i.MX: Add GPIO device

Signed-off-by: Jean-Christophe Dubois <jcd@tribudubois.net>
Reviewed-by: Peter Crosthwaite <crosthwaite.peter@gmail.com>
Message-id: 5ea3b0021e47cf7f7d883a7edbabee44980f3df7.1441828793.git.jcd@tribudubois.net
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

2 files changed, 341 insertions, 0 deletions

diff --git a/hw/gpio/Makefile.objs b/hw/gpio/Makefile.objs
index 1abcf17..52233f7 100644
--- a/hw/gpio/Makefile.objs
+++ b/hw/gpio/Makefile.objs
@@ -5,3 +5,4 @@ common-obj-$(CONFIG_ZAURUS) += zaurus.o
 common-obj-$(CONFIG_E500) += mpc8xxx.o
 
 obj-$(CONFIG_OMAP) += omap_gpio.o
+obj-$(CONFIG_IMX) += imx_gpio.o
diff --git a/hw/gpio/imx_gpio.c b/hw/gpio/imx_gpio.c
new file mode 100644
index 0000000..d56ffcd
--- /dev/null
+++ b/hw/gpio/imx_gpio.c
@@ -0,0 +1,340 @@
+/*
+ * i.MX processors GPIO emulation.
+ *
+ * Copyright (C) 2015 Jean-Christophe Dubois <jcd@tribudubois.net>
+ *
+ * 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 or
+ * (at your option) version 3 of the License.
+ *
+ * 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/gpio/imx_gpio.h"
+
+#ifndef DEBUG_IMX_GPIO
+#define DEBUG_IMX_GPIO 0
+#endif
+
+typedef enum IMXGPIOLevel {
+    IMX_GPIO_LEVEL_LOW = 0,
+    IMX_GPIO_LEVEL_HIGH = 1,
+} IMXGPIOLevel;
+
+#define DPRINTF(fmt, args...) \
+          do { \
+              if (DEBUG_IMX_GPIO) { \
+                  fprintf(stderr, "%s: " fmt , __func__, ##args); \
+              } \
+          } while (0)
+
+static const char *imx_gpio_reg_name(uint32_t reg)
+{
+    switch (reg) {
+    case DR_ADDR:
+        return "DR";
+    case GDIR_ADDR:
+        return "GDIR";
+    case PSR_ADDR:
+        return "PSR";
+    case ICR1_ADDR:
+        return "ICR1";
+    case ICR2_ADDR:
+        return "ICR2";
+    case IMR_ADDR:
+        return "IMR";
+    case ISR_ADDR:
+        return "ISR";
+    case EDGE_SEL_ADDR:
+        return "EDGE_SEL";
+    default:
+        return "[?]";
+    }
+}
+
+static void imx_gpio_update_int(IMXGPIOState *s)
+{
+    qemu_set_irq(s->irq, (s->isr & s->imr) ? 1 : 0);
+}
+
+static void imx_gpio_set_int_line(IMXGPIOState *s, int line, IMXGPIOLevel level)
+{
+    /* if this signal isn't configured as an input signal, nothing to do */
+    if (!extract32(s->gdir, line, 1)) {
+        return;
+    }
+
+    /* When set, EDGE_SEL overrides the ICR config */
+    if (extract32(s->edge_sel, line, 1)) {
+        /* we detect interrupt on rising and falling edge */
+        if (extract32(s->psr, line, 1) != level) {
+            /* level changed */
+            s->isr = deposit32(s->isr, line, 1, 1);
+        }
+    } else if (extract64(s->icr, 2*line + 1, 1)) {
+        /* interrupt is edge sensitive */
+        if (extract32(s->psr, line, 1) != level) {
+            /* level changed */
+            if (extract64(s->icr, 2*line, 1) != level) {
+                s->isr = deposit32(s->isr, line, 1, 1);
+            }
+        }
+    } else {
+        /* interrupt is level sensitive */
+        if (extract64(s->icr, 2*line, 1) == level) {
+            s->isr = deposit32(s->isr, line, 1, 1);
+        }
+    }
+}
+
+static void imx_gpio_set(void *opaque, int line, int level)
+{
+    IMXGPIOState *s = IMX_GPIO(opaque);
+    IMXGPIOLevel imx_level = level ? IMX_GPIO_LEVEL_HIGH : IMX_GPIO_LEVEL_LOW;
+
+    imx_gpio_set_int_line(s, line, imx_level);
+
+    /* this is an input signal, so set PSR */
+    s->psr = deposit32(s->psr, line, 1, imx_level);
+
+    imx_gpio_update_int(s);
+}
+
+static void imx_gpio_set_all_int_lines(IMXGPIOState *s)
+{
+    int i;
+
+    for (i = 0; i < IMX_GPIO_PIN_COUNT; i++) {
+        IMXGPIOLevel imx_level = extract32(s->psr, i, 1);
+        imx_gpio_set_int_line(s, i, imx_level);
+    }
+
+    imx_gpio_update_int(s);
+}
+
+static inline void imx_gpio_set_all_output_lines(IMXGPIOState *s)
+{
+    int i;
+
+    for (i = 0; i < IMX_GPIO_PIN_COUNT; i++) {
+        /*
+         * if the line is set as output, then forward the line
+         * level to its user.
