diff options
Diffstat (limited to 'drivers/dma/stm32-dma.c')
| -rw-r--r-- | drivers/dma/stm32-dma.c | 1141 |
1 files changed, 1141 insertions, 0 deletions
diff --git a/drivers/dma/stm32-dma.c b/drivers/dma/stm32-dma.c new file mode 100644 index 000000000000..12f3a3eddba9 --- /dev/null +++ b/drivers/dma/stm32-dma.c @@ -0,0 +1,1141 @@ +/* + * Driver for STM32 DMA controller + * + * Inspired by dma-jz4740.c and tegra20-apb-dma.c + * + * Copyright (C) M'boumba Cedric Madianga 2015 + * Author: M'boumba Cedric Madianga <cedric.madianga@gmail.com> + * + * License terms: GNU General Public License (GPL), version 2 + */ + +#include <linux/clk.h> +#include <linux/delay.h> +#include <linux/dmaengine.h> +#include <linux/dma-mapping.h> +#include <linux/err.h> +#include <linux/init.h> +#include <linux/jiffies.h> +#include <linux/list.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/of_device.h> +#include <linux/of_dma.h> +#include <linux/platform_device.h> +#include <linux/reset.h> +#include <linux/sched.h> +#include <linux/slab.h> + +#include "virt-dma.h" + +#define STM32_DMA_LISR 0x0000 /* DMA Low Int Status Reg */ +#define STM32_DMA_HISR 0x0004 /* DMA High Int Status Reg */ +#define STM32_DMA_LIFCR 0x0008 /* DMA Low Int Flag Clear Reg */ +#define STM32_DMA_HIFCR 0x000c /* DMA High Int Flag Clear Reg */ +#define STM32_DMA_TCI BIT(5) /* Transfer Complete Interrupt */ +#define STM32_DMA_TEI BIT(3) /* Transfer Error Interrupt */ +#define STM32_DMA_DMEI BIT(2) /* Direct Mode Error Interrupt */ +#define STM32_DMA_FEI BIT(0) /* FIFO Error Interrupt */ + +/* DMA Stream x Configuration Register */ +#define STM32_DMA_SCR(x) (0x0010 + 0x18 * (x)) /* x = 0..7 */ +#define STM32_DMA_SCR_REQ(n) ((n & 0x7) << 25) +#define STM32_DMA_SCR_MBURST_MASK GENMASK(24, 23) +#define STM32_DMA_SCR_MBURST(n) ((n & 0x3) << 23) +#define STM32_DMA_SCR_PBURST_MASK GENMASK(22, 21) +#define STM32_DMA_SCR_PBURST(n) ((n & 0x3) << 21) +#define STM32_DMA_SCR_PL_MASK GENMASK(17, 16) +#define STM32_DMA_SCR_PL(n) ((n & 0x3) << 16) +#define STM32_DMA_SCR_MSIZE_MASK GENMASK(14, 13) +#define STM32_DMA_SCR_MSIZE(n) ((n & 0x3) << 13) +#define STM32_DMA_SCR_PSIZE_MASK GENMASK(12, 11) +#define STM32_DMA_SCR_PSIZE(n) ((n & 0x3) << 11) +#define STM32_DMA_SCR_PSIZE_GET(n) ((n & STM32_DMA_SCR_PSIZE_MASK) >> 11) +#define STM32_DMA_SCR_DIR_MASK GENMASK(7, 6) +#define STM32_DMA_SCR_DIR(n) ((n & 0x3) << 6) +#define STM32_DMA_SCR_CT BIT(19) /* Target in double buffer */ +#define STM32_DMA_SCR_DBM BIT(18) /* Double Buffer Mode */ +#define STM32_DMA_SCR_PINCOS BIT(15) /* Peripheral inc offset size */ +#define STM32_DMA_SCR_MINC BIT(10) /* Memory increment mode */ +#define STM32_DMA_SCR_PINC BIT(9) /* Peripheral increment mode */ +#define STM32_DMA_SCR_CIRC BIT(8) /* Circular mode */ +#define STM32_DMA_SCR_PFCTRL BIT(5) /* Peripheral Flow Controller */ +#define STM32_DMA_SCR_TCIE BIT(4) /* Transfer Cplete Int Enable*/ +#define STM32_DMA_SCR_TEIE BIT(2) /* Transfer Error Int Enable */ +#define STM32_DMA_SCR_DMEIE BIT(1) /* Direct Mode Err Int Enable */ +#define STM32_DMA_SCR_EN BIT(0) /* Stream Enable */ +#define STM32_DMA_SCR_CFG_MASK (STM32_DMA_SCR_PINC \ + | STM32_DMA_SCR_MINC \ + | STM32_DMA_SCR_PINCOS \ + | STM32_DMA_SCR_PL_MASK) +#define STM32_DMA_SCR_IRQ_MASK (STM32_DMA_SCR_TCIE \ + | STM32_DMA_SCR_TEIE \ + | STM32_DMA_SCR_DMEIE) + +/* DMA Stream x number of data register */ +#define STM32_DMA_SNDTR(x) (0x0014 + 0x18 * (x)) + +/* DMA stream peripheral address register */ +#define STM32_DMA_SPAR(x) (0x0018 + 0x18 * (x)) + +/* DMA stream x memory 0 address register */ +#define STM32_DMA_SM0AR(x) (0x001c + 0x18 * (x)) + +/* DMA stream x memory 1 address register */ +#define STM32_DMA_SM1AR(x) (0x0020 + 0x18 * (x)) + +/* DMA stream x FIFO control register */ +#define STM32_DMA_SFCR(x) (0x0024 + 0x18 * (x)) +#define STM32_DMA_SFCR_FTH_MASK GENMASK(1, 0) +#define STM32_DMA_SFCR_FTH(n) (n & STM32_DMA_SFCR_FTH_MASK) +#define STM32_DMA_SFCR_FEIE BIT(7) /* FIFO error interrupt enable */ +#define STM32_DMA_SFCR_DMDIS BIT(2) /* Direct mode disable */ +#define