diff options
Diffstat (limited to 'arch/arm/plat-mxc/sdma/dma_sdma.c')
-rw-r--r-- | arch/arm/plat-mxc/sdma/dma_sdma.c | 697 |
1 files changed, 697 insertions, 0 deletions
diff --git a/arch/arm/plat-mxc/sdma/dma_sdma.c b/arch/arm/plat-mxc/sdma/dma_sdma.c new file mode 100644 index 000000000000..156127dbbaeb --- /dev/null +++ b/arch/arm/plat-mxc/sdma/dma_sdma.c @@ -0,0 +1,697 @@ +/* + * Copyright 2004-2011 Freescale Semiconductor, Inc. All Rights Reserved. + */ + +/* + * The code contained herein is licensed under the GNU General Public + * License. You may obtain a copy of the GNU General Public License + * Version 2 or later at the following locations: + * + * http://www.opensource.org/licenses/gpl-license.html + * http://www.gnu.org/copyleft/gpl.html + */ + +/*! + * @file plat-mxc/sdma/dma_sdma.c + * @brief Front-end to the DMA handling. This handles the allocation/freeing + * of DMA channels, and provides a unified interface to the machines + * DMA facilities. This file contains functions for Smart DMA. + * + * @ingroup SDMA + */ + +#include <linux/init.h> +#include <linux/clk.h> +#include <linux/dma-mapping.h> +#include <linux/slab.h> +#include <mach/dma.h> +#include <mach/hardware.h> + +#ifdef CONFIG_MXC_SDMA_API + +static mxc_dma_channel_t mxc_sdma_channels[MAX_DMA_CHANNELS]; +static mxc_dma_channel_private_t mxc_sdma_private[MAX_DMA_CHANNELS]; + +extern struct clk *mxc_sdma_ahb_clk, *mxc_sdma_ipg_clk; + +/*! + * Tasket to handle processing the channel buffers + * + * @param arg channel id + */ +static void mxc_sdma_channeltasklet(unsigned long arg) +{ + dma_request_t request_t; + dma_channel_params chnl_param; + mxc_dma_channel_t *chnl_info; + mxc_dma_channel_private_t *data_priv; + int bd_intr = 0, error = MXC_DMA_DONE; + + chnl_info = &mxc_sdma_channels[arg]; + data_priv = chnl_info->private; + chnl_param = + mxc_sdma_get_channel_params(chnl_info->channel)->chnl_params; + + mxc_dma_get_config(arg, &request_t, data_priv->buf_tail); + + while (request_t.bd_done == 0) { + bd_intr = mxc_dma_get_bd_intr(arg, data_priv->buf_tail); + data_priv->buf_tail += 1; + if (data_priv->buf_tail >= chnl_param.bd_number) { + data_priv->buf_tail = 0; + } + chnl_info->active = 0; + if (request_t.bd_error) { + error = MXC_DMA_TRANSFER_ERROR; + } + + if (bd_intr != 0) { + chnl_info->cb_fn(chnl_info->cb_args, error, + request_t.count); + error = MXC_DMA_DONE; + } + + if (data_priv->buf_tail == chnl_info->curr_buf) { + break; + } + memset(&request_t, 0, sizeof(dma_request_t)); + mxc_dma_get_config(arg, &request_t, data_priv->buf_tail); + } +} + +/*! + * This function is generally called by the driver at open time. + * The DMA driver would do any initialization steps that is required + * to get the channel ready for data transfer. + * + * @param channel_id a pre-defined id. The peripheral driver would specify + * the id associated with its peripheral. This would be + * used by the DMA driver to identify the peripheral + * requesting DMA and do the necessary setup on the + * channel associated with the particular peripheral. + * The DMA driver could use static or dynamic DMA channel + * allocation. + * @param dev_name module name or device name + * @return returns a negative number on error if request for a DMA channel did not + * succeed, returns the channel number to be used on success. + */ +int mxc_dma_request_ext(mxc_dma_device_t channel_id, char *dev_name, + struct dma_channel_info *info) +{ + mxc_sdma_channel_params_t *chnl; + mxc_dma_channel_private_t *data_priv; + int ret = 0, i = 0, channel_num = 0; + mxc_sdma_channel_ext_params_t *p; + + chnl = mxc_sdma_get_channel_params(channel_id); + if (chnl == NULL) { + return -EINVAL; + } + + if (info) { + if (!chnl->chnl_params.ext) + return -EINVAL; + p = (mxc_sdma_channel_ext_params_t *)chnl; + memcpy(&p->chnl_ext_params.info, info, sizeof(info)); + } + + + /* Enable the SDMA clock */ + clk_enable(mxc_sdma_ahb_clk); + clk_enable(mxc_sdma_ipg_clk); + + channel_num = chnl->channel_num; + if (chnl->channel_num == MXC_DMA_DYNAMIC_CHANNEL) { + /* Get the first free channel */ + for (i = (MAX_DMA_CHANNELS - 1); i > 0; i--) { + /* See if channel is available */ + if ((mxc_sdma_channels[i].dynamic != 1) + || (mxc_sdma_channels[i].lock != 0)) { + continue; + } + channel_num = i; + /* Check to see if we can get this channel */ + ret = mxc_request_dma(&channel_num, dev_name); + if (ret == 0) { + break; + } else { + continue; + } + } + if (ret != 0) { + /* No free channel */ + goto err_ret; + } + } else { + if (mxc_sdma_channels[chnl->channel_num].lock == 1) { + ret = -ENODEV; + goto err_ret; + } + ret = mxc_request_dma(&channel_num, dev_name); + if (ret != 0) { + goto err_ret; + } + } + + ret = mxc_dma_setup_channel(channel_num, &chnl->chnl_params); + + if (ret == 0) { + if (chnl->chnl_priority != MXC_SDMA_DEFAULT_PRIORITY) { + ret = + mxc_dma_set_channel_priority(channel_num, + chnl->chnl_priority); + if (ret != 0) { + pr_info("Failed to set channel prority,\ + continue with the existing \ + priority\n"); + goto err_ret; + } + } + mxc_sdma_channels[channel_num].lock = 1; + if ((chnl->chnl_params.transfer_type == per_2_emi) + || (chnl->chnl_params.transfer_type == dsp_2_emi)) { + mxc_sdma_channels[channel_num].mode = MXC_DMA_MODE_READ; + } else { + mxc_sdma_channels[channel_num].mode = + MXC_DMA_MODE_WRITE; + } + mxc_sdma_channels[channel_num].channel = channel_id; + data_priv = mxc_sdma_channels[channel_num].private; + tasklet_init(&data_priv->chnl_tasklet, + mxc_sdma_channeltasklet, channel_num); + if ((channel_id == MXC_DMA_ATA_RX) + || (channel_id == MXC_DMA_ATA_TX)) { + data_priv->intr_after_every_bd = 0; + } else { + data_priv->intr_after_every_bd = 1; + } + } + err_ret: + if (ret != 0) { + clk_disable(mxc_sdma_ahb_clk); + clk_disable(mxc_sdma_ipg_clk); + channel_num = -ENODEV; + } + + return channel_num; +} + +/*! + * This function is generally called by the driver at close time. The DMA + * driver would do any cleanup associated with this channel. + * + * @param channel_num the channel number returned at request time. This + * would be used by the DMA driver to identify the calling + * driver and do the necessary cleanup on the channel + * associated with the particular peripheral + * @return returns a negative number on error or 0 on success + */ +int mxc_dma_free(int channel_num) +{ + mxc_dma_channel_private_t *data_priv; + + if ((channel_num >= MAX_DMA_CHANNELS) || (channel_num < 0)) { + return -EINVAL; + } + + if (mxc_sdma_channels[channel_num].lock != 1) { + return -ENODEV; + } + + mxc_free_dma(channel_num); + + /* Disable the SDMA clock */ + clk_disable(mxc_sdma_ahb_clk); + clk_disable(mxc_sdma_ipg_clk); + + mxc_sdma_channels[channel_num].lock = 0; + mxc_sdma_channels[channel_num].active = 0; + mxc_sdma_channels[channel_num].curr_buf = 0; + data_priv = mxc_sdma_channels[channel_num].private; + data_priv->buf_tail = 0; + tasklet_kill(&data_priv->chnl_tasklet); + + return 0; +} + +/*! + * Callback function called from the SDMA Interrupt routine + * + * @param arg driver specific argument that was registered + */ +static void mxc_dma_chnl_callback(void *arg) +{ + int priv; + mxc_dma_channel_private_t *data_priv; + + priv = (int)arg; + data_priv = mxc_sdma_channels[priv].private; + /* Process the buffers in a tasklet */ + tasklet_schedule(&data_priv->chnl_tasklet); +} + +/*! + * This function would just configure the buffers specified by the user into + * dma channel. The caller must call mxc_dma_enable to start this transfer. + * + * @param channel_num the channel number returned at request time. This + * would be used by the DMA driver to identify the