[PATCH v1 0/2] Add the SiFive PWM device

[PATCH v1 0/2] Add the SiFive PWM device

[Alistair Francis]

This series adds a the SiFive PWM device and connects it to the
sifive_u machine. This has been tested as a timer with seL4.

Alistair Francis (2):
  sifive_u_pwm: Initial commit
  sifive_u: Connect the SiFive PWM device

 include/hw/dma/sifive_pdma.h    |   2 +-
 include/hw/riscv/sifive_u.h     |  14 +-
 include/hw/timer/sifive_u_pwm.h |  62 ++++
 hw/riscv/sifive_u.c             |  23 +-
 hw/timer/sifive_u_pwm.c         | 483 ++++++++++++++++++++++++++++++++
 MAINTAINERS                     |   2 +
 hw/riscv/Kconfig                |   1 +
 hw/timer/Kconfig                |   3 +
 hw/timer/meson.build            |   1 +
 9 files changed, 588 insertions(+), 3 deletions(-)
 create mode 100644 include/hw/timer/sifive_u_pwm.h
 create mode 100644 hw/timer/sifive_u_pwm.c

-- 
2.31.0

[PATCH v1 0/2] Add the SiFive PWM device

[Alistair Francis]

This series adds a the SiFive PWM device and connects it to the
sifive_u machine. This has been tested as a timer with seL4.

Alistair Francis (2):
  sifive_u_pwm: Initial commit
  sifive_u: Connect the SiFive PWM device

 include/hw/dma/sifive_pdma.h    |   2 +-
 include/hw/riscv/sifive_u.h     |  14 +-
 include/hw/timer/sifive_u_pwm.h |  62 ++++
 hw/riscv/sifive_u.c             |  23 +-
 hw/timer/sifive_u_pwm.c         | 483 ++++++++++++++++++++++++++++++++
 MAINTAINERS                     |   2 +
 hw/riscv/Kconfig                |   1 +
 hw/timer/Kconfig                |   3 +
 hw/timer/meson.build            |   1 +
 9 files changed, 588 insertions(+), 3 deletions(-)
 create mode 100644 include/hw/timer/sifive_u_pwm.h
 create mode 100644 hw/timer/sifive_u_pwm.c

-- 
2.31.0

[PATCH v1 1/2] sifive_u_pwm: Initial commit

[Alistair Francis]

Signed-off-by: Justin Restivo <jrestivo@draper.com>
Signed-off-by: Alexandra Clifford <aclifford@draper.com>
Signed-off-by: Amanda Strnad <astrnad@draper.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
---
 include/hw/dma/sifive_pdma.h    |   2 +-
 include/hw/timer/sifive_u_pwm.h |  62 ++++
 hw/timer/sifive_u_pwm.c         | 483 ++++++++++++++++++++++++++++++++
 MAINTAINERS                     |   2 +
 hw/riscv/Kconfig                |   1 +
 hw/timer/Kconfig                |   3 +
 hw/timer/meson.build            |   1 +
 7 files changed, 553 insertions(+), 1 deletion(-)
 create mode 100644 include/hw/timer/sifive_u_pwm.h
 create mode 100644 hw/timer/sifive_u_pwm.c

diff --git a/include/hw/dma/sifive_pdma.h b/include/hw/dma/sifive_pdma.h
index e319bbd6c4..fbd394fa29 100644
--- a/include/hw/dma/sifive_pdma.h
+++ b/include/hw/dma/sifive_pdma.h
@@ -37,7 +37,7 @@ struct sifive_pdma_chan {
 };
 
 #define SIFIVE_PDMA_CHANS           4
-#define SIFIVE_PDMA_IRQS            (SIFIVE_PDMA_CHANS * 2)
+#define SIFIVE_PDMA_IRQS            (SIFIVE_PDMA_CHANS)
 #define SIFIVE_PDMA_REG_SIZE        0x100000
 #define SIFIVE_PDMA_CHAN_NO(reg)    ((reg & (SIFIVE_PDMA_REG_SIZE - 1)) >> 12)
 
diff --git a/include/hw/timer/sifive_u_pwm.h b/include/hw/timer/sifive_u_pwm.h
new file mode 100644
index 0000000000..d0c7801f79
--- /dev/null
+++ b/include/hw/timer/sifive_u_pwm.h
@@ -0,0 +1,62 @@
+/*
+ * SiFive FU540 PWM
+ *
+ * Copyright (c) 2020 Western Digital
+ *
+ * Author:  Alistair Francis <alistair.francis@wdc.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#ifndef HW_SIFIVE_U_PWM_H
+#define HW_SIFIVE_U_PWM_H
+
+#include "hw/sysbus.h"
+#include "qemu/timer.h"
+#include "qom/object.h"
+
+#define TYPE_SIFIVE_U_PWM "sifive-u-pwm"
+
+#define SIFIVE_U_PWM(obj) \
+    OBJECT_CHECK(SiFiveUPwmState, (obj), TYPE_SIFIVE_U_PWM)
+
+#define SIFIVE_U_PWM_CHANS          4
+#define SIFIVE_U_PWM_IRQS           SIFIVE_U_PWM_CHANS
+
+typedef struct SiFiveUPwmState {
+    /* <private> */
+    SysBusDevice parent_obj;
+
+    /* <public> */
+    MemoryRegion mmio;
+    QEMUTimer timer[SIFIVE_U_PWM_CHANS];
+    /*
+     * if en bit(s) set, is the number of ticks when pwmcount was 0
+     * if en bit(s) not set, is the number of ticks in pwmcount
+     */
+    uint64_t tick_offset;
+    uint64_t freq_hz;
+
+    uint32_t pwmcfg;
+    uint32_t pwmcmp[SIFIVE_U_PWM_CHANS];
+
+    qemu_irq irqs[SIFIVE_U_PWM_IRQS];
+} SiFiveUPwmState;
+
+#endif /* HW_SIFIVE_U_PWM_H */
diff --git a/hw/timer/sifive_u_pwm.c b/hw/timer/sifive_u_pwm.c
new file mode 100644
index 0000000000..047a659659
--- /dev/null
+++ b/hw/timer/sifive_u_pwm.c
@@ -0,0 +1,483 @@
+/*
+ * SiFive FU540 PWM
+ *
+ * Copyright (c) 2020 Western Digital
+ *
+ * Author:  Alistair Francis <alistair.francis@wdc.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "qemu/osdep.h"
+#include "hw/irq.h"
+#include "hw/timer/sifive_u_pwm.h"
+#include "hw/qdev-properties.h"
+#include "hw/registerfields.h"
+#include "migration/vmstate.h"
+#include "qemu/log.h"
+#include "qemu/module.h"
+
+#ifndef STM_SYSCFG_ERR_DEBUG
+#define STM_SYSCFG_ERR_DEBUG 0
+#endif
+
+#define DB_PRINT_L(lvl, fmt, args...) do { \
+    if (STM_SYSCFG_ERR_DEBUG >= lvl) { \
+        qemu_log("%s: " fmt, __func__, ## args); \
+    } \
+} while (0)
+
+#define DB_PRINT(fmt, args...) DB_PRINT_L(1, fmt, ## args)
+
+#define HAS_PWM_EN_BITS(cfg) ((cfg & R_CONFIG_ENONESHOT_MASK) || \
+                              (cfg & R_CONFIG_ENALWAYS_MASK))
+
+#define PWMCMP_MASK 0xFFFF
+#define PWMCOUNT_MASK 0x7FFFFFFF
+
+REG32(CONFIG,                   0x00)
+    FIELD(CONFIG, SCALE,        0, 4)
+    FIELD(CONFIG, STICKY,       8, 1)
+    FIELD(CONFIG, ZEROCMP,      9, 1)
+    FIELD(CONFIG, DEGLITCH,     10, 1)
+    FIELD(CONFIG, ENALWAYS,     12, 1)
+    FIELD(CONFIG, ENONESHOT,    13, 1)
+    FIELD(CONFIG, CMP0CENTER,   16, 1)
+    FIELD(CONFIG, CMP1CENTER,   17, 1)
+    FIELD(CONFIG, CMP2CENTER,   18, 1)
+    FIELD(CONFIG, CMP3CENTER,   19, 1)
+    FIELD(CONFIG, CMP0GANG,     24, 1)
+    FIELD(CONFIG, CMP1GANG,     25, 1)
+    FIELD(CONFIG, CMP2GANG,     26, 1)
+    FIELD(CONFIG, CMP3GANG,     27, 1)
+    FIELD(CONFIG, CMP0IP,       28, 1)
+    FIELD(CONFIG, CMP1IP,       29, 1)
+    FIELD(CONFIG, CMP2IP,       30, 1)
+    FIELD(CONFIG, CMP3IP,       31, 1)
+REG32(COUNT,                   0x08)
+REG32(PWMS,                    0x10)
+REG32(PWMCMP0,                 0x20)
+REG32(PWMCMP1,                 0x24)
+REG32(PWMCMP2,                 0x28)
+REG32(PWMCMP3,                 0x2C)
+
+static inline uint64_t sifive_u_pwm_ns_to_ticks(SiFiveUPwmState *s,
+                                                uint64_t time)
+{
+    return muldiv64(time, s->freq_hz, NANOSECONDS_PER_SECOND);
+}
+
+static inline uint64_t sifive_u_pwm_ticks_to_ns(SiFiveUPwmState *s,
+                                                uint64_t ticks)
+{
+    return muldiv64(ticks, NANOSECONDS_PER_SECOND, s->freq_hz);
+}
+
+static inline uint64_t sifive_u_pwm_compute_scale(SiFiveUPwmState *s)
+{
+    return s->pwmcfg & R_CONFIG_SCALE_MASK;
+}
+
+static void sifive_u_pwm_set_alarms(SiFiveUPwmState *s)
+{
+    uint64_t now_ns = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
+
+    if (HAS_PWM_EN_BITS(s->pwmcfg)) {
+        /*
+         * Subtract ticks from number of ticks when the timer was zero
+         * and mask to the register width.
+         */
+        uint64_t pwmcount = (sifive_u_pwm_ns_to_ticks(s, now_ns) -
+                             s->tick_offset) & PWMCOUNT_MASK;
+        uint64_t scale = sifive_u_pwm_compute_scale(s);
+        /* PWMs only contains PWMCMP_MASK bits starting at scale */
+        uint64_t pwms = (pwmcount & (PWMCMP_MASK << scale)) >> scale;
+
+        for (int i = 0; i < SIFIVE_U_PWM_CHANS; i++) {
+            uint64_t pwmcmp = s->pwmcmp[i] & PWMCMP_MASK;
+            uint64_t pwmcmp_ticks = pwmcmp << scale;
+
+            /*
+             * Per circuit diagram and spec, both cases raises corresponding
+             * IP bit one clock cycle after time expires.
+             */
+            if (pwmcmp > pwms) {
+                uint64_t offset = pwmcmp_ticks - pwmcount + 1;
+                uint64_t when_to_fire = now_ns +
+                                          sifive_u_pwm_ticks_to_ns(s, offset);
+
+                DB_PRINT("Setting alarm to: 0x%lx, now: 0x%lx\n",
+                         when_to_fire, now_ns);
+                timer_mod(&s->timer[i], when_to_fire);
+            } else {
+                /* Schedule interrupt for next cycle */
+                DB_PRINT("Setting alarm to: 0x%lx, now: 0x%lx\n",
+                         now_ns + 1, now_ns);
+                timer_mod(&s->timer[i], now_ns + 1);
+            }
+
+        }
+    } else {
+        /*
+         * If timer incrementing disabled, just do pwms > pwmcmp check since
+         * a write may have happened to PWMs.
+         */
+        uint64_t pwmcount = (s->tick_offset) & PWMCOUNT_MASK;
+        uint64_t scale = sifive_u_pwm_compute_scale(s);
+        uint64_t pwms = (pwmcount & (PWMCMP_MASK << scale)) >> scale;
+
+        for (int i = 0; i < SIFIVE_U_PWM_CHANS; i++) {
+            uint64_t pwmcmp = s->pwmcmp[i] & PWMCMP_MASK;
+
+            if (pwms >= pwmcmp) {
+                DB_PRINT("Setting alarm to: 0x%lx, now: 0x%lx\n",
+                         now_ns + 1, now_ns);
+                timer_mod(&s->timer[i], now_ns + 1);
+            } else {
+                /* Effectively disable timer by scheduling far in future. */
+                DB_PRINT("Setting alarm to: 0x%lx, now: 0x%lx\n",
+                         0xFFFFFFFFFFFFFF, now_ns);
+                timer_mod(&s->timer[i], 0xFFFFFFFFFFFFFF);
+            }
+        }
+    }
+}
+
+static void sifive_u_pwm_interrupt(SiFiveUPwmState *s, int num)
+{
+    uint64_t now = sifive_u_pwm_ns_to_ticks(s,
+                                        qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL));
+    bool was_incrementing = HAS_PWM_EN_BITS(s->pwmcfg);
+
+    DB_PRINT("Interrupt %d\n", num);
+
+    s->pwmcfg |= R_CONFIG_CMP0IP_MASK << num;
+    qemu_irq_raise(s->irqs[num]);
+
+    /*
+     * If the zerocmp is set and pwmcmp0 raised the interrupt
+     * reset the zero ticks.
+     */
+    if ((s->pwmcfg & R_CONFIG_ZEROCMP_MASK) && (num == 0)) {
+        /* If reset signal conditions, disable ENONESHOT. */
+        s->pwmcfg &= ~R_CONFIG_ENONESHOT_MASK;
+
+        if (was_incrementing) {
+            /* If incrementing, time in ticks is when pwmcount is zero */
+            s->tick_offset = now;
+        } else {
+            /* If not incrementing, pwmcount = 0 */
+            s->tick_offset = 0;
+        }
+    }
+
+    /*
+     * If carryout bit set, which we discern via looking for overflow,
+     * also reset ENONESHOT.
+     */
+    if (was_incrementing &&
+        ((now & PWMCOUNT_MASK) < (s->tick_offset & PWMCOUNT_MASK))) {
+        s->pwmcfg &= ~R_CONFIG_ENONESHOT_MASK;
+    }
+
+    /* Schedule or disable interrupts */
+    sifive_u_pwm_set_alarms(s);
+
+    /* If was enabled, and now not enabled, switch tick rep */
+    if (was_incrementing && !HAS_PWM_EN_BITS(s->pwmcfg)) {
+        s->tick_offset = (now - s->tick_offset) & PWMCOUNT_MASK;
+    }
+}
+
+static void sifive_u_pwm_interrupt_0(void *opaque)
+{
+    SiFiveUPwmState *s = opaque;
+
+    sifive_u_pwm_interrupt(s, 0);
+}
+
+static void sifive_u_pwm_interrupt_1(void *opaque)
+{
+    SiFiveUPwmState *s = opaque;
+
+    sifive_u_pwm_interrupt(s, 1);
+}
+
+static void sifive_u_pwm_interrupt_2(void *opaque)
+{
+    SiFiveUPwmState *s = opaque;
+
+    sifive_u_pwm_interrupt(s, 2);
+}
+
+static void sifive_u_pwm_interrupt_3(void *opaque)
+{
+    SiFiveUPwmState *s = opaque;
+
+    sifive_u_pwm_interrupt(s, 3);
+}
+
+static uint64_t sifive_u_pwm_read(void *opaque, hwaddr addr,
+                                  unsigned int size)
+{
+    SiFiveUPwmState *s = opaque;
+    uint64_t cur_time, scale;
+    uint64_t now = sifive_u_pwm_ns_to_ticks(s,
+                                        qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL));
+
+    DB_PRINT("0x%"HWADDR_PRIx"\n", addr);
+
+    switch (addr) {
+    case A_CONFIG:
+        return s->pwmcfg;
+    case A_COUNT:
+        cur_time = s->tick_offset;
+
+        if (HAS_PWM_EN_BITS(s->pwmcfg)) {
+            cur_time = now - cur_time;
+        }
+
+        /*
+         * Return the value in the counter with bit 31 always 0
+         * This is allowed to wrap around so we don't need to check that.
+         */
+        return cur_time & PWMCOUNT_MASK;
+    case A_PWMS:
+        cur_time = s->tick_offset;
+        scale = sifive_u_pwm_compute_scale(s);
+
+        if (HAS_PWM_EN_BITS(s->pwmcfg)) {
+            cur_time = now - cur_time;
+        }
+
+        return ((cur_time & PWMCOUNT_MASK) >> scale) & PWMCMP_MASK;
+    case A_PWMCMP0:
+        return s->pwmcmp[0] & PWMCMP_MASK;
+    case A_PWMCMP1:
+        return s->pwmcmp[1] & PWMCMP_MASK;
+    case A_PWMCMP2:
+        return s->pwmcmp[2] & PWMCMP_MASK;
+    case A_PWMCMP3:
+        return s->pwmcmp[3] & PWMCMP_MASK;
+    default:
+        qemu_log_mask(LOG_GUEST_ERROR,
+                      "%s: Bad offset 0x%"HWADDR_PRIx"\n", __func__, addr);
+        return 0;
+    }
+
+    return 0;
+}
+
+static void sifive_u_pwm_write(void *opaque, hwaddr addr,
+                               uint64_t val64, unsigned int size)
+{
+    SiFiveUPwmState *s = opaque;
+    uint32_t value = val64;
+    uint64_t new_offset, scale;
+    uint64_t now = sifive_u_pwm_ns_to_ticks(s,
+                                        qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL));
+
+    DB_PRINT("0x%x, 0x%"HWADDR_PRIx"\n", value, addr);
+
+    switch (addr) {
+    case A_CONFIG:
+        if (value & (R_CONFIG_CMP0CENTER_MASK | R_CONFIG_CMP1CENTER_MASK |
+                     R_CONFIG_CMP2CENTER_MASK | R_CONFIG_CMP3CENTER_MASK)) {
+            qemu_log_mask(LOG_UNIMP, "%s: CMPxCENTER is not supported\n",
+                          __func__);
+        }
+
+        if (value & (R_CONFIG_CMP0GANG_MASK | R_CONFIG_CMP1GANG_MASK |
+                     R_CONFIG_CMP2GANG_MASK | R_CONFIG_CMP3GANG_MASK)) {
+            qemu_log_mask(LOG_UNIMP, "%s: CMPxGANG is not supported\n",
+                          __func__);
+        }
+
+        if (value & (R_CONFIG_CMP0IP_MASK | R_CONFIG_CMP1IP_MASK |
+                     R_CONFIG_CMP2IP_MASK | R_CONFIG_CMP3IP_MASK)) {
+            qemu_log_mask(LOG_UNIMP, "%s: CMPxIP is not supported\n",
+                          __func__);
+        }
+
+        if (!(value & R_CONFIG_CMP0IP_MASK)) {
+            qemu_irq_lower(s->irqs[0]);
+        }
+
+        if (!(value & R_CONFIG_CMP1IP_MASK)) {
+            qemu_irq_lower(s->irqs[1]);
+        }
+
+        if (!(value & R_CONFIG_CMP2IP_MASK)) {
+            qemu_irq_lower(s->irqs[2]);
+        }
+
+        if (!(value & R_CONFIG_CMP3IP_MASK)) {
+            qemu_irq_lower(s->irqs[3]);
+        }
+
+        /*
+         * If this write enables the timer increment
+         * set the time when pwmcount was zero to be cur_time - pwmcount.
+         * If this write disables the timer increment
+         * convert back from pwmcount to the time in ticks
+         * when pwmcount was zero.
+         */
+        if ((!HAS_PWM_EN_BITS(s->pwmcfg) && HAS_PWM_EN_BITS(value)) ||
+            (HAS_PWM_EN_BITS(s->pwmcfg) && !HAS_PWM_EN_BITS(value))) {
+            s->tick_offset = (now - s->tick_offset) & PWMCOUNT_MASK;
+        }
+
+        s->pwmcfg = value;
+        break;
+    case A_COUNT:
+        /* The guest changed the counter, updated the offset value. */
+        new_offset = value;
+
+        if (HAS_PWM_EN_BITS(s->pwmcfg)) {
+            new_offset = now - new_offset;
+        }
+
+        s->tick_offset = new_offset;
+        break;
+    case A_PWMS:
+        scale = sifive_u_pwm_compute_scale(s);
+        new_offset = (((value & PWMCMP_MASK) << scale) & PWMCOUNT_MASK);
+
+        if (HAS_PWM_EN_BITS(s->pwmcfg)) {
+            new_offset = now - new_offset;
+        }
+
+        s->tick_offset = new_offset;
+        break;
+    case A_PWMCMP0:
+        s->pwmcmp[0] = value & PWMCMP_MASK;
+        break;
+    case A_PWMCMP1:
+        s->pwmcmp[1] = value & PWMCMP_MASK;
+        break;
+    case A_PWMCMP2:
+        s->pwmcmp[2] = value & PWMCMP_MASK;
+        break;
+    case A_PWMCMP3:
+        s->pwmcmp[3] = value & PWMCMP_MASK;
+        break;
+    default:
+        qemu_log_mask(LOG_GUEST_ERROR,
+                      "%s: Bad offset 0x%"HWADDR_PRIx"\n", __func__, addr);
+    }
+
+    /* Update the alarms to reflect possible updated values */
+    sifive_u_pwm_set_alarms(s);
+}
+
+static void sifive_u_pwm_reset(DeviceState *dev)
+{
+    SiFiveUPwmState *s = SIFIVE_U_PWM(dev);
+    uint64_t now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
+
+    s->pwmcfg = 0x00000000;
+    s->pwmcmp[0] = 0x00000000;
+    s->pwmcmp[1] = 0x00000000;
+    s->pwmcmp[2] = 0x00000000;
+    s->pwmcmp[3] = 0x00000000;
+
+    s->tick_offset = sifive_u_pwm_ns_to_ticks(s, now);
+}
+
+static const MemoryRegionOps sifive_u_pwm_ops = {
+    .read = sifive_u_pwm_read,
+    .write = sifive_u_pwm_write,
+    .endianness = DEVICE_NATIVE_ENDIAN,
+};
+
+static const VMStateDescription vmstate_sifive_u_pwm = {
+    .name = TYPE_SIFIVE_U_PWM,
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .fields = (VMStateField[]) {
+        VMSTATE_TIMER_ARRAY(timer, SiFiveUPwmState, 4),
+        VMSTATE_UINT64(tick_offset, SiFiveUPwmState),
+        VMSTATE_UINT32(pwmcfg, SiFiveUPwmState),
+        VMSTATE_UINT32_ARRAY(pwmcmp, SiFiveUPwmState, 4),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+static Property sifive_u_pwm_properties[] = {
+    /* 0.5Ghz per spec after FSBL */
+    DEFINE_PROP_UINT64("clock-frequency", struct SiFiveUPwmState,
+                       freq_hz, 500000000ULL),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
+static void sifive_u_pwm_init(Object *obj)
+{
+    SiFiveUPwmState *s = SIFIVE_U_PWM(obj);
+    int i;
+
+    for (i = 0; i < SIFIVE_U_PWM_IRQS; i++) {
+        sysbus_init_irq(SYS_BUS_DEVICE(obj), &s->irqs[i]);
+    }
+
+    memory_region_init_io(&s->mmio, obj, &sifive_u_pwm_ops, s,
+                          TYPE_SIFIVE_U_PWM, 0x100);
+    sysbus_init_mmio(SYS_BUS_DEVICE(obj), &s->mmio);
+}
+
+static void sifive_u_pwm_realize(DeviceState *dev, Error **errp)
+{
+    SiFiveUPwmState *s = SIFIVE_U_PWM(dev);
+
+    timer_init_ns(&s->timer[0], QEMU_CLOCK_VIRTUAL,
+                  sifive_u_pwm_interrupt_0, s);
+
+    timer_init_ns(&s->timer[1], QEMU_CLOCK_VIRTUAL,
+                  sifive_u_pwm_interrupt_1, s);
+
+    timer_init_ns(&s->timer[2], QEMU_CLOCK_VIRTUAL,
+                  sifive_u_pwm_interrupt_2, s);
+
+    timer_init_ns(&s->timer[3], QEMU_CLOCK_VIRTUAL,
+                  sifive_u_pwm_interrupt_3, s);
+}
+
+static void sifive_u_pwm_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+
+    dc->reset = sifive_u_pwm_reset;
+    device_class_set_props(dc, sifive_u_pwm_properties);
+    dc->vmsd = &vmstate_sifive_u_pwm;
+    dc->realize = sifive_u_pwm_realize;
+}
+
+static const TypeInfo sifive_u_pwm_info = {
+    .name          = TYPE_SIFIVE_U_PWM,
+    .parent        = TYPE_SYS_BUS_DEVICE,
+    .instance_size = sizeof(SiFiveUPwmState),
+    .instance_init = sifive_u_pwm_init,
+    .class_init    = sifive_u_pwm_class_init,
+};
+
+static void sifive_u_pwm_register_types(void)
+{
+    type_register_static(&sifive_u_pwm_info);
+}
+
+type_init(sifive_u_pwm_register_types)
diff --git a/MAINTAINERS b/MAINTAINERS
index 554be84b32..32fdc8a4ca 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -303,7 +303,9 @@ L: qemu-riscv@nongnu.org
 S: Supported
 F: target/riscv/
 F: hw/riscv/
+F: hw/*/*sifive*
 F: include/hw/riscv/
+F: include/hw/*/*sifive*
 F: linux-user/host/riscv32/
 F: linux-user/host/riscv64/
 