STM32_DMA_SFCR_MASK (STM32_DMA_SFCR_FEIE \ + | STM32_DMA_SFCR_DMDIS) + +/* DMA direction */ +#define STM32_DMA_DEV_TO_MEM 0x00 +#define STM32_DMA_MEM_TO_DEV 0x01 +#define STM32_DMA_MEM_TO_MEM 0x02 + +/* DMA priority level */ +#define STM32_DMA_PRIORITY_LOW 0x00 +#define STM32_DMA_PRIORITY_MEDIUM 0x01 +#define STM32_DMA_PRIORITY_HIGH 0x02 +#define STM32_DMA_PRIORITY_VERY_HIGH 0x03 + +/* DMA FIFO threshold selection */ +#define STM32_DMA_FIFO_THRESHOLD_1QUARTERFULL 0x00 +#define STM32_DMA_FIFO_THRESHOLD_HALFFULL 0x01 +#define STM32_DMA_FIFO_THRESHOLD_3QUARTERSFULL 0x02 +#define STM32_DMA_FIFO_THRESHOLD_FULL 0x03 + +#define STM32_DMA_MAX_DATA_ITEMS 0xffff +#define STM32_DMA_MAX_CHANNELS 0x08 +#define STM32_DMA_MAX_REQUEST_ID 0x08 +#define STM32_DMA_MAX_DATA_PARAM 0x03 + +enum stm32_dma_width { + STM32_DMA_BYTE, + STM32_DMA_HALF_WORD, + STM32_DMA_WORD, +}; + +enum stm32_dma_burst_size { + STM32_DMA_BURST_SINGLE, + STM32_DMA_BURST_INCR4, + STM32_DMA_BURST_INCR8, + STM32_DMA_BURST_INCR16, +}; + +struct stm32_dma_cfg { + u32 channel_id; + u32 request_line; + u32 stream_config; + u32 threshold; +}; + +struct stm32_dma_chan_reg { + u32 dma_lisr; + u32 dma_hisr; + u32 dma_lifcr; + u32 dma_hifcr; + u32 dma_scr; + u32 dma_sndtr; + u32 dma_spar; + u32 dma_sm0ar; + u32 dma_sm1ar; + u32 dma_sfcr; +}; + +struct stm32_dma_sg_req { + u32 len; + struct stm32_dma_chan_reg chan_reg; +}; + +struct stm32_dma_desc { + struct virt_dma_desc vdesc; + bool cyclic; + u32 num_sgs; + struct stm32_dma_sg_req sg_req[]; +}; + +struct stm32_dma_chan { + struct virt_dma_chan vchan; + bool config_init; + bool busy; + u32 id; + u32 irq; + struct stm32_dma_desc *desc; + u32 next_sg; + struct dma_slave_config dma_sconfig; + struct stm32_dma_chan_reg chan_reg; +}; + +struct stm32_dma_device { + struct dma_device ddev; + void __iomem *base; + struct clk *clk; + struct reset_control *rst; + bool mem2mem; + struct stm32_dma_chan chan[STM32_DMA_MAX_CHANNELS]; +}; + +static struct stm32_dma_device *stm32_dma_get_dev(struct stm32_dma_chan *chan) +{ + return container_of(chan->vchan.chan.device, struct stm32_dma_device, + ddev); +} + +static struct stm32_dma_chan *to_stm32_dma_chan(struct dma_chan *c) +{ + return container_of(c, struct stm32_dma_chan, vchan.chan); +} + +static struct stm32_dma_desc *to_stm32_dma_desc(struct virt_dma_desc *vdesc) +{ + return container_of(vdesc, struct stm32_dma_desc, vdesc); +} + +static struct device *chan2dev(struct stm32_dma_chan *chan) +{ + return &chan->vchan.chan.dev->device; +} + +static u32 stm32_dma_read(struct stm32_dma_device *dmadev, u32 reg) +{ + return readl_relaxed(dmadev->base + reg); +} + +static void stm32_dma_write(struct stm32_dma_device *dmadev, u32 reg, u32 val) +{ + writel_relaxed(val, dmadev->base + reg); +} + +static struct stm32_dma_desc *stm32_dma_alloc_desc(u32 num_sgs) +{ + return kzalloc(sizeof(struct stm32_dma_desc) + + sizeof(struct stm32_dma_sg_req) * num_sgs, GFP_NOWAIT); +} + +static int stm32_dma_get_width(struct stm32_dma_chan *chan, + enum dma_slave_buswidth width) +{ + switch (width) { + case DMA_SLAVE_BUSWIDTH_1_BYTE: + return STM32_DMA_BYTE; + case DMA_SLAVE_BUSWIDTH_2_BYTES: + return STM32_DMA_HALF_WORD; + case DMA_SLAVE_BUSWIDTH_4_BYTES: + return STM32_DMA_WORD; + default: + dev_err(chan2dev(chan), "Dma bus width not supported\n"); + return -EINVAL; + } +} + +static int stm32_dma_get_burst(struct stm32_dma_chan *chan, u32 maxburst) +{ + switch (maxburst) { + case 0: + case 1: + return STM32_DMA_BURST_SINGLE; + case 4: + return STM32_DMA_BURST_INCR4; + case 8: + return STM32_DMA_BURST_INCR8; + case 16: + return STM32_DMA_BURST_INCR16; + default: + dev_err(chan2dev(chan), "Dma burst size not supported\n"); + return -EINVAL; + } +} + +static void stm32_dma_set_fifo_config(struct stm32_dma_chan *chan, + u32 src_maxburst, u32 dst_maxburst) +{ + chan->chan_reg.dma_sfcr &= ~STM32_DMA_SFCR_MASK; + chan->chan_reg.dma_scr &= ~STM32_DMA_SCR_DMEIE; + + if ((!src_maxburst) && (!dst_maxburst)) { + /* Using direct mode */ + chan->chan_reg.dma_scr |= STM32_DMA_SCR_DMEIE; + } else { + /* Using FIFO mode */ + chan->chan_reg.dma_sfcr |= STM32_DMA_SFCR_MASK; + } +} + +static int stm32_dma_slave_config(struct dma_chan *c, + struct dma_slave_config *config) +{ + struct stm32_dma_chan *chan = to_stm32_dma_chan(c); + + memcpy(&chan->dma_sconfig, config, sizeof(*config)); + + chan->config_init = true; + + return 0; +} + +static u32 stm32_dma_irq_status(struct stm32_dma_chan *chan) +{ + struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan); + u32 flags, dma_isr; + + /* + * Read "flags" from DMA_xISR register corresponding to the selected + * DMA channel at the correct bit offset inside that register. + * + * If (ch % 4) is 2 or 3, left shift the mask by 16 bits. + * If (ch % 4) is 1 or 3, additionally left shift the mask by 6 bits. + */ + + if (chan->id & 4) + dma_isr = stm32_dma_read(dmadev, STM32_DMA_HISR); + else + dma_isr = stm32_dma_read(dmadev, STM32_DMA_LISR); + + flags = dma_isr >> (((chan->id & 2) << 3) | ((chan->id & 1) * 6)); + + return flags; +} + +static void stm32_dma_irq_clear(struct stm32_dma_chan *chan, u32 flags) +{ + struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan); + u32 dma_ifcr; + + /* + * Write "flags" to the DMA_xIFCR register corresponding to the selected + * DMA channel at the correct bit offset inside that register. + * + * If (ch % 4) is 2 or 3, left shift the mask by 16 bits. + * If (ch % 4) is 1 or 3, additionally left shift the mask by 6 bits. + */ + dma_ifcr = flags << (((chan->id & 2) << 3) | ((chan->id & 1) * 6)); + + if (chan->id & 4) + stm32_dma_write(dmadev, STM32_DMA_HIFCR, dma_ifcr); + else + stm32_dma_write(dmadev, STM32_DMA_LIFCR, dma_ifcr); +} + +static int stm32_dma_disable_chan(struct stm32_dma_chan *chan) +{ + struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan); + unsigned long timeout = jiffies + msecs_to_jiffies(5000); + u32 dma_scr, id; + + id = chan->id; + dma_scr = stm32_dma_read(dmadev, STM32_DMA_SCR(id)); + + if (dma_scr & STM32_DMA_SCR_EN) { + dma_scr &= ~STM32_DMA_SCR_EN; + stm32_dma_write(dmadev, STM32_DMA_SCR(id), dma_scr); + + do { + dma_scr = stm32_dma_read(dmadev, STM32_DMA_SCR(id)); + dma_scr &= STM32_DMA_SCR_EN; + if (!dma_scr) + break; + + if (time_after_eq(jiffies, timeout)) { + dev_err(chan2dev(chan), "%s: timeout!\n", + __func__); + return -EBUSY; + } + cond_resched(); + } while (1); + } + + return 0; +} + +static void stm32_dma_stop(struct stm32_dma_chan *chan) +{ + struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan); + u32 dma_scr, dma_sfcr, status; + int ret; + + /* Disable interrupts */ + dma_scr = stm32_dma_read(dmadev, STM32_DMA_SCR(chan->id)); + dma_scr &= ~STM32_DMA_SCR_IRQ_MASK; + stm32_dma_write(dmadev, STM32_DMA_SCR(chan->id), dma_scr); + dma_sfcr = stm32_dma_read(dmadev, STM32_DMA_SFCR(chan->id)); + dma_sfcr &= ~STM32_DMA_SFCR_FEIE; + stm32_dma_write(dmadev, STM32_DMA_SFCR(chan->id), dma_sfcr); + + /* Disable DMA */ + ret = stm32_dma_disable_chan(chan); + if (ret < 0) + return; + + /* Clear interrupt status if it is there */ + status = stm32_dma_irq_status(chan); + if (status) { + dev_dbg(chan2dev(chan), "%s(): clearing interrupt: 0x%08x\n", + __func__, status); + stm32_dma_irq_clear(chan, status); + } + + chan->busy = false; +} + +static int stm32_dma_terminate_all(struct dma_chan *c) +{ + struct stm32_dma_chan *chan = to_stm32_dma_chan(c); + unsigned long flags; + LIST_HEAD(head); + + spin_lock_irqsave(&chan->vchan.lock, flags); + + if (chan->busy) { + stm32_dma_stop(chan); + chan->desc = NULL; + } + + vchan_get_all_descriptors(&chan->vchan, &head); + spin_unlock_irqrestore(&chan->vchan.lock, flags); + vchan_dma_desc_free_list(&chan->vchan, &head); + + return 0; +} + +static void stm32_dma_dump_reg(struct stm32_dma_chan *chan) +{ + struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan); + u32 scr = stm32_dma_read(dmadev, STM32_DMA_SCR(chan->id)); + u32 ndtr = stm32_dma_read(dmadev, STM32_DMA_SNDTR(chan->id)); + u32 spar = stm32_dma_read(dmadev, STM32_DMA_SPAR(chan->id)); + u32 sm0ar = stm32_dma_read(dmadev, STM32_DMA_SM0AR(chan->id)); + u32 sm1ar = stm32_dma_read(dmadev, STM32_DMA_SM1AR(chan->id)); + u32 sfcr = stm32_dma_read(dmadev, STM32_DMA_SFCR(chan->id)); + + dev_dbg(chan2dev(chan), "SCR: 0x%08x\n", scr); + dev_dbg(chan2dev(chan), "NDTR: 0x%08x\n", ndtr); + dev_dbg(chan2dev(chan), "SPAR: 0x%08x\n", spar); + dev_dbg(chan2dev(chan), "SM0AR: 0x%08x\n", sm0ar); + dev_dbg(chan2dev(chan), "SM1AR: 0x%08x\n", sm1ar); + dev_dbg(chan2dev(chan), "SFCR: 0x%08x\n", sfcr); +} + +static int stm32_dma_start_transfer(struct stm32_dma_chan *chan) +{ + struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan); + struct virt_dma_desc *vdesc; + struct stm32_dma_sg_req *sg_req; + struct stm32_dma_chan_reg *reg; + u32 status; + int ret; + + ret = stm32_dma_disable_chan(chan); + if (ret < 0) + return ret; + + if (!chan->desc) { + vdesc = vchan_next_desc(&chan->vchan); + if (!vdesc) + return 0; + + chan->desc = to_stm32_dma_desc(vdesc); + chan->next_sg = 0; + } + + if (chan->next_sg == chan->desc->num_sgs) + chan->next_sg = 0; + + sg_req = &chan->desc->sg_req[chan->next_sg]; + reg = &sg_req->chan_reg; + + stm32_dma_write(dmadev, STM32_DMA_SCR(chan->id), reg->dma_scr); + stm32_dma_write(dmadev, STM32_DMA_SPAR(chan->id), reg->dma_spar); + stm32_dma_write(dmadev, STM32_DMA_SM0AR(chan->id), reg->dma_sm0ar); + stm32_dma_write(dmadev, STM32_DMA_SFCR(chan->id), reg->dma_sfcr); + stm32_dma_write(dmadev, STM32_DMA_SM1AR(chan->id), reg->dma_sm1ar); + stm32_dma_write(dmadev, STM32_DMA_SNDTR(chan->id), reg->dma_sndtr); + + chan->next_sg++; + + /* Clear interrupt status if it is there */ + status = stm32_dma_irq_status(chan); + if (status) + stm32_dma_irq_clear(chan, status); + + stm32_dma_dump_reg(chan); + + /* Start DMA */ + reg->dma_scr |= STM32_DMA_SCR_EN; + stm32_dma_write(dmadev, STM32_DMA_SCR(chan->id), reg->dma_scr); + + chan->busy = true; + + return 0; +} + +static void stm32_dma_configure_next_sg(struct stm32_dma_chan *chan) +{ + struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan); + struct stm32_dma_sg_req *sg_req; + u32 dma_scr, dma_sm0ar, dma_sm1ar, id; + + id = chan->id; + dma_scr = stm32_dma_read(dmadev, STM32_DMA_SCR(id)); + + if (dma_scr & STM32_DMA_SCR_DBM) { + if (chan->next_sg == chan->desc->num_sgs) + chan->next_sg = 0; + + sg_req = &chan->desc->sg_req[chan->next_sg]; + + if (dma_scr & STM32_DMA_SCR_CT) { + dma_sm0ar = sg_req->chan_reg.dma_sm0ar; + stm32_dma_write(dmadev, STM32_DMA_SM0AR(id), dma_sm0ar); + dev_dbg(chan2dev(chan), "CT=1 <=> SM0AR: 0x%08x\n", + stm32_dma_read(dmadev, STM32_DMA_SM0AR(id))); + } else { + dma_sm1ar = sg_req->chan_reg.dma_sm1ar; + stm32_dma_write(dmadev, STM32_DMA_SM1AR(id), dma_sm1ar); + dev_dbg(chan2dev(chan), "CT=0 <=> SM1AR: 0x%08x\n", + stm32_dma_read(dmadev, STM32_DMA_SM1AR(id))); + } + + chan->next_sg++; + } +} + +static void stm32_dma_handle_chan_done(struct stm32_dma_chan *chan) +{ + if (chan->desc) { + if (chan->desc->cyclic) { + vchan_cyclic_callback(&chan->desc->vdesc); + stm32_dma_configure_next_sg(chan); + } else { + chan->busy = false; + if (chan->next_sg == chan->desc->num_sgs) { + list_del(&chan->desc->vdesc.node); + vchan_cookie_complete(&chan->desc->vdesc); + chan->desc = NULL; + } + stm32_dma_start_transfer(chan); + } + } +} + +static irqreturn_t stm32_dma_chan_irq(int irq, void *devid) +{ + struct stm32_dma_chan *chan = devid; + struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan); + u32 status, scr, sfcr; + + spin_lock(&chan->vchan.lock); + + status = stm32_dma_irq_status(chan); + scr = stm32_dma_read(dmadev, STM32_DMA_SCR(chan->id)); + sfcr = stm32_dma_read(dmadev, STM32_DMA_SFCR(chan->id)); + + if ((status & STM32_DMA_TCI) && (scr & STM32_DMA_SCR_TCIE)) { + stm32_dma_irq_clear(chan, STM32_DMA_TCI); + stm32_dma_handle_chan_done(chan); + + } else { + stm32_dma_irq_clear(chan, status); + dev_err(chan2dev(chan), "DMA error: status=0x%08x\n", status); + } + + spin_unlock(&chan->vchan.lock); + + return IRQ_HANDLED; +} + +static void stm32_dma_issue_pending(struct dma_chan *c) +{ + struct stm32_dma_chan *chan = to_stm32_dma_chan(c); + unsigned long flags; + int