1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257
|
// SPDX-License-Identifier: GPL-2.0
/* ebus.c: EBUS DMA library code.
*
* Copyright (C) 1997 Eddie C. Dost (ecd@skynet.be)
* Copyright (C) 1999 David S. Miller (davem@redhat.com)
*/
#include <linux/export.h>
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <asm/ebus_dma.h>
#include <asm/io.h>
#define EBDMA_CSR 0x00UL /* Control/Status */
#define EBDMA_ADDR 0x04UL /* DMA Address */
#define EBDMA_COUNT 0x08UL /* DMA Count */
#define EBDMA_CSR_INT_PEND 0x00000001
#define EBDMA_CSR_ERR_PEND 0x00000002
#define EBDMA_CSR_DRAIN 0x00000004
#define EBDMA_CSR_INT_EN 0x00000010
#define EBDMA_CSR_RESET 0x00000080
#define EBDMA_CSR_WRITE 0x00000100
#define EBDMA_CSR_EN_DMA 0x00000200
#define EBDMA_CSR_CYC_PEND 0x00000400
#define EBDMA_CSR_DIAG_RD_DONE 0x00000800
#define EBDMA_CSR_DIAG_WR_DONE 0x00001000
#define EBDMA_CSR_EN_CNT 0x00002000
#define EBDMA_CSR_TC 0x00004000
#define EBDMA_CSR_DIS_CSR_DRN 0x00010000
#define EBDMA_CSR_BURST_SZ_MASK 0x000c0000
#define EBDMA_CSR_BURST_SZ_1 0x00080000
#define EBDMA_CSR_BURST_SZ_4 0x00000000
#define EBDMA_CSR_BURST_SZ_8 0x00040000
#define EBDMA_CSR_BURST_SZ_16 0x000c0000
#define EBDMA_CSR_DIAG_EN 0x00100000
#define EBDMA_CSR_DIS_ERR_PEND 0x00400000
#define EBDMA_CSR_TCI_DIS 0x00800000
#define EBDMA_CSR_EN_NEXT 0x01000000
#define EBDMA_CSR_DMA_ON 0x02000000
#define EBDMA_CSR_A_LOADED 0x04000000
#define EBDMA_CSR_NA_LOADED 0x08000000
#define EBDMA_CSR_DEV_ID_MASK 0xf0000000
#define EBUS_DMA_RESET_TIMEOUT 10000
static void __ebus_dma_reset(struct ebus_dma_info *p, int no_drain)
{
int i;
u32 val = 0;
writel(EBDMA_CSR_RESET, p->regs + EBDMA_CSR);
udelay(1);
if (no_drain)
return;
for (i = EBUS_DMA_RESET_TIMEOUT; i > 0; i--) {
val = readl(p->regs + EBDMA_CSR);
if (!(val & (EBDMA_CSR_DRAIN | EBDMA_CSR_CYC_PEND)))
break;
udelay(10);
}
}
static irqreturn_t ebus_dma_irq(int irq, void *dev_id)
{
struct ebus_dma_info *p = dev_id;
unsigned long flags;
u32 csr = 0;
spin_lock_irqsave(&p->lock, flags);
csr = readl(p->regs + EBDMA_CSR);
writel(csr, p->regs + EBDMA_CSR);
spin_unlock_irqrestore(&p->lock, flags);
if (csr & EBDMA_CSR_ERR_PEND) {
printk(KERN_CRIT "ebus_dma(%s): DMA error!\n", p->name);
p->callback(p, EBUS_DMA_EVENT_ERROR, p->client_cookie);
return IRQ_HANDLED;
} else if (csr & EBDMA_CSR_INT_PEND) {
p->callback(p,
(csr & EBDMA_CSR_TC) ?
