diff options
author | Long Cheng <long.cheng@mediatek.com> | 2018-12-05 16:42:59 +0800 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-12-05 11:02:39 +0100 |
commit | 85b5c1dd04560f95d10c9eee71ba45adaa87deec (patch) | |
tree | 766f156b10957ad9ca0b9b3372eb20a5384357c8 /drivers/tty | |
parent | 89212465c194853becaa17f82dfc1d7d30b56d5e (diff) |
serial: 8250-mtk: add uart DMA support
Modify uart register to support DMA function.
Signed-off-by: Long Cheng <long.cheng@mediatek.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty')
-rw-r--r-- | drivers/tty/serial/8250/8250_mtk.c | 210 |
1 files changed, 209 insertions, 1 deletions
diff --git a/drivers/tty/serial/8250/8250_mtk.c b/drivers/tty/serial/8250/8250_mtk.c index dd5e1cede2b5..1da73e895be6 100644 --- a/drivers/tty/serial/8250/8250_mtk.c +++ b/drivers/tty/serial/8250/8250_mtk.c @@ -14,6 +14,10 @@ #include <linux/pm_runtime.h> #include <linux/serial_8250.h> #include <linux/serial_reg.h> +#include <linux/console.h> +#include <linux/dma-mapping.h> +#include <linux/tty.h> +#include <linux/tty_flip.h> #include "8250.h" @@ -22,12 +26,172 @@ #define UART_MTK_SAMPLE_POINT 0x0b /* Sample point register */ #define MTK_UART_RATE_FIX 0x0d /* UART Rate Fix Register */ +#define MTK_UART_DMA_EN 0x13 /* DMA Enable register */ +#define MTK_UART_DMA_EN_TX 0x2 +#define MTK_UART_DMA_EN_RX 0x5 + +#define MTK_UART_TX_SIZE UART_XMIT_SIZE +#define MTK_UART_RX_SIZE 0x8000 +#define MTK_UART_TX_TRIGGER 1 +#define MTK_UART_RX_TRIGGER MTK_UART_RX_SIZE + +#ifdef CONFIG_SERIAL_8250_DMA +enum dma_rx_status { + DMA_RX_START = 0, + DMA_RX_RUNNING = 1, + DMA_RX_SHUTDOWN = 2, +}; +#endif + struct mtk8250_data { int line; + unsigned int rx_pos; struct clk *uart_clk; struct clk *bus_clk; + struct uart_8250_dma *dma; +#ifdef CONFIG_SERIAL_8250_DMA + enum dma_rx_status rx_status; +#endif }; +#ifdef CONFIG_SERIAL_8250_DMA +static void mtk8250_rx_dma(struct uart_8250_port *up); + +static void mtk8250_dma_rx_complete(void *param) +{ + struct uart_8250_port *up = param; + struct uart_8250_dma *dma = up->dma; + struct mtk8250_data *data = up->port.private_data; + struct tty_port *tty_port = &up->port.state->port; + struct dma_tx_state state; + unsigned char *ptr; + int copied; + + dma_sync_single_for_cpu(dma->rxchan->device->dev, dma->rx_addr, + dma->rx_size, DMA_FROM_DEVICE); + + dmaengine_tx_status(dma->rxchan, dma->rx_cookie, &state); + + if (data->rx_status == DMA_RX_SHUTDOWN) + return; + + if ((data->rx_pos + state.residue) <= dma->rx_size) { + ptr = (unsigned char *)(data->rx_pos + dma->rx_buf); + copied = tty_insert_flip_string(tty_port, ptr, state.residue); + } else { + ptr = (unsigned char *)(data->rx_pos + dma->rx_buf); + copied = tty_insert_flip_string(tty_port, ptr, + dma->rx_size - data->rx_pos); + ptr = (unsigned char *)(dma->rx_buf); + copied += tty_insert_flip_string(tty_port, ptr, + data->rx_pos + state.residue - dma->rx_size); + } + up->port.icount.rx += copied; + + tty_flip_buffer_push(tty_port); + + mtk8250_rx_dma(up); +} + +static void mtk8250_rx_dma(struct uart_8250_port *up) +{ + struct uart_8250_dma *dma = up->dma; + struct mtk8250_data *data = up->port.private_data; + struct dma_async_tx_descriptor *desc; + struct dma_tx_state state; + + desc = dmaengine_prep_slave_single(dma->rxchan, dma->rx_addr, + dma->rx_size, DMA_DEV_TO_MEM, + DMA_PREP_INTERRUPT | DMA_CTRL_ACK); + if (!desc) { + pr_err("failed to prepare rx slave single\n"); + return; + } + + desc->callback = mtk8250_dma_rx_complete; + desc->callback_param = up; + + dma->rx_cookie = dmaengine_submit(desc); + + dmaengine_tx_status(dma->rxchan, dma->rx_cookie, &state); + data->rx_pos = state.residue; + + dma_sync_single_for_device(dma->rxchan->device->dev, dma->rx_addr, + dma->rx_size, DMA_FROM_DEVICE); + + dma_async_issue_pending(dma->rxchan); +} + +static void mtk8250_dma_enable(struct uart_8250_port *up) +{ + struct uart_8250_dma *dma = up->dma; + struct mtk8250_data *data = up->port.private_data; + int lcr = serial_in(up, UART_LCR); + + if (data->rx_status != DMA_RX_START) + return; + + dma->rxconf.direction = DMA_DEV_TO_MEM; + dma->rxconf.src_addr_width = dma->rx_size / 1024; + dma->rxconf.src_addr = dma->rx_addr; + + dma->txconf.direction = DMA_MEM_TO_DEV; + dma->txconf.dst_addr_width = MTK_UART_TX_SIZE / 1024; + dma->txconf.dst_addr = dma->tx_addr; + + serial_out(up, UART_FCR, UART_FCR_ENABLE_FIFO | UART_FCR_CLEAR_RCVR | + UART_FCR_CLEAR_XMIT); + serial_out(up, MTK_UART_DMA_EN, + MTK_UART_DMA_EN_RX | MTK_UART_DMA_EN_TX); + + serial_out(up, UART_LCR, UART_LCR_CONF_MODE_B); + serial_out(up, UART_EFR, UART_EFR_ECB); + serial_out(up, UART_LCR, lcr); + + if (dmaengine_slave_config(dma->rxchan, &dma->rxconf) != 0) + pr_err("failed to configure rx dma channel\n"); + if (dmaengine_slave_config(dma->txchan, &dma->txconf) != 0) + pr_err("failed to configure tx dma channel\n"); + + data->rx_status = DMA_RX_RUNNING; + data->rx_pos = 0; + mtk8250_rx_dma(up); +} +#endif + +static int mtk8250_startup(struct uart_port *port) +{ +#ifdef CONFIG_SERIAL_8250_DMA + struct uart_8250_port *up = up_to_u8250p(port); + struct mtk8250_data *data = port->private_data; + + /* disable DMA for console */ + if (uart_console(port)) + up->dma = NULL; + + if (up->dma) { + data->rx_status = DMA_RX_START; + uart_circ_clear(&port->state->xmit); + } +#endif + memset(&port->icount, 0, sizeof(port->icount)); + + return serial8250_do_startup(port); +} + +static void mtk8250_shutdown(struct uart_port *port) +{ +#ifdef CONFIG_SERIAL_8250_DMA + struct uart_8250_port *up = up_to_u8250p(port); + struct mtk8250_data *data = port->private_data; + + if (up->dma) + data->rx_status = DMA_RX_SHUTDOWN; +#endif + + return serial8250_do_shutdown(port); +} + static void mtk8250_set_termios(struct uart_port *port, struct ktermios *termios, struct ktermios *old) @@ -36,6 +200,17 @@ mtk8250_set_termios(struct uart_port *port, struct ktermios *termios, unsigned long flags; unsigned int baud, quot; +#ifdef CONFIG_SERIAL_8250_DMA + if (up->dma) { + if (uart_console(port)) { + devm_kfree(up->port.dev, up->dma); + up->dma = NULL; + } else { + mtk8250_dma_enable(up); + } + } +#endif + serial8250_do_set_termios(port, termios, old); /* @@ -143,9 +318,20 @@ mtk8250_do_pm(struct uart_port *port, unsigned int