diff --git a/hw/riscv/Kconfig b/hw/riscv/Kconfig
index 1de18cdcf1..aca8ad67a2 100644
--- a/hw/riscv/Kconfig
+++ b/hw/riscv/Kconfig
@@ -59,6 +59,7 @@ config SIFIVE_U
     select SIFIVE_U_PRCI
     select SSI_M25P80
     select SSI_SD
+    select SIFIVE_U_PWM
     select UNIMP
 
 config SPIKE
diff --git a/hw/timer/Kconfig b/hw/timer/Kconfig
index bac2511715..f39eb16e4e 100644
--- a/hw/timer/Kconfig
+++ b/hw/timer/Kconfig
@@ -25,6 +25,9 @@ config ALLWINNER_A10_PIT
     bool
     select PTIMER
 
+config SIFIVE_U_PWM
+    bool
+
 config STM32F2XX_TIMER
     bool
 
diff --git a/hw/timer/meson.build b/hw/timer/meson.build
index 598d058506..481f7f915b 100644
--- a/hw/timer/meson.build
+++ b/hw/timer/meson.build
@@ -36,5 +36,6 @@ softmmu_ss.add(when: 'CONFIG_SSE_COUNTER', if_true: files('sse-counter.c'))
 softmmu_ss.add(when: 'CONFIG_SSE_TIMER', if_true: files('sse-timer.c'))
 softmmu_ss.add(when: 'CONFIG_STM32F2XX_TIMER', if_true: files('stm32f2xx_timer.c'))
 softmmu_ss.add(when: 'CONFIG_XILINX', if_true: files('xilinx_timer.c'))
+softmmu_ss.add(when: 'CONFIG_SIFIVE_U_PWM', if_true: files('sifive_u_pwm.c'))
 
 specific_ss.add(when: 'CONFIG_AVR_TIMER16', if_true: files('avr_timer16.c'))
-- 
2.31.0

[PATCH v1 1/2] sifive_u_pwm: Initial commit

[Alistair Francis]

Signed-off-by: Justin Restivo <jrestivo@draper.com>
Signed-off-by: Alexandra Clifford <aclifford@draper.com>
Signed-off-by: Amanda Strnad <astrnad@draper.com>
Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
---
 include/hw/dma/sifive_pdma.h    |   2 +-
 include/hw/timer/sifive_u_pwm.h |  62 ++++
 hw/timer/sifive_u_pwm.c         | 483 ++++++++++++++++++++++++++++++++
 MAINTAINERS                     |   2 +
 hw/riscv/Kconfig                |   1 +
 hw/timer/Kconfig                |   3 +
 hw/timer/meson.build            |   1 +
 7 files changed, 553 insertions(+), 1 deletion(-)
 create mode 100644 include/hw/timer/sifive_u_pwm.h
 create mode 100644 hw/timer/sifive_u_pwm.c

diff --git a/include/hw/dma/sifive_pdma.h b/include/hw/dma/sifive_pdma.h
index e319bbd6c4..fbd394fa29 100644
--- a/include/hw/dma/sifive_pdma.h
+++ b/include/hw/dma/sifive_pdma.h
@@ -37,7 +37,7 @@ struct sifive_pdma_chan {
 };
 