calling + * driver and do the necessary cleanup on the channel + * associated with the particular peripheral + * @param dma_buf an array of physical addresses to the user defined + * buffers. The caller must guarantee the dma_buf is + * available until the transfer is completed. + * @param num_buf number of buffers in the array + * @param mode specifies whether this is READ or WRITE operation + * @return This function returns a negative number on error if buffer could not be + * added with DMA for transfer. On Success, it returns 0 + */ +int mxc_dma_config(int channel_num, mxc_dma_requestbuf_t *dma_buf, + int num_buf, mxc_dma_mode_t mode) +{ + int ret = 0, i = 0, prev_buf; + mxc_dma_channel_t *chnl_info; + mxc_dma_channel_private_t *data_priv; + mxc_sdma_channel_params_t *chnl; + dma_channel_params chnl_param; + dma_request_t request_t; + + if ((channel_num >= MAX_DMA_CHANNELS) || (channel_num < 0)) { + return -EINVAL; + } + + if (num_buf <= 0) { + return -EINVAL; + } + + chnl_info = &mxc_sdma_channels[channel_num]; + data_priv = chnl_info->private; + if (chnl_info->lock != 1) { + return -ENODEV; + } + + /* Check to see if all buffers are taken */ + if (chnl_info->active == 1) { + return -EBUSY; + } + + chnl = mxc_sdma_get_channel_params(chnl_info->channel); + chnl_param = chnl->chnl_params; + + /* Re-setup the SDMA channel if the transfer direction is changed */ + if ((chnl_param.peripheral_type != MEMORY) && (mode != chnl_info->mode)) { + if (chnl_param.peripheral_type == DSP) { + if (mode == MXC_DMA_MODE_READ) { + chnl_param.transfer_type = dsp_2_emi; + } else { + chnl_param.transfer_type = emi_2_dsp; + } + } else if (chnl_param.peripheral_type == FIFO_MEMORY) { + if (mode == MXC_DMA_MODE_READ) + chnl_param.per_address = MXC_FIFO_MEM_SRC_FIXED; + else + chnl_param.per_address = + MXC_FIFO_MEM_DEST_FIXED; + } else { + if (mode == MXC_DMA_MODE_READ) { + chnl_param.transfer_type = per_2_emi; + } else { + chnl_param.transfer_type = emi_2_per; + } + } + chnl_param.callback = mxc_dma_chnl_callback; + chnl_param.arg = (void *)channel_num; + ret = mxc_dma_setup_channel(channel_num, &chnl_param); + if (ret != 0) { + return ret; + } + if (chnl->chnl_priority != MXC_SDMA_DEFAULT_PRIORITY) { + ret = + mxc_dma_set_channel_priority(channel_num, + chnl->chnl_priority); + if (ret != 0) { + pr_info("Failed to set channel prority,\ + continue with the existing \ + priority\n"); + } + } + chnl_info->mode = mode; + } + + for (i = 0; i < num_buf; i++, dma_buf++) { + /* Check to see if all buffers are taken */ + if (chnl_info->active == 1) { + break; + } + request_t.destAddr = (__u8 *) dma_buf->dst_addr; + request_t.sourceAddr = (__u8 *) dma_buf->src_addr; + request_t.count = dma_buf->num_of_bytes; + request_t.bd_cont = 1; + ret = mxc_dma_set_config(channel_num, &request_t, + chnl_info->curr_buf); + if (ret != 0) { + break; + } + if (data_priv->intr_after_every_bd == 0) { + if (i == num_buf - 1) { + mxc_dma_set_bd_intr(channel_num, + chnl_info->curr_buf, 1); + } else { + mxc_dma_set_bd_intr(channel_num, + chnl_info->curr_buf, 0); + } + } + + prev_buf = chnl_info->curr_buf; + chnl_info->curr_buf += 1; + if (chnl_info->curr_buf >= chnl_param.bd_number) { + chnl_info->curr_buf = 0; + } + if (chnl_info->curr_buf == data_priv->buf_tail) { + if ((data_priv->intr_after_every_bd == 0) + && (i != num_buf - 1)) { + /* + * Set the BD_INTR flag on the last BD that + * was queued + */ + mxc_dma_set_bd_intr(channel_num, prev_buf, 1); + } + chnl_info->active = 1; + } + } + + if (i == 0) { + return -EBUSY; + } + return 0; +} + +/*! + * This function would just configure the scatterlist specified by the + * user into dma channel. This is a slight variation of mxc_dma_config(), + * it is provided for the convenience of drivers that have a scatterlist + * passed into them. It is the calling