EBUS_DMA_EVENT_DMA : EBUS_DMA_EVENT_DEVICE,
p->client_cookie);
return IRQ_HANDLED;
}
return IRQ_NONE;
}
int ebus_dma_register(struct ebus_dma_info *p)
{
u32 csr;
if (!p->regs)
return -EINVAL;
if (p->flags & ~(EBUS_DMA_FLAG_USE_EBDMA_HANDLER |
EBUS_DMA_FLAG_TCI_DISABLE))
return -EINVAL;
if ((p->flags & EBUS_DMA_FLAG_USE_EBDMA_HANDLER) && !p->callback)
return -EINVAL;
if (!strlen(p->name))
return -EINVAL;
__ebus_dma_reset(p, 1);
csr = EBDMA_CSR_BURST_SZ_16 | EBDMA_CSR_EN_CNT;
if (p->flags & EBUS_DMA_FLAG_TCI_DISABLE)
csr |= EBDMA_CSR_TCI_DIS;
writel(csr, p->regs + EBDMA_CSR);
return 0;
}
EXPORT_SYMBOL(ebus_dma_register);
int ebus_dma_irq_enable(struct ebus_dma_info *p, int on)
{
unsigned long flags;
u32 csr;
if (on) {
if (p->flags & EBUS_DMA_FLAG_USE_EBDMA_HANDLER) {
if (request_irq(p->irq, ebus_dma_irq, IRQF_SHARED, p->name, p))
return -EBUSY;
}
spin_lock_irqsave(&p->lock, flags);
csr = readl(p->regs + EBDMA_CSR);
csr |= EBDMA_CSR_INT_EN;
writel(csr, p->regs + EBDMA_CSR);
spin_unlock_irqrestore(&p->lock, flags);
} else {
spin_lock_irqsave(&p->lock, flags);
csr = readl(p->regs + EBDMA_CSR);
csr &= ~EBDMA_CSR_INT_EN;
writel(csr, p->regs + EBDMA_CSR);
spin_unlock_irqrestore(&p->lock, flags);
if (p->flags & EBUS_DMA_FLAG_USE_EBDMA_HANDLER) {
free_irq(p->irq, p);
}
}
return 0;
}
EXPORT_SYMBOL(ebus_dma_irq_enable);
void ebus_dma_unregister(struct ebus_dma_info *p)
{
unsigned long flags;
u32 csr;
int irq_on = 0;
spin_lock_irqsave(&p->lock, flags);
csr = readl(p->regs + EBDMA_CSR);
if (csr & EBDMA_CSR_INT_EN) {
csr &= ~EBDMA_CSR_INT_EN;
writel(csr, p->regs + EBDMA_CSR);
irq_on = 1;
}
spin_unlock_irqrestore(&p->lock, flags);
if (irq_on)
free_irq(p->irq, p);
}
EXPORT_SYMBOL(ebus_dma_unregister);
int ebus_dma_request(struct ebus_dma_info *p, dma_addr_t bus_addr, size_t len)
{
unsigned long flags;
u32 csr;
int err;
if (len >= (1 << 24))
return -EINVAL;
spin_lock_irqsave(&p->lock, flags);
csr = readl(p->regs + EBDMA_CSR);
err = -EINVAL;
if (!(csr & EBDMA_CSR_EN_DMA))
goto out;
err = -EBUSY;
if (csr & EBDMA_CSR_NA_LOADED)
goto out;
writel(len, p->regs + EBDMA_COUNT);
writel(bus_addr, p->regs + EBDMA_ADDR);
err = 0;
out:
spin_unlock_irqrestore(&p->lock, flags);
return err;
}
EXPORT_SYMBOL(ebus_dma_request);
void ebus_dma_prepare(struct ebus_dma_info *p, int write)
{
unsigned long flags;
u32 csr;
spin_lock_irqsave(&p->lock, flags);
__ebus_dma_reset(p, 0);
csr = (EBDMA_CSR_INT_EN |
EBDMA_CSR_EN_CNT |
EBDMA_CSR_BURST_SZ_16 |
EBDMA_CSR_EN_NEXT);
if (write)
csr |= EBDMA_CSR_WRITE;
if (p->flags & EBUS_DMA_FLAG_TCI_DISABLE)
csr |= EBDMA_CSR_TCI_DIS;
writel(csr, p->regs + EBDMA_CSR);
spin_unlock_irqrestore(&p->lock, flags);
}
EXPORT_SYMBOL(ebus_dma_prepare);
unsigned int ebus_dma_residue(struct ebus_dma_info *p)
{
return readl(p->regs + EBDMA_COUNT);
}
EXPORT_SYMBOL(ebus_dma_residue);
unsigned int ebus_dma_addr(struct ebus_dma_info *p)
{
return readl(p->regs + EBDMA_ADDR);
}
EXPORT_SYMBOL(ebus_dma_addr);
void ebus_dma_enable(struct ebus_dma_info *p, int on)
{
unsigned long flags;
u32 orig_csr, csr;
spin_lock_irqsave(&p->lock, flags);
orig_csr = csr = readl(p->regs + EBDMA_CSR);
if (on)
csr |= EBDMA_CSR_EN_DMA;
else
csr &= ~EBDMA_CSR_EN_DMA;
if ((orig_csr & EBDMA_CSR_EN_DMA) !=
(csr & EBDMA_CSR_EN_DMA))
writel(csr, p->regs + EBDMA_CSR);
spin_unlock_irqrestore(&p->lock, flags);
}
EXPORT_SYMBOL(ebus_dma_enable);
|