diff options
Diffstat (limited to 'drivers/reset/reset-berlin.c')
-rw-r--r-- | drivers/reset/reset-berlin.c | 110 |
1 files changed, 110 insertions, 0 deletions
diff --git a/drivers/reset/reset-berlin.c b/drivers/reset/reset-berlin.c new file mode 100644 index 000000000..2537ec05e --- /dev/null +++ b/drivers/reset/reset-berlin.c @@ -0,0 +1,110 @@ +/* + * Copyright (C) 2014 Marvell Technology Group Ltd. + * + * Marvell Berlin reset driver + * + * 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/mfd/syscon.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/platform_device.h> +#include <linux/regmap.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 { + struct regmap *regmap; + 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); + + regmap_write(priv->regmap, offset, mask); + + /* let the reset be effective */ + udelay(10); + + return 0; +} + +static const 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) +{ + unsigned int offset, bit; + + offset = reset_spec->args[0]; + bit = reset_spec->args[1]; + + if (bit >= BERLIN_MAX_RESETS) + return -EINVAL; + + return (offset << 8) | bit; +} + +static int berlin2_reset_probe(struct platform_device *pdev) +{ + struct device_node *parent_np = of_get_parent(pdev->dev.of_node); + struct berlin_reset_priv *priv; + + priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + priv->regmap = syscon_node_to_regmap(parent_np); + of_node_put(parent_np); + if (IS_ERR(priv->regmap)) + return PTR_ERR(priv->regmap); + + priv->rcdev.owner = THIS_MODULE; + priv->rcdev.ops = &berlin_reset_ops; + priv->rcdev.of_node = pdev->dev.of_node; + priv->rcdev.of_reset_n_cells = 2; + priv->rcdev.of_xlate = berlin_reset_xlate; + + return reset_controller_register(&priv->rcdev); +} + +static const struct of_device_id berlin_reset_dt_match[] = { + { .compatible = "marvell,berlin2-reset" }, + { }, +}; +MODULE_DEVICE_TABLE(of, berlin_reset_dt_match); + +static struct platform_driver berlin_reset_driver = { + .probe = berlin2_reset_probe, + .driver = { + .name = "berlin2-reset", + .of_match_table = berlin_reset_dt_match, + }, +}; +module_platform_driver(berlin_reset_driver); + +MODULE_AUTHOR("Antoine Tenart <antoine.tenart@free-electrons.com>"); +MODULE_AUTHOR("Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>"); +MODULE_DESCRIPTION("Synaptics Berlin reset controller"); +MODULE_LICENSE("GPL"); |