From 5d1646d90e1f2cceb9f0828f4b28318cd0ec7744 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sat, 27 Apr 2024 12:05:51 +0200 Subject: Adding upstream version 5.10.209. Signed-off-by: Daniel Baumann --- arch/arm/mach-rpc/dma.c | 393 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 393 insertions(+) create mode 100644 arch/arm/mach-rpc/dma.c (limited to 'arch/arm/mach-rpc/dma.c') diff --git a/arch/arm/mach-rpc/dma.c b/arch/arm/mach-rpc/dma.c new file mode 100644 index 000000000..50e0f97af --- /dev/null +++ b/arch/arm/mach-rpc/dma.c @@ -0,0 +1,393 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * linux/arch/arm/mach-rpc/dma.c + * + * Copyright (C) 1998 Russell King + * + * DMA functions specific to RiscPC architecture + */ +#include +#include +#include +#include +#include + +#include +#include +#include +#include +#include +#include + +#include +#include + +struct iomd_dma { + struct dma_struct dma; + void __iomem *base; /* Controller base address */ + int irq; /* Controller IRQ */ + unsigned int state; + dma_addr_t cur_addr; + unsigned int cur_len; + dma_addr_t dma_addr; + unsigned int dma_len; +}; + +#if 0 +typedef enum { + dma_size_8 = 1, + dma_size_16 = 2, + dma_size_32 = 4, + dma_size_128 = 16 +} dma_size_t; +#endif + +#define TRANSFER_SIZE 2 + +#define CURA (0) +#define ENDA (IOMD_IO0ENDA - IOMD_IO0CURA) +#define CURB (IOMD_IO0CURB - IOMD_IO0CURA) +#define ENDB (IOMD_IO0ENDB - IOMD_IO0CURA) +#define CR (IOMD_IO0CR - IOMD_IO0CURA) +#define ST (IOMD_IO0ST - IOMD_IO0CURA) + +static void iomd_get_next_sg(struct iomd_dma *idma) +{ + unsigned long end, offset, flags = 0; + + if (idma->dma.sg) { + idma->cur_addr = idma->dma_addr; + offset = idma->cur_addr & ~PAGE_MASK; + + end = offset + idma->dma_len; + + if (end > PAGE_SIZE) + end = PAGE_SIZE; + + if (offset + TRANSFER_SIZE >= end) + flags |= DMA_END_L; + + idma->cur_len = end - TRANSFER_SIZE; + + idma->dma_len -= end - offset; + idma->dma_addr += end - offset; + + if (idma->dma_len == 0) { + if (idma->dma.sgcount > 1) { + idma->dma.sg = sg_next(idma->dma.sg); + idma->dma_addr = idma->dma.sg->dma_address; + idma->dma_len = idma->dma.sg->length; + idma->dma.sgcount--; + } else { + idma->dma.sg = NULL; + flags |= DMA_END_S; + } + } + } else { + flags = DMA_END_S | DMA_END_L; + idma->cur_addr = 0; + idma->cur_len = 0; + } + + idma->cur_len |= flags; +} + +static irqreturn_t iomd_dma_handle(int irq, void *dev_id) +{ + struct iomd_dma *idma = dev_id; + void __iomem *base = idma->base; + unsigned int state = idma->state; + unsigned int status, cur, end; + + do { + status = readb(base + ST); + if (!(status & DMA_ST_INT)) + goto out; + + if ((state ^ status) & DMA_ST_AB) + iomd_get_next_sg(idma); + + // This efficiently implements state = OFL != AB ? AB : 0 + state = ((status >> 2) ^ status) & DMA_ST_AB; + if (state) { + cur = CURA; + end = ENDA; + } else { + cur = CURB; + end = ENDB; + } + writel(idma->cur_addr, base + cur); + writel(idma->cur_len, base + end); + + if (status & DMA_ST_OFL && + idma->cur_len == (DMA_END_S|DMA_END_L)) + break; + } while (1); + + state = ~DMA_ST_AB; + disable_irq_nosync(irq); +out: + idma->state = state; + return IRQ_HANDLED; +} + +static int iomd_request_dma(unsigned int chan, dma_t *dma) +{ + struct iomd_dma *idma = container_of(dma, struct iomd_dma, dma); + + return request_irq(idma->irq, iomd_dma_handle, + 0, idma->dma.device_id, idma); +} + +static void iomd_free_dma(unsigned int chan, dma_t *dma) +{ + struct iomd_dma *idma = container_of(dma, struct iomd_dma, dma); + + free_irq(idma->irq, idma); +} + +static struct device isa_dma_dev = { + .init_name = "fallback device", + .coherent_dma_mask = ~(dma_addr_t)0, + .dma_mask = &isa_dma_dev.coherent_dma_mask, +}; + +static void iomd_enable_dma(unsigned int chan, dma_t *dma) +{ + struct iomd_dma *idma = container_of(dma, struct iomd_dma, dma); + void __iomem *base = idma->base; + unsigned int ctrl = TRANSFER_SIZE | DMA_CR_E; + + if (idma->dma.invalid) { + idma->dma.invalid = 0; + + /* + * Cope with ISA-style drivers which expect cache + * coherence. + */ + if (!idma->dma.sg) { + idma->dma.sg = &idma->dma.buf; + idma->dma.sgcount = 1; + idma->dma.buf.length = idma->dma.count; + idma->dma.buf.dma_address = dma_map_single(&isa_dma_dev, + idma->dma.addr, idma->dma.count, + idma->dma.dma_mode == DMA_MODE_READ ? + DMA_FROM_DEVICE : DMA_TO_DEVICE); + } + + idma->dma_addr = idma->dma.sg->dma_address; + idma->dma_len = idma->dma.sg->length; + + writeb(DMA_CR_C, base + CR); + idma->state = DMA_ST_AB; + } + + if (idma->dma.dma_mode == DMA_MODE_READ) + ctrl |= DMA_CR_D; + + writeb(ctrl, base + CR); + enable_irq(idma->irq); +} + +static void iomd_disable_dma(unsigned int chan, dma_t *dma) +{ + struct iomd_dma *idma = container_of(dma, struct iomd_dma, dma); + void __iomem *base = idma->base; + unsigned long flags; + + local_irq_save(flags); + if (idma->state != ~DMA_ST_AB) + disable_irq(idma->irq); + writeb(0, base + CR); + local_irq_restore(flags); +} + +static int iomd_set_dma_speed(unsigned int chan, dma_t *dma, int cycle) +{ + int tcr, speed; + + if (cycle < 188) + speed = 3; + else if (cycle <= 250) + speed = 2; + else if (cycle < 438) + speed = 1; + else + speed = 0; + + tcr = iomd_readb(IOMD_DMATCR); + speed &= 3; + + switch (chan) { + case DMA_0: + tcr = (tcr & ~0x03) | speed; + break; + + case DMA_1: + tcr = (tcr & ~0x0c) | (speed << 2); + break; + + case DMA_2: + tcr = (tcr & ~0x30) | (speed << 4); + break; + + case DMA_3: + tcr = (tcr & ~0xc0) | (speed << 6); + break; + + default: + break; + } + + iomd_writeb(tcr, IOMD_DMATCR); + + return speed; +} + +static struct dma_ops iomd_dma_ops = { + .type = "IOMD", + .request = iomd_request_dma, + .free = iomd_free_dma, + .enable = iomd_enable_dma, + .disable = iomd_disable_dma, + .setspeed = iomd_set_dma_speed, +}; + +static struct fiq_handler fh = { + .name = "floppydma" +}; + +struct floppy_dma { + struct dma_struct dma; + unsigned int fiq; +}; + +static void floppy_enable_dma(unsigned int chan, dma_t *dma) +{ + struct floppy_dma *fdma = container_of(dma, struct floppy_dma, dma); + void *fiqhandler_start; + unsigned int fiqhandler_length; + struct pt_regs regs; + + if (fdma->dma.sg) + BUG(); + + if (fdma->dma.dma_mode == DMA_MODE_READ) { + extern unsigned char floppy_fiqin_start, floppy_fiqin_end; + fiqhandler_start = &floppy_fiqin_start; + fiqhandler_length = &floppy_fiqin_end - &floppy_fiqin_start; + } else { + extern unsigned char floppy_fiqout_start, floppy_fiqout_end; + fiqhandler_start = &floppy_fiqout_start; + fiqhandler_length = &floppy_fiqout_end - &floppy_fiqout_start; + } + + regs.ARM_r9 = fdma->dma.count; + regs.ARM_r10 = (unsigned long)fdma->dma.addr; + regs.ARM_fp = (unsigned long)FLOPPYDMA_BASE; + + if (claim_fiq(&fh)) { + printk("floppydma: couldn't claim FIQ.\n"); + return; + } + + set_fiq_handler(fiqhandler_start, fiqhandler_length); + set_fiq_regs(®s); + enable_fiq(fdma->fiq); +} + +static void floppy_disable_dma(unsigned int chan, dma_t *dma) +{ + struct floppy_dma *fdma = container_of(dma, struct floppy_dma, dma); + disable_fiq(fdma->fiq); + release_fiq(&fh); +} + +static int floppy_get_residue(unsigned int chan, dma_t *dma) +{ + struct pt_regs regs; + get_fiq_regs(®s); + return regs.ARM_r9; +} + +static struct dma_ops floppy_dma_ops = { + .type = "FIQDMA", + .enable = floppy_enable_dma, + .disable = floppy_disable_dma, + .residue = floppy_get_residue, +}; + +/* + * This is virtual DMA - we don't need anything here. + */ +static void sound_enable_disable_dma(unsigned int chan, dma_t *dma) +{ +} + +static struct dma_ops sound_dma_ops = { + .type = "VIRTUAL", + .enable = sound_enable_disable_dma, + .disable = sound_enable_disable_dma, +}; + +static struct iomd_dma iomd_dma[6]; + +static struct floppy_dma floppy_dma = { + .dma = { + .d_ops = &floppy_dma_ops, + }, + .fiq = FIQ_FLOPPYDATA, +}; + +static dma_t sound_dma = { + .d_ops = &sound_dma_ops, +}; + +static int __init rpc_dma_init(void) +{ + unsigned int i; + int ret; + + iomd_writeb(0, IOMD_IO0CR); + iomd_writeb(0, IOMD_IO1CR); + iomd_writeb(0, IOMD_IO2CR); + iomd_writeb(0, IOMD_IO3CR); + + iomd_writeb(0xa0, IOMD_DMATCR); + + /* + * Setup DMA channels 2,3 to be for podules + * and channels 0,1 for internal devices + */ + iomd_writeb(DMA_EXT_IO3|DMA_EXT_IO2, IOMD_DMAEXT); + + iomd_dma[DMA_0].base = IOMD_BASE + IOMD_IO0CURA; + iomd_dma[DMA_0].irq = IRQ_DMA0; + iomd_dma[DMA_1].base = IOMD_BASE + IOMD_IO1CURA; + iomd_dma[DMA_1].irq = IRQ_DMA1; + iomd_dma[DMA_2].base = IOMD_BASE + IOMD_IO2CURA; + iomd_dma[DMA_2].irq = IRQ_DMA2; + iomd_dma[DMA_3].base = IOMD_BASE + IOMD_IO3CURA; + iomd_dma[DMA_3].irq = IRQ_DMA3; + iomd_dma[DMA_S0].base = IOMD_BASE + IOMD_SD0CURA; + iomd_dma[DMA_S0].irq = IRQ_DMAS0; + iomd_dma[DMA_S1].base = IOMD_BASE + IOMD_SD1CURA; + iomd_dma[DMA_S1].irq = IRQ_DMAS1; + + for (i = DMA_0; i <= DMA_S1; i++) { + iomd_dma[i].dma.d_ops = &iomd_dma_ops; + + ret = isa_dma_add(i, &iomd_dma[i].dma); + if (ret) + printk("IOMDDMA%u: unable to register: %d\n", i, ret); + } + + ret = isa_dma_add(DMA_VIRTUAL_FLOPPY, &floppy_dma.dma); + if (ret) + printk("IOMDFLOPPY: unable to register: %d\n", ret); + ret = isa_dma_add(DMA_VIRTUAL_SOUND, &sound_dma); + if (ret) + printk("IOMDSOUND: unable to register: %d\n", ret); + return 0; +} +core_initcall(rpc_dma_init); -- cgit v1.2.3