+         */
+        if (extract32(s->gdir, i, 1) && s->output[i]) {
+            qemu_set_irq(s->output[i], extract32(s->dr, i, 1));
+        }
+    }
+}
+
+static uint64_t imx_gpio_read(void *opaque, hwaddr offset, unsigned size)
+{
+    IMXGPIOState *s = IMX_GPIO(opaque);
+    uint32_t reg_value = 0;
+
+    switch (offset) {
+    case DR_ADDR:
+        /*
+         * depending on the "line" configuration, the bit values
+         * are coming either from DR or PSR
+         */
+        reg_value = (s->dr & s->gdir) | (s->psr & ~s->gdir);
+        break;
+
+    case GDIR_ADDR:
+        reg_value = s->gdir;
+        break;
+
+    case PSR_ADDR:
+        reg_value = s->psr & ~s->gdir;
+        break;
+
+    case ICR1_ADDR:
+        reg_value = extract64(s->icr, 0, 32);
+        break;
+
+    case ICR2_ADDR:
+        reg_value = extract64(s->icr, 32, 32);
+        break;
+
+    case IMR_ADDR:
+        reg_value = s->imr;
+        break;
+
+    case ISR_ADDR:
+        reg_value = s->isr;
+        break;
+
+    case EDGE_SEL_ADDR:
+        if (s->has_edge_sel) {
+            reg_value = s->edge_sel;
+        } else {
+            qemu_log_mask(LOG_GUEST_ERROR, "%s[%s]: EDGE_SEL register not "
+                          "present on this version of GPIO device\n",
+                          TYPE_IMX_GPIO, __func__);
+        }
+        break;
+
+    default:
+        qemu_log_mask(LOG_GUEST_ERROR, "%s[%s]: Bad register at offset %d\n",
+                      TYPE_IMX_GPIO, __func__, (int)offset);
+        break;
+    }
+
+    DPRINTF("(%s) = 0x%"PRIx32"\n", imx_gpio_reg_name(offset), reg_value);
+
+    return reg_value;
+}
+
+static void imx_gpio_write(void *opaque, hwaddr offset, uint64_t value,
+                           unsigned size)
+{
+    IMXGPIOState *s = IMX_GPIO(opaque);
+
+    DPRINTF("(%s, value = 0x%"PRIx32")\n", imx_gpio_reg_name(offset),
+            (uint32_t)value);
+
+    switch (offset) {
+    case DR_ADDR:
+        s->dr = value;
+        imx_gpio_set_all_output_lines(s);
+        break;
+
+    case GDIR_ADDR:
+        s->gdir = value;
+        imx_gpio_set_all_output_lines(s);
+        imx_gpio_set_all_int_lines(s);
+        break;
+
+    case ICR1_ADDR:
+        s->icr = deposit64(s->icr, 0, 32, value);
+        imx_gpio_set_all_int_lines(s);
+        break;
+
+    case ICR2_ADDR:
+        s->icr = deposit64(s->icr, 32, 32, value);
+        imx_gpio_set_all_int_lines(s);
+        break;
+
+    case IMR_ADDR:
+        s->imr = value;
+        imx_gpio_update_int(s);
+        break;
+
+    case ISR_ADDR:
+        s->isr |= ~value;
+        imx_gpio_set_all_int_lines(s);
+        break;
+
+    case EDGE_SEL_ADDR:
+        if (s->has_edge_sel) {
+            s->edge_sel = value;
+            imx_gpio_set_all_int_lines(s);
+        } else {
