diff options
author | br <br@FreeBSD.org> | 2014-02-27 09:59:15 +0000 |
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committer | br <br@FreeBSD.org> | 2014-02-27 09:59:15 +0000 |
commit | ffacc2e731141a2db73600987f49c73d6ab5e3fa (patch) | |
tree | af9600a3fb736f231e7ee5e67e422897d55a69a1 /sys/arm/freescale/vybrid | |
parent | d56f1a0d6d3b0c1fb6b15ba10ae2ed83877e6347 (diff) | |
download | FreeBSD-src-ffacc2e731141a2db73600987f49c73d6ab5e3fa.zip FreeBSD-src-ffacc2e731141a2db73600987f49c73d6ab5e3fa.tar.gz |
Add driver for Inter-Integrated Circuit (I2C).
Diffstat (limited to 'sys/arm/freescale/vybrid')
-rw-r--r-- | sys/arm/freescale/vybrid/files.vybrid | 1 | ||||
-rw-r--r-- | sys/arm/freescale/vybrid/vf_i2c.c | 498 |
2 files changed, 499 insertions, 0 deletions
diff --git a/sys/arm/freescale/vybrid/files.vybrid b/sys/arm/freescale/vybrid/files.vybrid index 890e23e..1103f13 100644 --- a/sys/arm/freescale/vybrid/files.vybrid +++ b/sys/arm/freescale/vybrid/files.vybrid @@ -23,6 +23,7 @@ arm/freescale/vybrid/vf_mscm.c standard arm/freescale/vybrid/vf_src.c standard arm/freescale/vybrid/vf_edma.c standard arm/freescale/vybrid/vf_dmamux.c standard +arm/freescale/vybrid/vf_i2c.c optional iicbus arm/freescale/vybrid/vf_tcon.c optional vt arm/freescale/vybrid/vf_dcu4.c optional vt arm/freescale/vybrid/vf_nfc.c optional nand diff --git a/sys/arm/freescale/vybrid/vf_i2c.c b/sys/arm/freescale/vybrid/vf_i2c.c new file mode 100644 index 0000000..96219b1 --- /dev/null +++ b/sys/arm/freescale/vybrid/vf_i2c.c @@ -0,0 +1,498 @@ +/*- + * Copyright (c) 2014 Ruslan Bukin <br@bsdpad.com> + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +/* + * Vybrid Family Inter-Integrated Circuit (I2C) + * Chapter 48, Vybrid Reference Manual, Rev. 5, 07/2013 + */ + +/* + * This driver is based on the I2C driver for IMX (imx/i2c.c). + */ + +#include <sys/cdefs.h> +__FBSDID("$FreeBSD$"); + +#include <sys/param.h> +#include <sys/systm.h> +#include <sys/bus.h> +#include <sys/kernel.h> +#include <sys/module.h> +#include <sys/malloc.h> +#include <sys/rman.h> +#include <sys/timeet.h> +#include <sys/timetc.h> + +#include <dev/iicbus/iiconf.h> +#include <dev/iicbus/iicbus.h> + +#include "iicbus_if.h" + +#include <dev/fdt/fdt_common.h> +#include <dev/ofw/openfirm.h> +#include <dev/ofw/ofw_bus.h> +#include <dev/ofw/ofw_bus_subr.h> + +#include <machine/bus.h> +#include <machine/fdt.h> +#include <machine/cpu.h> +#include <machine/intr.h> + +#include <arm/freescale/vybrid/vf_common.h> + +#define I2C_IBAD 0x0 /* I2C Bus Address Register */ +#define I2C_IBFD 0x1 /* I2C Bus Frequency Divider Register */ +#define I2C_IBCR 0x2 /* I2C Bus Control Register */ +#define IBCR_MDIS (1 << 7) /* Module disable. */ +#define IBCR_IBIE (1 << 6) /* I-Bus Interrupt Enable. */ +#define IBCR_MSSL (1 << 5) /* Master/Slave mode select. */ +#define IBCR_TXRX (1 << 4) /* Transmit/Receive mode select. */ +#define IBCR_NOACK (1 << 3) /* Data Acknowledge disable. */ +#define IBCR_RSTA (1 << 2) /* Repeat Start. */ +#define IBCR_DMAEN (1 << 1) /* DMA Enable. */ +#define I2C_IBSR 0x3 /* I2C Bus Status Register */ +#define IBSR_TCF (1 << 7) /* Transfer complete. */ +#define IBSR_IAAS (1 << 6) /* Addressed as a slave. */ +#define IBSR_IBB (1 << 5) /* Bus busy. */ +#define IBSR_IBAL (1 << 4) /* Arbitration Lost. */ +#define IBSR_SRW (1 << 2) /* Slave Read/Write. */ +#define IBSR_IBIF (1 << 1) /* I-Bus Interrupt Flag. */ +#define IBSR_RXAK (1 << 0) /* Received Acknowledge. */ +#define I2C_IBDR 0x4 /* I2C Bus Data I/O Register */ +#define I2C_IBIC 0x5 /* I2C Bus Interrupt Config Register */ +#define IBIC_BIIE (1 << 7) /* Bus Idle Interrupt Enable bit. */ +#define I2C_IBDBG 0x6 /* I2C Bus Debug Register */ + +#ifdef DEBUG +#define vf_i2c_dbg(_sc, fmt, args...) \ + device_printf((_sc)->dev, fmt, ##args) +#else +#define vf_i2c_dbg(_sc, fmt, args...) +#endif + +static int i2c_repeated_start(device_t, u_char, int); +static int i2c_start(device_t, u_char, int); +static int i2c_stop(device_t); +static int i2c_reset(device_t, u_char, u_char, u_char *); +static int i2c_read(device_t, char *, int, int *, int, int); +static int i2c_write(device_t, const char *, int, int *, int); + +struct i2c_softc { + struct resource *res[2]; + bus_space_tag_t bst; + bus_space_handle_t bsh; + void *ih; + device_t dev; + device_t iicbus; + struct mtx mutex; + int ibif; +}; + +static struct resource_spec i2c_spec[] = { + { SYS_RES_MEMORY, 0, RF_ACTIVE }, + { SYS_RES_IRQ, 0, RF_ACTIVE }, + { -1, 0 } +}; + +static void +i2c_intr(void *arg) +{ + struct i2c_softc *sc; + + sc = arg; + + if (READ1(sc, I2C_IBSR) & IBSR_IBIF) { + WRITE1(sc, I2C_IBSR, IBSR_IBIF); + sc->ibif = 1; + } +} + +static int +i2c_probe(device_t dev) +{ + + if (!ofw_bus_status_okay(dev)) + return (ENXIO); + + if (!ofw_bus_is_compatible(dev, "fsl,mvf600-i2c")) + return (ENXIO); + + device_set_desc(dev, "Vybrid Family Inter-Integrated Circuit (I2C)"); + return (BUS_PROBE_DEFAULT); +} + +static int +i2c_attach(device_t dev) +{ + struct i2c_softc *sc; + int err; + + sc = device_get_softc(dev); + sc->dev = dev; + + mtx_init(&sc->mutex, device_get_nameunit(dev), "I2C", MTX_DEF); + + if (bus_alloc_resources(dev, i2c_spec, sc->res)) { + device_printf(dev, "could not allocate resources\n"); + return (ENXIO); + } + + /* Memory interface */ + sc->bst = rman_get_bustag(sc->res[0]); + sc->bsh = rman_get_bushandle(sc->res[0]); + + /* Setup interrupt handler */ + err = bus_setup_intr(dev, sc->res[1], INTR_TYPE_BIO | INTR_MPSAFE, + NULL, i2c_intr, sc, &sc->ih); + if (err) { + device_printf(dev, "Unable to alloc interrupt resource.