state, unsigned int old) pm_runtime_put_sync_suspend(port->dev); } +#ifdef CONFIG_SERIAL_8250_DMA +static bool mtk8250_dma_filter(struct dma_chan *chan, void *param) +{ + return false; +} +#endif + static int mtk8250_probe_of(struct platform_device *pdev, struct uart_port *p, struct mtk8250_data *data) { +#ifdef CONFIG_SERIAL_8250_DMA + int dmacnt; +#endif + data->uart_clk = devm_clk_get(&pdev->dev, "baud"); if (IS_ERR(data->uart_clk)) { /* @@ -162,7 +348,23 @@ static int mtk8250_probe_of(struct platform_device *pdev, struct uart_port *p, } data->bus_clk = devm_clk_get(&pdev->dev, "bus"); - return PTR_ERR_OR_ZERO(data->bus_clk); + if (IS_ERR(data->bus_clk)) + return PTR_ERR(data->bus_clk); + + data->dma = NULL; +#ifdef CONFIG_SERIAL_8250_DMA + dmacnt = of_property_count_strings(pdev->dev.of_node, "dma-names"); + if (dmacnt == 2) { + data->dma = devm_kzalloc(&pdev->dev, sizeof(*data->dma), + GFP_KERNEL); + data->dma->fn = mtk8250_dma_filter; + data->dma->rx_size = MTK_UART_RX_SIZE; + data->dma->rxconf.src_maxburst = MTK_UART_RX_TRIGGER; + data->dma->txconf.dst_maxburst = MTK_UART_TX_TRIGGER; + } +#endif + + return 0; } static int mtk8250_probe(s /* internal.h: mm/ internal definitions
*
* Copyright (C) 2004 Red Hat, Inc. All Rights Reserved.
* Written by David Howells (dhowells@redhat.com)
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version
* 2 of the License, or (at your option) any later version.
*/
#ifndef __MM_INTERNAL_H
#define __MM_INTERNAL_H
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/pagemap.h>
#include <linux/tracepoint-defs.h>
/*
* The set of flags that only affect watermark checking and reclaim
* behaviour. This is used by the MM to obey the caller constraints
* about IO, FS and watermark checking while ignoring placement
* hints such as HIGHMEM usage.
*/
#define GFP_RECLAIM_MASK (__GFP_RECLAIM|__GFP_HIGH|__GFP_IO|__GFP_FS|\
__GFP_NOWARN|__GFP_REPEAT|__GFP_NOFAIL|\
__GFP_NORETRY|__GFP_MEMALLOC|__GFP_NOMEMALLOC|\
__GFP_ATOMIC)
/* The GFP flags allowed during early boot */
#define GFP_BOOT_MASK (__GFP_BITS_MASK & ~(__GFP_RECLAIM|__GFP_IO|__GFP_FS))
/* Control allocation cpuset and node placement constraints */
#define GFP_CONSTRAINT_MASK (__GFP_HARDWALL|__GFP_THISNODE)
/* Do not use these with a slab allocator */
#define GFP_SLAB_BUG_MASK (__GFP_DMA32|__GFP_HIGHMEM|~__GFP_BITS_MASK)
void free_pgtables(struct mmu_gather *tlb, struct vm_area_struct *start_vma,
unsigned long floor, unsigned long ceiling);
void unmap_page_range(struct mmu_gather *tlb,
struct vm_area_struct *vma,
unsigned long addr, unsigned long end,
struct zap_details *details);
extern int __do_page_cache_readahead(struct address_space *mapping,
struct file *filp, pgoff_t offset, unsigned long nr_to_read,
unsigned long lookahead_size);
/*
* Submit IO for the read-ahead request in file_ra_state.
*/
static inline unsigned long ra_submit(struct file_ra_state *ra,
struct address_space *mapping, struct file *filp)
{
return __do_page_cache_readahead(mapping, filp,
ra->start, ra->size, ra->async_size);
}
/*
* Turn a non-refcounted page (->_refcount == 0) into refcounted with
* a count of one.
