/* * TI OMAP on-chip I2C controller. Only "new I2C" mode supported. * * Copyright (C) 2007 Andrzej Zaborowski <balrog@zabor.org> * * 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. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License along * with this program; if not, see <http://www.gnu.org/licenses/>. */ #include "hw.h" #include "i2c.h" #include "omap.h" struct omap_i2c_s { MemoryRegion iomem; qemu_irq irq; qemu_irq drq[2]; i2c_bus *bus; uint8_t revision; uint8_t mask; uint16_t stat; uint16_t dma; uint16_t count; int count_cur; uint32_t fifo; int rxlen; int txlen; uint16_t control; uint16_t addr[2]; uint8_t divider; uint8_t times[2]; uint16_t test; }; #define OMAP2_INTR_REV 0x34 #define OMAP2_GC_REV 0x34 static void omap_i2c_interrupts_update(struct omap_i2c_s *s) { qemu_set_irq(s->irq, s->stat & s->mask); if ((s->dma >> 15) & 1) /* RDMA_EN */ qemu_set_irq(s->drq[0], (s->stat >> 3) & 1); /* RRDY */ if ((s->dma >> 7) & 1) /* XDMA_EN */ qemu_set_irq(s->drq[1], (s->stat >> 4) & 1); /* XRDY */ } static void omap_i2c_fifo_run(struct omap_i2c_s *s) { int ack = 1; if (!i2c_bus_busy(s->bus)) return; if ((s->control >> 2) & 1) { /* RM */ if ((s->control >> 1) & 1) { /* STP */ i2c_end_transfer(s->bus); s->control &= ~(1 << 1); /* STP */ s->count_cur = s->count; s->txlen = 0; } else if ((s->control >> 9) & 1) { /* TRX */ while (ack && s->txlen) ack = (i2c_send(s->bus, (s->fifo >> ((-- s->txlen) << 3)) & 0xff) >= 0); s->stat |= 1 << 4; /* XRDY */ } else { while (s->rxlen < 4) s->fifo |= i2c_recv(s->bus) << ((s->rxlen ++) << 3); s->stat |= 1 << 3; /* RRDY */ } } else { if ((s->control >> 9) & 1) { /* TRX */ while (ack && s->count_cur && s->txlen) { ack = (i2c_send(s->bus, (s->fifo >> ((-- s->txlen) << 3)) & 0xff) >= 0); s->count_cur --; } if (ack && s->count_cur) s->stat |= 1 << 4; /* XRDY */ else s->stat &= ~(1 << 4); /* XRDY */ if (!s->count_cur) { s->stat |= 1 << 2; /* ARDY */ s->control &= ~(1 << 10); /* MST */ } } else { while (s->count_cur && s->rxlen < 4) { s->fifo |= i2c_recv(s->bus) << ((s->rxlen ++) << 3); s->count_cur --; } if (s->rxlen) s->stat |= 1 << 3; /* RRDY */ else s->stat &= ~(1 << 3); /* RRDY */ } if (!s->count_cur) { if ((s->control >> 1) & 1) { /* STP */ i2c_end_transfer(s->bus); s->control &= ~(1 << 1); /* STP */ s->count_cur = s->count; s->txlen = 0; } else { s->stat |= 1 << 2; /* ARDY */ s->control &= ~(1 << 10); /* MST */ } } } s->stat |= (!ack) << 1; /* NACK */ if (!ack) s->control &= ~(1 << 1); /* STP */ } void omap_i2c_reset(struct omap_i2c_s *s) { s->mask = 0; s->stat = 0; s->dma = 0; s->count = 0; s->count_cur = 0; s->fifo = 0; s->rxlen = 0; s->txlen = 0; s->control = 0; s->addr[0] = 0; s->addr[1] = 0; s->divider = 0; s->times[0] = 0; s->times[1] = 0; s->test = 0; } static uint32_t omap_i2c_read(void *opaque, target_phys_addr_t addr) { struct omap_i2c_s *s = (struct omap_i2c_s *) opaque; int offset = addr & OMAP_MPUI_REG_MASK; uint16_t ret; switch (offset) { case 0x00: /* I2C_REV */ return s->revision; /* REV */ case 0x04: /* I2C_IE */ return s->mask; case 0x08: /* I2C_STAT */ return s->stat | (i2c_bus_busy(s->bus) << 12); case 0x0c: /* I2C_IV */ if (s->revision >= OMAP2_INTR_REV) break; ret = ffs(s->stat & s->mask); if (ret) s->stat ^= 1 << (ret - 1); omap_i2c_interrupts_update(s); return ret; case 0x10: /* I2C_SYSS */ return (s->control >> 15) & 1; /* I2C_EN */ case 0x14: /* I2C_BUF */ return s->dma; case 0x18: /* I2C_CNT */ return s->count_cur; /* DCOUNT */ case 0x1c: /* I2C_DATA */ ret = 0; if (s->control & (1 << 14)) { /* BE */ ret |= ((s->fifo >> 0) & 0xff) << 8; ret |= ((s->fifo >> 8) & 0xff) << 0; } else { ret |= ((s->fifo >> 8) & 0xff) << 8; ret |= ((s->fifo >> 0) & 0xff) << 0; } if (s->rxlen == 1) { s->stat |= 1 << 15; /* SBD */ s->rxlen = 0; } else if (s->rxlen > 1) { if (s->rxlen > 2) s->fifo >>= 16; s->rxlen -= 2; } else { /* XXX: remote access (qualifier) error - what's that? */ } if (!s->rxlen) { s->stat &= ~(1 << 3); /* RRDY */ if (((s->control >> 10) & 1) && /* MST */ ((~s->control >> 9) & 1)) { /* TRX */ s->stat |= 1 << 2; /* ARDY */ s->control &= ~(1 << 10); /* MST */ } } s->stat &= ~(1 << 11); /* ROVR */ omap_i2c_fifo_run(s); omap_i2c_interrupts_update(s); return ret; case 0x20: /* I2C_SYSC */ return 0; case 0x24: /* I2C_CON */ return s->control; case 0x28: /* I2C_OA */ return s->addr[0]; case 0x2c: /* I2C_SA */ return s->addr[1]; case 0x30: /* I2C_PSC */ return s->divider; case 0x34: /* I2C_SCLL */ return s->times[0]; case 0x38: /* I2C_SCLH */ return s->times[1]; case 0x3c: /* I2C_SYSTEST */ if (s->test & (1 << 15)) { /* ST_EN */ s->test ^= 0xa; return s->test; } else return s->test & ~0x300f; } OMAP_BAD_REG(addr); return 0; } static void omap_i2c_write(void *opaque, target_phys_addr_t addr, uint32_t value) { struct omap_i2c_s *s = (struct omap_i2c_s *) opaque; int offset = addr & OMAP_MPUI_REG_MASK; int nack; switch (offset) { case 0x00: /* I2C_REV */ case 0x0c: /* I2C_IV */ case 0x10: /* I2C_SYSS */ OMAP_RO_REG(addr); return; case 0x04: /* I2C_IE */ s->mask = value & (s->revision < OMAP2_GC_REV ? 0x1f : 0x3f); break; case 0x08: /* I2C_STAT */ if (s->revision < OMAP2_INTR_REV) { OMAP_RO_REG(addr); return; } /* RRDY and XRDY are reset by hardware. (in all versions???) */ s->stat &= ~(value & 0x27); omap_i2c_interrupts_update(s); break; case 0x14: /* I2C_BUF */ s->dma = value & 0x8080; if (value & (1 << 15)) /* RDMA_EN */ s->mask &= ~(1 << 3); /* RRDY_IE */ if (value & (1 << 7)) /* XDMA_EN */ s->mask &= ~(1 << 4); /* XRDY_IE */ break; case 0x18: /* I2C_CNT */ s->count = value; /* DCOUNT */ break; case 0x1c: /* I2C_DATA */ if (s->txlen > 2) { /* XXX: remote access (qualifier) error - what's that? */ break; } s->fifo <<= 16; s->txlen += 2; if (s->control & (1 << 14)) { /* BE */ s->fifo |= ((value >> 8) & 0xff) << 8; s->fifo |= ((value >> 0) & 0xff) << 0; } else { s->fifo |= ((value >> 0) & 0xff) << 8; s->fifo |= ((value >> 8) & 0xff) << 0; } s->stat &= ~(1 << 10); /* XUDF */ if (s->txlen > 2) s->stat &= ~(1 << 4); /* XRDY */ omap_i2c_fifo_run(s); omap_i2c_interrupts_update(s); break; case 0x20: /* I2C_SYSC */ if (s->revision < OMAP2_INTR_REV) { OMAP_BAD_REG(addr); return; } if (value & 2) omap_i2c_reset(s); break; case 0x24: /* I2C_CON */ s->control = value & 0xcf87; if (~value & (1 << 15)) { /* I2C_EN */ if (s->revision < OMAP2_INTR_REV) omap_i2c_reset(s); break; } if ((value & (1 << 15)) && !