+            qemu_log_mask(LOG_GUEST_ERROR, "%s[%s]: EDGE_SEL register not "
+                          "present on this version of GPIO device\n",
+                          TYPE_IMX_GPIO, __func__);
+        }
+        break;
+
+    default:
+        qemu_log_mask(LOG_GUEST_ERROR, "%s[%s]: Bad register at offset %d\n",
+                      TYPE_IMX_GPIO, __func__, (int)offset);
+        break;
+    }
+
+    return;
+}
+
+static const MemoryRegionOps imx_gpio_ops = {
+    .read = imx_gpio_read,
+    .write = imx_gpio_write,
+    .valid.min_access_size = 4,
+    .valid.max_access_size = 4,
+    .endianness = DEVICE_NATIVE_ENDIAN,
+};
+
+static const VMStateDescription vmstate_imx_gpio = {
+    .name = TYPE_IMX_GPIO,
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .minimum_version_id_old = 1,
+    .fields = (VMStateField[]) {
+        VMSTATE_UINT32(dr, IMXGPIOState),
+        VMSTATE_UINT32(gdir, IMXGPIOState),
+        VMSTATE_UINT32(psr, IMXGPIOState),
+        VMSTATE_UINT64(icr, IMXGPIOState),
+        VMSTATE_UINT32(imr, IMXGPIOState),
+        VMSTATE_UINT32(isr, IMXGPIOState),
+        VMSTATE_BOOL(has_edge_sel, IMXGPIOState),
+        VMSTATE_UINT32(edge_sel, IMXGPIOState),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+static Property imx_gpio_properties[] = {
+    DEFINE_PROP_BOOL("has-edge-sel", IMXGPIOState, has_edge_sel, true),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
+static void imx_gpio_reset(DeviceState *dev)
+{
+    IMXGPIOState *s = IMX_GPIO(dev);
+
+    s->dr       = 0;
+    s->gdir     = 0;
+    s->psr      = 0;
+    s->icr      = 0;
+    s->imr      = 0;
+    s->isr      = 0;
+    s->edge_sel = 0;
+
+    imx_gpio_set_all_output_lines(s);
+    imx_gpio_update_int(s);
+}
+
+static void imx_gpio_realize(DeviceState *dev, Error **errp)
+{
+    IMXGPIOState *s = IMX_GPIO(dev);
+
+    memory_region_init_io(&s->iomem, OBJECT(s), &imx_gpio_ops, s,
+                          TYPE_IMX_GPIO, IMX_GPIO_MEM_SIZE);
+
+    qdev_init_gpio_in(DEVICE(s), imx_gpio_set, IMX_GPIO_PIN_COUNT);
+    qdev_init_gpio_out(DEVICE(s), s->output, IMX_GPIO_PIN_COUNT);
+
+    sysbus_init_irq(SYS_BUS_DEVICE(dev), &s->irq);
+    sysbus_init_mmio(SYS_BUS_DEVICE(dev), &s->iomem);
+}
+
+static void imx_gpio_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+
+    dc->realize = imx_gpio_realize;
+    dc->reset = imx_gpio_reset;
+    dc->props = imx_gpio_properties;
+    dc->vmsd = &vmstate_imx_gpio;
+    dc->desc = "i.MX GPIO controller";
+}
+
+static const TypeInfo imx_gpio_info = {
+    .name = TYPE_IMX_GPIO,
+    .parent = TYPE_SYS_BUS_DEVICE,
+    .instance_size = sizeof(IMXGPIOState),
+    .class_init = imx_gpio_class_init,
+};
+
+static void imx_gpio_register_types(void)
+{
+    type_register_static(&imx_gpio_info);
+}
+
+type_init(imx_gpio_register_types)