return 0; +} +arch_initcall(berlin_reset_init); |