diff options
| -rw-r--r-- | Documentation/dmaengine/pxa_dma.txt | 153 | ||||
| -rw-r--r-- | MAINTAINERS | 1 | ||||
| -rw-r--r-- | drivers/dma/Kconfig | 11 | ||||
| -rw-r--r-- | drivers/dma/Makefile | 1 | ||||
| -rw-r--r-- | drivers/dma/pxa_dma.c | 1467 | ||||
| -rw-r--r-- | include/linux/dma/pxa-dma.h | 27 |
6 files changed, 1660 insertions, 0 deletions
diff --git a/Documentation/dmaengine/pxa_dma.txt b/Documentation/dmaengine/pxa_dma.txt new file mode 100644 index 000000000000..413ef9cfaa4d --- /dev/null +++ b/Documentation/dmaengine/pxa_dma.txt @@ -0,0 +1,153 @@ +PXA/MMP - DMA Slave controller +============================== + +Constraints +----------- + a) Transfers hot queuing + A driver submitting a transfer and issuing it should be granted the transfer + is queued even on a running DMA channel. + This implies that the queuing doesn't wait for the previous transfer end, + and that the descriptor chaining is not only done in the irq/tasklet code + triggered by the end of the transfer. + A transfer which is submitted and issued on a phy doesn't wait for a phy to + stop and restart, but is submitted on a "running channel". The other + drivers, especially mmp_pdma waited for the phy to stop before relaunching + a new transfer. + + b) All transfers having asked for confirmation should be signaled + Any issued transfer with DMA_PREP_INTERRUPT should trigger a callback call. + This implies that even if an irq/tasklet is triggered by end of tx1, but + at the time of irq/dma tx2 is already finished, tx1->complete() and + tx2->complete() should be called. + + c) Channel running state + A driver should be able to query if a channel is running or not. For the + multimedia case, such as video capture, if a transfer is submitted and then + a check of the DMA channel reports a "stopped channel", the transfer should + not be issued until the next "start of frame interrupt", hence the need to + know if a channel is in running or stopped state. + + d) Bandwidth guarantee + The PXA architecture has 4 levels of DMAs priorities : high, normal, low. + The high prorities get twice as much bandwidth as the normal, which get twice + as much as the low priorities. + A driver should be able to request a priority, especially the real-time + ones such as pxa_camera with (big) throughputs. + +Design +------ + a) Virtual channels + Same concept as in sa11x0 driver, ie. a driver was assigned a "virtual + channel" linked to the requestor line, and the physical DMA channel is + assigned on the fly when the transfer is issued. + + b) Transfer anatomy for a scatter-gather transfer + +------------+-----+---------------+----------------+-----------------+ + | desc-sg[0] | ... | desc-sg[last] | status updater | finisher/linker | + +------------+-----+---------------+----------------+-----------------+ + + This structure is pointed by dma->sg_cpu. + The descriptors are used as follows : + - desc-sg[i]: i-th descriptor, transferring the i-th sg + element to the video buffer scatter gather + - status updater + Transfers a single u32 to a well known dma coherent memory to leave + a trace that this transfer is done. The "well known" is unique per + physical channel, meaning that a read of this value will tell which + is the last finished transfer at that point in time. + - finisher: has ddadr=DADDR_STOP, dcmd=ENDIRQEN + - linker: has ddadr= desc-sg[0] of next transfer, dcmd=0 + + c) Transfers hot-chaining + Suppose the running chain is : + Buffer 1 Buffer 2 + +---------+----+---+ +----+----+----+---+ + | d0 | .. | dN | l | | d0 | .. | dN | f | + +---------+----+-|-+ ^----+----+----+---+ + | | + +----+ + + After a call to dmaengine_submit(b3), the chain will look like : + Buffer 1 Buffer 2 Buffer 3 + +---------+----+---+ +----+----+----+---+ +----+----+----+---+ + | d0 | .. | dN | l | | d0 | .. | dN | l | | d0 | .. | dN | f | + +---------+----+-|-+ ^----+----+----+-|-+ ^----+----+----+---+ + | | | | + +----+ +----+ + new_link + + If while new_link was created the DMA