From 9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00 Mon Sep 17 00:00:00 2001 From: Yunhong Jiang Date: Tue, 4 Aug 2015 12:17:53 -0700 Subject: Add the rt linux 4.1.3-rt3 as base Import the rt linux 4.1.3-rt3 as OPNFV kvm base. It's from git://git.kernel.org/pub/scm/linux/kernel/git/rt/linux-rt-devel.git linux-4.1.y-rt and the base is: commit 0917f823c59692d751951bf5ea699a2d1e2f26a2 Author: Sebastian Andrzej Siewior Date: Sat Jul 25 12:13:34 2015 +0200 Prepare v4.1.3-rt3 Signed-off-by: Sebastian Andrzej Siewior We lose all the git history this way and it's not good. We should apply another opnfv project repo in future. Change-Id: I87543d81c9df70d99c5001fbdf646b202c19f423 Signed-off-by: Yunhong Jiang --- kernel/drivers/dma/of-dma.c | 260 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 260 insertions(+) create mode 100644 kernel/drivers/dma/of-dma.c (limited to 'kernel/drivers/dma/of-dma.c') diff --git a/kernel/drivers/dma/of-dma.c b/kernel/drivers/dma/of-dma.c new file mode 100644 index 000000000..cbd4a8aff --- /dev/null +++ b/kernel/drivers/dma/of-dma.c @@ -0,0 +1,260 @@ +/* + * 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 +#include +#include +#include +#include +#include +#include + +static LIST_HEAD(of_dma_list); +static DEFINE_MUTEX(of_dma_lock); + +/** + * of_dma_find_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 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_find_controller(struct of_phandle_args *dma_spec) +{ + struct of_dma *ofdma; + + list_for_each_entry(ofdma, &of_dma_list, of_dma_controllers) + if (ofdma->of_node == dma_spec->np) + return ofdma; + + pr_debug("%s: can't find DMA controller %s\n", __func__, + dma_spec->np->full_name); + + return NULL; +} + +/** + * 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; + + 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; + + ofdma->of_node = np; + ofdma->of_dma_xlate = of_dma_xlate; + ofdma->of_dma_data = data; + + /* Now queue of_dma controller structure in list */ + mutex_lock(&of_dma_lock); + list_add_tail(&ofdma->of_dma_controllers, &of_dma_list); + mutex_unlock(&of_dma_lock); + + 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. + */ +void of_dma_controller_free(struct device_node *np) +{ + struct of_dma *ofdma; + + mutex_lock(&of_dma_lock); + + list_for_each_entry(ofdma, &of_dma_list, of_dma_controllers) + if (ofdma->of_node == np) { + list_del(&ofdma->of_dma_controllers); + kfree(ofdma); + break; + } + + mutex_unlock(&of_dma_lock); +} +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, const 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 an error pointer. + */ +struct dma_chan *of_dma_request_slave_channel(struct device_node *np, + const char *name) +{ + struct of_phandle_args dma_spec; + struct of_dma *ofdma; + struct dma_chan *chan; + int count, i; + int ret_no_channel = -ENODEV; + + if (!np || !name) { + pr_err("%s: not enough information provided\n", __func__); + return ERR_PTR(-ENODEV); + } + + /* Silently fail if there is not even the "dmas" property */ + if (!of_find_property(np, "dmas", NULL)) + return ERR_PTR(-ENODEV); + + count = of_property_count_strings(np, "dma-names"); + if (count < 0) { + pr_err("%s: dma-names property of node '%s' missing or empty\n", + __func__, np->full_name); + return ERR_PTR(-ENODEV); + } + + for (i = 0; i < count; i++) { + if (of_dma_match_channel(np, name, i, &dma_spec)) + continue; + + mutex_lock(&of_dma_lock); + ofdma = of_dma_find_controller(&dma_spec); + + if (ofdma) { + chan = ofdma->of_dma_xlate(&dma_spec, ofdma); + } else { + ret_no_channel = -EPROBE_DEFER; + chan = NULL; + } + + mutex_unlock(&of_dma_lock); + + of_node_put(dma_spec.np); + + if (chan) + return chan; + } + + return ERR_PTR(ret_no_channel); +} +EXPORT_SYMBOL_GPL(of_dma_request_slave_channel); + +/** + * 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); + +/** + * of_dma_xlate_by_chan_id - Translate dt property to DMA channel by channel id + * @dma_spec: pointer to DMA specifier as found in the device tree + * @of_dma: pointer to DMA controller data + * + * This function can be used as the of xlate callback for DMA driver which wants + * to match the channel based on the channel id. When using this xlate function + * the #dma-cells propety of the DMA controller dt node needs to be set to 1. + * The data parameter of of_dma_controller_register must be a pointer to the + * dma_device struct the function should match upon. + * + * Returns pointer to appropriate dma channel on success or NULL on error. + */ +struct dma_chan *of_dma_xlate_by_chan_id(struct of_phandle_args *dma_spec, + struct of_dma *ofdma) +{ + struct dma_device *dev = ofdma->of_dma_data; + struct dma_chan *chan, *candidate = NULL; + + if (!dev || dma_spec->args_count != 1) + return NULL; + + list_for_each_entry(chan, &dev->channels, device_node) + if (chan->chan_id == dma_spec->args[0]) { + candidate = chan; + break; + } + + if (!candidate) + return NULL; + + return dma_get_slave_channel(candidate); +} +EXPORT_SYMBOL_GPL(of_dma_xlate_by_chan_id); -- cgit 1.2.3-korg