bcm2835_gpio: add bcm2835 gpio controller

This adds the BCM2835 GPIO controller.

It currently implements:
- The 54 GPIOs as outputs (qemu_irq)
- The SD controller selection via alternate function of GPIOs 48-53

Signed-off-by: Clement Deschamps <clement.deschamps@antfield.fr>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 1488293711-14195-4-git-send-email-peter.maydell@linaro.org
Message-id: 20170224164021.9066-4-clement.deschamps@antfield.fr
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 353 insertions, 0 deletions

diff --git a/hw/gpio/bcm2835_gpio.c b/hw/gpio/bcm2835_gpio.c
new file mode 100644
index 0000000000..acc2e3cf9e
--- /dev/null
+++ b/hw/gpio/bcm2835_gpio.c
@@ -0,0 +1,353 @@
+/*
+ * Raspberry Pi (BCM2835) GPIO Controller
+ *
+ * Copyright (c) 2017 Antfield SAS
+ *
+ * Authors:
+ *  Clement Deschamps <clement.deschamps@antfield.fr>
+ *  Luc Michel <luc.michel@antfield.fr>
+ *
+ * This work is licensed under the terms of the GNU GPL, version 2 or later.
+ * See the COPYING file in the top-level directory.
+ */
+
+#include "qemu/osdep.h"
+#include "qemu/log.h"
+#include "qemu/timer.h"
+#include "qapi/error.h"
+#include "hw/sysbus.h"
+#include "hw/sd/sd.h"
+#include "hw/gpio/bcm2835_gpio.h"
+
+#define GPFSEL0   0x00
+#define GPFSEL1   0x04
+#define GPFSEL2   0x08
+#define GPFSEL3   0x0C
+#define GPFSEL4   0x10
+#define GPFSEL5   0x14
+#define GPSET0    0x1C
+#define GPSET1    0x20
+#define GPCLR0    0x28
+#define GPCLR1    0x2C
+#define GPLEV0    0x34
+#define GPLEV1    0x38
+#define GPEDS0    0x40
+#define GPEDS1    0x44
+#define GPREN0    0x4C
+#define GPREN1    0x50
+#define GPFEN0    0x58
+#define GPFEN1    0x5C
+#define GPHEN0    0x64
+#define GPHEN1    0x68
+#define GPLEN0    0x70
+#define GPLEN1    0x74
+#define GPAREN0   0x7C
+#define GPAREN1   0x80
+#define GPAFEN0   0x88
+#define GPAFEN1   0x8C
+#define GPPUD     0x94
+#define GPPUDCLK0 0x98
+#define GPPUDCLK1 0x9C
+
+static uint32_t gpfsel_get(BCM2835GpioState *s, uint8_t reg)
+{
+    int i;
+    uint32_t value = 0;
+    for (i = 0; i < 10; i++) {
+        uint32_t index = 10 * reg + i;
+        if (index < sizeof(s->fsel)) {
+            value |= (s->fsel[index] & 0x7) << (3 * i);
+        }
+    }
+    return value;
+}
+
+static void gpfsel_set(BCM2835GpioState *s, uint8_t reg, uint32_t value)
+{
+    int i;
+    for (i = 0; i < 10; i++) {
+        uint32_t index = 10 * reg + i;
+        if (index < sizeof(s->fsel)) {
+            int fsel = (value >> (3 * i)) & 0x7;
+            s->fsel[index] = fsel;
+        }
+    }
+
+    /* SD controller selection (48-53) */
+    if (s->sd_fsel != 0
+            && (s->fsel[48] == 0) /* SD_CLK_R */
+            && (s->fsel[49] == 0) /* SD_CMD_R */
+            && (s->fsel[50] == 0) /* SD_DATA0_R */
+            && (s->fsel[51] == 0) /* SD_DATA1_R */
+            && (s->fsel[52] == 0) /* SD_DATA2_R */
+            && (s->fsel[53] == 0) /* SD_DATA3_R */
+            ) {
+        /* SDHCI controller selected */
+        sdbus_reparent_card(s->sdbus_sdhost, s->sdbus_sdhci);
+        s->sd_fsel = 0;
+    } else if (s->sd_fsel != 4
+            && (s->fsel[48] == 4) /* SD_CLK_R */
+            && (s->fsel[49] == 4) /* SD_CMD_R */