channel stopped, it is _not_ + restarted. Hot-chaining doesn't break the assumption that + dma_async_issue_pending() is to be used to ensure the transfer is actually started. + + One exception to this rule : + - if Buffer1 and Buffer2 had all their addresses 8 bytes aligned + - and if Buffer3 has at least one address not 4 bytes aligned + - then hot-chaining cannot happen, as the channel must be stopped, the + "align bit" must be set, and the channel restarted As a consequence, + such a transfer tx_submit() will be queued on the submitted queue, and + this specific case if the DMA is already running in aligned mode. + + d) Transfers completion updater + Each time a transfer is completed on a channel, an interrupt might be + generated or not, up to the client's request. But in each case, the last + descriptor of a transfer, the "status updater", will write the latest + transfer being completed into the physical channel's completion mark. + + This will speed up residue calculation, for large transfers such as video + buffers which hold around 6k descriptors or more. This also allows without + any lock to find out what is the latest completed transfer in a running + DMA chain. + + e) Transfers completion, irq and tasklet + When a transfer flagged as "DMA_PREP_INTERRUPT" is finished, the dma irq + is raised. Upon this interrupt, a tasklet is scheduled for the physical + channel. + The tasklet is responsible for : + - reading the physical channel last updater mark + - calling all the transfer callbacks of finished transfers, based on + that mark, and each transfer flags. + If a transfer is completed while this handling is done, a dma irq will + be raised, and the tasklet will be scheduled once again, having a new + updater mark. + + f) Residue + Residue granularity will be descriptor based. The issued but not completed + transfers will be scanned for all of their descriptors against the + currently running descriptor. + + g) Most complicated case of driver's tx queues + The most tricky situation is when : + - there are not "acked" transfers (tx0) + - a driver submitted an aligned tx1, not chained + - a driver submitted an aligned tx2 => tx2 is cold chained to tx1 + - a driver issued tx1+tx2 => channel is running in aligned mode + - a driver submitted an aligned tx3 => tx3 is hot-chained + - a driver submitted an unaligned tx4 => tx4 is put in submitted queue, + not chained + - a driver issued tx4 => tx4 is put in issued queue, not chained + - a driver submitted an aligned tx5 => tx5 is put in submitted queue, not + chained + - a driver submitted an aligned tx6 => tx6 is put in submitted queue, + cold chained to tx5 + + This translates into (after tx4 is issued) : + - issued queue + +-----+ +-----+ +-----+ +-----+ + | tx1 | | tx2 | | tx3 | | tx4 | + +---|-+ ^---|-+ ^-----+ +-----+ + | | | | + +---+ +---+ + - submitted queue + +-----+ +-----+ + | tx5 | | tx6 | + +---|-+ ^-----+ + | | + +---+ + - completed queue : empty + - allocated queue : tx0 + + It should be noted that after tx3 is completed, the channel is stopped, and + restarted in "unaligned mode" to handle tx4. + +Author: Robert Jarzmik <robert.jarzmik@free.fr> diff --git a/MAINTAINERS b/MAINTAINERS index 781e099495d3..238ea990ed29 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -7937,6 +7937,7 @@ T: git git://github.com/hzhuang1/linux.git T: git git://github.com/rjarzmik/linux.git S: Maintained F: arch/arm/mach-pxa/ +F: drivers/dma/pxa* F: drivers/pcmcia/pxa2xx* F: drivers/spi/spi-pxa2xx* F: drivers/usb/gadget/udc/pxa2* diff --git a/drivers/dma/Kconfig b/drivers/dma/Kconfig index 0205ade0ba32..88d474b78076 100644 --- a/drivers/dma/Kconfig +++ b/drivers/dma/Kconfig @@ -162,6 +162,17 @@ config MX3_IPU_IRQS To avoid bloating the irq_desc[] array we allocate a sufficient number of IRQ slots and map them dynamically to specific sources. +config PXA_DMA + bool "PXA DMA support" + depends on (ARCH_MMP || ARCH_PXA) + select DMA_ENGINE + select DMA_VIRTUAL_CHANNELS + help + Support the