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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /drivers/net/irda/vlsi_ir.h
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diff --git a/drivers/net/irda/vlsi_ir.h b/drivers/net/irda/vlsi_ir.h
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+
+/*********************************************************************
+ *
+ * vlsi_ir.h: VLSI82C147 PCI IrDA controller driver for Linux
+ *
+ * Version: 0.5
+ *
+ * Copyright (c) 2001-2003 Martin Diehl
+ *
+ * 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/>.
+ *
+ ********************************************************************/
+
+#ifndef IRDA_VLSI_FIR_H
+#define IRDA_VLSI_FIR_H
+
+/* ================================================================
+ * compatibility stuff
+ */
+
+/* definitions not present in pci_ids.h */
+
+#ifndef PCI_CLASS_WIRELESS_IRDA
+#define PCI_CLASS_WIRELESS_IRDA 0x0d00
+#endif
+
+#ifndef PCI_CLASS_SUBCLASS_MASK
+#define PCI_CLASS_SUBCLASS_MASK 0xffff
+#endif
+
+/* ================================================================ */
+
+/* non-standard PCI registers */
+
+enum vlsi_pci_regs {
+ VLSI_PCI_CLKCTL = 0x40, /* chip clock input control */
+ VLSI_PCI_MSTRPAGE = 0x41, /* addr [31:24] for all busmaster cycles */
+ VLSI_PCI_IRMISC = 0x42 /* mainly legacy UART related */
+};
+
+/* ------------------------------------------ */
+
+/* VLSI_PCI_CLKCTL: Clock Control Register (u8, rw) */
+
+/* Three possible clock sources: either on-chip 48MHz PLL or
+ * external clock applied to EXTCLK pin. External clock may
+ * be either 48MHz or 40MHz, which is indicated by XCKSEL.
+ * CLKSTP controls whether the selected clock source gets
+ * connected to the IrDA block.
+ *
+ * On my HP OB-800 the BIOS sets external 40MHz clock as source
+ * when IrDA enabled and I've never detected any PLL lock success.
+ * Apparently the 14.3...MHz OSC input required for the PLL to work
+ * is not connected and the 40MHz EXTCLK is provided externally.
+ * At least this is what makes the driver working for me.
+ */
+
+enum vlsi_pci_clkctl {
+
+ /* PLL control */
+
+ CLKCTL_PD_INV = 0x04, /* PD#: inverted power down signal,
+ * i.e. PLL is powered, if PD_INV set */
+ CLKCTL_LOCK = 0x40, /* (ro) set, if PLL is locked */
+
+ /* clock source selection */
+
+ CLKCTL_EXTCLK = 0x20, /* set to select external clock input, not PLL */
+ CLKCTL_XCKSEL = 0x10, /* set to indicate EXTCLK is 40MHz, not 48MHz */
+
+ /* IrDA block control */
+
+ CLKCTL_CLKSTP = 0x80, /* set to disconnect from selected clock source */
+ CLKCTL_WAKE = 0x08 /* set to enable wakeup feature: whenever IR activity
+ * is detected, PD_INV gets set(?) and CLKSTP cleared */
+};
+
+/* ------------------------------------------ */
+
+/* VLSI_PCI_MSTRPAGE: Master Page Register (u8, rw) and busmastering stuff */
+
+#define DMA_MASK_USED_BY_HW 0xffffffff
+#define DMA_MASK_MSTRPAGE 0x00ffffff
+#define MSTRPAGE_VALUE (DMA_MASK_MSTRPAGE >> 24)
+
+ /* PCI busmastering is somewhat special for this guy - in short:
+ *
+ * We select to operate using fixed MSTRPAGE=0, use ISA DMA
+ * address restrictions to make the PCI BM api aware of this,
+ * but ensure the hardware is dealing with real 32bit access.
+ *
+ * In detail:
+ * The chip executes normal 32bit busmaster cycles, i.e.
+ * drives all 32 address lines. These addresses however are
+ * composed of [0:23] taken from various busaddr-pointers
+ * and [24:31] taken from the MSTRPAGE register in the VLSI82C147
+ * config space. Therefore _all_ busmastering must be
+ * targeted to/from one single 16MB (busaddr-) superpage!
