diff options
Diffstat (limited to 'drivers/hid/intel-ish-hid/ishtp/dma-if.c')
| -rw-r--r-- | drivers/hid/intel-ish-hid/ishtp/dma-if.c | 175 |
1 files changed, 175 insertions, 0 deletions
diff --git a/drivers/hid/intel-ish-hid/ishtp/dma-if.c b/drivers/hid/intel-ish-hid/ishtp/dma-if.c new file mode 100644 index 000000000000..2783f3666114 --- /dev/null +++ b/drivers/hid/intel-ish-hid/ishtp/dma-if.c @@ -0,0 +1,175 @@ +/* + * ISHTP DMA I/F functions + * + * Copyright (c) 2003-2016, Intel Corporation. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for + * more details. + * + */ + +#include <linux/slab.h> +#include <linux/sched.h> +#include <linux/wait.h> +#include <linux/delay.h> +#include <linux/dma-mapping.h> +#include "ishtp-dev.h" +#include "client.h" + +/** + * ishtp_cl_alloc_dma_buf() - Allocate DMA RX and TX buffer + * @dev: ishtp device + * + * Allocate RX and TX DMA buffer once during bus setup. + * It allocates 1MB, RX and TX DMA buffer, which are divided + * into slots. + */ +void ishtp_cl_alloc_dma_buf(struct ishtp_device *dev) +{ + dma_addr_t h; + + if (dev->ishtp_host_dma_tx_buf) + return; + + dev->ishtp_host_dma_tx_buf_size = 1024*1024; + dev->ishtp_host_dma_rx_buf_size = 1024*1024; + + /* Allocate Tx buffer and init usage bitmap */ + dev->ishtp_host_dma_tx_buf = dma_alloc_coherent(dev->devc, + dev->ishtp_host_dma_tx_buf_size, + &h, GFP_KERNEL); + if (dev->ishtp_host_dma_tx_buf) + dev->ishtp_host_dma_tx_buf_phys = h; + + dev->ishtp_dma_num_slots = dev->ishtp_host_dma_tx_buf_size / + DMA_SLOT_SIZE; + + dev->ishtp_dma_tx_map = kcalloc(dev->ishtp_dma_num_slots, + sizeof(uint8_t), + GFP_KERNEL); + spin_lock_init(&dev->ishtp_dma_tx_lock); + + /* Allocate Rx buffer */ + dev->ishtp_host_dma_rx_buf = dma_alloc_coherent(dev->devc, + dev->ishtp_host_dma_rx_buf_size, + &h, GFP_KERNEL); + + if (dev->ishtp_host_dma_rx_buf) + dev->ishtp_host_dma_rx_buf_phys = h; +} + +/** + * ishtp_cl_free_dma_buf() - Free DMA RX and TX buffer + * @dev: ishtp device + * + * Free DMA buffer when all clients are released. This is + * only happens during error path in ISH built in driver + * model + */ +void ishtp_cl_free_dma_buf(struct ishtp_device *dev) +{ + dma_addr_t h; + + if (dev->ishtp_host_dma_tx_buf) { + h = dev->ishtp_host_dma_tx_buf_phys; + dma_free_coherent(dev->devc, dev->ishtp_host_dma_tx_buf_size, + dev->ishtp_host_dma_tx_buf, h); + } + + if (dev->ishtp_host_dma_rx_buf) { + h = dev->ishtp_host_dma_rx_buf_phys; + dma_free_coherent(dev->devc, dev->ishtp_host_dma_rx_buf_size, + dev->ishtp_host_dma_rx_buf, h); + } + + kfree(dev->ishtp_dma_tx_map); + dev->ishtp_host_dma_tx_buf = NULL; + dev->ishtp_host_dma_rx_buf = NULL; + dev->ishtp_dma_tx_map = NULL; +} + +/* + * ishtp_cl_get_dma_send_buf() - Get a DMA memory slot + * @dev: ishtp device + * @size: Size of memory to get + * + * Find and return free address of "size" bytes in dma tx buffer. + * the function will mark this address as "in-used" memory. + * + * Return: NULL when no free buffer else a buffer to copy + */ +void *ishtp_cl_get_dma_send_buf(struct ishtp_device *dev, + uint32_t size) +{ + unsigned long flags; + int i, j, free; + /* additional slot is needed if there is rem */ + int required_slots = (size / DMA_SLOT_SIZE) + + 1 * (size % DMA_SLOT_SIZE != 0); + + spin_lock_irqsave(&dev->ishtp_dma_tx_lock, flags); + for (i = 0; i <= (dev->ishtp_dma_num_slots - required_slots); i++) { + free = 1; + for (j = 0; j < required_slots; j++) + if (dev->ishtp_dma_tx_map[i+j]) { + free = 0; + i += j; + break; + } + if (free) { + /* mark memory as "caught" */ + for (j = 0; j < required_slots; j++) + dev->ishtp_dma_tx_map[i+j] = 1; + spin_unlock_irqrestore(&dev->ishtp_dma_tx_lock, flags); + return (i * DMA_SLOT_SIZE) + + (unsigned char *)dev->ishtp_host_dma_tx_buf; + } + } + spin_unlock_irqrestore(&dev->ishtp_dma_tx_lock, flags); + dev_err(dev->devc, "No free DMA buffer to send msg\n"); + return NULL; +} + +/* + * ishtp_cl_release_dma_acked_mem() - Release DMA memory slot + * @dev: ishtp device + * @msg_addr: message address of slot + * @size: Size of memory to get + * + * Release_dma_acked_mem - returnes the acked memory to free list. + * (from msg_addr, size bytes long) + */ +void ishtp_cl_release_dma_acked_mem(struct ishtp_device *dev, + void *msg_addr, + uint8_t size) +{ + unsigned long flags; + int acked_slots = (size / DMA_SLOT_SIZE) + + 1 * (size % DMA_SLOT_SIZE != 0); + int i, j; + + if ((msg_addr - dev->ishtp_host_dma_tx_buf) % DMA_SLOT_SIZE) { + dev_err(dev->devc, "Bad DMA Tx ack address\n"); + return; + } + + i = (msg_addr - dev->ishtp_host_dma_tx_buf) / DMA_SLOT_SIZE; + spin_lock_irqsave(&dev->ishtp_dma_tx_lock, flags); + for (j = 0; j < acked_slots; j++) { + if ((i + j) >= dev->ishtp_dma_num_slots || + !dev->ishtp_dma_tx_map[i+j]) { + /* no such slot, or memory is already free */ + spin_unlock_irqrestore(&dev->ishtp_dma_tx_lock, flags); + dev_err(dev->devc, "Bad DMA Tx ack address\n"); + return; + } + dev->ishtp_dma_tx_map[i+j] = 0; + } + spin_unlock_irqrestore(&dev->ishtp_dma_tx_lock, flags); +} |