DMA engine for PXA. It is also compatible with MMP PDMA + platform. The internal DMA IP of all PXA variants is supported, with + 16 to 32 channels for peripheral to memory or memory to memory + transfers. + config TXX9_DMAC tristate "Toshiba TXx9 SoC DMA support" depends on MACH_TX49XX || MACH_TX39XX diff --git a/drivers/dma/Makefile b/drivers/dma/Makefile index 535919559f12..6a4d6f2827da 100644 --- a/drivers/dma/Makefile +++ b/drivers/dma/Makefile @@ -25,6 +25,7 @@ obj-$(CONFIG_AMCC_PPC440SPE_ADMA) += ppc4xx/ obj-$(CONFIG_IMX_SDMA) += imx-sdma.o obj-$(CONFIG_IMX_DMA) += imx-dma.o obj-$(CONFIG_MXS_DMA) += mxs-dma.o +obj-$(CONFIG_PXA_DMA) += pxa_dma.o obj-$(CONFIG_TIMB_DMA) += timb_dma.o obj-$(CONFIG_SIRF_DMA) += sirf-dma.o obj-$(CONFIG_TI_EDMA) += edma.o diff --git a/drivers/dma/pxa_dma.c b/drivers/dma/pxa_dma.c new file mode 100644 index 000000000000..ddcbbf5cd9e9 --- /dev/null +++ b/drivers/dma/pxa_dma.c @@ -0,0 +1,1467 @@ +/* + * Copyright 2015 Robert Jarzmik <robert.jarzmik@free.fr> + * + * 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/err.h> +#include <linux/module.h> +#include <linux/init.h> +#include <linux/types.h> +#include <linux/interrupt.h> +#include <linux/dma-mapping.h> +#include <linux/slab.h> +#include <linux/dmaengine.h> +#include <linux/platform_device.h> +#include <linux/device.h> +#include <linux/platform_data/mmp_dma.h> +#include <linux/dmapool.h> +#include <linux/of_device.h> +#include <linux/of_dma.h> +#include <linux/of.h> +#include <linux/dma/pxa-dma.h> + +#include "dmaengine.h" +#include "virt-dma.h" + +#define DCSR(n) (0x0000 + ((n) << 2)) +#define DALGN(n) 0x00a0 +#define DINT 0x00f0 +#define DDADR(n) (0x0200 + ((n) << 4)) +#define DSADR(n) (0x0204 + ((n) << 4)) +#define DTADR(n) (0x0208 + ((n) << 4)) +#define DCMD(n) (0x020c + ((n) << 4)) + +#define PXA_DCSR_RUN BIT(31) /* Run Bit (read / write) */ +#define PXA_DCSR_NODESC BIT(30) /* No-Descriptor Fetch (read / write) */ +#define PXA_DCSR_STOPIRQEN BIT(29) /* Stop Interrupt Enable (R/W) */ +#define PXA_DCSR_REQPEND BIT(8) /* Request Pending (read-only) */ +#define PXA_DCSR_STOPSTATE BIT(3) /* Stop State (read-only) */ +#define PXA_DCSR_ENDINTR BIT(2) /* End Interrupt (read / write) */ +#define PXA_DCSR_STARTINTR BIT(1) /* Start Interrupt (read / write) */ +#define PXA_DCSR_BUSERR BIT(0) /* Bus Error Interrupt (read / write) */ + +#define PXA_DCSR_EORIRQEN BIT(28) /* End of Receive IRQ Enable (R/W) */ +#define PXA_DCSR_EORJMPEN BIT(27) /* Jump to next descriptor on EOR */ +#define PXA_DCSR_EORSTOPEN BIT(26) /* STOP on an EOR */ +#define PXA_DCSR_SETCMPST BIT(25) /* Set Descriptor Compare Status */ +#define PXA_DCSR_CLRCMPST BIT(24) /* Clear Descriptor Compare Status */ +#define PXA_DCSR_CMPST BIT(10) /* The Descriptor Compare Status */ +#define PXA_DCSR_EORINTR BIT(9) /* The end of Receive */ + +#define DRCMR_MAPVLD BIT(7) /* Map Valid (read / write) */ +#define DRCMR_CHLNUM 0x1f /* mask for Channel Number (read / write) */ + +#define DDADR_DESCADDR 0xfffffff0 /* Address of next descriptor (mask) */ +#define DDADR_STOP BIT(0) /* Stop (read / write) */ + +#define PXA_DCMD_INCSRCADDR BIT(31) /* Source Address Increment Setting. */ +#define PXA_DCMD_INCTRGADDR BIT(30) /* Target Address Increment Setting. */ +#define PXA_DCMD_FLOWSRC BIT(29) /* Flow Control by the source. */ +#define PXA_DCMD_FLOWTRG BIT(28) /* Flow Control by the target. */ +#define PXA_DCMD_STARTIRQEN BIT(22) /* Start Interrupt Enable */ +#define PXA_DCMD_ENDIRQEN BIT(21) /* End Interrupt Enable */ +#define PXA_DCMD_ENDIAN BIT(18) /* Device Endian-ness. */ +#define PXA_DCMD_BURST8 (1 << 16) /* 8 byte burst */ +#define PXA_DCMD_BURST16 (2 << 16) /* 16 byte burst */ +#define PXA_DCMD_BURST32 (3 << 16) /* 32 byte burst */ +#define PXA_DCMD_WIDTH1 (1 << 14) /* 1 byte width */ +#define PXA_DCMD_WIDTH2 (2 << 14) /* 2 byte width (HalfWord) */ +#define PXA_DCMD_WIDTH4 (3 << 14) /* 4 byte width (Word) */ +#define PXA_DCMD_LENGTH 0x01fff /* length mask (max = 8K - 1) */ + +#define PDMA_ALIGNMENT 