+ * The point is to make sure all the allocations for memory
+ * locations with busmaster access (ring descriptors, buffers)
+ * are indeed bus-mappable to the same 16MB range (for x86 this
+ * means they must reside in the same 16MB physical memory address
+ * range). The only constraint we have which supports "several objects
+ * mappable to common 16MB range" paradigma, is the old ISA DMA
+ * restriction to the first 16MB of physical address range.
+ * Hence the approach here is to enable PCI busmaster support using
+ * the correct 32bit dma-mask used by the chip. Afterwards the device's
+ * dma-mask gets restricted to 24bit, which must be honoured somehow by
+ * all allocations for memory areas to be exposed to the chip ...
+ *
+ * Note:
+ * Don't be surprised to get "Setting latency timer..." messages every
+ * time when PCI busmastering is enabled for the chip.
+ * The chip has its PCI latency timer RO fixed at 0 - which is not a
+ * problem here, because it is never requesting _burst_ transactions.
+ */
+
+/* ------------------------------------------ */
+
+/* VLSI_PCIIRMISC: IR Miscellaneous Register (u8, rw) */
+
+/* legacy UART emulation - not used by this driver - would require:
+ * (see below for some register-value definitions)
+ *
+ * - IRMISC_UARTEN must be set to enable UART address decoding
+ * - IRMISC_UARTSEL configured
+ * - IRCFG_MASTER must be cleared
+ * - IRCFG_SIR must be set
+ * - IRENABLE_PHYANDCLOCK must be asserted 0->1 (and hence IRENABLE_SIR_ON)
+ */
+
+enum vlsi_pci_irmisc {
+
+ /* IR transceiver control */
+
+ IRMISC_IRRAIL = 0x40, /* (ro?) IR rail power indication (and control?)
+ * 0=3.3V / 1=5V. Probably set during power-on?
+ * unclear - not touched by driver */
+ IRMISC_IRPD = 0x08, /* transceiver power down, if set */
+
+ /* legacy UART control */
+
+ IRMISC_UARTTST = 0x80, /* UART test mode - "always write 0" */
+ IRMISC_UARTEN = 0x04, /* enable UART address decoding */
+
+ /* bits [1:0] IRMISC_UARTSEL to select legacy UART address */
+
+ IRMISC_UARTSEL_3f8 = 0x00,
+ IRMISC_UARTSEL_2f8 = 0x01,
+ IRMISC_UARTSEL_3e8 = 0x02,
+ IRMISC_UARTSEL_2e8 = 0x03
+};
+
+/* ================================================================ */
+
+/* registers mapped to 32 byte PCI IO space */
+
+/* note: better access all registers at the indicated u8/u16 size
+ * although some of them contain only 1 byte of information.
+ * some of them (particaluarly PROMPT and IRCFG) ignore
+ * access when using the wrong addressing mode!
+ */
+
+enum vlsi_pio_regs {
+ VLSI_PIO_IRINTR = 0x00, /* interrupt enable/request (u8, rw) */
+ VLSI_PIO_RINGPTR = 0x02, /* rx/tx ring pointer (u16, ro) */
+ VLSI_PIO_RINGBASE = 0x04, /* [23:10] of ring address (u16, rw) */
+ VLSI_PIO_RINGSIZE = 0x06, /* rx/tx ring size (u16, rw) */
+ VLSI_PIO_PROMPT = 0x08, /* triggers ring processing (u16, wo) */
+ /* 0x0a-0x0f: reserved / duplicated UART regs */
+ VLSI_PIO_IRCFG = 0x10, /* configuration select (u16, rw) */
+ VLSI_PIO_SIRFLAG = 0x12, /* BOF/EOF for filtered SIR (u16, ro) */
+ VLSI_PIO_IRENABLE = 0x14, /* enable and status register (u16, rw/ro) */
+ VLSI_PIO_PHYCTL = 0x16, /* physical layer current status (u16, ro) */
+ VLSI_PIO_NPHYCTL = 0x18, /* next physical layer select (u16, rw) */