 #define SIFIVE_PDMA_CHANS           4
-#define SIFIVE_PDMA_IRQS            (SIFIVE_PDMA_CHANS * 2)
+#define SIFIVE_PDMA_IRQS            (SIFIVE_PDMA_CHANS)
 #define SIFIVE_PDMA_REG_SIZE        0x100000
 #define SIFIVE_PDMA_CHAN_NO(reg)    ((reg & (SIFIVE_PDMA_REG_SIZE - 1)) >> 12)
 
diff --git a/include/hw/timer/sifive_u_pwm.h b/include/hw/timer/sifive_u_pwm.h
new file mode 100644
index 0000000000..d0c7801f79
--- /dev/null
+++ b/include/hw/timer/sifive_u_pwm.h
@@ -0,0 +1,62 @@
+/*
+ * SiFive FU540 PWM
+ *
+ * Copyright (c) 2020 Western Digital
+ *
+ * Author:  Alistair Francis <alistair.francis@wdc.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#ifndef HW_SIFIVE_U_PWM_H
+#define HW_SIFIVE_U_PWM_H
+
+#include "hw/sysbus.h"
+#include "qemu/timer.h"
+#include "qom/object.h"
+
+#define TYPE_SIFIVE_U_PWM "sifive-u-pwm"
+
+#define SIFIVE_U_PWM(obj) \
+    OBJECT_CHECK(SiFiveUPwmState, (obj), TYPE_SIFIVE_U_PWM)
+
+#define SIFIVE_U_PWM_CHANS          4
+#define SIFIVE_U_PWM_IRQS           SIFIVE_U_PWM_CHANS
+
+typedef struct SiFiveUPwmState {
+    /* <private> */
+    SysBusDevice parent_obj;
+
+    /* <public> */
+    MemoryRegion mmio;
+    QEMUTimer timer[SIFIVE_U_PWM_CHANS];
+    /*
+     * if en bit(s) set, is the number of ticks when pwmcount was 0
+     * if en bit(s) not set, is the number of ticks in pwmcount
+     */
+    uint64_t tick_offset;
+    uint64_t freq_hz;
+
+    uint32_t pwmcfg;
+    uint32_t pwmcmp[SIFIVE_U_PWM_CHANS];
+
+    qemu_irq irqs[SIFIVE_U_PWM_IRQS];
+} SiFiveUPwmState;
+
+#endif /* HW_SIFIVE_U_PWM_H */
diff --git a/hw/timer/sifive_u_pwm.c b/hw/timer/sifive_u_pwm.c
new file mode 100644
index 0000000000..047a659659
--- /dev/null
+++ b/hw/timer/sifive_u_pwm.c
@@ -0,0 +1,483 @@
+/*
+ * SiFive FU540 PWM
+ *
+ * Copyright (c) 2020 Western Digital
+ *
+ * Author:  Alistair Francis <alistair.francis@wdc.com>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+#include "qemu/osdep.h"
+#include "hw/irq.h"
+#include "hw/timer/sifive_u_pwm.h"
+#include "hw/qdev-properties.h"
+#include "hw/registerfields.h"
+#include "migration/vmstate.h"
+#include "qemu/log.h"
+#include "qemu/module.h"
+
+#ifndef STM_SYSCFG_ERR_DEBUG
+#define STM_SYSCFG_ERR_DEBUG 0
+#endif
+
+#define DB_PRINT_L(lvl, fmt, args...) do { \
+    if (STM_SYSCFG_ERR_DEBUG >= lvl) { \
+        qemu_log("%s: " fmt, __func__, ## args); \
+    } \
+} while (0)
+
+#define DB_PRINT(fmt, args...) DB_PRINT_L(1, fmt, ## args)
+
+#define HAS_PWM_EN_BITS(cfg) ((cfg & R_CONFIG_ENONESHOT_MASK) || \
+                              (cfg & R_CONFIG_ENALWAYS_MASK))
+
+#define PWMCMP_MASK 0xFFFF
+#define PWMCOUNT_MASK 0x7FFFFFFF
+
+REG32(CONFIG,                   0x00)
+    FIELD(CONFIG, SCALE,        0, 4)
+    FIELD(CONFIG, STICKY,       8, 1)
+    FIELD(CONFIG, ZEROCMP,      9, 1)
+    FIELD(CONFIG, DEGLITCH,     10, 1)
+    FIELD(CONFIG, ENALWAYS,     12, 1)
+    FIELD(CONFIG, ENONESHOT,    13, 1)
+    FIELD(CONFIG, CMP0CENTER,   16, 1)
+    FIELD(CONFIG, CMP1CENTER,   17, 1)
+    FIELD(CONFIG, CMP2CENTER,   18, 1)
+    FIELD(CONFIG, CMP3CENTER,   19, 1)
+    FIELD(CONFIG, CMP0GANG,     24, 1)
+    FIELD(CONFIG, CMP1GANG,     25, 1)
+    FIELD(CONFIG, CMP2GANG,     26, 1)
+    FIELD(CONFIG, CMP3GANG,     27, 1)
+    FIELD(CONFIG, CMP0IP,       28, 1)
+    FIELD(CONFIG, CMP1IP,       29, 1)
+    FIELD(CONFIG, CMP2IP,       30, 1)
+    FIELD(CONFIG, CMP3IP,       31, 1)
+REG32(COUNT,                   0x08)
+REG32(PWMS,                    0x10)
+REG32(PWMCMP0,                 0x20)
+REG32(PWMCMP1,                 0x24)
+REG32(PWMCMP2,                 0x28)
+REG32(PWMCMP3,                 0x2C)
+
+static inline uint64_t sifive_u_pwm_ns_to_ticks(SiFiveUPwmState *s,
+                                                uint64_t time)
+{
+    return muldiv64(time, s->freq_hz, NANOSECONDS_PER_SECOND);
+}
+
+static inline uint64_t sifive_u_pwm_ticks_to_ns(SiFiveUPwmState *s,
+                                                uint64_t ticks)
+{
+    return muldiv64(ticks, NANOSECONDS_PER_SECOND, s->freq_hz);
+}
+
+static inline uint64_t sifive_u_pwm_compute_scale(SiFiveUPwmState *s)
+{
+    return s->pwmcfg & R_CONFIG_SCALE_MASK;
+}
+
+static void sifive_u_pwm_set_alarms(SiFiveUPwmState *s)
+{
+    uint64_t now_ns = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
+
+    if (HAS_PWM_EN_BITS(s->pwmcfg)) {
+        /*
+         * Subtract ticks from number of ticks when the timer was zero
+         * and mask to the register width.
+         */
+        uint64_t pwmcount = (sifive_u_pwm_ns_to_ticks(s, now_ns) -
+                             s->tick_offset) & PWMCOUNT_MASK;
+        uint64_t scale = sifive_u_pwm_compute_scale(s);
+        /* PWMs only contains PWMCMP_MASK bits starting at scale */
+        uint64_t pwms = (pwmcount & (PWMCMP_MASK << scale)) >> scale;
+
+        for (int i = 0; i < SIFIVE_U_PWM_CHANS; i++) {
+            uint64_t pwmcmp = s->pwmcmp[i] & PWMCMP_MASK;
+            uint64_t pwmcmp_ticks = pwmcmp << scale;
+
+            /*
+             * Per circuit diagram and spec, both cases raises corresponding
+             * IP bit one clock cycle after time expires.
+             */
+            if (pwmcmp > pwms) {
+                uint64_t offset = pwmcmp_ticks - pwmcount + 1;
+                uint64_t when_to_fire = now_ns +
+                                          sifive_u_pwm_ticks_to_ns(s, offset);
+
+                DB_PRINT("Setting alarm to: 0x%lx, now: 0x%lx\n",
+                         when_to_fire, now_ns);
+                timer_mod(&s->timer[i], when_to_fire);
+            } else {
+                /* Schedule interrupt for next cycle */
+                DB_PRINT("Setting alarm to: 0x%lx, now: 0x%lx\n",
+                         now_ns + 1, now_ns);
+                timer_mod(&s->timer[i], now_ns + 1);
+            }
+
+        }
+    } else {
+        /*
+         * If timer incrementing disabled, just do pwms > pwmcmp check since
+         * a write may have happened to PWMs.
+         */
+        uint64_t pwmcount = (s->tick_offset) & PWMCOUNT_MASK;
+        uint64_t scale = sifive_u_pwm_compute_scale(s);
+        uint64_t pwms = (pwmcount & (PWMCMP_MASK << scale)) >> scale;
+
+        for (int i = 0; i < SIFIVE_U_PWM_CHANS; i++) {
+            uint64_t pwmcmp = s->pwmcmp[i] & PWMCMP_MASK;
+
+            if (pwms >= pwmcmp) {
+                DB_PRINT("Setting alarm to: 0x%lx, now: 0x%lx\n",
+                         now_ns + 1, now_ns);
+                timer_mod(&s->timer[i], now_ns + 1);
+            } else {
+                /* Effectively disable timer by scheduling far in future. */
+                DB_PRINT("Setting alarm to: 0x%lx, now: 0x%lx\n",
+                         0xFFFFFFFFFFFFFF, now_ns);
+                timer_mod(&s->timer[i], 0xFFFFFFFFFFFFFF);
+            }
+        }
+    }
+}
+
+static void sifive_u_pwm_interrupt(SiFiveUPwmState *s, int num)
+{
+    uint64_t now = sifive_u_pwm_ns_to_ticks(s,
+                                        qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL));
+    bool was_incrementing = HAS_PWM_EN_BITS(s->pwmcfg);
+
+    DB_PRINT("Interrupt %d\n", num);
+
+    s->pwmcfg |= R_CONFIG_CMP0IP_MASK << num;
+    qemu_irq_raise(s->irqs[num]);
+
+    /*
+     * If the zerocmp is set and pwmcmp0 raised the interrupt
+     * reset the zero ticks.
+     */
+    if ((s->pwmcfg & R_CONFIG_ZEROCMP_MASK) && (num == 0)) {
+        /* If reset signal conditions, disable ENONESHOT. */
+        s->pwmcfg &= ~R_CONFIG_ENONESHOT_MASK;
+
+        if (was_incrementing) {
+            /* If incrementing, time in ticks is when pwmcount is zero */
+            s->tick_offset = now;
+        } else {
+            /* If not incrementing, pwmcount = 0 */
+            s->tick_offset = 0;
+        }
+    }
+
+    /*
+     * If carryout bit set, which we discern via looking for overflow,
+     * also reset ENONESHOT.
+     */
+    if (was_incrementing &&
+        ((now & PWMCOUNT_MASK) < (s->tick_offset & PWMCOUNT_MASK))) {
+        s->pwmcfg &= ~R_CONFIG_ENONESHOT_MASK;
+    }
+
+    /* Schedule or disable interrupts */
+    sifive_u_pwm_set_alarms(s);
+
+    /* If was enabled, and now not enabled, switch tick rep */
+    if (was_incrementing && !HAS_PWM_EN_BITS(s->pwmcfg)) {
+        s->tick_offset = (now - s->tick_offset) & PWMCOUNT_MASK;
+    }
+}
+
+static void sifive_u_pwm_interrupt_0(void *opaque)
+{
+    SiFiveUPwmState *s = opaque;
+
+    sifive_u_pwm_interrupt(s, 0);
+}
+
+static void sifive_u_pwm_interrupt_1(void *opaque)
+{
+    SiFiveUPwmState *s = opaque;
+
+    sifive_u_pwm_interrupt(s, 1);
+}
+
+static void sifive_u_pwm_interrupt_2(void *opaque)
+{
+    SiFiveUPwmState *s = opaque;
+
+    sifive_u_pwm_interrupt(s, 2);
+}
+
+static void sifive_u_pwm_interrupt_3(void *opaque)
+{
+    SiFiveUPwmState *s = opaque;
+
+    sifive_u_pwm_interrupt(s, 3);
+}
+
+static uint64_t sifive_u_pwm_read(void *opaque, hwaddr addr,
+                                  unsigned int size)
+{
+    SiFiveUPwmState *s = opaque;
+    uint64_t cur_time, scale;
+    uint64_t now = sifive_u_pwm_ns_to_ticks(s,
+                                        qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL));
+
+    DB_PRINT("0x%"HWADDR_PRIx"\n", addr);
+
+    switch (addr) {
+    case A_CONFIG:
+        return s->pwmcfg;
+    case A_COUNT:
+        cur_time = s->tick_offset;
+
+        if (HAS_PWM_EN_BITS(s->pwmcfg)) {
+            cur_time = now - cur_time;
+        }
+
+        /*
+         * Return the value in the counter with bit 31 always 0
+         * This is allowed to wrap around so we don't need to check that.
+         */
+        return cur_time & PWMCOUNT_MASK;
+    case A_PWMS:
+        cur_time = s->tick_offset;
+        scale = sifive_u_pwm_compute_scale(s);
+
+        if (HAS_PWM_EN_BITS(s->pwmcfg)) {
+            cur_time = now - cur_time;
+        }
+
+        return ((cur_time & PWMCOUNT_MASK) >> scale) & PWMCMP_MASK;
+    case A_PWMCMP0:
+        return s->pwmcmp[0] & PWMCMP_MASK;
+    case A_PWMCMP1:
+        return s->pwmcmp[1] & PWMCMP_MASK;
+    case A_PWMCMP2:
+        return s->pwmcmp[2] & PWMCMP_MASK;
+    case A_PWMCMP3:
+        return s->pwmcmp[3] & PWMCMP_MASK;
+    default:
+        qemu_log_mask(LOG_GUEST_ERROR,
+                      "%s: Bad offset 0x%"HWADDR_PRIx"\n", __func__, addr);
+        return 0;
+    }
+
+    return 0;
+}
+
+static void sifive_u_pwm_write(void *opaque, hwaddr addr,
+                               uint64_t val64, unsigned int size)
+{
+    SiFiveUPwmState *s = opaque;
+    uint32_t value = val64;
+    uint64_t new_offset, scale;
+    uint64_t now = sifive_u_pwm_ns_to_ticks(s,
+                                        qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL));
+
+    DB_PRINT("0x%x, 0x%"HWADDR_PRIx"\n", value, addr);
+
+    switch (addr) {
+    case A_CONFIG:
+        if (value & (R_CONFIG_CMP0CENTER_MASK | R_CONFIG_CMP1CENTER_MASK |
+                     R_CONFIG_CMP2CENTER_MASK | R_CONFIG_CMP3CENTER_MASK)) {
+            qemu_log_mask(LOG_UNIMP, "%s: CMPxCENTER is not supported\n",
+                          __func__);
+        }
+
+        if (value & (R_CONFIG_CMP0GANG_MASK | R_CONFIG_CMP1GANG_MASK |
+                     R_CONFIG_CMP2GANG_MASK | R_CONFIG_CMP3GANG_MASK)) {
+            qemu_log_mask(LOG_UNIMP, "%s: CMPxGANG is not supported\n",
+                          __func__);
+        }
+
+        if (value & (R_CONFIG_CMP0IP_MASK | R_CONFIG_CMP1IP_MASK |
+                     R_CONFIG_CMP2IP_MASK | R_CONFIG_CMP3IP_MASK)) {
+            qemu_log_mask(LOG_UNIMP, "%s: CMPxIP is not supported\n",
+                          __func__);
+        }
+
+        if (!(value & R_CONFIG_CMP0IP_MASK)) {
+            qemu_irq_lower(s->irqs[0]);
+        }
+
+        if (!(value & R_CONFIG_CMP1IP_MASK)) {
+            qemu_irq_lower(s->irqs[1]);
+        }
+
+        if (!(value & R_CONFIG_CMP2IP_MASK)) {
+            qemu_irq_lower(s->irqs[2]);
+        }
+
+        if (!(value & R_CONFIG_CMP3IP_MASK)) {
+            qemu_irq_lower(s->irqs[3]);
+        }
+
+        /*
+         * If this write enables the timer increment
+         * set the time when pwmcount was zero to be cur_time - pwmcount.
+         * If this write disables the timer increment
+         * convert back from pwmcount to the time in ticks
+         * when pwmcount was zero.
+         */
+        if ((!HAS_PWM_EN_BITS(s->pwmcfg) && HAS_PWM_EN_BITS(value)) ||
+            (HAS_PWM_EN_BITS(s->pwmcfg) && !HAS_PWM_EN_BITS(value))) {
+            s->tick_offset = (now - s->tick_offset) & PWMCOUNT_MASK;
+        }
+
+        s->pwmcfg = value;
+        break;
+    case A_COUNT:
+        /* The guest changed the counter, updated the offset value. */
+        new_offset = value;
+
+        if (HAS_PWM_EN_BITS(s->pwmcfg)) {
+            new_offset = now - new_offset;
+        }
+
+        s->tick_offset = new_offset;
+        break;
+    case A_PWMS:
+        scale = sifive_u_pwm_compute_scale(s);
+        new_offset = (((value & PWMCMP_MASK) << scale) & PWMCOUNT_MASK);
+
+        if (HAS_PWM_EN_BITS(s->pwmcfg)) {
+            new_offset = now - new_offset;
+        }
+
+        s->tick_offset = new_offset;
+        break;
+    case A_PWMCMP0:
+        s->pwmcmp[0] = value & PWMCMP_MASK;
+        break;
+    case A_PWMCMP1:
+        s->pwmcmp[1] = value & PWMCMP_MASK;
+        break;
+    case A_PWMCMP2:
+        s->pwmcmp[2] = value & PWMCMP_MASK;
+        break;
+    case A_PWMCMP3:
+        s->pwmcmp[3] = value & PWMCMP_MASK;
+        break;
+    default:
+        qemu_log_mask(LOG_GUEST_ERROR,
+                      "%s: Bad offset 0x%"HWADDR_PRIx"\n", __func__, addr);
+    }
+
+    /* Update the alarms to reflect possible updated values */
+    sifive_u_pwm_set_alarms(s);
+}
+
+static void sifive_u_pwm_reset(DeviceState *dev)
+{
+    SiFiveUPwmState *s = SIFIVE_U_PWM(dev);
+    uint64_t now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
+
+    s->pwmcfg = 0x00000000;
+    s->pwmcmp[0] = 0x00000000;
+    s->pwmcmp[1] = 0x00000000;
+    s->pwmcmp[2] = 0x00000000;
+    s->pwmcmp[3] = 0x00000000;
+
+    s->tick_offset = sifive_u_pwm_ns_to_ticks(s, now);
+}
+
+static const MemoryRegionOps sifive_u_pwm_ops = {
+    .read = sifive_u_pwm_read,
+    .write = sifive_u_pwm_write,
+    .endianness = DEVICE_NATIVE_ENDIAN,
+};
+
+static const VMStateDescription vmstate_sifive_u_pwm = {
+    .name = TYPE_SIFIVE_U_PWM,
+    .version_id = 1,
+    .minimum_version_id = 1,
+    .fields = (VMStateField[]) {
+        VMSTATE_TIMER_ARRAY(timer, SiFiveUPwmState, 4),
+        VMSTATE_UINT64(tick_offset, SiFiveUPwmState),
+        VMSTATE_UINT32(pwmcfg, SiFiveUPwmState),
+        VMSTATE_UINT32_ARRAY(pwmcmp, SiFiveUPwmState, 4),
+        VMSTATE_END_OF_LIST()
+    }
+};
+
+static Property sifive_u_pwm_properties[] = {
+    /* 0.5Ghz per spec after FSBL */
+    DEFINE_PROP_UINT64("clock-frequency", struct SiFiveUPwmState,
+                       freq_hz, 500000000ULL),
+    DEFINE_PROP_END_OF_LIST(),
+};
+
+static void sifive_u_pwm_init(Object *obj)
+{
+    SiFiveUPwmState *s = SIFIVE_U_PWM(obj);
+    int i;
+
+    for (i = 0; i < SIFIVE_U_PWM_IRQS; i++) {
+        sysbus_init_irq(SYS_BUS_DEVICE(obj), &s->irqs[i]);
+    }
+
+    memory_region_init_io(&s->mmio, obj, &sifive_u_pwm_ops, s,
+                          TYPE_SIFIVE_U_PWM, 0x100);
+    sysbus_init_mmio(SYS_BUS_DEVICE(obj), &s->mmio);
+}
+
+static void sifive_u_pwm_realize(DeviceState *dev, Error **errp)
+{
+    SiFiveUPwmState *s = SIFIVE_U_PWM(dev);
+
+    timer_init_ns(&s->timer[0], QEMU_CLOCK_VIRTUAL,
+                  sifive_u_pwm_interrupt_0, s);
+
+    timer_init_ns(&s->timer[1], QEMU_CLOCK_VIRTUAL,
+                  sifive_u_pwm_interrupt_1, s);
+
+    timer_init_ns(&s->timer[2], QEMU_CLOCK_VIRTUAL,
+                  sifive_u_pwm_interrupt_2, s);
+
+    timer_init_ns(&s->timer[3], QEMU_CLOCK_VIRTUAL,
+                  sifive_u_pwm_interrupt_3, s);
+}
+
+static void sifive_u_pwm_class_init(ObjectClass *klass, void *data)
+{
+    DeviceClass *dc = DEVICE_CLASS(klass);
+
+    dc->reset = sifive_u_pwm_reset;
+    device_class_set_props(dc, sifive_u_pwm_properties);
+    dc->vmsd = &vmstate_sifive_u_pwm;
+    dc->realize = sifive_u_pwm_realize;
+}
+
+static const TypeInfo sifive_u_pwm_info = {
+    .name          = TYPE_SIFIVE_U_PWM,
+    .parent        = TYPE_SYS_BUS_DEVICE,
+    .instance_size = sizeof(SiFiveUPwmState),
+    .instance_init = sifive_u_pwm_init,
+    .class_init    = sifive_u_pwm_class_init,
+};
+
+static void sifive_u_pwm_register_types(void)
+{
+    type_register_static(&sifive_u_pwm_info);
+}
+
+type_init(sifive_u_pwm_register_types)
diff --git a/MAINTAINERS b/MAINTAINERS
index 554be84b32..32fdc8a4ca 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -303,7 +303,9 @@ L: qemu-riscv@nongnu.org
 S: Supported
 F: target/riscv/
 F: hw/riscv/
+F: hw/*/*sifive*
 F: include/hw/riscv/
+F: include/hw/*/*sifive*
 F: linux-user/host/riscv32/
 F: linux-user/host/riscv64/
 