\n"); + return (ENXIO); + } + + WRITE1(sc, I2C_IBIC, IBIC_BIIE); + + sc->iicbus = device_add_child(dev, "iicbus", -1); + if (sc->iicbus == NULL) { + device_printf(dev, "could not add iicbus child"); + mtx_destroy(&sc->mutex); + return (ENXIO); + } + + bus_generic_attach(dev); + + return (0); +} + +/* Wait for transfer interrupt flag */ +static int +wait_for_iif(struct i2c_softc *sc) +{ + int retry; + + retry = 1000; + while (retry --) { + if (sc->ibif == 1) + return (IIC_NOERR); + DELAY(10); + } + + return (IIC_ETIMEOUT); +} + +/* Wait for free bus */ +static int +wait_for_nibb(struct i2c_softc *sc) +{ + int retry; + + retry = 1000; + while (retry --) { + if ((READ1(sc, I2C_IBSR) & IBSR_IBB) == 0) + return (IIC_NOERR); + DELAY(10); + } + + return (IIC_ETIMEOUT); +} + +/* Wait for transfer complete+interrupt flag */ +static int +wait_for_icf(struct i2c_softc *sc) +{ + int retry; + + retry = 1000; + while (retry --) { + if (READ1(sc, I2C_IBSR) & IBSR_TCF) { + if (sc->ibif == 1) + return (IIC_NOERR); + } + DELAY(10); + } + + return (IIC_ETIMEOUT); +} + +static int +i2c_repeated_start(device_t dev, u_char slave, int timeout) +{ + struct i2c_softc *sc; + int error; + int reg; + + sc = device_get_softc(dev); + + vf_i2c_dbg(sc, "i2c repeated start\n"); + + mtx_lock(&sc->mutex); + + WRITE1(sc, I2C_IBAD, slave); + + if ((READ1(sc, I2C_IBSR) & IBSR_IBB) == 0) { + mtx_unlock(&sc->mutex); + return (IIC_EBUSBSY); + } + + /* Set repeated start condition */ + DELAY(10); + + reg = READ1(sc, I2C_IBCR); + reg |= (IBCR_RSTA | IBCR_IBIE); + WRITE1(sc, I2C_IBCR, reg); + + DELAY(10); + + sc->ibif = 0; + + /* Write target address - LSB is R/W bit */ + WRITE1(sc, I2C_IBDR, slave); + + error = wait_for_iif(sc); + + mtx_unlock(&sc->mutex); + + if (error) + return (error); + + return (IIC_NOERR); +} + +static int +i2c_start(device_t dev, u_char slave, int timeout) +{ + struct i2c_softc *sc; + int error; + int reg; + + sc = device_get_softc(dev); + + vf_i2c_dbg(sc, "i2c start\n"); + + mtx_lock(&sc->mutex); + + WRITE1(sc, I2C_IBAD, slave); + + if (READ1(sc, I2C_IBSR) & IBSR_IBB) { + mtx_unlock(&sc->mutex); + vf_i2c_dbg(sc, "cant i2c start: IIC_EBUSBSY\n"); + return (IIC_EBUSBSY); + } + + /* Set start condition */ + reg = (IBCR_MSSL | IBCR_NOACK | IBCR_IBIE); + WRITE1(sc, I2C_IBCR, reg); + + DELAY(100); + + reg |= (IBCR_TXRX); + WRITE1(sc, I2C_IBCR, reg); + + sc->ibif = 0; + + /* Write target address - LSB is R/W bit */ + WRITE1(sc, I2C_IBDR, slave); + + error = wait_for_iif(sc); + + mtx_unlock(&sc->mutex); + if (error) { + vf_i2c_dbg(sc, "cant i2c start: iif error\n"); + return (error); + } + + return (IIC_NOERR); +} + +static int +i2c_stop(device_t dev) +{ + struct i2c_softc *sc; + + sc = device_get_softc(dev); + + vf_i2c_dbg(sc, "i2c stop\n"); + + mtx_lock(&sc->mutex); + + WRITE1(sc, I2C_IBCR, IBCR_NOACK | IBCR_IBIE); + + DELAY(100); + + /* Reset controller if bus still busy after STOP */ + if (wait_for_nibb(sc) == IIC_ETIMEOUT) { + WRITE1(sc, I2C_IBCR, IBCR_MDIS); + DELAY(1000); + WRITE1(sc, I2C_IBCR, IBCR_NOACK); + } + mtx_unlock(&sc->mutex); + + return (IIC_NOERR); +} + +static int +i2c_reset(device_t dev, u_char speed, u_char addr, u_char *oldadr) +{ + struct i2c_softc *sc; + + sc = device_get_softc(dev); + + vf_i2c_dbg(sc, "i2c reset\n"); + + switch (speed) { + case IIC_FAST: + case IIC_SLOW: + case IIC_UNKNOWN: + case IIC_FASTEST: + default: + break; + } + + mtx_lock(&sc->mutex); + WRITE1(sc, I2C_IBCR, IBCR_MDIS); + + DELAY(1000); + + WRITE1(sc, I2C_IBFD, 20); + WRITE1(sc, I2C_IBCR, 0x0); /* Enable i2c */ + + DELAY(1000); + + mtx_unlock(&sc->mutex); + + return (IIC_NOERR); +} + +static int +i2c_read(device_t dev, char *buf, int len, int *read, int last, int delay) +{ + struct i2c_softc *sc; + int error; + + sc = device_get_softc(dev); + + vf_i2c_dbg(sc, "i2c read\n"); + + *read = 0; + + mtx_lock(&sc->mutex); + + if (len) { + if (len == 1) + WRITE1(sc, I2C_IBCR, IBCR_IBIE | IBCR_MSSL | \ + IBCR_NOACK); + else + WRITE1(sc, I2C_IBCR, IBCR_IBIE | IBCR_MSSL); + + /* dummy read */ + sc->ibif = 0; + READ1(sc, I2C_IBDR); + DELAY(1000); + } + + while (*read < len) { + error = wait_for_icf(sc); + if (error) { + mtx_unlock(&sc->mutex); + return (error); + } + + if ((*read == len - 2) && last) { + /* NO ACK on last byte */ + WRITE1(sc, I2C_IBCR, IBCR_IBIE | IBCR_MSSL | \ + IBCR_NOACK); + } + + if ((*read == len - 1) && last) { + /* Transfer done, remove master bit */ + WRITE1(sc, I2C_IBCR, IBCR_IBIE | IBCR_NOACK); + } + + sc->ibif = 0; + *buf++ = READ1(sc, I2C_IBDR); + (*read)++; + } + mtx_unlock(&sc->mutex); + + return (IIC_NOERR); +} + +static int +i2c_write(device_t dev, const char *buf, int len, int *sent, int timeout) +{ + struct i2c_softc *sc; + int error; + + sc = device_get_softc(dev); + + vf_i2c_dbg(sc, "i2c write\n"); + + *sent = 0; + + mtx_lock(&sc->mutex); + while (*sent < len) { + sc->ibif = 0; + + WRITE1(sc, I2C_IBDR, *buf++); + + error = wait_for_iif(sc); + if (error) { + mtx_unlock(&sc->mutex); + return (error); + } + + (*sent)++; + } + mtx_unlock(&sc->mutex); + + return (IIC_NOERR); +} + +static device_method_t i2c_methods[] = { + DEVMETHOD(device_probe, i2c_probe), + DEVMETHOD(device_attach, i2c_attach), + + DEVMETHOD(iicbus_callback, iicbus_null_callback), + DEVMETHOD(iicbus_repeated_start, i2c_repeated_start), + DEVMETHOD(iicbus_start, i2c_start), + DEVMETHOD(iicbus_stop, i2c_stop), + DEVMETHOD(iicbus_reset, i2c_reset), + DEVMETHOD(iicbus_read, i2c_read), + DEVMETHOD(iicbus_write, i2c_write), + DEVMETHOD(iicbus_transfer, iicbus_transfer_gen), + + { 0, 0 } +}; + +static driver_t i2c_driver = { + "i2c", + i2c_methods, + sizeof(struct i2c_softc), +}; + +static devclass_t i2c_devclass; + +DRIVER_MODULE(i2c, simplebus, i2c_driver, i2c_devclass, 0, 0); +DRIVER_MODULE(iicbus, i2c, iicbus_driver, iicbus_devclass, 0, 0); |