+ VLSI_PIO_MAXPKT = 0x1a, /* [11:0] max len for packet receive (u16, rw) */
+ VLSI_PIO_RCVBCNT = 0x1c /* current receive-FIFO byte count (u16, ro) */
+ /* 0x1e-0x1f: reserved / duplicated UART regs */
+};
+
+/* ------------------------------------------ */
+
+/* VLSI_PIO_IRINTR: Interrupt Register (u8, rw) */
+
+/* enable-bits:
+ * 1 = enable / 0 = disable
+ * interrupt condition bits:
+ * set according to corresponding interrupt source
+ * (regardless of the state of the enable bits)
+ * enable bit status indicates whether interrupt gets raised
+ * write-to-clear
+ * note: RPKTINT and TPKTINT behave different in legacy UART mode (which we don't use :-)
+ */
+
+enum vlsi_pio_irintr {
+ IRINTR_ACTEN = 0x80, /* activity interrupt enable */
+ IRINTR_ACTIVITY = 0x40, /* activity monitor (traffic detected) */
+ IRINTR_RPKTEN = 0x20, /* receive packet interrupt enable*/
+ IRINTR_RPKTINT = 0x10, /* rx-packet transferred from fifo to memory finished */
+ IRINTR_TPKTEN = 0x08, /* transmit packet interrupt enable */
+ IRINTR_TPKTINT = 0x04, /* last bit of tx-packet+crc shifted to ir-pulser */
+ IRINTR_OE_EN = 0x02, /* UART rx fifo overrun error interrupt enable */
+ IRINTR_OE_INT = 0x01 /* UART rx fifo overrun error (read LSR to clear) */
+};
+
+/* we use this mask to check whether the (shared PCI) interrupt is ours */
+
+#define IRINTR_INT_MASK (IRINTR_ACTIVITY|IRINTR_RPKTINT|IRINTR_TPKTINT)
+
+/* ------------------------------------------ */
+
+/* VLSI_PIO_RINGPTR: Ring Pointer Read-Back Register (u16, ro) */
+
+/* _both_ ring pointers are indices relative to the _entire_ rx,tx-ring!
+ * i.e. the referenced descriptor is located
+ * at RINGBASE + PTR * sizeof(descr) for rx and tx
+ * therefore, the tx-pointer has offset MAX_RING_DESCR
+ */
+
+#define MAX_RING_DESCR 64 /* tx, rx rings may contain up to 64 descr each */
+
+#define RINGPTR_RX_MASK (MAX_RING_DESCR-1)
+#define RINGPTR_TX_MASK ((MAX_RING_DESCR-1)<<8)
+
+#define RINGPTR_GET_RX(p) ((p)&RINGPTR_RX_MASK)
+#define RINGPTR_GET_TX(p) (((p)&RINGPTR_TX_MASK)>>8)
+
+/* ------------------------------------------ */
+
+/* VLSI_PIO_RINGBASE: Ring Pointer Base Address Register (u16, ro) */
+
+/* Contains [23:10] part of the ring base (bus-) address
+ * which must be 1k-alinged. [31:24] is taken from
+ * VLSI_PCI_MSTRPAGE above.
+ * The controller initiates non-burst PCI BM cycles to
+ * fetch and update the descriptors in the ring.
+ * Once fetched, the descriptor remains cached onchip
+ * until it gets closed and updated due to the ring
+ * processing state machine.
+ * The entire ring area is split in rx and tx areas with each
+ * area consisting of 64 descriptors of 8 bytes each.
+ * The rx(tx) ring is located at ringbase+0 (ringbase+64*8).
+ */
+
+#define BUS_TO_RINGBASE(p) (((p)>>10)&0x3fff)
+
+/* ------------------------------------------ */
+
+/* VLSI_PIO_RINGSIZE: Ring Size Register (u16, rw) */
+
+/* bit mask to indicate the ring size to be used for rx and tx.
+ * possible values encoded bits
+ * 4 0000
+ * 8 0001
+ * 16 0011
+ * 32 0111
+ * 64 1111
+ * located at [15:12] for tx and [11:8] for rx ([7:0] unused)
+ *
+ * note: probably a good idea to have IRCFG_MSTR cleared when writing
+ * this so the state machines are stopped and the RINGPTR is reset!