diff --git a/hw/riscv/Kconfig b/hw/riscv/Kconfig
index 1de18cdcf1..aca8ad67a2 100644
--- a/hw/riscv/Kconfig
+++ b/hw/riscv/Kconfig
@@ -59,6 +59,7 @@ config SIFIVE_U
     select SIFIVE_U_PRCI
     select SSI_M25P80
     select SSI_SD
+    select SIFIVE_U_PWM
     select UNIMP
 
 config SPIKE
diff --git a/hw/timer/Kconfig b/hw/timer/Kconfig
index bac2511715..f39eb16e4e 100644
--- a/hw/timer/Kconfig
+++ b/hw/timer/Kconfig
@@ -25,6 +25,9 @@ config ALLWINNER_A10_PIT
     bool
     select PTIMER
 
+config SIFIVE_U_PWM
+    bool
+
 config STM32F2XX_TIMER
     bool
 
diff --git a/hw/timer/meson.build b/hw/timer/meson.build
index 598d058506..481f7f915b 100644
--- a/hw/timer/meson.build
+++ b/hw/timer/meson.build
@@ -36,5 +36,6 @@ softmmu_ss.add(when: 'CONFIG_SSE_COUNTER', if_true: files('sse-counter.c'))
 softmmu_ss.add(when: 'CONFIG_SSE_TIMER', if_true: files('sse-timer.c'))
 softmmu_ss.add(when: 'CONFIG_STM32F2XX_TIMER', if_true: files('stm32f2xx_timer.c'))
 softmmu_ss.add(when: 'CONFIG_XILINX', if_true: files('xilinx_timer.c'))
+softmmu_ss.add(when: 'CONFIG_SIFIVE_U_PWM', if_true: files('sifive_u_pwm.c'))
 
 specific_ss.add(when: 'CONFIG_AVR_TIMER16', if_true: files('avr_timer16.c'))
-- 
2.31.0

Re: [PATCH v1 1/2] sifive_u_pwm: Initial commit

[Bin Meng]

On Fri, Apr 2, 2021 at 8:46 PM Alistair Francis
<alistair.francis@wdc.com> wrote:
>

nits: it's better to write the commit title as: "hw/timer: Add SiFive
PWM support"

Also please write something to describe the hardware in the commit message.

> Signed-off-by: Justin Restivo <jrestivo@draper.com>
> Signed-off-by: Alexandra Clifford <aclifford@draper.com>
> Signed-off-by: Amanda Strnad <astrnad@draper.com>
> Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
> ---
>  include/hw/dma/sifive_pdma.h    |   2 +-
>  include/hw/timer/sifive_u_pwm.h |  62 ++++
>  hw/timer/sifive_u_pwm.c         | 483 ++++++++++++++++++++++++++++++++
>  MAINTAINERS                     |   2 +
>  hw/riscv/Kconfig                |   1 +
>  hw/timer/Kconfig                |   3 +
>  hw/timer/meson.build            |   1 +
>  7 files changed, 553 insertions(+), 1 deletion(-)
>  create mode 100644 include/hw/timer/sifive_u_pwm.h
>  create mode 100644 hw/timer/sifive_u_pwm.c
>
> diff --git a/include/hw/dma/sifive_pdma.h b/include/hw/dma/sifive_pdma.h
> index e319bbd6c4..fbd394fa29 100644
> --- a/include/hw/dma/sifive_pdma.h
> +++ b/include/hw/dma/sifive_pdma.h
> @@ -37,7 +37,7 @@ struct sifive_pdma_chan {
>  };
>
>  #define SIFIVE_PDMA_CHANS           4
> -#define SIFIVE_PDMA_IRQS            (SIFIVE_PDMA_CHANS * 2)
> +#define SIFIVE_PDMA_IRQS            (SIFIVE_PDMA_CHANS)

This looks irrelevant?

>  #define SIFIVE_PDMA_REG_SIZE        0x100000
>  #define SIFIVE_PDMA_CHAN_NO(reg)    ((reg & (SIFIVE_PDMA_REG_SIZE - 1)) >> 12)
>
> diff --git a/include/hw/timer/sifive_u_pwm.h b/include/hw/timer/sifive_u_pwm.h
> new file mode 100644
> index 0000000000..d0c7801f79
> --- /dev/null
> +++ b/include/hw/timer/sifive_u_pwm.h

Based on the DT binding in the kernel
(Documentation/devicetree/bindings/pwm/pwm-sifive.yaml), this seems to
be SiFive generic IP not SoC specific, so should be named as
sifive_pwm.h

> @@ -0,0 +1,62 @@
> +/*
> + * SiFive FU540 PWM

nits: SiFive PWM

> + *
> + * Copyright (c) 2020 Western Digital
> + *
> + * Author:  Alistair Francis <alistair.francis@wdc.com>
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a copy
> + * of this software and associated documentation files (the "Software"), to deal
> + * in the Software without restriction, including without limitation the rights
> + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
> + * copies of the Software, and to permit persons to whom the Software is
> + * furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice shall be included in
> + * all copies or substantial portions of the Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
> + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
> + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
> + * THE SOFTWARE.
> + */
> +
> +#ifndef HW_SIFIVE_U_PWM_H
> +#define HW_SIFIVE_U_PWM_H
> +
> +#include "hw/sysbus.h"
> +#include "qemu/timer.h"
> +#include "qom/object.h"
> +
> +#define TYPE_SIFIVE_U_PWM "sifive-u-pwm"

nits: the convention seems to be "sifive.pwm"

> +
> +#define SIFIVE_U_PWM(obj) \
> +    OBJECT_CHECK(SiFiveUPwmState, (obj), TYPE_SIFIVE_U_PWM)
> +
> +#define SIFIVE_U_PWM_CHANS          4
> +#define SIFIVE_U_PWM_IRQS           SIFIVE_U_PWM_CHANS
> +
> +typedef struct SiFiveUPwmState {
> +    /* <private> */
> +    SysBusDevice parent_obj;
> +
> +    /* <public> */
> +    MemoryRegion mmio;
> +    QEMUTimer timer[SIFIVE_U_PWM_CHANS];
> +    /*
> +     * if en bit(s) set, is the number of ticks when pwmcount was 0
> +     * if en bit(s) not set, is the number of ticks in pwmcount
> +     */
> +    uint64_t tick_offset;
> +    uint64_t freq_hz;
> +
> +    uint32_t pwmcfg;
> +    uint32_t pwmcmp[SIFIVE_U_PWM_CHANS];
> +
> +    qemu_irq irqs[SIFIVE_U_PWM_IRQS];
> +} SiFiveUPwmState;
> +
> +#endif /* HW_SIFIVE_U_PWM_H */
> diff --git a/hw/timer/sifive_u_pwm.c b/hw/timer/sifive_u_pwm.c
> new file mode 100644
> index 0000000000..047a659659
> --- /dev/null
> +++ b/hw/timer/sifive_u_pwm.c
> @@ -0,0 +1,483 @@
> +/*
> + * SiFive FU540 PWM
> + *
> + * Copyright (c) 2020 Western Digital
> + *
> + * Author:  Alistair Francis <alistair.francis@wdc.com>
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a copy
> + * of this software and associated documentation files (the "Software"), to deal
> + * in the Software without restriction, including without limitation the rights
> + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
> + * copies of the Software, and to permit persons to whom the Software is
> + * furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice shall be included in
> + * all copies or substantial portions of the Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
> + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
> + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
> + * THE SOFTWARE.
> + */
> +
> +#include "qemu/osdep.h"
> +#include "hw/irq.h"
> +#include "hw/timer/sifive_u_pwm.h"
> +#include "hw/qdev-properties.h"
> +#include "hw/registerfields.h"
> +#include "migration/vmstate.h"
> +#include "qemu/log.h"
> +#include "qemu/module.h"
> +
> +#ifndef STM_SYSCFG_ERR_DEBUG
> +#define STM_SYSCFG_ERR_DEBUG 0
> +#endif
> +
> +#define DB_PRINT_L(lvl, fmt, args...) do { \

This macro is never used by any codes?

> +    if (STM_SYSCFG_ERR_DEBUG >= lvl) { \
> +        qemu_log("%s: " fmt, __func__, ## args); \
> +    } \
> +} while (0)
> +
> +#define DB_PRINT(fmt, args...) DB_PRINT_L(1, fmt, ## args)

This macro is used, but it calls DB_PRINT_L() with lvl hard-coded as
1, so maybe we can simplify this a little bit?