3 +#define PDMA_MAX_DESC_BYTES (PXA_DCMD_LENGTH & ~((1 << PDMA_ALIGNMENT) - 1)) + +struct pxad_desc_hw { + u32 ddadr; /* Points to the next descriptor + flags */ + u32 dsadr; /* DSADR value for the current transfer */ + u32 dtadr; /* DTADR value for the current transfer */ + u32 dcmd; /* DCMD value for the current transfer */ +} __aligned(16); + +struct pxad_desc_sw { + struct virt_dma_desc vd; /* Virtual descriptor */ + int nb_desc; /* Number of hw. descriptors */ + size_t len; /* Number of bytes xfered */ + dma_addr_t first; /* First descriptor's addr */ + + /* At least one descriptor has an src/dst address not multiple of 8 */ + bool misaligned; + bool cyclic; + struct dma_pool *desc_pool; /* Channel's used allocator */ + + struct pxad_desc_hw *hw_desc[]; /* DMA coherent descriptors */ +}; + +struct pxad_phy { + int idx; + void __iomem *base; + struct pxad_chan *vchan; +}; + +struct pxad_chan { + struct virt_dma_chan vc; /* Virtual channel */ + u32 drcmr; /* Requestor of the channel */ + enum pxad_chan_prio prio; /* Required priority of phy */ + /* + * At least one desc_sw in submitted or issued transfers on this channel + * has one address such as: addr % 8 != 0. This implies the DALGN + * setting on the phy. + */ + bool misaligned; + struct dma_slave_config cfg; /* Runtime config */ + + /* protected by vc->lock */ + struct pxad_phy *phy; + struct dma_pool *desc_pool; /* Descriptors pool */ +}; + +struct pxad_device { + struct dma_device slave; + int nr_chans; + void __iomem *base; + struct pxad_phy *phys; + spinlock_t phy_lock; /* Phy association */ +#ifdef CONFIG_DEBUG_FS + struct dentry *dbgfs_root; + struct dentry *dbgfs_state; + struct dentry **dbgfs_chan; +#endif +}; + +#define tx_to_pxad_desc(tx) \ + container_of(tx, struct pxad_desc_sw, async_tx) +#define to_pxad_chan(dchan) \ + container_of(dchan, struct pxad_chan, vc.chan) +#define to_pxad_dev(dmadev) \ + container_of(dmadev, struct pxad_device, slave) +#define to_pxad_sw_desc(_vd) \ + container_of((_vd), struct pxad_desc_sw, vd) + +#define _phy_readl_relaxed(phy, _reg) \ + readl_relaxed((phy)->base + _reg((phy)->idx)) +#define phy_readl_relaxed(phy, _reg) \ + ({ \ + u32 _v; \ + _v = readl_relaxed((phy)->base + _reg((phy)->idx)); \ + dev_vdbg(&phy->vchan->vc.chan.dev->device, \ + "%s(): readl(%s): 0x%08x\n", __func__, #_reg, \ + _v); \ + _v; \ + }) +#define phy_writel(phy, val, _reg) \ + do { \ + writel((val), (phy)->base + _reg((phy)->idx)); \ + dev_vdbg(&phy->vchan->vc.chan.dev->device, \ + "%s(): writel(0x%08x, %s)\n", \ + __func__, (u32)(val), #_reg); \ + } while (0) +#define phy_writel_relaxed(phy, val, _reg) \ + do { \ + writel_relaxed((val), (phy)->base + _reg((phy)->idx)); \ + dev_vdbg(&phy->vchan->vc.chan.dev->device, \ + "%s(): writel_relaxed(0x%08x, %s)\n", \ + __func__, (u32)(val), #_reg); \ + } while (0) + +static unsigned int pxad_drcmr(unsigned int line) +{ + if (line < 64) + return 0x100 + line * 4; + return 0x1000 + line * 4; +} + +/* + * Debug fs + */ +#ifdef CONFIG_DEBUG_FS +#include <linux/debugfs.h> +#include <linux/uaccess.h> +#include <linux/seq_file.h> + +static int dbg_show_requester_chan(struct seq_file *s, void *p) +{ + int pos = 0; + struct pxad_phy *phy = s->private; + int i; + u32 drcmr; + + pos += seq_printf(s, "DMA channel %d requester :\n", phy->idx); + for (i = 0; i < 70; i++) { + drcmr = readl_relaxed(phy->base + pxad_drcmr(i)); + if ((drcmr & DRCMR_CHLNUM) == phy->idx) + pos += seq_printf(s, "\tRequester %d (MAPVLD=%d)\n", i, + !!(drcmr & DRCMR_MAPVLD)); + } + return pos; +} + +static inline int dbg_burst_from_dcmd(u32 dcmd) +{ + int burst = (dcmd >> 16) & 0x3; + + return burst ? 