+ */
+
+#define SIZE_TO_BITS(num) ((((num)-1)>>2)&0x0f)
+#define TX_RX_TO_RINGSIZE(tx,rx) ((SIZE_TO_BITS(tx)<<12)|(SIZE_TO_BITS(rx)<<8))
+#define RINGSIZE_TO_RXSIZE(rs) ((((rs)&0x0f00)>>6)+4)
+#define RINGSIZE_TO_TXSIZE(rs) ((((rs)&0xf000)>>10)+4)
+
+
+/* ------------------------------------------ */
+
+/* VLSI_PIO_PROMPT: Ring Prompting Register (u16, write-to-start) */
+
+/* writing any value kicks the ring processing state machines
+ * for both tx, rx rings as follows:
+ * - active rings (currently owning an active descriptor)
+ * ignore the prompt and continue
+ * - idle rings fetch the next descr from the ring and start
+ * their processing
+ */
+
+/* ------------------------------------------ */
+
+/* VLSI_PIO_IRCFG: IR Config Register (u16, rw) */
+
+/* notes:
+ * - not more than one SIR/MIR/FIR bit must be set at any time
+ * - SIR, MIR, FIR and CRC16 select the configuration which will
+ * be applied on next 0->1 transition of IRENABLE_PHYANDCLOCK (see below).
+ * - besides allowing the PCI interface to execute busmaster cycles
+ * and therefore the ring SM to operate, the MSTR bit has side-effects:
+ * when MSTR is cleared, the RINGPTR's get reset and the legacy UART mode
+ * (in contrast to busmaster access mode) gets enabled.
+ * - clearing ENRX or setting ENTX while data is received may stall the
+ * receive fifo until ENRX reenabled _and_ another packet arrives
+ * - SIRFILT means the chip performs the required unwrapping of hardware
+ * headers (XBOF's, BOF/EOF) and un-escaping in the _receive_ direction.
+ * Only the resulting IrLAP payload is copied to the receive buffers -
+ * but with the 16bit FCS still encluded. Question remains, whether it
+ * was already checked or we should do it before passing the packet to IrLAP?
+ */
+
+enum vlsi_pio_ircfg {
+ IRCFG_LOOP = 0x4000, /* enable loopback test mode */
+ IRCFG_ENTX = 0x1000, /* transmit enable */
+ IRCFG_ENRX = 0x0800, /* receive enable */
+ IRCFG_MSTR = 0x0400, /* master enable */
+ IRCFG_RXANY = 0x0200, /* receive any packet */
+ IRCFG_CRC16 = 0x0080, /* 16bit (not 32bit) CRC select for MIR/FIR */
+ IRCFG_FIR = 0x0040, /* FIR 4PPM encoding mode enable */
+ IRCFG_MIR = 0x0020, /* MIR HDLC encoding mode enable */
+ IRCFG_SIR = 0x0010, /* SIR encoding mode enable */
+ IRCFG_SIRFILT = 0x0008, /* enable SIR decode filter (receiver unwrapping) */
+ IRCFG_SIRTEST = 0x0004, /* allow SIR decode filter when not in SIR mode */
+ IRCFG_TXPOL = 0x0002, /* invert tx polarity when set */
+ IRCFG_RXPOL = 0x0001 /* invert rx polarity when set */
+};
+
+/* ------------------------------------------ */
+
+/* VLSI_PIO_SIRFLAG: SIR Flag Register (u16, ro) */
+
+/* register contains hardcoded BOF=0xc0 at [7:0] and EOF=0xc1 at [15:8]
+ * which is used for unwrapping received frames in SIR decode-filter mode
+ */
+
+/* ------------------------------------------ */
+
+/* VLSI_PIO_IRENABLE: IR Enable Register (u16, rw/ro) */
+
+/* notes:
+ * - IREN acts as gate for latching the configured IR mode information
+ * from IRCFG and IRPHYCTL when IREN=reset and applying them when
+ * IREN gets set afterwards.