driver's responsibility to have the + * correct physical address filled in the "dma_address" field of the + * scatterlist. + * + * @param channel_num the channel number returned at request time. This + * would be used by the DMA driver to identify the calling + * driver and do the necessary cleanup on the channel + * associated with the particular peripheral + * @param sg a scatterlist of buffers. The caller must guarantee + * the dma_buf is available until the transfer is + * completed. + * @param num_buf number of buffers in the array + * @param num_of_bytes total number of bytes to transfer. If set to 0, this + * would imply to use the length field of the scatterlist + * for each DMA transfer. Else it would calculate the size + * for each DMA transfer. + * @param mode specifies whether this is READ or WRITE operation + * @return This function returns a negative number on error if buffer could not + * be added with DMA for transfer. On Success, it returns 0 + */ +int mxc_dma_sg_config(int channel_num, struct scatterlist *sg, + int num_buf, int num_of_bytes, mxc_dma_mode_t mode) +{ + int ret = 0, i = 0; + mxc_dma_requestbuf_t *dma_buf; + + if ((channel_num >= MAX_DMA_CHANNELS) || (channel_num < 0)) { + return -EINVAL; + } + + if (mxc_sdma_channels[channel_num].lock != 1) { + return -ENODEV; + } + + dma_buf = + (mxc_dma_requestbuf_t *) kmalloc(num_buf * + sizeof(mxc_dma_requestbuf_t), + GFP_KERNEL); + + if (dma_buf == NULL) { + return -EFAULT; + } + + for (i = 0; i < num_buf; i++) { + if (mode == MXC_DMA_MODE_READ) { + (dma_buf + i)->dst_addr = sg->dma_address; + } else { + (dma_buf + i)->src_addr = sg->dma_address; + } + + if ((num_of_bytes > sg->length) || (num_of_bytes == 0)) { + (dma_buf + i)->num_of_bytes = sg->length; + } else { + (dma_buf + i)->num_of_bytes = num_of_bytes; + } + sg++; + num_of_bytes -= (dma_buf + i)->num_of_bytes; + } + + ret = mxc_dma_config(channel_num, dma_buf, num_buf, mode); + kfree(dma_buf); + return ret; +} + +/*! + * This function is provided if the driver would like to set/change its + * callback function. + * + * @param channel_num the channel number returned at request time. This + * would be used by the DMA driver to identify the calling + * driver and do the necessary cleanup on the channel + * associated with the particular peripheral + * @param callback a callback function to provide notification on transfer + * completion, user could specify NULL if he does not wish + * to be notified + * @param arg an argument that gets passed in to the callback + * function, used by the user to do any driver specific + * operations. + * @return this function returns a negative number on error if the callback + * could not be set for the channel or 0 on success + */ +int mxc_dma_callback_set(int channel_num, + mxc_dma_callback_t callback, void *arg) +{ + if ((channel_num >= MAX_DMA_CHANNELS) || (channel_num < 0)) { + return -EINVAL; + } + + if (mxc_sdma_channels[channel_num].lock != 1) { + return -ENODEV; + } + + mxc_sdma_channels[channel_num].cb_fn = callback; + mxc_sdma_channels[channel_num].cb_args = arg; + + mxc_dma_set_callback(channel_num, mxc_dma_chnl_callback, + (void *)channel_num); + + return 0; +} + +/*! + * This stops the DMA channel and any ongoing transfers. Subsequent use of + * mxc_dma_enable() will restart the channel and restart the transfer. + * + * @param channel_num the channel number returned at request time. This + * would be used by the DMA driver to identify the calling + * driver and do the necessary cleanup on the channel + * associated with the particular peripheral + * @return returns a negative number on error or 0 on success + */ +int mxc_dma_disable(int channel_num) +{ + if ((channel_num >= MAX_DMA_CHANNELS) || (channel_num < 0)) { + return -EINVAL; + } + + if (mxc_sdma_channels[channel_num].lock != 1) { + return -ENODEV; + } + + mxc_dma_stop(channel_num); + return 0; +} + +/*! + * This starts DMA transfer. Or it restarts DMA on a stopped channel + * previously stopped with mxc_dma_disable(). + * + * @param channel_num the channel number returned at request time. This + * would be used by the DMA driver to identify the calling + * driver and do the necessary cleanup on the channel + * associated with the particular peripheral + * @return returns a negative number on error or 0 on success + */ +int mxc_dma_enable(int channel_num) +{ + if ((channel_num >= MAX_DMA_CHANNELS) || (channel_num < 0)) { + return -EINVAL; + } + + if (mxc_sdma_channels[channel_num].lock != 1) { + return -ENODEV; + } + + mxc_dma_start(channel_num); + return 0; +} + +/*! + * Initializes dma structure with dma_operations + * + * @param dma dma structure + * @return returns 0 on success + */ +static int __init mxc_dma_init(void) +{ + int i; + for (i = 0; i < MAX_DMA_CHANNELS; i++) { + mxc_sdma_channels[i].active = 0; + mxc_sdma_channels[i].lock = 0; + mxc_sdma_channels[i].curr_buf = 0; + mxc_sdma_channels[i].dynamic = 1; + mxc_sdma_private[i].buf_tail = 0; + mxc_sdma_channels[i].private = &mxc_sdma_private[i]; + } + /* + * Make statically allocated channels unavailable for dynamic channel + * requests + */ + mxc_get_static_channels(mxc_sdma_channels); + + return 0; +} + +arch_initcall(mxc_dma_init); + +#else +int mxc_request_dma(int *channel, const char *devicename) +{ + return -ENODEV; +} + +int mxc_dma_setup_channel(int channel, dma_channel_params *p) +{ + return -ENODEV; +} + +int mxc_dma_set_channel_priority(unsigned int channel, unsigned int priority) +{ + return -ENODEV; +} + +int mxc_dma_set_config(int channel, dma_request_t *p, int bd_index) +{ + return -ENODEV; +} + +int mxc_dma_get_config(int channel, dma_request_t *p, int bd_index) +{ + return -ENODEV; +} + +int mxc_dma_start(int channel) +{ + return -ENODEV; +} + +int mxc_dma_stop(int channel) +{ + return -ENODEV; +} + +void mxc_free_dma(int channel) +{ +} + +void mxc_dma_set_callback(int channel, dma_callback_t callback, void *arg) +{ +} + +void *sdma_malloc(size_t size) +{ + return 0; +} + +void sdma_free(void *buf) +{ +} + +void *sdma_phys_to_virt(unsigned long buf) +{ + return 0; +} + +unsigned long sdma_virt_to_phys(void *buf) +{ + return 0; +} + +int mxc_dma_request(mxc_dma_device_t channel_id, char *dev_name) +{ + return -ENODEV; +} + +int mxc_dma_free(int channel_num) +{ + return -ENODEV; +} + +int mxc_dma_config(int channel_num, mxc_dma_requestbuf_t *dma_buf, + int num_buf, mxc_dma_mode_t mode) +{ + return -ENODEV; +} + +int mxc_dma_sg_config(int channel_num, struct scatterlist *sg, + int num_buf, int num_of_bytes, mxc_dma_mode_t mode) +{ + return -ENODEV; +} + +int mxc_dma_callback_set(int channel_num, mxc_dma_callback_t callback, + void *arg) +{ + return -ENODEV; +} + +int mxc_dma_disable(int channel_num) +{ + return -ENODEV; +} + +int mxc_dma_enable(int channel_num) +{ + return -ENODEV; +} + +EXPORT_SYMBOL(mxc_request_dma); +EXPORT_SYMBOL(mxc_dma_setup_channel); +EXPORT_SYMBOL(mxc_dma_set_channel_priority); +EXPORT_SYMBOL(mxc_dma_set_config); +EXPORT_SYMBOL(mxc_dma_get_config); +EXPORT_SYMBOL(mxc_dma_start); +EXPORT_SYMBOL(mxc_dma_stop); +EXPORT_SYMBOL(mxc_free_dma); +EXPORT_SYMBOL(mxc_dma_set_callback); +EXPORT_SYMBOL(sdma_malloc); +EXPORT_SYMBOL(sdma_free); +EXPORT_SYMBOL(sdma_phys_to_virt); +EXPORT_SYMBOL(sdma_virt_to_phys); + +#endif + +EXPORT_SYMBOL(mxc_dma_request_ext); +EXPORT_SYMBOL(mxc_dma_free); +EXPORT_SYMBOL(mxc_dma_config); +EXPORT_SYMBOL(mxc_dma_sg_config); +EXPORT_SYMBOL(mxc_dma_callback_set); +EXPORT_SYMBOL(mxc_dma_disable); +EXPORT_SYMBOL(mxc_dma_enable); + +MODULE_AUTHOR("Freescale Semiconductor, Inc."); +MODULE_DESCRIPTION("MXC Linux SDMA API"); +MODULE_LICENSE("GPL"); |