> +
> +#define HAS_PWM_EN_BITS(cfg) ((cfg & R_CONFIG_ENONESHOT_MASK) || \
> +                              (cfg & R_CONFIG_ENALWAYS_MASK))
> +
> +#define PWMCMP_MASK 0xFFFF
> +#define PWMCOUNT_MASK 0x7FFFFFFF
> +
> +REG32(CONFIG,                   0x00)
> +    FIELD(CONFIG, SCALE,        0, 4)
> +    FIELD(CONFIG, STICKY,       8, 1)
> +    FIELD(CONFIG, ZEROCMP,      9, 1)
> +    FIELD(CONFIG, DEGLITCH,     10, 1)
> +    FIELD(CONFIG, ENALWAYS,     12, 1)
> +    FIELD(CONFIG, ENONESHOT,    13, 1)
> +    FIELD(CONFIG, CMP0CENTER,   16, 1)
> +    FIELD(CONFIG, CMP1CENTER,   17, 1)
> +    FIELD(CONFIG, CMP2CENTER,   18, 1)
> +    FIELD(CONFIG, CMP3CENTER,   19, 1)
> +    FIELD(CONFIG, CMP0GANG,     24, 1)
> +    FIELD(CONFIG, CMP1GANG,     25, 1)
> +    FIELD(CONFIG, CMP2GANG,     26, 1)
> +    FIELD(CONFIG, CMP3GANG,     27, 1)
> +    FIELD(CONFIG, CMP0IP,       28, 1)
> +    FIELD(CONFIG, CMP1IP,       29, 1)
> +    FIELD(CONFIG, CMP2IP,       30, 1)
> +    FIELD(CONFIG, CMP3IP,       31, 1)
> +REG32(COUNT,                   0x08)

nits: 0x08 not aligned to above lines, the same to below registers

> +REG32(PWMS,                    0x10)
> +REG32(PWMCMP0,                 0x20)
> +REG32(PWMCMP1,                 0x24)
> +REG32(PWMCMP2,                 0x28)
> +REG32(PWMCMP3,                 0x2C)
> +
> +static inline uint64_t sifive_u_pwm_ns_to_ticks(SiFiveUPwmState *s,
> +                                                uint64_t time)
> +{
> +    return muldiv64(time, s->freq_hz, NANOSECONDS_PER_SECOND);
> +}
> +
> +static inline uint64_t sifive_u_pwm_ticks_to_ns(SiFiveUPwmState *s,
> +                                                uint64_t ticks)
> +{
> +    return muldiv64(ticks, NANOSECONDS_PER_SECOND, s->freq_hz);
> +}
> +
> +static inline uint64_t sifive_u_pwm_compute_scale(SiFiveUPwmState *s)
> +{
> +    return s->pwmcfg & R_CONFIG_SCALE_MASK;
> +}
> +
> +static void sifive_u_pwm_set_alarms(SiFiveUPwmState *s)
> +{
> +    uint64_t now_ns = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
> +
> +    if (HAS_PWM_EN_BITS(s->pwmcfg)) {
> +        /*
> +         * Subtract ticks from number of ticks when the timer was zero
> +         * and mask to the register width.
> +         */
> +        uint64_t pwmcount = (sifive_u_pwm_ns_to_ticks(s, now_ns) -
> +                             s->tick_offset) & PWMCOUNT_MASK;
> +        uint64_t scale = sifive_u_pwm_compute_scale(s);
> +        /* PWMs only contains PWMCMP_MASK bits starting at scale */
> +        uint64_t pwms = (pwmcount & (PWMCMP_MASK << scale)) >> scale;
> +
> +        for (int i = 0; i < SIFIVE_U_PWM_CHANS; i++) {
> +            uint64_t pwmcmp = s->pwmcmp[i] & PWMCMP_MASK;
> +            uint64_t pwmcmp_ticks = pwmcmp << scale;
> +
> +            /*
> +             * Per circuit diagram and spec, both cases raises corresponding
> +             * IP bit one clock cycle after time expires.
> +             */
> +            if (pwmcmp > pwms) {
> +                uint64_t offset = pwmcmp_ticks - pwmcount + 1;
> +                uint64_t when_to_fire = now_ns +
> +                                          sifive_u_pwm_ticks_to_ns(s, offset);
> +
> +                DB_PRINT("Setting alarm to: 0x%lx, now: 0x%lx\n",
> +                         when_to_fire, now_ns);
> +                timer_mod(&s->timer[i], when_to_fire);
> +            } else {
> +                /* Schedule interrupt for next cycle */
> +                DB_PRINT("Setting alarm to: 0x%lx, now: 0x%lx\n",
> +                         now_ns + 1, now_ns);
> +                timer_mod(&s->timer[i], now_ns + 1);
> +            }
> +
> +        }
> +    } else {
> +        /*
> +         * If timer incrementing disabled, just do pwms > pwmcmp check since
> +         * a write may have happened to PWMs.
> +         */
> +        uint64_t pwmcount = (s->tick_offset) & PWMCOUNT_MASK;
> +        uint64_t scale = sifive_u_pwm_compute_scale(s);
> +        uint64_t pwms = (pwmcount & (PWMCMP_MASK << scale)) >> scale;
> +
> +        for (int i = 0; i < SIFIVE_U_PWM_CHANS; i++) {
> +            uint64_t pwmcmp = s->pwmcmp[i] & PWMCMP_MASK;
> +
> +            if (pwms >= pwmcmp) {
> +                DB_PRINT("Setting alarm to: 0x%lx, now: 0x%lx\n",
> +                         now_ns + 1, now_ns);
> +                timer_mod(&s->timer[i], now_ns + 1);
> +            } else {
> +                /* Effectively disable timer by scheduling far in future. */
> +                DB_PRINT("Setting alarm to: 0x%lx, now: 0x%lx\n",
> +                         0xFFFFFFFFFFFFFF, now_ns);
> +                timer_mod(&s->timer[i], 0xFFFFFFFFFFFFFF);
> +            }
> +        }
> +    }
> +}
> +
> +static void sifive_u_pwm_interrupt(SiFiveUPwmState *s, int num)
> +{
> +    uint64_t now = sifive_u_pwm_ns_to_ticks(s,
> +                                        qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL));
> +    bool was_incrementing = HAS_PWM_EN_BITS(s->pwmcfg);
> +
> +    DB_PRINT("Interrupt %d\n", num);
> +
> +    s->pwmcfg |= R_CONFIG_CMP0IP_MASK << num;
> +    qemu_irq_raise(s->irqs[num]);
> +
> +    /*
> +     * If the zerocmp is set and pwmcmp0 raised the interrupt
> +     * reset the zero ticks.
> +     */
> +    if ((s->pwmcfg & R_CONFIG_ZEROCMP_MASK) && (num == 0)) {
> +        /* If reset signal conditions, disable ENONESHOT. */
> +        s->pwmcfg &= ~R_CONFIG_ENONESHOT_MASK;
> +
> +        if (was_incrementing) {
> +            /* If incrementing, time in ticks is when pwmcount is zero */
> +            s->tick_offset = now;
> +        } else {
> +            /* If not incrementing, pwmcount = 0 */
> +            s->tick_offset = 0;
> +        }
> +    }
> +
> +    /*
> +     * If carryout bit set, which we discern via looking for overflow,
> +     * also reset ENONESHOT.
> +     */
> +    if (was_incrementing &&
> +        ((now & PWMCOUNT_MASK) < (s->tick_offset & PWMCOUNT_MASK))) {
> +        s->pwmcfg &= ~R_CONFIG_ENONESHOT_MASK;
> +    }
> +
> +    /* Schedule or disable interrupts */
> +    sifive_u_pwm_set_alarms(s);
> +
> +    /* If was enabled, and now not enabled, switch tick rep */
> +    if (was_incrementing && !HAS_PWM_EN_BITS(s->pwmcfg)) {
> +        s->tick_offset = (now - s->tick_offset) & PWMCOUNT_MASK;
> +    }
> +}
> +
> +static void sifive_u_pwm_interrupt_0(void *opaque)
> +{
> +    SiFiveUPwmState *s = opaque;
> +
> +    sifive_u_pwm_interrupt(s, 0);
> +}
> +
> +static void sifive_u_pwm_interrupt_1(void *opaque)
> +{
> +    SiFiveUPwmState *s = opaque;
> +
> +    sifive_u_pwm_interrupt(s, 1);
> +}
> +
> +static void sifive_u_pwm_interrupt_2(void *opaque)
> +{
> +    SiFiveUPwmState *s = opaque;
> +
> +    sifive_u_pwm_interrupt(s, 2);
> +}
> +
> +static void sifive_u_pwm_interrupt_3(void *opaque)
> +{
> +    SiFiveUPwmState *s = opaque;
> +
> +    sifive_u_pwm_interrupt(s, 3);
> +}
> +
> +static uint64_t sifive_u_pwm_read(void *opaque, hwaddr addr,
> +                                  unsigned int size)
> +{
> +    SiFiveUPwmState *s = opaque;
> +    uint64_t cur_time, scale;
> +    uint64_t now = sifive_u_pwm_ns_to_ticks(s,
> +                                        qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL));
> +
> +    DB_PRINT("0x%"HWADDR_PRIx"\n", addr);
> +
> +    switch (addr) {
> +    case A_CONFIG:
> +        return s->pwmcfg;
> +    case A_COUNT:
> +        cur_time = s->tick_offset;
> +
> +        if (HAS_PWM_EN_BITS(s->pwmcfg)) {
> +            cur_time = now - cur_time;
> +        }
> +
> +        /*
> +         * Return the value in the counter with bit 31 always 0
> +         * This is allowed to wrap around so we don't need to check that.
> +         */
> +        return cur_time & PWMCOUNT_MASK;
> +    case A_PWMS:
> +        cur_time = s->tick_offset;
> +        scale = sifive_u_pwm_compute_scale(s);
> +
> +        if (HAS_PWM_EN_BITS(s->pwmcfg)) {
> +            cur_time = now - cur_time;
> +        }
> +
> +        return ((cur_time & PWMCOUNT_MASK) >> scale) & PWMCMP_MASK;
> +    case A_PWMCMP0:
> +        return s->pwmcmp[0] & PWMCMP_MASK;
> +    case A_PWMCMP1:
> +        return s->pwmcmp[1] & PWMCMP_MASK;
> +    case A_PWMCMP2:
> +        return s->pwmcmp[2] & PWMCMP_MASK;
> +    case A_PWMCMP3:
> +        return s->pwmcmp[3] & PWMCMP_MASK;
> +    default:
> +        qemu_log_mask(LOG_GUEST_ERROR,
> +                      "%s: Bad offset 0x%"HWADDR_PRIx"\n", __func__, addr);
> +        return 0;
> +    }
> +
> +    return 0;
> +}
> +
> +static void sifive_u_pwm_write(void *opaque, hwaddr addr,
> +                               uint64_t val64, unsigned int size)
> +{
> +    SiFiveUPwmState *s = opaque;
> +    uint32_t value = val64;
> +    uint64_t new_offset, scale;
> +    uint64_t now = sifive_u_pwm_ns_to_ticks(s,
> +                                        qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL));
> +
> +    DB_PRINT("0x%x, 0x%"HWADDR_PRIx"\n", value, addr);
> +
> +    switch (addr) {
> +    case A_CONFIG:
> +        if (value & (R_CONFIG_CMP0CENTER_MASK | R_CONFIG_CMP1CENTER_MASK |
> +                     R_CONFIG_CMP2CENTER_MASK | R_CONFIG_CMP3CENTER_MASK)) {
> +            qemu_log_mask(LOG_UNIMP, "%s: CMPxCENTER is not supported\n",
> +                          __func__);
> +        }
> +
> +        if (value & (R_CONFIG_CMP0GANG_MASK | R_CONFIG_CMP1GANG_MASK |
> +                     R_CONFIG_CMP2GANG_MASK | R_CONFIG_CMP3GANG_MASK)) {
> +            qemu_log_mask(LOG_UNIMP, "%s: CMPxGANG is not supported\n",
> +                          __func__);
> +        }
> +
> +        if (value & (R_CONFIG_CMP0IP_MASK | R_CONFIG_CMP1IP_MASK |
> +                     R_CONFIG_CMP2IP_MASK | R_CONFIG_CMP3IP_MASK)) {
> +            qemu_log_mask(LOG_UNIMP, "%s: CMPxIP is not supported\n",
> +                          __func__);
> +        }
> +
> +        if (!(value & R_CONFIG_CMP0IP_MASK)) {
> +            qemu_irq_lower(s->irqs[0]);
> +        }
> +
> +        if (!(value & R_CONFIG_CMP1IP_MASK)) {
> +            qemu_irq_lower(s->irqs[1]);
> +        }
> +
> +        if (!(value & R_CONFIG_CMP2IP_MASK)) {
> +            qemu_irq_lower(s->irqs[2]);
> +        }
> +
> +        if (!(value & R_CONFIG_CMP3IP_MASK)) {
> +            qemu_irq_lower(s->irqs[3]);
> +        }
> +
> +        /*
> +         * If this write enables the timer increment
> +         * set the time when pwmcount was zero to be cur_time - pwmcount.
> +         * If this write disables the timer increment
> +         * convert back from pwmcount to the time in ticks
> +         * when pwmcount was zero.
> +         */
> +        if ((!HAS_PWM_EN_BITS(s->pwmcfg) && HAS_PWM_EN_BITS(value)) ||
> +            (HAS_PWM_EN_BITS(s->pwmcfg) && !HAS_PWM_EN_BITS(value))) {
> +            s->tick_offset = (now - s->tick_offset) & PWMCOUNT_MASK;
> +        }
> +
> +        s->pwmcfg = value;
> +        break;
> +    case A_COUNT:
> +        /* The guest changed the counter, updated the offset value. */
> +        new_offset = value;
> +
> +        if (HAS_PWM_EN_BITS(s->pwmcfg)) {
> +            new_offset = now - new_offset;
> +        }
> +
> +        s->tick_offset = new_offset;
> +        break;
> +    case A_PWMS:
> +        scale = sifive_u_pwm_compute_scale(s);
> +        new_offset = (((value & PWMCMP_MASK) << scale) & PWMCOUNT_MASK);
> +
> +        if (HAS_PWM_EN_BITS(s->pwmcfg)) {
> +            new_offset = now - new_offset;
> +        }
> +
> +        s->tick_offset = new_offset;
> +        break;
> +    case A_PWMCMP0:
> +        s->pwmcmp[0] = value & PWMCMP_MASK;
> +        break;
> +    case A_PWMCMP1:
> +        s->pwmcmp[1] = value & PWMCMP_MASK;
> +        break;
> +    case A_PWMCMP2:
> +        s->pwmcmp[2] = value & PWMCMP_MASK;
> +        break;
> +    case A_PWMCMP3:
> +        s->pwmcmp[3] = value & PWMCMP_MASK;
> +        break;
> +    default:
> +        qemu_log_mask(LOG_GUEST_ERROR,
> +                      "%s: Bad offset 0x%"HWADDR_PRIx"\n", __func__, addr);
> +    }
> +
> +    /* Update the alarms to reflect possible updated values */
> +    sifive_u_pwm_set_alarms(s);
> +}
> +
> +static void sifive_u_pwm_reset(DeviceState *dev)
> +{
> +    SiFiveUPwmState *s = SIFIVE_U_PWM(dev);
> +    uint64_t now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
> +
> +    s->pwmcfg = 0x00000000;
> +    s->pwmcmp[0] = 0x00000000;
> +    s->pwmcmp[1] = 0x00000000;
> +    s->pwmcmp[2] = 0x00000000;
> +    s->pwmcmp[3] = 0x00000000;
> +
> +    s->tick_offset = sifive_u_pwm_ns_to_ticks(s, now);
> +}
> +
> +static const MemoryRegionOps sifive_u_pwm_ops = {
> +    .read = sifive_u_pwm_read,
> +    .write = sifive_u_pwm_write,
> +    .endianness = DEVICE_NATIVE_ENDIAN,
> +};
> +
> +static const VMStateDescription vmstate_sifive_u_pwm = {
> +    .name = TYPE_SIFIVE_U_PWM,
> +    .version_id = 1,
> +    .minimum_version_id = 1,
> +    .fields = (VMStateField[]) {
> +        VMSTATE_TIMER_ARRAY(timer, SiFiveUPwmState, 4),
> +        VMSTATE_UINT64(tick_offset, SiFiveUPwmState),
> +        VMSTATE_UINT32(pwmcfg, SiFiveUPwmState),
> +        VMSTATE_UINT32_ARRAY(pwmcmp, SiFiveUPwmState, 4),
> +        VMSTATE_END_OF_LIST()
> +    }
> +};
> +
> +static Property sifive_u_pwm_properties[] = {
> +    /* 0.5Ghz per spec after FSBL */

Where is this value from? Is the clock from PRCI module?