+ * - ENTXST reflects IRCFG_ENTX
+ * - ENRXST = IRCFG_ENRX && (!IRCFG_ENTX || IRCFG_LOOP)
+ */
+
+enum vlsi_pio_irenable {
+ IRENABLE_PHYANDCLOCK = 0x8000, /* enable IR phy and gate the mode config (rw) */
+ IRENABLE_CFGER = 0x4000, /* mode configuration error (ro) */
+ IRENABLE_FIR_ON = 0x2000, /* FIR on status (ro) */
+ IRENABLE_MIR_ON = 0x1000, /* MIR on status (ro) */
+ IRENABLE_SIR_ON = 0x0800, /* SIR on status (ro) */
+ IRENABLE_ENTXST = 0x0400, /* transmit enable status (ro) */
+ IRENABLE_ENRXST = 0x0200, /* Receive enable status (ro) */
+ IRENABLE_CRC16_ON = 0x0100 /* 16bit (not 32bit) CRC enabled status (ro) */
+};
+
+#define IRENABLE_MASK 0xff00 /* Read mask */
+
+/* ------------------------------------------ */
+
+/* VLSI_PIO_PHYCTL: IR Physical Layer Current Control Register (u16, ro) */
+
+/* read-back of the currently applied physical layer status.
+ * applied from VLSI_PIO_NPHYCTL at rising edge of IRENABLE_PHYANDCLOCK
+ * contents identical to VLSI_PIO_NPHYCTL (see below)
+ */
+
+/* ------------------------------------------ */
+
+/* VLSI_PIO_NPHYCTL: IR Physical Layer Next Control Register (u16, rw) */
+
+/* latched during IRENABLE_PHYANDCLOCK=0 and applied at 0-1 transition
+ *
+ * consists of BAUD[15:10], PLSWID[9:5] and PREAMB[4:0] bits defined as follows:
+ *
+ * SIR-mode: BAUD = (115.2kHz / baudrate) - 1
+ * PLSWID = (pulsetime * freq / (BAUD+1)) - 1
+ * where pulsetime is the requested IrPHY pulse width
+ * and freq is 8(16)MHz for 40(48)MHz primary input clock
+ * PREAMB: don't care for SIR
+ *
+ * The nominal SIR pulse width is 3/16 bit time so we have PLSWID=12
+ * fixed for all SIR speeds at 40MHz input clock (PLSWID=24 at 48MHz).
+ * IrPHY also allows shorter pulses down to the nominal pulse duration
+ * at 115.2kbaud (minus some tolerance) which is 1.41 usec.
+ * Using the expression PLSWID = 12/(BAUD+1)-1 (multiplied by two for 48MHz)
+ * we get the minimum acceptable PLSWID values according to the VLSI
+ * specification, which provides 1.5 usec pulse width for all speeds (except
+ * for 2.4kbaud getting 6usec). This is fine with IrPHY v1.3 specs and
+ * reduces the transceiver power which drains the battery. At 9.6kbaud for
+ * example this amounts to more than 90% battery power saving!
+ *
+ * MIR-mode: BAUD = 0
+ * PLSWID = 9(10) for 40(48) MHz input clock
+ * to get nominal MIR pulse width
+ * PREAMB = 1
+ *
+ * FIR-mode: BAUD = 0
+ * PLSWID: don't care
+ * PREAMB = 15
+ */
+
+#define PHYCTL_BAUD_SHIFT 10
+#define PHYCTL_BAUD_MASK 0xfc00
+#define PHYCTL_PLSWID_SHIFT 5
+#define PHYCTL_PLSWID_MASK 0x03e0
+#define PHYCTL_PREAMB_SHIFT 0
+#define PHYCTL_PREAMB_MASK 0x001f
+
+#define PHYCTL_TO_BAUD(bwp) (((bwp)&PHYCTL_BAUD_MASK)>>PHYCTL_BAUD_SHIFT)
+#define PHYCTL_TO_PLSWID(bwp) (((bwp)&PHYCTL_PLSWID_MASK)>>PHYCTL_PLSWID_SHIFT)
+#define PHYCTL_TO_PREAMB(bwp) (((bwp)&PHYCTL_PREAMB_MASK)>>PHYCTL_PREAMB_SHIFT)
+
+#define BWP_TO_PHYCTL(b,w,p) ((((b)<<PHYCTL_BAUD_SHIFT)&PHYCTL_BAUD_MASK) \
+ | (((w)<<PHYCTL_PLSWID_SHIFT)&PHYCTL_PLSWID_MASK) \
+ | (((p)<<PHYCTL_PREAMB_SHIFT)&PHYCTL_PREAMB_MASK))
+
+#define BAUD_BITS(br) ((115200/(br))-1)
+
+static inline unsigned
+calc_width_bits(unsigned baudrate, unsigned widthselect, unsigned clockselect)
+{
+ unsigned tmp;
+
+ if (widthselect) /* nominal 3/16 puls width */
+ return (clockselect) ? 12 : 24;
+
+ tmp = ((clockselect) ? 12 : 24) / (BAUD_BITS(baudrate)+1);
+
+ /* intermediate result of integer division needed here */
+
+ return (tmp>0) ? (tmp-1) : 0;
+}
+
+#define PHYCTL_SIR(br,ws,cs) BWP_TO_PHYCTL(BAUD_BITS(br),calc_width_bits((br),(ws),(cs)),0)
+#define PHYCTL_MIR(cs) BWP_TO_PHYCTL(0,((cs)?9:10),1)
+#define PHYCTL_FIR BWP_TO_PHYCTL(0,0,15)
+
+/* quite ugly, I know. But implementing these calculations here avoids
+ * having magic numbers in the code and allows some playing with pulsewidths
+ * without risk to violate the standards.
