diff options
Diffstat (limited to 'drivers/of')
-rw-r--r-- | drivers/of/Makefile | 2 | ||||
-rw-r--r-- | drivers/of/dma.c | 264 |
2 files changed, 1 insertions, 265 deletions
diff --git a/drivers/of/Makefile b/drivers/of/Makefile index eafa107aed40..e027f444d10c 100644 --- a/drivers/of/Makefile +++ b/drivers/of/Makefile @@ -1,4 +1,4 @@ -obj-y = base.o dma.o +obj-y = base.o obj-$(CONFIG_OF_FLATTREE) += fdt.o obj-$(CONFIG_OF_PROMTREE) += pdt.o obj-$(CONFIG_OF_ADDRESS) += address.o diff --git a/drivers/of/dma.c b/drivers/of/dma.c deleted file mode 100644 index 59631b2c4666..000000000000 --- a/drivers/of/dma.c +++ /dev/null @@ -1,264 +0,0 @@ -/* - * Device tree helpers for DMA request / controller - * - * Based on of_gpio.c - * - * Copyright (C) 2012 Texas Instruments Incorporated - http://www.ti.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. - */ - -#include <linux/device.h> -#include <linux/err.h> -#include <linux/module.h> -#include <linux/rculist.h> -#include <linux/slab.h> -#include <linux/of.h> -#include <linux/of_dma.h> - -static LIST_HEAD(of_dma_list); -static DEFINE_SPINLOCK(of_dma_lock); - -/** - * of_dma_get_controller - Get a DMA controller in DT DMA helpers list - * @dma_spec: pointer to DMA specifier as found in the device tree - * - * Finds a DMA controller with matching device node and number for dma cells - * in a list of registered DMA controllers. If a match is found the use_count - * variable is increased and a valid pointer to the DMA data stored is retuned. - * A NULL pointer is returned if no match is found. - */ -static struct of_dma *of_dma_get_controller(struct of_phandle_args *dma_spec) -{ - struct of_dma *ofdma; - - spin_lock(&of_dma_lock); - - if (list_empty(&of_dma_list)) { - spin_unlock(&of_dma_lock); - return NULL; - } - - list_for_each_entry(ofdma, &of_dma_list, of_dma_controllers) - if ((ofdma->of_node == dma_spec->np) && - (ofdma->of_dma_nbcells == dma_spec->args_count)) { - ofdma->use_count++; - spin_unlock(&of_dma_lock); - return ofdma; - } - - spin_unlock(&of_dma_lock); - - pr_debug("%s: can't find DMA controller %s\n", __func__, - dma_spec->np->full_name); - - return NULL; -} - -/** - * of_dma_put_controller - Decrement use count for a registered DMA controller - * @of_dma: pointer to DMA controller data - * - * Decrements the use_count variable in the DMA data structure. This function - * should be called only when a valid pointer is returned from - * of_dma_get_controller() and no further accesses to data referenced by that - * pointer are needed. - */ -static void of_dma_put_controller(struct of_dma *ofdma) -{ - spin_lock(&of_dma_lock); - ofdma->use_count--; - spin_unlock(&of_dma_lock); -} - -/** - * of_dma_controller_register - Register a DMA controller to DT DMA helpers - * @np: device node of DMA controller - * @of_dma_xlate: translation function which converts a phandle - * arguments list into a dma_chan structure - * @data pointer to controller specific data to be used by - * translation function - * - * Returns 0 on success or appropriate errno value on error. - * - * Allocated memory should be freed with appropriate of_dma_controller_free() - * call. - */ -int of_dma_controller_register(struct device_node *np, - struct dma_chan *(*of_dma_xlate) - (struct of_phandle_args *, struct of_dma *), - void *data) -{ - struct of_dma *ofdma; - int nbcells; - - if (!np || !of_dma_xlate) { - pr_err("%s: not enough information provided\n", __func__); - return -EINVAL; - } - - ofdma = kzalloc(sizeof(*ofdma), GFP_KERNEL); - if (!ofdma) - return -ENOMEM; - - nbcells = be32_to_cpup(of_get_property(np, "#dma-cells", NULL)); - if (!nbcells) { - pr_err("%s: #dma-cells property is missing or invalid\n", - __func__); - return -EINVAL; - } - - ofdma->of_node = np; - ofdma->of_dma_nbcells = nbcells; - ofdma->of_dma_xlate = of_dma_xlate; - ofdma->of_dma_data = data; - ofdma->use_count = 0; - - /* Now queue of_dma controller structure in list */ - list_add_tail(&ofdma->of_dma_controllers, &of_dma_list); - - return 0; -} -EXPORT_SYMBOL_GPL(of_dma_controller_register); - -/** - * of_dma_controller_free - Remove a DMA controller from DT DMA helpers list - * @np: device node of DMA controller - * - * Memory allocated by of_dma_controller_register() is freed here. - */ -int of_dma_controller_free(struct device_node *np) -{ - struct of_dma *ofdma; - - spin_lock(&of_dma_lock); - - if (list_empty(&of_dma_list)) { - spin_unlock(&of_dma_lock); - return -ENODEV; - } - - list_for_each_entry(ofdma, &of_dma_list, of_dma_controllers) - if (ofdma->of_node == np) { - if (ofdma->use_count) { - spin_unlock(&of_dma_lock); - return -EBUSY; - } - - list_del(&ofdma->of_dma_controllers); - spin_unlock(&of_dma_lock); - kfree(ofdma); - return 0; - } - - spin_unlock(&of_dma_lock); - return -ENODEV; -} -EXPORT_SYMBOL_GPL(of_dma_controller_free); - -/** - * of_dma_match_channel - Check if a DMA specifier matches name - * @np: device node to look for DMA channels - * @name: channel name to be matched - * @index: index of DMA specifier in list of DMA specifiers - * @dma_spec: pointer to DMA specifier as found in the device tree - * - * Check if the DMA specifier pointed to by the index in a list of DMA - * specifiers, matches the name provided. Returns 0 if the name matches and - * a valid pointer to the DMA specifier is found. Otherwise returns -ENODEV. - */ -static int of_dma_match_channel(struct device_node *np, char *name, int index, - struct of_phandle_args *dma_spec) -{ - const char *s; - - if (of_property_read_string_index(np, "dma-names", index, &s)) - return -ENODEV; - - if (strcmp(name, s)) - return -ENODEV; - - if (of_parse_phandle_with_args(np, "dmas", "#dma-cells", index, - dma_spec)) - return -ENODEV; - - return 0; -} - -/** - * of_dma_request_slave_channel - Get the DMA slave channel - * @np: device node to get DMA request from - * @name: name of desired channel - * - * Returns pointer to appropriate dma channel on success or NULL on error. - */ -struct dma_chan *of_dma_request_slave_channel(struct device_node *np, - char *name) -{ - struct of_phandle_args dma_spec; - struct of_dma *ofdma; - struct dma_chan *chan; - int count, i; - - if (!np || !name) { - pr_err("%s: not enough information provided\n", __func__); - return NULL; - } - - count = of_property_count_strings(np, "dma-names"); - if (count < 0) { - pr_err("%s: dma-names property missing or empty\n", __func__); - return NULL; - } - - for (i = 0; i < count; i++) { - if (of_dma_match_channel(np, name, i, &dma_spec)) - continue; - - ofdma = of_dma_get_controller(&dma_spec); - - if (!ofdma) - continue; - - chan = ofdma->of_dma_xlate(&dma_spec, ofdma); - - of_dma_put_controller(ofdma); - - of_node_put(dma_spec.np); - - if (chan) - return chan; - } - - return NULL; -} - -/** - * of_dma_simple_xlate - Simple DMA engine translation function - * @dma_spec: pointer to DMA specifier as found in the device tree - * @of_dma: pointer to DMA controller data - * - * A simple translation function for devices that use a 32-bit value for the - * filter_param when calling the DMA engine dma_request_channel() function. - * Note that this translation function requires that #dma-cells is equal to 1 - * and the argument of the dma specifier is the 32-bit filter_param. Returns - * pointer to appropriate dma channel on success or NULL on error. - */ -struct dma_chan *of_dma_simple_xlate(struct of_phandle_args *dma_spec, - struct of_dma *ofdma) -{ - int count = dma_spec->args_count; - struct of_dma_filter_info *info = ofdma->of_dma_data; - - if (!info || !info->filter_fn) - return NULL; - - if (count != 1) - return NULL; - - return dma_request_channel(info->dma_cap, info->filter_fn, - &dma_spec->args[0]); -} -EXPORT_SYMBOL_GPL(of_dma_simple_xlate); |