+            && (s->fsel[50] == 4) /* SD_DATA0_R */
+            && (s->fsel[51] == 4) /* SD_DATA1_R */
+            && (s->fsel[52] == 4) /* SD_DATA2_R */
+            && (s->fsel[53] == 4) /* SD_DATA3_R */
+            ) {
+        /* SDHost controller selected */
+        sdbus_reparent_card(s->sdbus_sdhci, s->sdbus_sdhost);
+        s->sd_fsel = 4;
+    }
+}
+
+static int gpfsel_is_out(BCM2835GpioState *s, int index)
+{
+    if (index >= 0 && index < 54) {
+        return s->fsel[index] == 1;
+    }
+    return 0;
+}
+
+static void gpset(BCM2835GpioState *s,
+        uint32_t val, uint8_t start, uint8_t count, uint32_t *lev)
+{
+    uint32_t changes = val & ~*lev;
+    uint32_t cur = 1;
+
+    int i;
+    for (i = 0; i < count; i++) {
+        if ((changes & cur) && (gpfsel_is_out(s, start + i))) {
+            qemu_set_irq(s->out[start + i], 1);
+        }
+        cur <<= 1;
+    }
+
+    *lev |= val;
+}
+
+static void gpclr(BCM2835GpioState *s,
+        uint32_t val, uint8_t start, uint8_t count, uint32_t *lev)
+{
+    uint32_t changes = val & *lev;
+    uint32_t cur = 1;
+
+    int i;
+    for (i = 0; i < count; i++) {
+        if ((changes & cur) && (gpfsel_is_out(s, start + i))) {
+            qemu_set_irq(s->out[start + i], 0);
+        }
+        cur <<= 1;
+    }
+
+    *lev &= ~val;
+}
+
+static uint64_t bcm2835_gpio_read(void *opaque, hwaddr offset,
+        unsigned size)
+{
+    BCM2835GpioState *s = (BCM2835GpioState *)opaque;
+
+    switch (offset) {
+    case GPFSEL0:
+    case GPFSEL1:
+    case GPFSEL2:
+    case GPFSEL3:
+    case GPFSEL4:
+    case GPFSEL5:
+        return gpfsel_get(s, offset / 4);
+    case GPSET0:
+    case GPSET1:
+        /* Write Only */
+        return 0;
+    case GPCLR0:
+    case GPCLR1:
+        /* Write Only */
+        return 0;
+    case GPLEV0:
+        return s->lev0;
+    case GPLEV1:
+        return s->lev1;
+    case GPEDS0:
+    case GPEDS1:
+    case GPREN0:
+    case GPREN1:
+    case GPFEN0:
+    case GPFEN1:
+    case GPHEN0:
+    case GPHEN1:
+    case GPLEN0:
+    case GPLEN1:
+    case GPAREN0:
+    case GPAREN1:
+    case GPAFEN0:
+    case GPAFEN1:
+    case GPPUD:
+    case GPPUDCLK0:
+    case GPPUDCLK1:
+        /* Not implemented */
+        return 0;
+    default:
+        qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset %"HWADDR_PRIx"\n",
+                __func__, offset);
+        break;
+    }
+
+    return 0;
+}
+
+static void bcm2835_gpio_write(void *opaque, hwaddr offset,
+        uint64_t value, unsigned size)
+{
+    BCM2835GpioState *s = (BCM2835GpioState *)opaque;
+
+    switch (offset) {
+    case GPFSEL0:
+    case GPFSEL1:
+    case GPFSEL2:
+    case GPFSEL3:
+    case GPFSEL4:
+    case GPFSEL5:
+        gpfsel_set(s, offset / 4, value);
+        break;
+    case GPSET0:
+        gpset(s, value, 0, 32, &s->lev0);
+        break;
+    case GPSET1:
+        gpset(s, value, 32, 22, &s->lev1);
+        break;
+    case GPCLR0:
+        gpclr(s, value, 0, 32, &s->lev0);
+        break;
+    case GPCLR1:
+        gpclr(s, value, 32, 22, &s->lev1);
+        break;
+    case GPLEV0:
+    case GPLEV1:
+        /* Read Only */
+        break;
+    case GPEDS0:
+    case GPEDS1:
+    case GPREN0:
+    case GPREN1:
+    case GPFEN0:
+    case GPFEN1:
+    case GPHEN0:
+    case GPHEN1:
+    case GPLEN0:
+    case GPLEN1:
+    case GPAREN0:
+    case GPAREN1:
+    case GPAFEN0:
+    case GPAFEN1:
+    case GPPUD:
+    case GPPUDCLK0:
+    case GPPUDCLK1:
+        /* Not implemented */
+        break;
+    default:
+        goto err_out;
+    }
+    return;
+
+err_out:
+    qemu_log_mask(LOG_GUEST_ERROR, "%s: Bad offset %"HWADDR_PRIx"\n",
+            __func__, offset);
+}
+
+static void bcm2835_gpio_reset(DeviceState *dev)
+{
+    BCM2835GpioState *s = BCM2835_GPIO(dev);
+
+    int i;
+    for (i = 0; i < 6; i++) {
+        gpfsel_set(s, i, 0);
+    }
+
+    s->sd_fsel = 0;
+
+    /* SDHCI is selected by default */
+    sdbus_reparent_card(&s->sdbus, s->sdbus_sdhci);
+
+    s->lev0 = 0;
+    s->lev1 = 0;
+}
+
+static const MemoryRegionOps bcm2835_gpio_ops = {
+    .read = bcm2835_gpio_read,
+    .write = bcm2835_gpio_write,
+    .endianness = DEVICE_NATIVE_ENDIAN,
+};
+
+static const VMStateDescription vmstate_bcm2835_gpio = {
+    .name = "bcm2835_gpio",
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .fields = (VMStateField[]) {
+        VMSTATE_UINT8_ARRAY(fsel, BCM2835GpioState, 54),
+        VMSTATE_UINT32(lev0, BCM2835GpioState),
+        VMSTATE_UINT32(lev1, BCM2835GpioState),
+        VMSTATE_UINT8(sd_fsel, BCM2835GpioState),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+static void bcm2835_gpio_init(Object *obj)
+{
+    BCM2835GpioState *s = BCM2835_GPIO(obj);
+    DeviceState *dev = DEVICE(obj);
+    SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
+
+    qbus_create_inplace(&s->sdbus, sizeof(s->sdbus),
+                        TYPE_SD_BUS, DEVICE(s), "sd-bus");
+
+    memory_region_init_io(&s->iomem, obj,
+            &bcm2835_gpio_ops, s, "bcm2835_gpio", 0x1000);
+    sysbus_init_mmio(sbd, &s->iomem);
+    qdev_init_gpio_out(dev, s->out, 54);
+}
+
+static void bcm2835_gpio_realize(DeviceState *dev, Error **errp)
+{
+    BCM2835GpioState *s = BCM2835_GPIO(dev);
+    Object *obj;
+    Error *err = NULL;
+
+    obj = object_property_get_link(OBJECT(dev), "sdbus-sdhci", &err);
+    if (obj == NULL) {
+        error_setg(errp, "%s: required sdhci link not found: %s",
+                __func__, error_get_pretty(err));
+        return;
+    }
+    s->sdbus_sdhci = SD_BUS(obj);
+
+    obj = object_property_get_link(OBJECT(dev), "sdbus-sdhost", &err);
+    if (obj == NULL) {
+        error_setg(errp, "%s: required sdhost link not found: %s",
+                __func__, error_get_pretty(err));
+        return;
+    }
+    s->sdbus_sdhost = SD_BUS(obj);
+}
+
+static void bcm2835_gpio_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+
+    dc->vmsd = &vmstate_bcm2835_gpio;
+    dc->realize = &bcm2835_gpio_realize;
+    dc->reset = &bcm2835_gpio_reset;
+}
+
+static const TypeInfo bcm2835_gpio_info = {
+    .name          = TYPE_BCM2835_GPIO,
+    .parent        = TYPE_SYS_BUS_DEVICE,
+    .instance_size = sizeof(BCM2835GpioState),
+    .instance_init = bcm2835_gpio_init,
+    .class_init    = bcm2835_gpio_class_init,
+};
+
+static void bcm2835_gpio_register_types(void)
+{
+    type_register_static(&bcm2835_gpio_info);
+}
+
+type_init(bcm2835_gpio_register_types)