> +    DEFINE_PROP_UINT64("clock-frequency", struct SiFiveUPwmState,
> +                       freq_hz, 500000000ULL),
> +    DEFINE_PROP_END_OF_LIST(),
> +};
> +
> +static void sifive_u_pwm_init(Object *obj)
> +{
> +    SiFiveUPwmState *s = SIFIVE_U_PWM(obj);
> +    int i;
> +
> +    for (i = 0; i < SIFIVE_U_PWM_IRQS; i++) {
> +        sysbus_init_irq(SYS_BUS_DEVICE(obj), &s->irqs[i]);
> +    }
> +
> +    memory_region_init_io(&s->mmio, obj, &sifive_u_pwm_ops, s,
> +                          TYPE_SIFIVE_U_PWM, 0x100);
> +    sysbus_init_mmio(SYS_BUS_DEVICE(obj), &s->mmio);
> +}
> +
> +static void sifive_u_pwm_realize(DeviceState *dev, Error **errp)
> +{
> +    SiFiveUPwmState *s = SIFIVE_U_PWM(dev);
> +
> +    timer_init_ns(&s->timer[0], QEMU_CLOCK_VIRTUAL,
> +                  sifive_u_pwm_interrupt_0, s);
> +
> +    timer_init_ns(&s->timer[1], QEMU_CLOCK_VIRTUAL,
> +                  sifive_u_pwm_interrupt_1, s);
> +
> +    timer_init_ns(&s->timer[2], QEMU_CLOCK_VIRTUAL,
> +                  sifive_u_pwm_interrupt_2, s);
> +
> +    timer_init_ns(&s->timer[3], QEMU_CLOCK_VIRTUAL,
> +                  sifive_u_pwm_interrupt_3, s);
> +}
> +
> +static void sifive_u_pwm_class_init(ObjectClass *klass, void *data)
> +{
> +    DeviceClass *dc = DEVICE_CLASS(klass);
> +
> +    dc->reset = sifive_u_pwm_reset;
> +    device_class_set_props(dc, sifive_u_pwm_properties);
> +    dc->vmsd = &vmstate_sifive_u_pwm;
> +    dc->realize = sifive_u_pwm_realize;
> +}
> +
> +static const TypeInfo sifive_u_pwm_info = {
> +    .name          = TYPE_SIFIVE_U_PWM,
> +    .parent        = TYPE_SYS_BUS_DEVICE,
> +    .instance_size = sizeof(SiFiveUPwmState),
> +    .instance_init = sifive_u_pwm_init,
> +    .class_init    = sifive_u_pwm_class_init,
> +};
> +
> +static void sifive_u_pwm_register_types(void)
> +{
> +    type_register_static(&sifive_u_pwm_info);
> +}
> +
> +type_init(sifive_u_pwm_register_types)
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 554be84b32..32fdc8a4ca 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -303,7 +303,9 @@ L: qemu-riscv@nongnu.org
>  S: Supported
>  F: target/riscv/
>  F: hw/riscv/
> +F: hw/*/*sifive*
>  F: include/hw/riscv/
> +F: include/hw/*/*sifive*

This is the RISC-V CPU section. The SiFive machine section already covers this.

>  F: linux-user/host/riscv32/
>  F: linux-user/host/riscv64/
>
> diff --git a/hw/riscv/Kconfig b/hw/riscv/Kconfig
> index 1de18cdcf1..aca8ad67a2 100644
> --- a/hw/riscv/Kconfig
> +++ b/hw/riscv/Kconfig
> @@ -59,6 +59,7 @@ config SIFIVE_U
>      select SIFIVE_U_PRCI
>      select SSI_M25P80
>      select SSI_SD
> +    select SIFIVE_U_PWM

This change belongs to the 2nd patch in this series.

>      select UNIMP
>
>  config SPIKE
> diff --git a/hw/timer/Kconfig b/hw/timer/Kconfig
> index bac2511715..f39eb16e4e 100644
> --- a/hw/timer/Kconfig
> +++ b/hw/timer/Kconfig
> @@ -25,6 +25,9 @@ config ALLWINNER_A10_PIT
>      bool
>      select PTIMER
>
> +config SIFIVE_U_PWM
> +    bool
> +
>  config STM32F2XX_TIMER
>      bool
>
> diff --git a/hw/timer/meson.build b/hw/timer/meson.build
> index 598d058506..481f7f915b 100644
> --- a/hw/timer/meson.build
> +++ b/hw/timer/meson.build
> @@ -36,5 +36,6 @@ softmmu_ss.add(when: 'CONFIG_SSE_COUNTER', if_true: files('sse-counter.c'))
>  softmmu_ss.add(when: 'CONFIG_SSE_TIMER', if_true: files('sse-timer.c'))
>  softmmu_ss.add(when: 'CONFIG_STM32F2XX_TIMER', if_true: files('stm32f2xx_timer.c'))
>  softmmu_ss.add(when: 'CONFIG_XILINX', if_true: files('xilinx_timer.c'))
> +softmmu_ss.add(when: 'CONFIG_SIFIVE_U_PWM', if_true: files('sifive_u_pwm.c'))
>
>  specific_ss.add(when: 'CONFIG_AVR_TIMER16', if_true: files('avr_timer16.c'))
> --

Regards,
Bin

Re: [PATCH v1 1/2] sifive_u_pwm: Initial commit

[Bin Meng]

On Fri, Apr 2, 2021 at 8:46 PM Alistair Francis
<alistair.francis@wdc.com> wrote:
>

nits: it's better to write the commit title as: "hw/timer: Add SiFive
PWM support"

Also please write something to describe the hardware in the commit message.

> Signed-off-by: Justin Restivo <jrestivo@draper.com>
> Signed-off-by: Alexandra Clifford <aclifford@draper.com>
> Signed-off-by: Amanda Strnad <astrnad@draper.com>
> Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
> ---
>  include/hw/dma/sifive_pdma.h    |   2 +-
>  include/hw/timer/sifive_u_pwm.h |  62 ++++
>  hw/timer/sifive_u_pwm.c         | 483 ++++++++++++++++++++++++++++++++
>  MAINTAINERS                     |   2 +
>  hw/riscv/Kconfig                |   1 +
>  hw/timer/Kconfig                |   3 +
>  hw/timer/meson.build            |   1 +
>  7 files changed, 553 insertions(+), 1 deletion(-)
>  create mode 100644 include/hw/timer/sifive_u_pwm.h
>  create mode 100644 hw/timer/sifive_u_pwm.c
>
> diff --git a/include/hw/dma/sifive_pdma.h b/include/hw/dma/sifive_pdma.h
> index e319bbd6c4..fbd394fa29 100644
> --- a/include/hw/dma/sifive_pdma.h
> +++ b/include/hw/dma/sifive_pdma.h
> @@ -37,7 +37,7 @@ struct sifive_pdma_chan {
>  };
>
>  #define SIFIVE_PDMA_CHANS           4
> -#define SIFIVE_PDMA_IRQS            (SIFIVE_PDMA_CHANS * 2)
> +#define SIFIVE_PDMA_IRQS            (SIFIVE_PDMA_CHANS)

This looks irrelevant?

>  #define SIFIVE_PDMA_REG_SIZE        0x100000
>  #define SIFIVE_PDMA_CHAN_NO(reg)    ((reg & (SIFIVE_PDMA_REG_SIZE - 1)) >> 12)
>
> diff --git a/include/hw/timer/sifive_u_pwm.h b/include/hw/timer/sifive_u_pwm.h
> new file mode 100644
> index 0000000000..d0c7801f79
> --- /dev/null
> +++ b/include/hw/timer/sifive_u_pwm.h

Based on the DT binding in the kernel
(Documentation/devicetree/bindings/pwm/pwm-sifive.yaml), this seems to
be SiFive generic IP not SoC specific, so should be named as
sifive_pwm.h

> @@ -0,0 +1,62 @@
> +/*
> + * SiFive FU540 PWM

nits: SiFive PWM

> + *
> + * Copyright (c) 2020 Western Digital
> + *
> + * Author:  Alistair Francis <alistair.francis@wdc.com>
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a copy
> + * of this software and associated documentation files (the "Software"), to deal
> + * in the Software without restriction, including without limitation the rights
> + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
> + * copies of the Software, and to permit persons to whom the Software is
> + * furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice shall be included in
> + * all copies or substantial portions of the Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
> + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
> + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
> + * THE SOFTWARE.
> + */
> +
> +#ifndef HW_SIFIVE_U_PWM_H
> +#define HW_SIFIVE_U_PWM_H
> +
> +#include "hw/sysbus.h"
> +#include "qemu/timer.h"
> +#include "qom/object.h"
> +
> +#define TYPE_SIFIVE_U_PWM "sifive-u-pwm"

nits: the convention seems to be "sifive.pwm"

> +
> +#define SIFIVE_U_PWM(obj) \
> +    OBJECT_CHECK(SiFiveUPwmState, (obj), TYPE_SIFIVE_U_PWM)
> +
> +#define SIFIVE_U_PWM_CHANS          4
> +#define SIFIVE_U_PWM_IRQS           SIFIVE_U_PWM_CHANS
> +
> +typedef struct SiFiveUPwmState {
> +    /* <private> */
> +    SysBusDevice parent_obj;
> +
> +    /* <public> */
> +    MemoryRegion mmio;
> +    QEMUTimer timer[SIFIVE_U_PWM_CHANS];
> +    /*
> +     * if en bit(s) set, is the number of ticks when pwmcount was 0
> +     * if en bit(s) not set, is the number of ticks in pwmcount
> +     */
> +    uint64_t tick_offset;
> +    uint64_t freq_hz;
> +
> +    uint32_t pwmcfg;
> +    uint32_t pwmcmp[SIFIVE_U_PWM_CHANS];
> +
> +    qemu_irq irqs[SIFIVE_U_PWM_IRQS];
> +} SiFiveUPwmState;
> +
> +#endif /* HW_SIFIVE_U_PWM_H */
> diff --git a/hw/timer/sifive_u_pwm.c b/hw/timer/sifive_u_pwm.c
> new file mode 100644
> index 0000000000..047a659659
> --- /dev/null
> +++ b/hw/timer/sifive_u_pwm.c
> @@ -0,0 +1,483 @@
> +/*
> + * SiFive FU540 PWM
> + *
> + * Copyright (c) 2020 Western Digital
> + *
> + * Author:  Alistair Francis <alistair.francis@wdc.com>
> + *
> + * Permission is hereby granted, free of charge, to any person obtaining a copy
> + * of this software and associated documentation files (the "Software"), to deal
> + * in the Software without restriction, including without limitation the rights
> + * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
> + * copies of the Software, and to permit persons to whom the Software is
> + * furnished to do so, subject to the following conditions:
> + *
> + * The above copyright notice and this permission notice shall be included in
> + * all copies or substantial portions of the Software.
> + *
> + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
> + * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
> + * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
> + * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
> + * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
> + * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
> + * THE SOFTWARE.
> + */
> +
> +#include "qemu/osdep.h"
> +#include "hw/irq.h"
> +#include "hw/timer/sifive_u_pwm.h"
> +#include "hw/qdev-properties.h"
> +#include "hw/registerfields.h"
> +#include "migration/vmstate.h"
> +#include "qemu/log.h"
> +#include "qemu/module.h"
> +
> +#ifndef STM_SYSCFG_ERR_DEBUG
> +#define STM_SYSCFG_ERR_DEBUG 0
> +#endif
> +
> +#define DB_PRINT_L(lvl, fmt, args...) do { \

This macro is never used by any codes?

> +    if (STM_SYSCFG_ERR_DEBUG >= lvl) { \
> +        qemu_log("%s: " fmt, __func__, ## args); \
> +    } \
> +} while (0)
> +
> +#define DB_PRINT(fmt, args...) DB_PRINT_L(1, fmt, ## args)

This macro is used, but it calls DB_PRINT_L() with lvl hard-coded as
1, so maybe we can simplify this a little bit?