(value & (1 << 10))) { /* MST */ fprintf(stderr, "%s: I^2C slave mode not supported\n", __FUNCTION__); break; } if ((value & (1 << 15)) && value & (1 << 8)) { /* XA */ fprintf(stderr, "%s: 10-bit addressing mode not supported\n", __FUNCTION__); break; } if ((value & (1 << 15)) && value & (1 << 0)) { /* STT */ nack = !!i2c_start_transfer(s->bus, s->addr[1], /* SA */ (~value >> 9) & 1); /* TRX */ s->stat |= nack << 1; /* NACK */ s->control &= ~(1 << 0); /* STT */ s->fifo = 0; if (nack) s->control &= ~(1 << 1); /* STP */ else { s->count_cur = s->count; omap_i2c_fifo_run(s); } omap_i2c_interrupts_update(s); } break; case 0x28: /* I2C_OA */ s->addr[0] = value & 0x3ff; break; case 0x2c: /* I2C_SA */ s->addr[1] = value & 0x3ff; break; case 0x30: /* I2C_PSC */ s->divider = value; break; case 0x34: /* I2C_SCLL */ s->times[0] = value; break; case 0x38: /* I2C_SCLH */ s->times[1] = value; break; case 0x3c: /* I2C_SYSTEST */ s->test = value & 0xf80f; if (value & (1 << 11)) /* SBB */ if (s->revision >= OMAP2_INTR_REV) { s->stat |= 0x3f; omap_i2c_interrupts_update(s); } if (value & (1 << 15)) /* ST_EN */ fprintf(stderr, "%s: System Test not supported\n", __FUNCTION__); break; default: OMAP_BAD_REG(addr); return; } } static void omap_i2c_writeb(void *opaque, target_phys_addr_t addr, uint32_t value) { struct omap_i2c_s *s = (struct omap_i2c_s *) opaque; int offset = addr & OMAP_MPUI_REG_MASK; switch (offset) { case 0x1c: /* I2C_DATA */ if (s->txlen > 2) { /* XXX: remote access (qualifier) error - what's that? */ break; } s->fifo <<= 8; s->txlen += 1; s->fifo |= value & 0xff; s->stat &= ~(1 << 10); /* XUDF */ if (s->txlen > 2) s->stat &= ~(1 << 4); /* XRDY */ omap_i2c_fifo_run(s); omap_i2c_interrupts_update(s); break; default: OMAP_BAD_REG(addr); return; } } static const MemoryRegionOps omap_i2c_ops = { .old_mmio = { .read = { omap_badwidth_read16, omap_i2c_read, omap_badwidth_read16, }, .write = { omap_i2c_writeb, /* Only the last fifo write can be 8 bit. */ omap_i2c_write, omap_badwidth_write16, }, }, .endianness = DEVICE_NATIVE_ENDIAN, }; struct omap_i2c_s *omap_i2c_init(MemoryRegion *sysmem, target_phys_addr_t base, qemu_irq irq, qemu_irq *dma, omap_clk clk) { struct omap_i2c_s *s = (struct omap_i2c_s *) g_malloc0(sizeof(struct omap_i2c_s)); /* TODO: set a value greater or equal to real hardware */ s->revision = 0x11; s->irq = irq; s->drq[0] = dma[0]; s->drq[1] = dma[1]; s->bus = i2c_init_bus(NULL, "i2c"); omap_i2c_reset(s); memory_region_init_io(&s->iomem, &omap_i2c_ops, s, "omap.i2c", 0x800); memory_region_add_subregion(sysmem, base, &s->iomem); return s; } struct omap_i2c_s *omap2_i2c_init(struct omap_target_agent_s *ta, qemu_irq irq, qemu_irq *dma, omap_clk fclk, omap_clk iclk) { struct omap_i2c_s *s = (struct omap_i2c_s *) g_malloc0(sizeof(struct omap_i2c_s)); s->revision = 0x34; s->irq = irq; s->drq[0] = dma[0]; s->drq[1] = dma[1]; s->bus = i2c_init_bus(NULL, "i2c"); omap_i2c_reset(s); memory_region_init_io(&s->iomem, &omap_i2c_ops, s, "omap2.i2c", omap_l4_region_size(ta, 0)); omap_l4_attach(ta, 0, &s->iomem); return s; } i2c_bus *omap_i2c_bus(struct omap_i2c_s *s) { return s->bus; }