4 << burst : 0; +} + +static int is_phys_valid(unsigned long addr) +{ + return pfn_valid(__phys_to_pfn(addr)); +} + +#define PXA_DCSR_STR(flag) (dcsr & PXA_DCSR_##flag ? #flag" " : "") +#define PXA_DCMD_STR(flag) (dcmd & PXA_DCMD_##flag ? #flag" " : "") + +static int dbg_show_descriptors(struct seq_file *s, void *p) +{ + struct pxad_phy *phy = s->private; + int i, max_show = 20, burst, width; + u32 dcmd; + unsigned long phys_desc, ddadr; + struct pxad_desc_hw *desc; + + phys_desc = ddadr = _phy_readl_relaxed(phy, DDADR); + + seq_printf(s, "DMA channel %d descriptors :\n", phy->idx); + seq_printf(s, "[%03d] First descriptor unknown\n", 0); + for (i = 1; i < max_show && is_phys_valid(phys_desc); i++) { + desc = phys_to_virt(phys_desc); + dcmd = desc->dcmd; + burst = dbg_burst_from_dcmd(dcmd); + width = (1 << ((dcmd >> 14) & 0x3)) >> 1; + + seq_printf(s, "[%03d] Desc at %08lx(virt %p)\n", + i, phys_desc, desc); + seq_printf(s, "\tDDADR = %08x\n", desc->ddadr); + seq_printf(s, "\tDSADR = %08x\n", desc->dsadr); + seq_printf(s, "\tDTADR = %08x\n", desc->dtadr); + seq_printf(s, "\tDCMD = %08x (%s%s%s%s%s%s%sburst=%d width=%d len=%d)\n", + dcmd, + PXA_DCMD_STR(INCSRCADDR), PXA_DCMD_STR(INCTRGADDR), + PXA_DCMD_STR(FLOWSRC), PXA_DCMD_STR(FLOWTRG), + PXA_DCMD_STR(STARTIRQEN), PXA_DCMD_STR(ENDIRQEN), + PXA_DCMD_STR(ENDIAN), burst, width, + dcmd & PXA_DCMD_LENGTH); + phys_desc = desc->ddadr; + } + if (i == max_show) + seq_printf(s, "[%03d] Desc at %08lx ... max display reached\n", + i, phys_desc); + else + seq_printf(s, "[%03d] Desc at %08lx is %s\n", + i, phys_desc, phys_desc == DDADR_STOP ? + "DDADR_STOP" : "invalid"); + + return 0; +} + +static int dbg_show_chan_state(struct seq_file *s, void *p) +{ + struct pxad_phy *phy = s->private; + u32 dcsr, dcmd; + int burst, width; + static const char * const str_prio[] = { + "high", "normal", "low", "invalid" + }; + + dcsr = _phy_readl_relaxed(phy, DCSR); + dcmd = _phy_readl_relaxed(phy, DCMD); + burst = dbg_burst_from_dcmd(dcmd); + width = (1 << ((dcmd >> 14) & 0x3)) >> 1; + + seq_printf(s, "DMA channel %d\n", phy->idx); + seq_printf(s, "\tPriority : %s\n", + str_prio[(phy->idx & 0xf) / 4]); + seq_printf(s, "\tUnaligned transfer bit: %s\n", + _phy_readl_relaxed(phy, DALGN) & BIT(phy->idx) ? + "yes" : "no"); + seq_printf(s, "\tDCSR = %08x (%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s)\n", + dcsr, PXA_DCSR_STR(RUN), PXA_DCSR_STR(NODESC), + PXA_DCSR_STR(STOPIRQEN), PXA_DCSR_STR(EORIRQEN), + PXA_DCSR_STR(EORJMPEN), PXA_DCSR_STR(EORSTOPEN), + PXA_DCSR_STR(SETCMPST), PXA_DCSR_STR(CLRCMPST), + PXA_DCSR_STR(CMPST), PXA_DCSR_STR(EORINTR), + PXA_DCSR_STR(REQPEND), PXA_DCSR_STR(STOPSTATE), + PXA_DCSR_STR(ENDINTR), PXA_DCSR_STR(STARTINTR), + PXA_DCSR_STR(BUSERR)); + + seq_printf(s, "\tDCMD = %08x (%s%s%s%s%s%s%sburst=%d width=%d len=%d)\n", + dcmd, + PXA_DCMD_STR(INCSRCADDR), PXA_DCMD_STR(INCTRGADDR), + PXA_DCMD_STR(FLOWSRC), PXA_DCMD_STR(FLOWTRG), + PXA_DCMD_STR(STARTIRQEN), PXA_DCMD_STR(ENDIRQEN), + PXA_DCMD_STR(ENDIAN), burst, width, dcmd & PXA_DCMD_LENGTH); + seq_printf(s, "\tDSADR = %08x\n", _phy_readl_relaxed(phy, DSADR)); + seq_printf(s, "\tDTADR = %08x\n", _phy_readl_relaxed(phy, DTADR)); + seq_printf(s, "\tDDADR = %08x\n", _phy_readl_relaxed(phy, DDADR)); + + return 0; +} + +static int dbg_show_state(struct seq_file *s, void *p) +{ + struct pxad_device *pdev = s->private; + + /* basic device status */ + seq_puts(s, "DMA engine status\n"); + seq_printf(s, "\tChannel number: %d\n", pdev->nr_chans); + + return 0; +} + +#define DBGFS_FUNC_DECL(name) \ +static int dbg_open_##name(struct inode *inode, struct file *file) \ +{ \ + return single_open(file, dbg_show_##name, inode->i_private); \ +} \ +static const struct file_operations dbg_fops_##name = { \ + .owner = THIS_MODULE, \ + .open = dbg_open_##name, \ + .llseek = seq_lseek, \ + .read = seq_read, \ + .release = single_release, \ +} + +DBGFS_FUNC_DECL(state); +DBGFS_FUNC_DECL(chan_state); +DBGFS_FUNC_DECL(descriptors); +DBGFS_FUNC_DECL(requester_chan); + +static struct dentry *pxad_dbg_alloc_chan(struct pxad_device *pdev, + int ch, struct dentry *chandir) +{ + char chan_name[11]; + struct dentry *chan, *chan_state = NULL, *chan_descr = NULL; + struct dentry *chan_reqs = NULL; + void *dt; + + scnprintf(chan_name, sizeof(chan_name), "%d", ch); + chan = debugfs_create_dir(chan_name, chandir); + dt = (void *)&pdev->phys[ch]; + + if (chan) + chan_state = debugfs_create_file("state", 0400, chan, dt, + &dbg_fops_chan_state); + if (chan_state) + chan_descr = debugfs_create_file("descriptors", 0400, chan, dt, + &dbg_fops_descriptors); + if (chan_descr) + chan_reqs = debugfs_create_file("requesters", 0400, chan, dt, + &dbg_fops_requester_chan); + if (!chan_reqs) + goto err_state; + + return chan; + +err_state: + debugfs_remove_recursive(chan); + return NULL; +} + +static void pxad_init_debugfs(struct pxad_device *pdev) +{ + int i; + struct dentry *chandir; + + pdev->dbgfs_root = debugfs_create_dir(dev_name(pdev->slave.dev), NULL); + if (IS_ERR(pdev->dbgfs_root) || !pdev->dbgfs_root) + goto err_root; + + pdev->dbgfs_state = debugfs_create_file("state", 0400, pdev->dbgfs_root, + pdev, &dbg_fops_state); + if (!pdev->dbgfs_state) + goto err_state; + + pdev->dbgfs_chan = + kmalloc_array(pdev->nr_chans, sizeof(*pdev->dbgfs_state), + GFP_KERNEL); + if (!pdev->dbgfs_chan) + goto err_alloc; + + chandir = debugfs_create_dir("channels", pdev->dbgfs_root); + if (!chandir) + goto err_chandir; + + for (i = 0; i < pdev->nr_chans; i++) { + pdev->dbgfs_chan[i] = pxad_dbg_alloc_chan(pdev, i, chandir); + if (!pdev->dbgfs_chan[i]) + goto err_chans; + } + + return; +err_chans: +err_chandir: + kfree(pdev->dbgfs_chan); +err_alloc: +err_state: + debugfs_remove_recursive(pdev->dbgfs_root); +err_root: + pr_err("pxad: debugfs is not available\n"); +} + +static void pxad_cleanup_debugfs(struct pxad_device *pdev) +{ + debugfs_remove_recursive(pdev->dbgfs_root); +} +#else +static inline void pxad_init_debugfs(struct pxad_device *pdev) {} +static inline void pxad_cleanup_debugfs(struct pxad_device *pdev) {} +#endif + +/* + * In the transition phase where legacy pxa handling is done at the same time as + * mmp_dma, the DMA physical channel split between the 2 DMA providers is done + * through legacy_reserved. Legacy code reserves DMA channels by settings + * corresponding bits in legacy_reserved. + */ +static u32 legacy_reserved; +static u32 legacy_unavailable; + +static struct pxad_phy *lookup_phy(struct pxad_chan *pchan) +{ + int prio, i; + struct pxad_device *pdev = to_pxad_dev(pchan->vc.chan.device); + struct pxad_phy *phy, *found = NULL; + unsigned long flags; + + /* + * dma channel priorities + * ch 0 - 3, 16 - 19 <--> (0) + * ch 4 - 7, 20 - 23 <--> (1) + * ch 8 - 11, 24 - 27 <--> (2) + * ch 12 - 15, 28 - 31 <--> (3) + */ + + spin_lock_irqsave(&pdev->phy_lock, flags); + for (prio = pchan->prio; prio >= PXAD_PRIO_HIGHEST; prio--) { + for (i = 0; i < pdev->nr_chans; i++) { + if (prio != (i & 0xf) >> 2) + continue; + if ((i < 32) && (legacy_reserved & BIT(i))) + continue; + phy = &pdev->phys[i]; + if (!phy->vchan) { + phy->vchan = pchan; + found = phy; + if (i < 32) + legacy_unavailable |= BIT(i); + goto out_unlock; + } + } + } + +out_unlock: + spin_unlock_irqrestore(&pdev->phy_lock, flags); + dev_dbg(&pchan->vc.chan.dev->device, + "%s(): phy=%p(%d)\n", __func__, found, + found ? found->idx : -1); + + return found; +} + +static void pxad_free_phy(struct pxad_chan *chan) +{ + struct pxad_device *pdev = to_pxad_dev(chan->vc.chan.device); + unsigned long flags; + u32 reg; + int i; + + dev_dbg(&chan->vc.chan.dev->device, + "%s(): freeing\n", __func__); + if (!chan->phy) + return; + + /* clear the channel mapping in DRCMR */ + reg = pxad_drcmr(chan->drcmr); + writel_relaxed(0, chan->phy->base + reg); + + spin_lock_irqsave(&pdev->phy_lock, flags); + for (i = 0; i < 32; i++) + if (chan->phy == &pdev->phys[i]) + legacy_unavailable &= ~BIT(i); + chan->phy->vchan = NULL; + chan->phy = NULL; + spin_unlock_irqrestore(&pdev->phy_lock, flags); +} + +static bool is_chan_running(struct pxad_chan *chan) +{ + u32 dcsr; + struct pxad_phy *phy = chan->phy; + + if (!phy) + return false; + dcsr = phy_readl_relaxed(phy, DCSR); + return dcsr & PXA_DCSR_RUN; +} + +static bool is_running_chan_misaligned(struct pxad_chan *chan) +{ + u32 dalgn; + + BUG_ON(!chan->phy); + dalgn = phy_readl_relaxed(chan->phy, DALGN); + return dalgn & (BIT(chan->phy->idx)); +} + +static void phy_enable(struct pxad_phy *phy, bool misaligned) +{ + u32 reg, dalgn; + + if (!phy->vchan) + return; + + dev_dbg(&phy->vchan->vc.chan.dev->device, + "%s(); phy=%p(%d) misaligned=%d\n", __func__, + phy, phy->idx, misaligned); + + reg = pxad_drcmr(phy->vchan->drcmr); + writel_relaxed(DRCMR_MAPVLD | phy->idx, phy->base + reg); + + dalgn = phy_readl_relaxed(phy, DALGN); + if (misaligned) + dalgn |= BIT(phy->idx); + else + dalgn &= ~BIT(phy->idx); + phy_writel_relaxed(phy, dalgn, DALGN); + + phy_writel(phy, PXA_DCSR_STOPIRQEN | PXA_DCSR_ENDINTR | + PXA_DCSR_BUSERR | PXA_DCSR_RUN, DCSR); +} + +static void phy_disable(struct pxad_phy *phy) +{ + u32 dcsr; + + if (!phy) + return; + + dcsr = phy_readl_relaxed(phy, DCSR); + dev_dbg(&phy->vchan->vc.chan.dev->device, + "%s(): phy=%p(%d)\n", __func__, phy, phy->idx); + phy_writel(phy, dcsr & ~PXA_DCSR_RUN & ~PXA_DCSR_STOPIRQEN, DCSR); +} + +static void pxad_launch_chan(struct pxad_chan *chan, + struct pxad_desc_sw *desc) +{ + dev_dbg(&chan->vc.chan.dev->device, + "%s(): desc=%p\n", __func__, desc); + if (!chan->phy) { + chan->phy = lookup_phy(chan); + if (!chan->phy) { + dev_dbg(&chan->vc.chan.dev->device, + "%s(): no free dma channel\n", __func__); + return; + } + } + + /* + * Program the descriptor's address into the DMA controller, + * then start the DMA transaction + */ + phy_writel(chan->phy, desc->first, DDADR); + phy_enable(chan->phy, chan->misaligned); +} + +static void set_updater_desc(struct pxad_desc_sw *sw_desc, + unsigned long flags) +{ + struct pxad_desc_hw *updater = + sw_desc->hw_desc[sw_desc->nb_desc - 1]; + dma_addr_t dma = sw_desc->hw_desc[sw_desc->nb_desc - 2]->ddadr; + + updater->ddadr = DDADR_STOP; + updater->dsadr = dma; + updater->dtadr = dma + 8; + updater->dcmd = PXA_DCMD_WIDTH4 | PXA_DCMD_BURST32 | + (PXA_DCMD_LENGTH & sizeof(u32)); + if (flags & DMA_PREP_INTERRUPT) + updater->dcmd |= PXA_DCMD_ENDIRQEN; +} + +static bool is_desc_completed(struct virt_dma_desc *vd) +{ + struct pxad_desc_sw *sw_desc = to_pxad_sw_desc(vd); + struct pxad_desc_hw *updater = + sw_desc->hw_desc[sw_desc->nb_desc - 1]; + + return updater->dtadr != (updater->dsadr + 8); +} + +static void pxad_desc_chain(struct virt_dma_desc *vd1, + struct virt_dma_desc *vd2) +{ + struct pxad_desc_sw *desc1 = to_pxad_sw_desc(vd1); + struct pxad_desc_sw *desc2 = to_pxad_sw_desc(vd2); + dma_addr_t dma_to_chain; + + dma_to_chain = desc2->first; + desc1->hw_desc[desc1->nb_desc - 1]->ddadr = dma_to_chain; +} + +static bool pxad_try_hotchain(struct virt_dma_chan *vc, + struct virt_dma_desc *vd) +{ + struct virt_dma_desc *vd_last_issued = NULL; + struct pxad_chan *chan = to_pxad_chan(&vc->chan); + + /* + * Attempt to hot chain the tx if the phy is still running. This is + * considered successful only if either the channel is still running + * after the chaining, or if the chained transfer is completed after + * having been hot chained. + * A change of alignment is not allowed, and forbids hotchaining. + */ + if (is_chan_running(chan)) { + BUG_ON(list_empty(&vc->desc_issued)); + + if (!is_running_chan_misaligned(chan) && + to_pxad_sw_desc(vd)->misaligned) + return false; + + vd_last_issued = list_entry(vc->desc_issued.prev, + struct virt_dma_desc, node); + pxad_desc_chain(vd_last_issued, vd); + if (is_chan_running(chan) || is_desc_completed(vd_last_issued)) + return true; + } + + return false; +} + +static unsigned int clear_chan_irq(struct pxad_phy *phy) +{ + u32 dcsr; + u32 dint = readl(phy->base + DINT); + + if (!