*/
static inline void set_page_refcounted(struct page *page)
{
VM_BUG_ON_PAGE(PageTail(page), page);
VM_BUG_ON_PAGE(page_ref_count(page), page);
set_page_count(page, 1);
}
extern unsigned long highest_memmap_pfn;
/*
* in mm/vmscan.c:
*/
extern int isolate_lru_page(struct page *page);
extern void putback_lru_page(struct page *page);
extern bool zone_reclaimable(struct zone *zone);
/*
* in mm/rmap.c:
*/
extern pmd_t *mm_find_pmd(struct mm_struct *mm, unsigned long address);
/*
* in mm/page_alloc.c
*/
/*
* Structure for holding the mostly immutable allocation parameters passed
* between functions involved in allocations, including the alloc_pages*
* family of functions.
*
* nodemask, migratetype and high_zoneidx are initialized only once in
* __alloc_pages_nodemask() and then never change.
*
* zonelist, preferred_zone and classzone_idx are set first in
* __alloc_pages_nodemask() for the fast path, and might be later changed
* in __alloc_pages_slowpath(). All other functions pass the whole strucure
* by a const pointer.
*/
struct alloc_context {
struct zonelist *zonelist;
nodemask_t *nodemask;
struct zoneref *preferred_zoneref;
int migratetype;
enum zone_type high_zoneidx;
bool spread_dirty_pages;
};
#define ac_classzone_idx(ac) zonelist_zone_idx(ac->preferred_zoneref)
/*
* Locate the struct page for both the matching buddy in our
* pair (buddy1) and the combined O(n+1) page they form (page).
*
* 1) Any buddy B1 will have an order O twin B2 which satisfies
* the following equation:
* B2 = B1 ^ (1 << O)
* For example, if the starting buddy (buddy2) is #8 its order
* 1 buddy is #10:
* B2 = 8 ^ (1 << 1) = 8 ^ 2 = 10
*
* 2) Any buddy B will have an order O+1 parent P which
* satisfies the following equation:
* P = B & ~(1 << O)
*
* Assumption: *_mem_map is contiguous at least up to MAX_ORDER
*/
static inline unsigned long
__find_buddy_index(unsigned long page_idx, unsigned int order)
{
return page_idx ^ (1 << order);
}
extern struct page *__pageblock_pfn_to_page(unsigned long start_pfn,
unsigned long end_pfn, struct zone *zone);
static inline struct page *pageblock_pfn_to_page(unsigned long start_pfn,
unsigned long end_pfn, struct zone *zone)
{
if (zone->contiguous)
return pfn_to_page(start_pfn);
return __pageblock_pfn_to_page(start_pfn, end_pfn, zone);
}
extern int __isolate_free_page(struct page *page, unsigned int order);
extern void __free_pages_bootmem(struct page *page, unsigned long pfn,
unsigned int order);
extern void prep_compound_page(struct page *page, unsigned int order);
extern int user_min_free_kbytes;
#if defined CONFIG_COMPACTION || defined CONFIG_CMA
/*
* in mm/compaction.c
*/
/*
* compact_control is used to track pages being migrated and the free pages
* they are being migrated to during memory compaction. The free_pfn starts
* at the end of a zone and migrate_pfn begins at the start. Movable pages
* are moved to the end of a zone during a compaction run and the run
* completes when free_pfn <= migrate_pfn
*/
struct compact_control {
struct list_head freepages; /* List of free pages to migrate to */
struct list_head migratepages; /* List of pages being migrated */
unsigned long nr_freepages; /* Number of isolated free pages */
unsigned long nr_migratepages; /* Number of pages to migrate */
unsigned long free_pfn; /* isolate_freepages search base */
unsigned long migrate_pfn; /* isolate_migratepages search base */
unsigned long last_migrated_pfn;/* Not yet flushed page being freed */
enum migrate_mode mode; /* Async or sync migration mode */
bool ignore_skip_hint; /* Scan blocks even if marked skip */
bool direct_compaction; /* False from kcompactd or /proc/... */
bool whole_zone; /* Whole zone has been scanned */
int order; /* order a direct compactor needs */
const gfp_t gfp_mask; /* gfp mask of a direct compactor */
const unsigned int alloc_flags; /* alloc flags of a direct compactor */
const int classzone_idx; /* zone index of a direct compactor */
struct zone *zone;
int contended; /* Signal need_sched() or lock
* contention detected during
* compaction
*/
};
unsigned long
isolate_freepages_range(struct compact_control *cc,
unsigned long start_pfn, unsigned long end_pfn);
unsigned long
isolate_migratepages_range(struct compact_control *cc,
unsigned long low_pfn, unsigned long end_pfn);
int find_suitable_fallback(struct free_area *area, unsigned int order,
int migratetype, bool only_stealable, bool *can_steal);
#endif
/*
* This function returns the order of a free page in the buddy system. In
* general, page_zone(page)->lock must be held by the caller to prevent the
* page from being allocated in parallel and returning garbage as the order.