+ * FWIW, here is the table for reference:
+ *
+ * baudrate BAUD min-PLSWID nom-PLSWID PREAMB
+ * 2400 47 0(0) 12(24) 0
+ * 9600 11 0(0) 12(24) 0
+ * 19200 5 1(2) 12(24) 0
+ * 38400 2 3(6) 12(24) 0
+ * 57600 1 5(10) 12(24) 0
+ * 115200 0 11(22) 12(24) 0
+ * MIR 0 - 9(10) 1
+ * FIR 0 - 0 15
+ *
+ * note: x(y) means x-value for 40MHz / y-value for 48MHz primary input clock
+ */
+
+/* ------------------------------------------ */
+
+
+/* VLSI_PIO_MAXPKT: Maximum Packet Length register (u16, rw) */
+
+/* maximum acceptable length for received packets */
+
+/* hw imposed limitation - register uses only [11:0] */
+#define MAX_PACKET_LENGTH 0x0fff
+
+/* IrLAP I-field (apparently not defined elsewhere) */
+#define IRDA_MTU 2048
+
+/* complete packet consists of A(1)+C(1)+I(<=IRDA_MTU) */
+#define IRLAP_SKB_ALLOCSIZE (1+1+IRDA_MTU)
+
+/* the buffers we use to exchange frames with the hardware need to be
+ * larger than IRLAP_SKB_ALLOCSIZE because we may have up to 4 bytes FCS
+ * appended and, in SIR mode, a lot of frame wrapping bytes. The worst
+ * case appears to be a SIR packet with I-size==IRDA_MTU and all bytes
+ * requiring to be escaped to provide transparency. Furthermore, the peer
+ * might ask for quite a number of additional XBOFs:
+ * up to 115+48 XBOFS 163
+ * regular BOF 1
+ * A-field 1
+ * C-field 1
+ * I-field, IRDA_MTU, all escaped 4096
+ * FCS (16 bit at SIR, escaped) 4
+ * EOF 1
+ * AFAICS nothing in IrLAP guarantees A/C field not to need escaping
+ * (f.e. 0xc0/0xc1 - i.e. BOF/EOF - are legal values there) so in the
+ * worst case we have 4269 bytes total frame size.
+ * However, the VLSI uses 12 bits only for all buffer length values,
+ * which limits the maximum useable buffer size <= 4095.
+ * Note this is not a limitation in the receive case because we use
+ * the SIR filtering mode where the hw unwraps the frame and only the
+ * bare packet+fcs is stored into the buffer - in contrast to the SIR
+ * tx case where we have to pass frame-wrapped packets to the hw.
+ * If this would ever become an issue in real life, the only workaround
+ * I see would be using the legacy UART emulation in SIR mode.