ret; + + spin_lock_irqsave(&chan->vchan.lock, flags); + if (!chan->busy) { + if (vchan_issue_pending(&chan->vchan) && !chan->desc) { + ret = stm32_dma_start_transfer(chan); + if ((chan->desc->cyclic) && (!ret)) + stm32_dma_configure_next_sg(chan); + } + } + spin_unlock_irqrestore(&chan->vchan.lock, flags); +} + +static int stm32_dma_set_xfer_param(struct stm32_dma_chan *chan, + enum dma_transfer_direction direction, + enum dma_slave_buswidth *buswidth) +{ + enum dma_slave_buswidth src_addr_width, dst_addr_width; + int src_bus_width, dst_bus_width; + int src_burst_size, dst_burst_size; + u32 src_maxburst, dst_maxburst; + dma_addr_t src_addr, dst_addr; + u32 dma_scr = 0; + + src_addr_width = chan->dma_sconfig.src_addr_width; + dst_addr_width = chan->dma_sconfig.dst_addr_width; + src_maxburst = chan->dma_sconfig.src_maxburst; + dst_maxburst = chan->dma_sconfig.dst_maxburst; + src_addr = chan->dma_sconfig.src_addr; + dst_addr = chan->dma_sconfig.dst_addr; + + switch (direction) { + case DMA_MEM_TO_DEV: + dst_bus_width = stm32_dma_get_width(chan, dst_addr_width); + if (dst_bus_width < 0) + return dst_bus_width; + + dst_burst_size = stm32_dma_get_burst(chan, dst_maxburst); + if (dst_burst_size < 0) + return dst_burst_size; + + if (!src_addr_width) + src_addr_width = dst_addr_width; + + src_bus_width = stm32_dma_get_width(chan, src_addr_width); + if (src_bus_width < 0) + return src_bus_width; + + src_burst_size = stm32_dma_get_burst(chan, src_maxburst); + if (src_burst_size < 0) + return src_burst_size; + + dma_scr = STM32_DMA_SCR_DIR(STM32_DMA_MEM_TO_DEV) | + STM32_DMA_SCR_PSIZE(dst_bus_width) | + STM32_DMA_SCR_MSIZE(src_bus_width) | + STM32_DMA_SCR_PBURST(dst_burst_size) | + STM32_DMA_SCR_MBURST(src_burst_size); + + chan->chan_reg.dma_spar = chan->dma_sconfig.dst_addr; + *buswidth = dst_addr_width; + break; + + case DMA_DEV_TO_MEM: + src_bus_width = stm32_dma_get_width(chan, src_addr_width); + if (src_bus_width < 0) + return src_bus_width; + + src_burst_size = stm32_dma_get_burst(chan, src_maxburst); + if (src_burst_size < 0) + return src_burst_size; + + if (!dst_addr_width) + dst_addr_width = src_addr_width; + + dst_bus_width = stm32_dma_get_width(chan, dst_addr_width); + if (dst_bus_width < 0) + return dst_bus_width; + + dst_burst_size = stm32_dma_get_burst(chan, dst_maxburst); + if (dst_burst_size < 0) + return dst_burst_size; + + dma_scr = STM32_DMA_SCR_DIR(STM32_DMA_DEV_TO_MEM) | + STM32_DMA_SCR_PSIZE(src_bus_width) | + STM32_DMA_SCR_MSIZE(dst_bus_width) | + STM32_DMA_SCR_PBURST(src_burst_size) | + STM32_DMA_SCR_MBURST(dst_burst_size); + + chan->chan_reg.dma_spar = chan->dma_sconfig.src_addr; + *buswidth = chan->dma_sconfig.src_addr_width; + break; + + default: + dev_err(chan2dev(chan), "Dma direction is not supported\n"); + return -EINVAL; + } + + stm32_dma_set_fifo_config(chan, src_maxburst, dst_maxburst); + + chan->chan_reg.dma_scr &= ~(STM32_DMA_SCR_DIR_MASK | + STM32_DMA_SCR_PSIZE_MASK | STM32_DMA_SCR_MSIZE_MASK | + STM32_DMA_SCR_PBURST_MASK | STM32_DMA_SCR_MBURST_MASK); + chan->chan_reg.dma_scr |= dma_scr; + + return 0; +} + +static void stm32_dma_clear_reg(struct stm32_dma_chan_reg *regs) +{ + memset(regs, 0, sizeof(struct stm32_dma_chan_reg)); +} + +static struct dma_async_tx_descriptor *stm32_dma_prep_slave_sg( + struct dma_chan *c, struct scatterlist *sgl, + u32 sg_len, enum dma_transfer_direction direction, + unsigned long flags, void *context) +{ + struct stm32_dma_chan *chan = to_stm32_dma_chan(c); + struct stm32_dma_desc *desc; + struct scatterlist *sg; + enum dma_slave_buswidth buswidth; + u32 nb_data_items; + int i, ret; + + if (!chan->config_init) { + dev_err(chan2dev(chan), "dma channel is not configured\n"); + return NULL; + } + + if (sg_len < 1) { + dev_err(chan2dev(chan), "Invalid segment length %d\n", sg_len); + return NULL; + } + + desc = stm32_dma_alloc_desc(sg_len); + if (!desc) + return NULL; + + ret = stm32_dma_set_xfer_param(chan, direction, &buswidth); + if (ret < 0) + goto err; + + /* Set peripheral flow controller */ + if (chan->dma_sconfig.device_fc) + chan->chan_reg.dma_scr |= STM32_DMA_SCR_PFCTRL; + else + chan->chan_reg.dma_scr &= ~STM32_DMA_SCR_PFCTRL; + + for_each_sg(sgl, sg, sg_len, i) { + desc->sg_req[i].len = sg_dma_len(sg); + + nb_data_items = desc->sg_req[i].len / buswidth; + if (nb_data_items > STM32_DMA_MAX_DATA_ITEMS) { + dev_err(chan2dev(chan), "nb items not supported\n"); + goto err; + } + + stm32_dma_clear_reg(&desc->sg_req[i].chan_reg); + desc->sg_req[i].chan_reg.dma_scr = chan->chan_reg.dma_scr; + desc->sg_req[i].chan_reg.dma_sfcr = chan->chan_reg.dma_sfcr; + desc->sg_req[i].chan_reg.dma_spar = chan->chan_reg.dma_spar; + desc->sg_req[i].chan_reg.dma_sm0ar = sg_dma_address(sg); + desc->sg_req[i].chan_reg.dma_sm1ar = sg_dma_address(sg); + desc->sg_req[i].chan_reg.dma_sndtr = nb_data_items; + } + + desc->num_sgs = sg_len; + desc->cyclic = false; + + return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags); + +err: + kfree(desc); + return NULL; +} + +static struct dma_async_tx_descriptor *stm32_dma_prep_dma_cyclic( + struct dma_chan *c, dma_addr_t buf_addr, size_t buf_len, + size_t period_len, enum dma_transfer_direction direction, + unsigned long flags) +{ + struct stm32_dma_chan *chan = to_stm32_dma_chan(c); + struct stm32_dma_desc *desc; + enum dma_slave_buswidth buswidth; + u32 num_periods, nb_data_items; + int i, ret; + + if (!buf_len || !period_len) { + dev_err(chan2dev(chan), "Invalid buffer/period len\n"); + return NULL; + } + + if (!chan->config_init) { + dev_err(chan2dev(chan), "dma channel is not configured\n"); + return NULL; + } + + if (buf_len % period_len) { + dev_err(chan2dev(chan), "buf_len not multiple of period_len\n"); + return NULL; + } + + /* + * We allow to take more number of requests till DMA is + * not started. The driver will loop over all requests. + * Once DMA is started then new requests can be queued only after + * terminating the DMA. + */ + if (chan->busy) { + dev_err(chan2dev(chan), "Request not allowed when dma busy\n"); + return NULL; + } + + ret = stm32_dma_set_xfer_param(chan, direction, &buswidth); + if (ret < 0) + return NULL; + + nb_data_items = period_len / buswidth; + if (nb_data_items > STM32_DMA_MAX_DATA_ITEMS) { + dev_err(chan2dev(chan), "number of items not supported\n"); + return NULL; + } + + /* Enable Circular mode or double buffer mode */ + if (buf_len == period_len) + chan->chan_reg.dma_scr |= STM32_DMA_SCR_CIRC; + else + chan->chan_reg.dma_scr |= STM32_DMA_SCR_DBM; + + /* Clear periph ctrl if client set it */ + chan->chan_reg.dma_scr &= ~STM32_DMA_SCR_PFCTRL; + + num_periods = buf_len / period_len; + + desc = stm32_dma_alloc_desc(num_periods); + if (!desc) + return NULL; + + for (i = 0; i < num_periods; i++) { + desc->sg_req[i].len = period_len; + + stm32_dma_clear_reg(&desc->sg_req[i].chan_reg); + desc->sg_req[i].chan_reg.dma_scr = chan->chan_reg.dma_scr; + desc->sg_req[i].chan_reg.dma_sfcr = chan->chan_reg.dma_sfcr; + desc->sg_req[i].chan_reg.dma_spar = chan->chan_reg.dma_spar; + desc->sg_req[i].chan_reg.dma_sm0ar = buf_addr; + desc->sg_req[i].chan_reg.dma_sm1ar = buf_addr; + desc->sg_req[i].chan_reg.dma_sndtr = nb_data_items; + buf_addr += period_len; + } + + desc->num_sgs = num_periods; + desc->cyclic = true; + + return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags); +} + +static struct dma_async_tx_descriptor *stm32_dma_prep_dma_memcpy( + struct dma_chan *c, dma_addr_t dest, + dma_addr_t src, size_t len, unsigned long flags) +{ + struct stm32_dma_chan *chan = to_stm32_dma_chan(c); + u32 num_sgs; + struct stm32_dma_desc *desc; + size_t xfer_count, offset; + int i; + + num_sgs = DIV_ROUND_UP(len, STM32_DMA_MAX_DATA_ITEMS); + desc = stm32_dma_alloc_desc(num_sgs); + if (!desc) + return NULL; + + for (offset = 0, i = 0; offset < len; offset += xfer_count, i++) { + xfer_count = min_t(size_t, len - offset, + STM32_DMA_MAX_DATA_ITEMS); + + desc->sg_req[i].len = xfer_count; + + stm32_dma_clear_reg(&desc->sg_req[i].chan_reg); + desc->sg_req[i].chan_reg.dma_scr = + STM32_DMA_SCR_DIR(STM32_DMA_MEM_TO_MEM) | + STM32_DMA_SCR_MINC | + STM32_DMA_SCR_PINC | + STM32_DMA_SCR_TCIE | + STM32_DMA_SCR_TEIE; + desc->sg_req[i].chan_reg.dma_sfcr = STM32_DMA_SFCR_DMDIS | + STM32_DMA_SFCR_FTH(STM32_DMA_FIFO_THRESHOLD_FULL) | + STM32_DMA_SFCR_FEIE; + desc->sg_req[i].chan_reg.dma_spar = src + offset; + desc->sg_req[i].chan_reg.dma_sm0ar = dest + offset; + desc->sg_req[i].chan_reg.dma_sndtr = xfer_count; + } + + desc->num_sgs = num_sgs; + desc->cyclic = false; + + return vchan_tx_prep(&chan->vchan, &desc->vdesc, flags); +} + +static size_t stm32_dma_desc_residue(struct stm32_dma_chan *chan, + struct stm32_dma_desc *desc, + u32 next_sg) +{ + struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan); + u32 dma_scr, width, residue, count; + int i; + + residue = 0; + + for (i = next_sg; i < desc->num_sgs; i++) + residue += desc->sg_req[i].len; + + if (next_sg != 0) { + dma_scr = stm32_dma_read(dmadev, STM32_DMA_SCR(chan->id)); + width = STM32_DMA_SCR_PSIZE_GET(dma_scr); + count = stm32_dma_read(dmadev, STM32_DMA_SNDTR(chan->id)); + + residue += count << width; + } + + return residue; +} + +static enum dma_status stm32_dma_tx_status(struct dma_chan *c, + dma_cookie_t cookie, + struct dma_tx_state *state) +{ + struct stm32_dma_chan *chan = to_stm32_dma_chan(c); + struct virt_dma_desc *vdesc; + enum dma_status status; + unsigned long flags; + u32 residue; + + status = dma_cookie_status(c, cookie, state); + if ((status == DMA_COMPLETE) || (!state)) + return status; + + spin_lock_irqsave(&chan->vchan.lock, flags); + vdesc = vchan_find_desc(&chan->vchan, cookie); + if (cookie == chan->desc->vdesc.tx.cookie) { + residue = stm32_dma_desc_residue(chan, chan->desc, + chan->next_sg); + } else if (vdesc) { + residue = stm32_dma_desc_residue(chan, + to_stm32_dma_desc(vdesc), 0); + } else { + residue = 0; + } + + dma_set_residue(state, residue); + + spin_unlock_irqrestore(&chan->vchan.lock, flags); + + return status; +} + +static int stm32_dma_alloc_chan_resources(struct dma_chan *c) +{ + struct stm32_dma_chan *chan = to_stm32_dma_chan(c); + struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan); + int ret; + + chan->config_init = false; + ret = clk_prepare_enable(dmadev->clk); + if (ret < 0) { + dev_err(chan2dev(chan), "clk_prepare_enable failed: %d\n", ret); + return ret; + } + + ret = stm32_dma_disable_chan(chan); + if (ret < 0) + clk_disable_unprepare(dmadev->clk); + + return ret; +} + +static void stm32_dma_free_chan_resources(struct dma_chan *c) +{ + struct stm32_dma_chan *chan = to_stm32_dma_chan(c); + struct stm32_dma_device *dmadev = stm32_dma_get_dev(chan); + unsigned long flags; + + dev_dbg(chan2dev(chan), "Freeing channel %d\n", chan->id); + + if (chan->busy) { + spin_lock_irqsave(&chan->vchan.lock, flags); + stm32_dma_stop(chan); + chan->desc = NULL; + spin_unlock_irqrestore(&chan->vchan.lock, flags); + } + + clk_disable_unprepare(dmadev->clk); + + vchan_free_chan_resources(to_virt_chan(c)); +} + +static void stm32_dma_desc_free(struct virt_dma_desc *vdesc) +{ + kfree(container_of(vdesc, struct stm32_dma_desc, vdesc)); +} + +void stm32_dma_set_config(struct stm32_dma_chan *chan, + struct stm32_dma_cfg *cfg) +{ + stm32_dma_clear_reg(&chan->chan_reg); + + chan->chan_reg.dma_scr = cfg->stream_config & STM32_DMA_SCR_CFG_MASK; + chan->chan_reg.dma_scr |= STM32_DMA_SCR_REQ(cfg->request_line); + + /* Enable Interrupts */ + chan->chan_reg.dma_scr |= STM32_DMA_SCR_TEIE | STM32_DMA_SCR_TCIE; + + chan->chan_reg.dma_sfcr = cfg->threshold & STM32_DMA_SFCR_FTH_MASK; +} + +static struct dma_chan *stm32_dma_of_xlate(struct of_phandle_args *dma_spec, + struct of_dma *ofdma) +{ + struct stm32_dma_device *dmadev = ofdma->of_dma_data; + struct stm32_dma_cfg cfg; + struct stm32_dma_chan *chan; + struct dma_chan *c; + + if (dma_spec->args_count < 3) + return NULL; + + cfg.channel_id = dma_spec->args[0]; + cfg.request_line = dma_spec->args[1]; + cfg.stream_config = dma_spec->args[2]; + cfg.threshold = 0; + + if ((cfg.channel_id >= STM32_DMA_MAX_CHANNELS) || (cfg.request_line >= + STM32_DMA_MAX_REQUEST_ID)) + return NULL; + + if (dma_spec->args_count > 3) + cfg.threshold = dma_spec->args[3]; + + chan = &dmadev->chan[cfg.channel_id]; + + c = dma_get_slave_channel(&chan->vchan.chan); + if (c) + stm32_dma_set_config(chan, &cfg); + + return c; +} + +static const struct of_device_id stm32_dma_of_match[] = { + { .compatible = "st,stm32-dma", }, + { /* sentinel */ }, +}; +MODULE_DEVICE_TABLE(of, stm32_dma_of_match); + +static int stm32_dma_probe(struct platform_device *pdev) +{ + struct stm32_dma_chan *chan; + struct stm32_dma_device *dmadev; + struct dma_device *dd; + const struct of_device_id *match; + struct resource *res; + int i, ret; + + match = of_match_device(stm32_dma_of_match, &pdev->dev); + if (!match) { + dev_err(&pdev->dev, "Error: No device match found\n"); + return -ENODEV; + } + + dmadev = devm_kzalloc(&pdev->dev, sizeof(*dmadev), GFP_KERNEL); + if (!dmadev) + return -ENOMEM; + + dd = &dmadev->ddev; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + dmadev->base = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(dmadev->base)) + return PTR_ERR(dmadev->base); + + dmadev->clk = devm_clk_get(&pdev->dev, NULL); + if (IS_ERR(dmadev->clk)) { + dev_err(&pdev->dev, "Error: Missing controller clock\n"); + return PTR_ERR(dmadev->clk); + } + + dmadev->mem2mem = of_property_read_bool(pdev->dev.of_node, + "st,mem2mem"); + + dmadev->rst = devm_reset_control_get(&pdev->dev, NULL); + if (!IS_ERR(dmadev->rst)) { + reset_control_assert(dmadev->rst); + udelay(2); + reset_control_deassert(dmadev->rst); + } + + dma_cap_set(DMA_SLAVE, dd->cap_mask); + dma_cap_set(DMA_PRIVATE, dd->cap_mask); + dma_cap_set(DMA_CYCLIC, dd->cap_mask); + dd->device_alloc_chan_resources = stm32_dma_alloc_chan_resources; + dd->device_free_chan_resources = stm32_dma_free_chan_resources; + dd->device_tx_status = stm32_dma_tx_status; + dd->device_issue_pending = stm32_dma_issue_pending; + dd->device_prep_slave_sg = stm32_dma_prep_slave_sg; + dd->device_prep_dma_cyclic = stm32_dma_prep_dma_cyclic; + dd->device_config = stm32_dma_slave_config; + dd->device_terminate_all = stm32_dma_terminate_all; + dd->src_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) | + BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) | + BIT(DMA_SLAVE_BUSWIDTH_4_BYTES); + dd->dst_addr_widths = BIT(DMA_SLAVE_BUSWIDTH_1_BYTE) | + BIT(DMA_SLAVE_BUSWIDTH_2_BYTES) | + BIT(DMA_SLAVE_BUSWIDTH_4_BYTES); + dd->directions = BIT(DMA_DEV_TO_MEM) | BIT(DMA_MEM_TO_DEV); + dd->residue_granularity = DMA_RESIDUE_GRANULARITY_BURST; + dd->dev = &pdev->dev; + INIT_LIST_HEAD(&dd->channels); + + if (dmadev->mem2mem) { + dma_cap_set(DMA_MEMCPY, dd->cap_mask); + dd->device_prep_dma_memcpy = stm32_dma_prep_dma_memcpy; + dd->directions |= BIT(DMA_MEM_TO_MEM); + } + + for (i = 0; i < STM32_DMA_MAX_CHANNELS; i++) { + chan = &dmadev->chan[i]; + chan->id = i; + chan->vchan.desc_free = stm32_dma_desc_free; + vchan_init(&chan->vchan, dd); + } + + ret = dma_async_device_register(dd); + if (ret) + return ret; + + for (i = 0; i < STM32_DMA_MAX_CHANNELS; i++) { + chan = &dmadev->chan[i]; + res = platform_get_resource(pdev, IORESOURCE_IRQ, i); + if (!res) { + ret = -EINVAL; + dev_err(&pdev->dev, "No irq resource for chan %d\n", i); + goto err_unregister; + } + chan->irq = res->start; + ret = devm_request_irq(&pdev->dev, chan->irq, + stm32_dma_chan_irq, 0, + dev_name(chan2dev(chan)), chan); + if (ret) { + dev_err(&pdev->dev, + "request_irq failed with err %d channel %d\n", + ret, i); + goto err_unregister; + } + } + + ret = of_dma_controller_register(pdev->dev.of_node, + stm32_dma_of_xlate, dmadev); + if (ret < 0) { + dev_err(&pdev->dev, + "STM32 DMA DMA OF registration failed %d\n", ret); + goto err_unregister; + } + + platform_set_drvdata(pdev, dmadev); + + dev_info(&pdev->dev, "STM32 DMA driver registered\n"); + + return 0; + +err_unregister: + dma_async_device_unregister(dd); + + return ret; +} + +static struct platform_driver stm32_dma_driver = { + .driver = { + .name = "stm32-dma", + .of_match_table = stm32_dma_of_match, + }, +}; + +static int __init stm32_dma_init(void) +{ + return platform_driver_probe(&stm32_dma_driver, stm32_dma_probe); +} +subsys_initcall(stm32_dma_init); |