> +
> +#define HAS_PWM_EN_BITS(cfg) ((cfg & R_CONFIG_ENONESHOT_MASK) || \
> +                              (cfg & R_CONFIG_ENALWAYS_MASK))
> +
> +#define PWMCMP_MASK 0xFFFF
> +#define PWMCOUNT_MASK 0x7FFFFFFF
> +
> +REG32(CONFIG,                   0x00)
> +    FIELD(CONFIG, SCALE,        0, 4)
> +    FIELD(CONFIG, STICKY,       8, 1)
> +    FIELD(CONFIG, ZEROCMP,      9, 1)
> +    FIELD(CONFIG, DEGLITCH,     10, 1)
> +    FIELD(CONFIG, ENALWAYS,     12, 1)
> +    FIELD(CONFIG, ENONESHOT,    13, 1)
> +    FIELD(CONFIG, CMP0CENTER,   16, 1)
> +    FIELD(CONFIG, CMP1CENTER,   17, 1)
> +    FIELD(CONFIG, CMP2CENTER,   18, 1)
> +    FIELD(CONFIG, CMP3CENTER,   19, 1)
> +    FIELD(CONFIG, CMP0GANG,     24, 1)
> +    FIELD(CONFIG, CMP1GANG,     25, 1)
> +    FIELD(CONFIG, CMP2GANG,     26, 1)
> +    FIELD(CONFIG, CMP3GANG,     27, 1)
> +    FIELD(CONFIG, CMP0IP,       28, 1)
> +    FIELD(CONFIG, CMP1IP,       29, 1)
> +    FIELD(CONFIG, CMP2IP,       30, 1)
> +    FIELD(CONFIG, CMP3IP,       31, 1)
> +REG32(COUNT,                   0x08)

nits: 0x08 not aligned to above lines, the same to below registers

> +REG32(PWMS,                    0x10)
> +REG32(PWMCMP0,                 0x20)
> +REG32(PWMCMP1,                 0x24)
> +REG32(PWMCMP2,                 0x28)
> +REG32(PWMCMP3,                 0x2C)
> +
> +static inline uint64_t sifive_u_pwm_ns_to_ticks(SiFiveUPwmState *s,
> +                                                uint64_t time)
> +{
> +    return muldiv64(time, s->freq_hz, NANOSECONDS_PER_SECOND);
> +}
> +
> +static inline uint64_t sifive_u_pwm_ticks_to_ns(SiFiveUPwmState *s,
> +                                                uint64_t ticks)
> +{
> +    return muldiv64(ticks, NANOSECONDS_PER_SECOND, s->freq_hz);
> +}
> +
> +static inline uint64_t sifive_u_pwm_compute_scale(SiFiveUPwmState *s)
> +{
> +    return s->pwmcfg & R_CONFIG_SCALE_MASK;
> +}
> +
> +static void sifive_u_pwm_set_alarms(SiFiveUPwmState *s)
> +{
> +    uint64_t now_ns = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
> +
> +    if (HAS_PWM_EN_BITS(s->pwmcfg)) {
> +        /*
> +         * Subtract ticks from number of ticks when the timer was zero
> +         * and mask to the register width.
> +         */
> +        uint64_t pwmcount = (sifive_u_pwm_ns_to_ticks(s, now_ns) -
> +                             s->tick_offset) & PWMCOUNT_MASK;
> +        uint64_t scale = sifive_u_pwm_compute_scale(s);
> +        /* PWMs only contains PWMCMP_MASK bits starting at scale */
> +        uint64_t pwms = (pwmcount & (PWMCMP_MASK << scale)) >> scale;
> +
> +        for (int i = 0; i < SIFIVE_U_PWM_CHANS; i++) {
> +            uint64_t pwmcmp = s->pwmcmp[i] & PWMCMP_MASK;
> +            uint64_t pwmcmp_ticks = pwmcmp << scale;
> +
> +            /*
> +             * Per circuit diagram and spec, both cases raises corresponding
> +             * IP bit one clock cycle after time expires.
> +             */
> +            if (pwmcmp > pwms) {
> +                uint64_t offset = pwmcmp_ticks - pwmcount + 1;
> +                uint64_t when_to_fire = now_ns +
> +                                          sifive_u_pwm_ticks_to_ns(s, offset);
> +
> +                DB_PRINT("Setting alarm to: 0x%lx, now: 0x%lx\n",
> +                         when_to_fire, now_ns);
> +                timer_mod(&s->timer[i], when_to_fire);
> +            } else {
> +                /* Schedule interrupt for next cycle */
> +                DB_PRINT("Setting alarm to: 0x%lx, now: 0x%lx\n",
> +                         now_ns + 1, now_ns);
> +                timer_mod(&s->timer[i], now_ns + 1);
> +            }
> +
> +        }
> +    } else {
> +        /*
> +         * If timer incrementing disabled, just do pwms > pwmcmp check since
> +         * a write may have happened to PWMs.
> +         */
> +        uint64_t pwmcount = (s->tick_offset) & PWMCOUNT_MASK;
> +        uint64_t scale = sifive_u_pwm_compute_scale(s);
> +        uint64_t pwms = (pwmcount & (PWMCMP_MASK << scale)) >> scale;
> +
> +        for (int i = 0; i < SIFIVE_U_PWM_CHANS; i++) {
> +            uint64_t pwmcmp = s->pwmcmp[i] & PWMCMP_MASK;
> +
> +            if (pwms >= pwmcmp) {
> +                DB_PRINT("Setting alarm to: 0x%lx, now: 0x%lx\n",
> +                         now_ns + 1, now_ns);
> +                timer_mod(&s->timer[i], now_ns + 1);
> +            } else {
> +                /* Effectively disable timer by scheduling far in future. */
> +                DB_PRINT("Setting alarm to: 0x%lx, now: 0x%lx\n",
> +                         0xFFFFFFFFFFFFFF, now_ns);
> +                timer_mod(&s->timer[i], 0xFFFFFFFFFFFFFF);
> +            }
> +        }
> +    }
> +}
> +
> +static void sifive_u_pwm_interrupt(SiFiveUPwmState *s, int num)
> +{
> +    uint64_t now = sifive_u_pwm_ns_to_ticks(s,
> +                                        qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL));
> +    bool was_incrementing = HAS_PWM_EN_BITS(s->pwmcfg);
> +
> +    DB_PRINT("Interrupt %d\n", num);
> +
> +    s->pwmcfg |= R_CONFIG_CMP0IP_MASK << num;
> +    qemu_irq_raise(s->irqs[num]);
> +
> +    /*
> +     * If the zerocmp is set and pwmcmp0 raised the interrupt
> +     * reset the zero ticks.
> +     */
> +    if ((s->pwmcfg & R_CONFIG_ZEROCMP_MASK) && (num == 0)) {
> +        /* If reset signal conditions, disable ENONESHOT. */
> +        s->pwmcfg &= ~R_CONFIG_ENONESHOT_MASK;
> +
> +        if (was_incrementing) {
> +            /* If incrementing, time in ticks is when pwmcount is zero */
> +            s->tick_offset = now;
> +        } else {
> +            /* If not incrementing, pwmcount = 0 */
> +            s->tick_offset = 0;
> +        }
> +    }
> +
> +    /*
> +     * If carryout bit set, which we discern via looking for overflow,
> +     * also reset ENONESHOT.
> +     */
> +    if (was_incrementing &&
> +        ((now & PWMCOUNT_MASK) < (s->tick_offset & PWMCOUNT_MASK))) {
> +        s->pwmcfg &= ~R_CONFIG_ENONESHOT_MASK;
> +    }
> +
> +    /* Schedule or disable interrupts */
> +    sifive_u_pwm_set_alarms(s);
> +
> +    /* If was enabled, and now not enabled, switch tick rep */
> +    if (was_incrementing && !HAS_PWM_EN_BITS(s->pwmcfg)) {
> +        s->tick_offset = (now - s->tick_offset) & PWMCOUNT_MASK;
> +    }
> +}
> +
> +static void sifive_u_pwm_interrupt_0(void *opaque)
> +{
> +    SiFiveUPwmState *s = opaque;
> +
> +    sifive_u_pwm_interrupt(s, 0);
> +}
> +
> +static void sifive_u_pwm_interrupt_1(void *opaque)
> +{
> +    SiFiveUPwmState *s = opaque;
> +
> +    sifive_u_pwm_interrupt(s, 1);
> +}
> +
> +static void sifive_u_pwm_interrupt_2(void *opaque)
> +{
> +    SiFiveUPwmState *s = opaque;
> +
> +    sifive_u_pwm_interrupt(s, 2);
> +}
> +
> +static void sifive_u_pwm_interrupt_3(void *opaque)
> +{
> +    SiFiveUPwmState *s = opaque;
> +
> +    sifive_u_pwm_interrupt(s, 3);
> +}
> +
> +static uint64_t sifive_u_pwm_read(void *opaque, hwaddr addr,
> +                                  unsigned int size)
> +{
> +    SiFiveUPwmState *s = opaque;
> +    uint64_t cur_time, scale;
> +    uint64_t now = sifive_u_pwm_ns_to_ticks(s,
> +                                        qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL));
> +
> +    DB_PRINT("0x%"HWADDR_PRIx"\n", addr);
> +
> +    switch (addr) {
> +    case A_CONFIG:
> +        return s->pwmcfg;
> +    case A_COUNT:
> +        cur_time = s->tick_offset;
> +
> +        if (HAS_PWM_EN_BITS(s->pwmcfg)) {
> +            cur_time = now - cur_time;
> +        }
> +
> +        /*
> +         * Return the value in the counter with bit 31 always 0
> +         * This is allowed to wrap around so we don't need to check that.
> +         */
> +        return cur_time & PWMCOUNT_MASK;
> +    case A_PWMS:
> +        cur_time = s->tick_offset;
> +        scale = sifive_u_pwm_compute_scale(s);
> +
> +        if (HAS_PWM_EN_BITS(s->pwmcfg)) {
> +            cur_time = now - cur_time;
> +        }
> +
> +        return ((cur_time & PWMCOUNT_MASK) >> scale) & PWMCMP_MASK;
> +    case A_PWMCMP0:
> +        return s->pwmcmp[0] & PWMCMP_MASK;
> +    case A_PWMCMP1:
> +        return s->pwmcmp[1] & PWMCMP_MASK;
> +    case A_PWMCMP2:
> +        return s->pwmcmp[2] & PWMCMP_MASK;
> +    case A_PWMCMP3:
> +        return s->pwmcmp[3] & PWMCMP_MASK;
> +    default:
> +        qemu_log_mask(LOG_GUEST_ERROR,
> +                      "%s: Bad offset 0x%"HWADDR_PRIx"\n", __func__, addr);
> +        return 0;
> +    }
> +
> +    return 0;
> +}
> +
> +static void sifive_u_pwm_write(void *opaque, hwaddr addr,
> +                               uint64_t val64, unsigned int size)
> +{
> +    SiFiveUPwmState *s = opaque;
> +    uint32_t value = val64;
> +    uint64_t new_offset, scale;
> +    uint64_t now = sifive_u_pwm_ns_to_ticks(s,
> +                                        qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL));
> +
> +    DB_PRINT("0x%x, 0x%"HWADDR_PRIx"\n", value, addr);
> +
> +    switch (addr) {
> +    case A_CONFIG:
> +        if (value & (R_CONFIG_CMP0CENTER_MASK | R_CONFIG_CMP1CENTER_MASK |
> +                     R_CONFIG_CMP2CENTER_MASK | R_CONFIG_CMP3CENTER_MASK)) {
> +            qemu_log_mask(LOG_UNIMP, "%s: CMPxCENTER is not supported\n",
> +                          __func__);
> +        }
> +
> +        if (value & (R_CONFIG_CMP0GANG_MASK | R_CONFIG_CMP1GANG_MASK |
> +                     R_CONFIG_CMP2GANG_MASK | R_CONFIG_CMP3GANG_MASK)) {
> +            qemu_log_mask(LOG_UNIMP, "%s: CMPxGANG is not supported\n",
> +                          __func__);
> +        }
> +
> +        if (value & (R_CONFIG_CMP0IP_MASK | R_CONFIG_CMP1IP_MASK |
> +                     R_CONFIG_CMP2IP_MASK | R_CONFIG_CMP3IP_MASK)) {
> +            qemu_log_mask(LOG_UNIMP, "%s: CMPxIP is not supported\n",
> +                          __func__);
> +        }
> +
> +        if (!(value & R_CONFIG_CMP0IP_MASK)) {
> +            qemu_irq_lower(s->irqs[0]);
> +        }
> +
> +        if (!(value & R_CONFIG_CMP1IP_MASK)) {
> +            qemu_irq_lower(s->irqs[1]);
> +        }
> +
> +        if (!(value & R_CONFIG_CMP2IP_MASK)) {
> +            qemu_irq_lower(s->irqs[2]);
> +        }
> +
> +        if (!(value & R_CONFIG_CMP3IP_MASK)) {
> +            qemu_irq_lower(s->irqs[3]);
> +        }
> +
> +        /*
> +         * If this write enables the timer increment
> +         * set the time when pwmcount was zero to be cur_time - pwmcount.
> +         * If this write disables the timer increment
> +         * convert back from pwmcount to the time in ticks
> +         * when pwmcount was zero.
> +         */
> +        if ((!HAS_PWM_EN_BITS(s->pwmcfg) && HAS_PWM_EN_BITS(value)) ||
> +            (HAS_PWM_EN_BITS(s->pwmcfg) && !HAS_PWM_EN_BITS(value))) {
> +            s->tick_offset = (now - s->tick_offset) & PWMCOUNT_MASK;
> +        }
> +
> +        s->pwmcfg = value;
> +        break;
> +    case A_COUNT:
> +        /* The guest changed the counter, updated the offset value. */
> +        new_offset = value;
> +
> +        if (HAS_PWM_EN_BITS(s->pwmcfg)) {
> +            new_offset = now - new_offset;
> +        }
> +
> +        s->tick_offset = new_offset;
> +        break;
> +    case A_PWMS:
> +        scale = sifive_u_pwm_compute_scale(s);
> +        new_offset = (((value & PWMCMP_MASK) << scale) & PWMCOUNT_MASK);
> +
> +        if (HAS_PWM_EN_BITS(s->pwmcfg)) {
> +            new_offset = now - new_offset;
> +        }
> +
> +        s->tick_offset = new_offset;
> +        break;
> +    case A_PWMCMP0:
> +        s->pwmcmp[0] = value & PWMCMP_MASK;
> +        break;
> +    case A_PWMCMP1:
> +        s->pwmcmp[1] = value & PWMCMP_MASK;
> +        break;
> +    case A_PWMCMP2:
> +        s->pwmcmp[2] = value & PWMCMP_MASK;
> +        break;
> +    case A_PWMCMP3:
> +        s->pwmcmp[3] = value & PWMCMP_MASK;
> +        break;
> +    default:
> +        qemu_log_mask(LOG_GUEST_ERROR,
> +                      "%s: Bad offset 0x%"HWADDR_PRIx"\n", __func__, addr);
> +    }
> +
> +    /* Update the alarms to reflect possible updated values */
> +    sifive_u_pwm_set_alarms(s);
> +}
> +
> +static void sifive_u_pwm_reset(DeviceState *dev)
> +{
> +    SiFiveUPwmState *s = SIFIVE_U_PWM(dev);
> +    uint64_t now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL);
> +
> +    s->pwmcfg = 0x00000000;
> +    s->pwmcmp[0] = 0x00000000;
> +    s->pwmcmp[1] = 0x00000000;
> +    s->pwmcmp[2] = 0x00000000;
> +    s->pwmcmp[3] = 0x00000000;
> +
> +    s->tick_offset = sifive_u_pwm_ns_to_ticks(s, now);
> +}
> +
> +static const MemoryRegionOps sifive_u_pwm_ops = {
> +    .read = sifive_u_pwm_read,
> +    .write = sifive_u_pwm_write,
> +    .endianness = DEVICE_NATIVE_ENDIAN,
> +};
> +
> +static const VMStateDescription vmstate_sifive_u_pwm = {
> +    .name = TYPE_SIFIVE_U_PWM,
> +    .version_id = 1,
> +    .minimum_version_id = 1,
> +    .fields = (VMStateField[]) {
> +        VMSTATE_TIMER_ARRAY(timer, SiFiveUPwmState, 4),
> +        VMSTATE_UINT64(tick_offset, SiFiveUPwmState),
> +        VMSTATE_UINT32(pwmcfg, SiFiveUPwmState),
> +        VMSTATE_UINT32_ARRAY(pwmcmp, SiFiveUPwmState, 4),
> +        VMSTATE_END_OF_LIST()
> +    }
> +};
> +
> +static Property sifive_u_pwm_properties[] = {
> +    /* 0.5Ghz per spec after FSBL */

Where is this value from? Is the clock from PRCI module?