(dint & BIT(phy->idx))) + return PXA_DCSR_RUN; + + /* clear irq */ + dcsr = phy_readl_relaxed(phy, DCSR); + phy_writel(phy, dcsr, DCSR); + if ((dcsr & PXA_DCSR_BUSERR) && (phy->vchan)) + dev_warn(&phy->vchan->vc.chan.dev->device, + "%s(chan=%p): PXA_DCSR_BUSERR\n", + __func__, &phy->vchan); + + return dcsr & ~PXA_DCSR_RUN; +} + +static irqreturn_t pxad_chan_handler(int irq, void *dev_id) +{ + struct pxad_phy *phy = dev_id; + struct pxad_chan *chan = phy->vchan; + struct virt_dma_desc *vd, *tmp; + unsigned int dcsr; + unsigned long flags; + + BUG_ON(!chan); + + dcsr = clear_chan_irq(phy); + if (dcsr & PXA_DCSR_RUN) + return IRQ_NONE; + + spin_lock_irqsave(&chan->vc.lock, flags); + list_for_each_entry_safe(vd, tmp, &chan->vc.desc_issued, node) { + dev_dbg(&chan->vc.chan.dev->device, + "%s(): checking txd %p[%x]: completed=%d\n", + __func__, vd, vd->tx.cookie, is_desc_completed(vd)); + if (is_desc_completed(vd)) { + list_del(&vd->node); + vchan_cookie_complete(vd); + } else { + break; + } + } + + if (dcsr & PXA_DCSR_STOPSTATE) { + dev_dbg(&chan->vc.chan.dev->device, + "%s(): channel stopped, submitted_empty=%d issued_empty=%d", + __func__, + list_empty(&chan->vc.desc_submitted), + list_empty(&chan->vc.desc_issued)); + phy_writel_relaxed(phy, dcsr & ~PXA_DCSR_STOPIRQEN, DCSR); + + if (list_empty(&chan->vc.desc_issued)) { + chan->misaligned = + !list_empty(&chan->vc.desc_submitted); + } else { + vd = list_first_entry(&chan->vc.desc_issued, + struct virt_dma_desc, node); + pxad_launch_chan(chan, to_pxad_sw_desc(vd)); + } + } + spin_unlock_irqrestore(&chan->vc.lock, flags); + + return IRQ_HANDLED; +} + +static irqreturn_t pxad_int_handler(int irq, void *dev_id) +{ + struct pxad_device *pdev = dev_id; + struct pxad_phy *phy; + u32 dint = readl(pdev->base + DINT); + int i, ret = IRQ_NONE; + + while (dint) { + i = __ffs(dint); + dint &= (dint - 1); + phy = &pdev->phys[i]; + if ((i < 32) && (legacy_reserved & BIT(i))) + continue; + if (pxad_chan_handler(irq, phy) == IRQ_HANDLED) + ret = IRQ_HANDLED; + } + + return ret; +} + +static int pxad_alloc_chan_resources(struct dma_chan *dchan) +{ + struct pxad_chan *chan = to_pxad_chan(dchan); + struct pxad_device *pdev = to_pxad_dev(chan->vc.chan.device); + + if (chan->desc_pool) + return 1; + + chan->desc_pool = dma_pool_create(dma_chan_name(dchan), + pdev->slave.dev, + sizeof(struct pxad_desc_hw), + __alignof__(struct pxad_desc_hw), + 0); + if (!chan->desc_pool) { + dev_err(&chan->vc.chan.dev->device, + "%s(): unable to allocate descriptor pool\n", + __func__); + return -ENOMEM; + } + + return 1; +} + +static void pxad_free_chan_resources(struct dma_chan *dchan) +{ + struct pxad_chan *chan = to_pxad_chan(dchan); + + vchan_free_chan_resources(&chan->vc); + dma_pool_destroy(chan->desc_pool); + chan->desc_pool = NULL; + +} + +static void pxad_free_desc(struct virt_dma_desc *vd) +{ + int i; + dma_addr_t dma; + struct pxad_desc_sw *sw_desc = to_pxad_sw_desc(vd); + + BUG_ON(sw_desc->nb_desc == 0); + for (i = sw_desc->nb_desc - 1; i >= 0; i--) { + if (i > 0) + dma = sw_desc->hw_desc[i - 1]->ddadr; + else + dma = sw_desc->first; + dma_pool_free(sw_desc->desc_pool, + sw_desc->hw_desc[i], dma); + } + sw_desc->nb_desc = 0; + kfree(sw_desc); +} + +static struct pxad_desc_sw * +pxad_alloc_desc(struct pxad_chan *chan, unsigned int nb_hw_desc) +{ + struct pxad_desc_sw *sw_desc; + dma_addr_t dma; + int i; + + sw_desc = kzalloc(sizeof(*sw_desc) + + nb_hw_desc * sizeof(struct pxad_desc_hw *), + GFP_NOWAIT); + if (!sw_desc) + return NULL; + sw_desc->desc_pool = chan->desc_pool; + + for (i = 0; i < nb_hw_desc; i++) { + sw_desc->hw_desc[i] = dma_pool_alloc(sw_desc->desc_pool, + GFP_NOWAIT, &dma); + if (!sw_desc->hw_desc[i]) { + dev_err(&chan->vc.chan.dev->device, + "%s(): Couldn't allocate the %dth hw_desc from dma_pool %p\n", + __func__, i, sw_desc->desc_pool); + goto err; + } + + if (i == 0) + sw_desc->first = dma; + else + sw_desc->hw_desc[i - 1]->ddadr = dma; + sw_desc->nb_desc++; + } + + return sw_desc; +err: + pxad_free_desc(&sw_desc->vd); + return NULL; +} + +static dma_cookie_t pxad_tx_submit(struct dma_async_tx_descriptor *tx) +{ + struct virt_dma_chan *vc = to_virt_chan(tx->chan); + struct pxad_chan *chan = to_pxad_chan(&vc->chan); + struct virt_dma_desc *vd_chained = NULL, + *vd = container_of(tx, struct virt_dma_desc, tx); + dma_cookie_t cookie; + unsigned long flags; + + set_updater_desc(to_pxad_sw_desc(vd), tx->flags); |