hw/gpio: Implement BCM2838 GPIO functionality

Signed-off-by: Sergey Kambalin <sergey.kambalin@auriga.com>
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Message-id: 20240226000259.2752893-8-sergey.kambalin@auriga.com
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

1 files changed, 190 insertions, 3 deletions

diff --git a/hw/gpio/bcm2838_gpio.c b/hw/gpio/bcm2838_gpio.c
index a312490..69d15db 100644
--- a/hw/gpio/bcm2838_gpio.c
+++ b/hw/gpio/bcm2838_gpio.c
@@ -18,6 +18,7 @@
 #include "hw/sysbus.h"
 #include "migration/vmstate.h"
 #include "hw/gpio/bcm2838_gpio.h"
+#include "hw/irq.h"
 
 #define GPFSEL0   0x00
 #define GPFSEL1   0x04
@@ -56,14 +57,139 @@
 #define RESET_VAL_CNTRL_REG2 0x50AAA95A
 #define RESET_VAL_CNTRL_REG3 0x00055555
 
+#define NUM_FSELN_IN_GPFSELN 10
+#define NUM_BITS_FSELN       3
+#define MASK_FSELN           0x7
+
 #define BYTES_IN_WORD        4
 
+static uint32_t gpfsel_get(BCM2838GpioState *s, uint8_t reg)
+{
+    int i;
+    uint32_t value = 0;
+    for (i = 0; i < NUM_FSELN_IN_GPFSELN; i++) {
+        uint32_t index = NUM_FSELN_IN_GPFSELN * reg + i;
+        if (index < sizeof(s->fsel)) {
+            value |= (s->fsel[index] & MASK_FSELN) << (NUM_BITS_FSELN * i);
+        }
+    }
+    return value;
+}
+
+static void gpfsel_set(BCM2838GpioState *s, uint8_t reg, uint32_t value)
+{
+    int i;
+    for (i = 0; i < NUM_FSELN_IN_GPFSELN; i++) {
+        uint32_t index = NUM_FSELN_IN_GPFSELN * reg + i;
+        if (index < sizeof(s->fsel)) {
+            int fsel = (value >> (NUM_BITS_FSELN * i)) & MASK_FSELN;
+            s->fsel[index] = fsel;
+        }
+    }
+}
+
+static int gpfsel_is_out(BCM2838GpioState *s, int index)
+{
+    if (index >= 0 && index < BCM2838_GPIO_NUM) {
+        return s->fsel[index] == 1;
+    }
+    return 0;
+}
+
+static void gpset(BCM2838GpioState *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(BCM2838GpioState *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 bcm2838_gpio_read(void *opaque, hwaddr offset, unsigned size)
 {
+    BCM2838GpioState *s = (BCM2838GpioState *)opaque;
     uint64_t value = 0;
 
-    qemu_log_mask(LOG_UNIMP, "%s: %s: not implemented for %"HWADDR_PRIx"\n",
-                  TYPE_BCM2838_GPIO, __func__, offset);
+    switch (offset) {
+    case GPFSEL0:
+    case GPFSEL1:
+    case GPFSEL2:
+    case GPFSEL3:
+    case GPFSEL4:
+    case GPFSEL5:
+        value = gpfsel_get(s, offset / BYTES_IN_WORD);
+        break;
+    case GPSET0:
+    case GPSET1:
+    case GPCLR0:
+    case GPCLR1:
+        /* Write Only */
+        qemu_log_mask(LOG_GUEST_ERROR, "%s: %s: Attempt reading from write only"
+                      " register. 0x%"PRIx64" will be returned."
+                      " Address 0x%"HWADDR_PRIx", size %u\n",
+                      TYPE_BCM2838_GPIO, __func__, value, offset, size);
+        break;
+    case GPLEV0:
+        value = s->lev0;
+        break;
+    case GPLEV1:
+        value = s->lev1;
+        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:
+        /* Not implemented */
+        qemu_log_mask(LOG_UNIMP, "%s: %s: not implemented for %"HWADDR_PRIx"\n",
+                      TYPE_BCM2838_GPIO, __func__, offset);
+        break;
+    case GPIO_PUP_PDN_CNTRL_REG0:
+    case GPIO_PUP_PDN_CNTRL_REG1:
+    case GPIO_PUP_PDN_CNTRL_REG2:
+    case GPIO_PUP_PDN_CNTRL_REG3:
+        value = s->pup_cntrl_reg[(offset - GPIO_PUP_PDN_CNTRL_REG0)
+                                 / sizeof(s->pup_cntrl_reg[0])];
+        break;
+    default:
+        qemu_log_mask(LOG_GUEST_ERROR, "%s: %s: bad offset %"HWADDR_PRIx"\n",
+                      TYPE_BCM2838_GPIO, __func__, offset);
+        break;
+    }
 
     return value;
 }
@@ -71,14 +197,75 @@ static uint64_t bcm2838_gpio_read(void *opaque, hwaddr offset, unsigned size)
 static void bcm2838_gpio_write(void *opaque, hwaddr offset, uint64_t value,
                                unsigned size)
 {
-    qemu_log_mask(LOG_UNIMP, "%s: %s: not implemented for %"HWADDR_PRIx"\n",
+    BCM2838GpioState *s = (BCM2838GpioState *)opaque;
+
+    switch (offset) {
+    case GPFSEL0:
+    case GPFSEL1:
+    case GPFSEL2:
+    case GPFSEL3:
+    case GPFSEL4:
+    case GPFSEL5:
+        gpfsel_set(s, offset / BYTES_IN_WORD, 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 */
+        qemu_log_mask(LOG_GUEST_ERROR, "%s: %s: Attempt writing 0x%"PRIx64""
+                      " to read only register. Ignored."
+                      " Address 0x%"HWADDR_PRIx", size %u\n",
+                      TYPE_BCM2838_GPIO, __func__, value, offset, size);
+        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:
+        /* Not implemented */
+        qemu_log_mask(LOG_UNIMP, "%s: %s: not implemented for %"HWADDR_PRIx"\n",
+                      TYPE_BCM2838_GPIO, __func__, offset);
+        break;
+    case GPIO_PUP_PDN_CNTRL_REG0:
+    case GPIO_PUP_PDN_CNTRL_REG1:
+    case GPIO_PUP_PDN_CNTRL_REG2:
+    case GPIO_PUP_PDN_CNTRL_REG3:
+        s->pup_cntrl_reg[(offset - GPIO_PUP_PDN_CNTRL_REG0)
+                         / sizeof(s->pup_cntrl_reg[0])] = value;
+        break;
+    default:
+        qemu_log_mask(LOG_GUEST_ERROR, "%s: %s: bad offset %"HWADDR_PRIx"\n",
                   TYPE_BCM2838_GPIO, __func__, offset);
+    }
+    return;
 }
 
 static void bcm2838_gpio_reset(DeviceState *dev)
 {
     BCM2838GpioState *s = BCM2838_GPIO(dev);
 
+    memset(s->fsel, 0, sizeof(s->fsel));
+
     s->lev0 = 0;
     s->lev1 = 0;