+ */
+
+#define XFER_BUF_SIZE MAX_PACKET_LENGTH
+
+/* ------------------------------------------ */
+
+/* VLSI_PIO_RCVBCNT: Receive Byte Count Register (u16, ro) */
+
+/* receive packet counter gets incremented on every non-filtered
+ * byte which was put in the receive fifo and reset for each
+ * new packet. Used to decide whether we are just in the middle
+ * of receiving
+ */
+
+/* better apply the [11:0] mask when reading, as some docs say the
+ * reserved [15:12] would return 1 when reading - which is wrong AFAICS
+ */
+#define RCVBCNT_MASK 0x0fff
+
+/******************************************************************/
+
+/* descriptors for rx/tx ring
+ *
+ * accessed by hardware - don't change!
+ *
+ * the descriptor is owned by hardware, when the ACTIVE status bit
+ * is set and nothing (besides reading status to test the bit)
+ * shall be done. The bit gets cleared by hw, when the descriptor
+ * gets closed. Premature reaping of descriptors owned be the chip
+ * can be achieved by disabling IRCFG_MSTR
+ *
+ * Attention: Writing addr overwrites status!
+ *
+ * ### FIXME: depends on endianess (but there ain't no non-i586 ob800 ;-)
+ */
+
+struct ring_descr_hw {
+ volatile __le16 rd_count; /* tx/rx count [11:0] */
+ __le16 reserved;
+ union {
+ __le32 addr; /* [23:0] of the buffer's busaddress */
+ struct {
+ u8 addr_res[3];
+ volatile u8 status; /* descriptor status */
+ } __packed rd_s;
+ } __packed rd_u;
+} __packed;
+
+#define rd_addr rd_u.addr
+#define rd_status rd_u.rd_s.status
+
+/* ring descriptor status bits */
+
+#define RD_ACTIVE 0x80 /* descriptor owned by hw (both TX,RX) */
+
+/* TX ring descriptor status */
+
+#define RD_TX_DISCRC 0x40 /* do not send CRC (for SIR) */
+#define RD_TX_BADCRC 0x20 /* force a bad CRC */
+#define RD_TX_PULSE 0x10 /* send indication pulse after this frame (MIR/FIR) */
+#define RD_TX_FRCEUND 0x08 /* force underrun */
+#define RD_TX_CLRENTX 0x04 /* clear ENTX after this frame */
+#define RD_TX_UNDRN 0x01 /* TX fifo underrun (probably PCI problem) */
+
+/* RX ring descriptor status */
+
+#define RD_RX_PHYERR 0x40 /* physical encoding error */
+#define RD_RX_CRCERR 0x20 /* CRC error (MIR/FIR) */
+#define RD_RX_LENGTH 0x10 /* frame exceeds buffer length */
+#define RD_RX_OVER 0x08 /* RX fifo overrun (probably PCI problem) */
+#define RD_RX_SIRBAD 0x04 /* EOF missing: BOF follows BOF (SIR, filtered) */
+
+#define RD_RX_ERROR 0x7c /* any error in received frame */
+
+/* the memory required to hold the 2 descriptor rings */
+#define HW_RING_AREA_SIZE (2 * MAX_RING_DESCR * sizeof(struct ring_descr_hw))
+
+/******************************************************************/
+
+/* sw-ring descriptors consists of a bus-mapped transfer buffer with
+ * associated skb and a pointer to the hw entry descriptor
+ */
+
+struct ring_descr {
+ struct ring_descr_hw *hw;
+ struct sk_buff *skb;
+ void *buf;
+};
+
+/* wrappers for operations on hw-exposed ring descriptors
+ * access to the hw-part of the descriptors must use these.
