| Message ID | 1403606121-6368-2-git-send-email-antoine.tenart@free-electrons.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi Antoine, Am Dienstag, den 24.06.2014, 12:35 +0200 schrieb Antoine Ténart: [...] > +++ b/drivers/reset/reset-berlin.c > @@ -0,0 +1,131 @@ > +/* > + * Copyright (C) 2014 Marvell Technology Group Ltd. > + * > + * Antoine Ténart <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 to_berlin_reset_priv(p) \ > + container_of((p), struct berlin_reset_priv, rcdev) > + > +struct berlin_reset_priv { > + spinlock_t lock; lock is not used anymore. [...] > +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 >= rcdev->nr_resets) > + return -EINVAL; This could be considered a misuse of nr_resets, even if the core only ever uses nr_resets in the _xlate function. Maybe it would be more clear to just leave nr_resets empty if you don't know the actual number and hardcode 32 here. [...] > +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.nr_resets = 32; Leave nr_resets empty, use the correct value, or at least add a comment that this is not the number of resets in the rcdev as documented in the structure documentation. > + 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); Other than the above, and with the understanding that this is going to be turned into a platform driver at some point in the future, Acked-by: Philipp Zabel <p.zabel@pengutronix.de> regards Philipp
Hi Philipp, On Tue, Jun 24, 2014 at 01:13:36PM +0200, Philipp Zabel wrote: > Am Dienstag, den 24.06.2014, 12:35 +0200 schrieb Antoine Ténart: > > + > > +struct berlin_reset_priv { > > + spinlock_t lock; > > lock is not used anymore. Oops. I'll remove it. > > [...] > > +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 >= rcdev->nr_resets) > > + return -EINVAL; > > This could be considered a misuse of nr_resets, even if the core only > ever uses nr_resets in the _xlate function. Maybe it would be more clear > to just leave nr_resets empty if you don't know the actual number and > hardcode 32 here. > > [...] > > +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.nr_resets = 32; > > Leave nr_resets empty, use the correct value, or at least add a comment > that this is not the number of resets in the rcdev as documented in the > structure documentation. Ok. I'll hardcode the value in the driver then. > > Other than the above, and with the understanding that this is going to > be turned into a platform driver at some point in the future, > > Acked-by: Philipp Zabel <p.zabel@pengutronix.de> Sure, that's the plan. Antoine
diff --git a/drivers/reset/Makefile b/drivers/reset/Makefile index 60fed3d7820b..157d421f755b 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 000000000000..c988c08825b4 --- /dev/null +++ b/drivers/reset/reset-berlin.c @@ -0,0 +1,131 @@ +/* + * Copyright (C) 2014 Marvell Technology Group Ltd. + * + * Antoine Ténart <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 to_berlin_reset_priv(p) \ + container_of((p), struct berlin_reset_priv, rcdev) + +struct berlin_reset_priv { + spinlock_t lock; + 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 & 0xff); + + 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 >= rcdev->nr_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.nr_resets = 32; + 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);