* If a caller does not hold page_zone(page)->lock, it must guarantee that the
* page cannot be allocated or merged in parallel. Alternatively, it must
* handle invalid values gracefully, and use page_order_unsafe() below.
*/
static inline unsigned int page_order(struct page *page)
{
/* PageBuddy() must be checked by the caller */
return page_private(page);
}
/*
* Like page_order(), but for callers who cannot afford to hold the zone lock.
* PageBuddy() should be checked first by the caller to minimize race window,
* and invalid values must be handled gracefully.
*
* READ_ONCE is used so that if the caller assigns the result into a local
* variable and e.g. tests it for valid range before using, the compiler cannot
* decide to remove the variable and inline the page_private(page) multiple
* times, potentially observing different values in the tests and the actual
* use of the result.
*/
#define page_order_unsafe(page) READ_ONCE(page_private(page))
static inline bool is_cow_mapping(vm_flags_t flags)
{
return (flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE;
}
/*
* These three helpers classifies VMAs for virtual memory accounting.
*/
/*
* Executable code area - executable, not writable, not stack
*/
static inline bool is_exec_mapping(vm_flags_t flags)
{
return (flags & (VM_EXEC | VM_WRITE | VM_STACK)) == VM_EXEC;
}
/*
* Stack area - atomatically grows in one direction
*
* VM_GROWSUP / VM_GROWSDOWN VMAs are always private anonymous:
* do_mmap() forbids all other combinations.
*/
static inline bool is_stack_mapping(vm_flags_t flags)
{
return (flags & VM_STACK) == VM_STACK;
}
/*
* Data area - private, writable, not stack
*/
static inline bool is_data_mapping(vm_flags_t flags)
{
return (flags & (VM_WRITE | VM_SHARED | VM_STACK)) == VM_WRITE;
}
/* mm/util.c */
void __vma_link_list(struct mm_struct *mm, struct vm_area_struct *vma,
struct vm_area_struct *prev, struct rb_node *rb_parent);
#ifdef CONFIG_MMU
extern long populate_vma_page_range(struct vm_area_struct *vma,
unsigned long start, unsigned long end, int *nonblocking);
extern void munlock_vma_pages_range(struct vm_area_struct *vma,
unsigned long start, unsigned long end);
static inline void munlock_vma_pages_all(struct vm_area_struct *vma)
{
munlock_vma_pages_range(vma, vma->vm_start, vma->vm_end);
}
/*
* must be called with vma's mmap_sem held for read or write, and page locked.
*/
extern void mlock_vma_page(struct page *page);
extern unsigned int munlock_vma_page(struct page *page);
/*
* Clear the page's PageMlocked(). This can be useful in a situation where
* we want to unconditionally remove a page from the pagecache -- e.g.,
* on truncation or freeing.
*
* It is legal to call this function for any page, mlocked or not.
* If called for a page that is still mapped by mlocked vmas, all we do
* is revert to lazy LRU behaviour -- semantics are not broken.
*/
extern void clear_page_mlock(struct page *page);
/*
* mlock_migrate_page - called only from migrate_misplaced_transhuge_page()
* (because that does not go through the full procedure of migration ptes):
* to migrate the Mlocked page flag; update statistics.
*/
static inline void mlock_migrate_page(struct page *newpage, struct page *page)
{
if (TestClearPageMlocked(page)) {
int nr_pages |