+ */
+
+static inline int rd_is_active(struct ring_descr *rd)
+{
+ return (rd->hw->rd_status & RD_ACTIVE) != 0;
+}
+
+static inline void rd_activate(struct ring_descr *rd)
+{
+ rd->hw->rd_status |= RD_ACTIVE;
+}
+
+static inline void rd_set_status(struct ring_descr *rd, u8 s)
+{
+ rd->hw->rd_status = s; /* may pass ownership to the hardware */
+}
+
+static inline void rd_set_addr_status(struct ring_descr *rd, dma_addr_t a, u8 s)
+{
+ /* order is important for two reasons:
+ * - overlayed: writing addr overwrites status
+ * - we want to write status last so we have valid address in
+ * case status has RD_ACTIVE set
+ */
+
+ if ((a & ~DMA_MASK_MSTRPAGE)>>24 != MSTRPAGE_VALUE) {
+ net_err_ratelimited("%s: pci busaddr inconsistency!\n",
+ __func__);
+ dump_stack();
+ return;
+ }
+
+ a &= DMA_MASK_MSTRPAGE; /* clear highbyte to make sure we won't write
+ * to status - just in case MSTRPAGE_VALUE!=0
+ */
+ rd->hw->rd_addr = cpu_to_le32(a);
+ wmb();
+ rd_set_status(rd, s); /* may pass ownership to the hardware */
+}
+
+static inline void rd_set_count(struct ring_descr *rd, u16 c)
+{
+ rd->hw->rd_count = cpu_to_le16(c);
+}
+
+static inline u8 rd_get_status(struct ring_descr *rd)
+{
+ return rd->hw->rd_status;
+}
+
+static inline dma_addr_t rd_get_addr(struct ring_descr *rd)
+{
+ dma_addr_t a;
+
+ a = le32_to_cpu(rd->hw->rd_addr);
+ return (a & DMA_MASK_MSTRPAGE) | (MSTRPAGE_VALUE << 24);
+}
+
+static inline u16 rd_get_count(struct ring_descr *rd)
+{
+ return le16_to_cpu(rd->hw->rd_count);
+}
+
+/******************************************************************/
+
+/* sw descriptor rings for rx, tx:
+ *
+ * operations follow producer-consumer paradigm, with the hw
+ * in the middle doing the processing.
+ * ring size must be power of two.
+ *
+ * producer advances r->tail after inserting for processing
+ * consumer advances r->head after removing processed rd
+ * ring is empty if head==tail / full if (tail+1)==head
+ */
+
+struct vlsi_ring {
+ struct pci_dev *pdev;
+ int dir;
+ unsigned len;
+ unsigned size;
+ unsigned mask;
+ atomic_t head, tail;
+ struct ring_descr *rd;
+};
+
+/* ring processing helpers */
+
+static inline struct ring_descr *ring_last(struct vlsi_ring *r)
+{
+ int t;
+
+ t = atomic_read(&r->tail) & r->mask;
+ return (((t+1) & r->mask) == (atomic_read(&r->head) & r->mask)) ? NULL : &r->rd[t];
+}
+
+static inline struct ring_descr *ring_put(struct vlsi_ring *r)
+{
+ atomic_inc(&r->tail);
+ return ring_last(r);
+}
+
+static inline struct ring_descr *ring_first(struct vlsi_ring *r)
+{
+ int h;
+
+ h = atomic_read(&r->head) & r->mask;
+ return (h == (atomic_read(&r->tail) & r->mask)) ? NULL : &r->rd[h];
+}
+
+static inline struct ring_descr *ring_get(struct vlsi_ring *r)
+{
+ atomic_inc(&r->head);
+ return ring_first(r);
+}
+
+/******************************************************************/
+
+/* our private compound VLSI-PCI-IRDA device information */
+
+typedef struct vlsi_irda_dev {
+ struct pci_dev *pdev;
+
+ struct irlap_cb *irlap;
+
+ struct qos_info qos;
+
+ unsigned mode;
+ int baud, new_baud;
+
+ dma_addr_t busaddr;
+ void *virtaddr;
+ struct vlsi_ring *tx_ring, *rx_ring;
+
+ ktime_t last_rx;
+
+ spinlock_t lock;
+ struct mutex mtx;
+
+ u8 resume_ok;
+ struct proc_dir_entry *proc_entry;
+
+} vlsi_irda_dev_t;
+
+/********************************************************/
+
+/* the remapped error flags we use for returning from frame
+ * post-processing in vlsi_process_tx/rx() after it was completed
+ * by the hardware. These functions either return the >=0 number
+ * of transferred bytes in case of success or the negative (-)
+ * of the or'ed error flags.
+ */
+
+#define VLSI_TX_DROP 0x0001
+#define VLSI_TX_FIFO 0x0002
+
+#define VLSI_RX_DROP 0x0100
+#define VLSI_RX_OVER 0x0200
+#define VLSI_RX_LENGTH 0x0400
+#define VLSI_RX_FRAME 0x0800
+#define VLSI_RX_CRC 0x1000
+
+/********************************************************/
+
+#endif /* IRDA_VLSI_FIR_H */
+