> +    DEFINE_PROP_UINT64("clock-frequency", struct SiFiveUPwmState,
> +                       freq_hz, 500000000ULL),
> +    DEFINE_PROP_END_OF_LIST(),
> +};
> +
> +static void sifive_u_pwm_init(Object *obj)
> +{
> +    SiFiveUPwmState *s = SIFIVE_U_PWM(obj);
> +    int i;
> +
> +    for (i = 0; i < SIFIVE_U_PWM_IRQS; i++) {
> +        sysbus_init_irq(SYS_BUS_DEVICE(obj), &s->irqs[i]);
> +    }
> +
> +    memory_region_init_io(&s->mmio, obj, &sifive_u_pwm_ops, s,
> +                          TYPE_SIFIVE_U_PWM, 0x100);
> +    sysbus_init_mmio(SYS_BUS_DEVICE(obj), &s->mmio);
> +}
> +
> +static void sifive_u_pwm_realize(DeviceState *dev, Error **errp)
> +{
> +    SiFiveUPwmState *s = SIFIVE_U_PWM(dev);
> +
> +    timer_init_ns(&s->timer[0], QEMU_CLOCK_VIRTUAL,
> +                  sifive_u_pwm_interrupt_0, s);
> +
> +    timer_init_ns(&s->timer[1], QEMU_CLOCK_VIRTUAL,
> +                  sifive_u_pwm_interrupt_1, s);
> +
> +    timer_init_ns(&s->timer[2], QEMU_CLOCK_VIRTUAL,
> +                  sifive_u_pwm_interrupt_2, s);
> +
> +    timer_init_ns(&s->timer[3], QEMU_CLOCK_VIRTUAL,
> +                  sifive_u_pwm_interrupt_3, s);
> +}
> +
> +static void sifive_u_pwm_class_init(ObjectClass *klass, void *data)
> +{
> +    DeviceClass *dc = DEVICE_CLASS(klass);
> +
> +    dc->reset = sifive_u_pwm_reset;
> +    device_class_set_props(dc, sifive_u_pwm_properties);
> +    dc->vmsd = &vmstate_sifive_u_pwm;
> +    dc->realize = sifive_u_pwm_realize;
> +}
> +
> +static const TypeInfo sifive_u_pwm_info = {
> +    .name          = TYPE_SIFIVE_U_PWM,
> +    .parent        = TYPE_SYS_BUS_DEVICE,
> +    .instance_size = sizeof(SiFiveUPwmState),
> +    .instance_init = sifive_u_pwm_init,
> +    .class_init    = sifive_u_pwm_class_init,
> +};
> +
> +static void sifive_u_pwm_register_types(void)
> +{
> +    type_register_static(&sifive_u_pwm_info);
> +}
> +
> +type_init(sifive_u_pwm_register_types)
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 554be84b32..32fdc8a4ca 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -303,7 +303,9 @@ L: qemu-riscv@nongnu.org
>  S: Supported
>  F: target/riscv/
>  F: hw/riscv/
> +F: hw/*/*sifive*
>  F: include/hw/riscv/
> +F: include/hw/*/*sifive*

This is the RISC-V CPU section. The SiFive machine section already covers this.

>  F: linux-user/host/riscv32/
>  F: linux-user/host/riscv64/
>
> diff --git a/hw/riscv/Kconfig b/hw/riscv/Kconfig
> index 1de18cdcf1..aca8ad67a2 100644
> --- a/hw/riscv/Kconfig
> +++ b/hw/riscv/Kconfig
> @@ -59,6 +59,7 @@ config SIFIVE_U
>      select SIFIVE_U_PRCI
>      select SSI_M25P80
>      select SSI_SD
> +    select SIFIVE_U_PWM

This change belongs to the 2nd patch in this series.

>      select UNIMP
>
>  config SPIKE
> diff --git a/hw/timer/Kconfig b/hw/timer/Kconfig
> index bac2511715..f39eb16e4e 100644
> --- a/hw/timer/Kconfig
> +++ b/hw/timer/Kconfig
> @@ -25,6 +25,9 @@ config ALLWINNER_A10_PIT
>      bool
>      select PTIMER
>
> +config SIFIVE_U_PWM
> +    bool
> +
>  config STM32F2XX_TIMER
>      bool
>
> diff --git a/hw/timer/meson.build b/hw/timer/meson.build
> index 598d058506..481f7f915b 100644
> --- a/hw/timer/meson.build
> +++ b/hw/timer/meson.build
> @@ -36,5 +36,6 @@ softmmu_ss.add(when: 'CONFIG_SSE_COUNTER', if_true: files('sse-counter.c'))
>  softmmu_ss.add(when: 'CONFIG_SSE_TIMER', if_true: files('sse-timer.c'))
>  softmmu_ss.add(when: 'CONFIG_STM32F2XX_TIMER', if_true: files('stm32f2xx_timer.c'))
>  softmmu_ss.add(when: 'CONFIG_XILINX', if_true: files('xilinx_timer.c'))
> +softmmu_ss.add(when: 'CONFIG_SIFIVE_U_PWM', if_true: files('sifive_u_pwm.c'))
>
>  specific_ss.add(when: 'CONFIG_AVR_TIMER16', if_true: files('avr_timer16.c'))
> --

Regards,
Bin

[PATCH v1 2/2] sifive_u: Connect the SiFive PWM device

[Alistair Francis]

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
---
 include/hw/riscv/sifive_u.h | 14 +++++++++++++-
 hw/riscv/sifive_u.c         | 23 ++++++++++++++++++++++-
 2 files changed, 35 insertions(+), 2 deletions(-)

diff --git a/include/hw/riscv/sifive_u.h b/include/hw/riscv/sifive_u.h
index 2656b39808..6e0779562d 100644
--- a/include/hw/riscv/sifive_u.h
+++ b/include/hw/riscv/sifive_u.h
@@ -27,6 +27,7 @@
 #include "hw/misc/sifive_u_otp.h"
 #include "hw/misc/sifive_u_prci.h"
 #include "hw/ssi/sifive_spi.h"
+#include "hw/timer/sifive_u_pwm.h"
 
 #define TYPE_RISCV_U_SOC "riscv.sifive.u.soc"
 #define RISCV_U_SOC(obj) \
@@ -49,6 +50,7 @@ typedef struct SiFiveUSoCState {
     SiFiveSPIState spi0;
     SiFiveSPIState spi2;
     CadenceGEMState gem;
+    SiFiveUPwmState pwm[2];
 
     uint32_t serial;
     char *cpu_type;
@@ -92,7 +94,9 @@ enum {
     SIFIVE_U_DEV_FLASH0,
     SIFIVE_U_DEV_DRAM,
     SIFIVE_U_DEV_GEM,
-    SIFIVE_U_DEV_GEM_MGMT
+    SIFIVE_U_DEV_GEM_MGMT,
+    SIFIVE_U_DEV_PWM0,
+    SIFIVE_U_DEV_PWM1
 };
 
 enum {
@@ -126,6 +130,14 @@ enum {
     SIFIVE_U_PDMA_IRQ5 = 28,
     SIFIVE_U_PDMA_IRQ6 = 29,
     SIFIVE_U_PDMA_IRQ7 = 30,
+    SIFIVE_U_DEV_PWM0_0 = 42,
+    SIFIVE_U_DEV_PWM0_1 = 43,
+    SIFIVE_U_DEV_PWM0_2 = 44,
+    SIFIVE_U_DEV_PWM0_3 = 45,
+    SIFIVE_U_DEV_PWM1_0 = 46,
+    SIFIVE_U_DEV_PWM1_1 = 47,
+    SIFIVE_U_DEV_PWM1_2 = 48,
+    SIFIVE_U_DEV_PWM1_3 = 49,
     SIFIVE_U_QSPI0_IRQ = 51,
     SIFIVE_U_GEM_IRQ = 53
 };
diff --git a/hw/riscv/sifive_u.c b/hw/riscv/sifive_u.c
index 7b59942369..ba36a91ef8 100644
--- a/hw/riscv/sifive_u.c
+++ b/hw/riscv/sifive_u.c
@@ -74,6 +74,8 @@ static const MemMapEntry sifive_u_memmap[] = {
     [SIFIVE_U_DEV_PRCI] =     { 0x10000000,     0x1000 },
     [SIFIVE_U_DEV_UART0] =    { 0x10010000,     0x1000 },
     [SIFIVE_U_DEV_UART1] =    { 0x10011000,     0x1000 },
+    [SIFIVE_U_DEV_PWM0] =     { 0x10020000,     0x1000 },
+    [SIFIVE_U_DEV_PWM1] =     { 0x10021000,     0x1000 },
     [SIFIVE_U_DEV_QSPI0] =    { 0x10040000,     0x1000 },
     [SIFIVE_U_DEV_QSPI2] =    { 0x10050000,     0x1000 },
     [SIFIVE_U_DEV_GPIO] =     { 0x10060000,     0x1000 },
@@ -757,6 +759,8 @@ static void sifive_u_soc_instance_init(Object *obj)
     object_initialize_child(obj, "pdma", &s->dma, TYPE_SIFIVE_PDMA);
     object_initialize_child(obj, "spi0", &s->spi0, TYPE_SIFIVE_SPI);
     object_initialize_child(obj, "spi2", &s->spi2, TYPE_SIFIVE_SPI);
+    object_initialize_child(obj, "pwm0", &s->pwm[0], TYPE_SIFIVE_U_PWM);
+    object_initialize_child(obj, "pwm1", &s->pwm[1], TYPE_SIFIVE_U_PWM);
 }
 
 static void sifive_u_soc_realize(DeviceState *dev, Error **errp)
@@ -769,7 +773,7 @@ static void sifive_u_soc_realize(DeviceState *dev, Error **errp)
     MemoryRegion *l2lim_mem = g_new(MemoryRegion, 1);
     char *plic_hart_config;
     size_t plic_hart_config_len;
-    int i;
+    int i, j;
     NICInfo *nd = &nd_table[0];
 
     qdev_prop_set_uint32(DEVICE(&s->u_cpus), "num-harts", ms->smp.cpus - 1);
@@ -896,6 +900,23 @@ static void sifive_u_soc_realize(DeviceState *dev, Error **errp)
     sysbus_connect_irq(SYS_BUS_DEVICE(&s->gem), 0,
                        qdev_get_gpio_in(DEVICE(s->plic), SIFIVE_U_GEM_IRQ));
 
+    /* PWM */
+    for (i = 0; i < 2; i++) {
+        if (!sysbus_realize(SYS_BUS_DEVICE(&s->pwm[i]), errp)) {
+            return;
+        }
+        sysbus_mmio_map(SYS_BUS_DEVICE(&s->pwm[i]), 0,
+                                memmap[SIFIVE_U_DEV_PWM0].base + (0x1000 * i));
+
+        /* Connect PWM interrupts to the PLIC */
+        for (j = 0; j < SIFIVE_U_PWM_IRQS; j++) {
+            sysbus_connect_irq(SYS_BUS_DEVICE(&s->pwm[i]), j,
+                               qdev_get_gpio_in(DEVICE(s->plic),
+                                            SIFIVE_U_DEV_PWM0_0 +
+                                                (i * SIFIVE_PDMA_IRQS) + j));
+        }
+    }
+
     create_unimplemented_device("riscv.sifive.u.gem-mgmt",
         memmap[SIFIVE_U_DEV_GEM_MGMT].base, memmap[SIFIVE_U_DEV_GEM_MGMT].size);
 
-- 
2.31.0

[PATCH v1 2/2] sifive_u: Connect the SiFive PWM device

[Alistair Francis]

Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
---
 include/hw/riscv/sifive_u.h | 14 +++++++++++++-
 hw/riscv/sifive_u.c         | 23 ++++++++++++++++++++++-
 2 files changed, 35 insertions(+), 2 deletions(-)

diff --git a/include/hw/riscv/sifive_u.h b/include/hw/riscv/sifive_u.h
index 2656b39808..6e0779562d 100644
--- a/include/hw/riscv/sifive_u.h
+++ b/include/hw/riscv/sifive_u.h
@@ -27,6 +27,7 @@
 #include "hw/misc/sifive_u_otp.h"
 #include "hw/misc/sifive_u_prci.h"
 #include "hw/ssi/sifive_spi.h"
+#include "hw/timer/sifive_u_pwm.h"
 
 #define TYPE_RISCV_U_SOC "riscv.sifive.u.soc"
 #define RISCV_U_SOC(obj) \
@@ -49,6 +50,7 @@ typedef struct SiFiveUSoCState {
     SiFiveSPIState spi0;
     SiFiveSPIState spi2;
     CadenceGEMState gem;
+    SiFiveUPwmState pwm[2];
 
     uint32_t serial;
     char *cpu_type;
@@ -92,7 +94,9 @@ enum {
     SIFIVE_U_DEV_FLASH0,
     SIFIVE_U_DEV_DRAM,
     SIFIVE_U_DEV_GEM,
-    SIFIVE_U_DEV_GEM_MGMT
+    SIFIVE_U_DEV_GEM_MGMT,
+    SIFIVE_U_DEV_PWM0,
+    SIFIVE_U_DEV_PWM1
 };
 
 enum {
@@ -126,6 +130,14 @@ enum {
     SIFIVE_U_PDMA_IRQ5 = 28,
     SIFIVE_U_PDMA_IRQ6 = 29,
     SIFIVE_U_PDMA_IRQ7 = 30,
+    SIFIVE_U_DEV_PWM0_0 = 42,
+    SIFIVE_U_DEV_PWM0_1 = 43,
+    SIFIVE_U_DEV_PWM0_2 = 44,
+    SIFIVE_U_DEV_PWM0_3 = 45,
+    SIFIVE_U_DEV_PWM1_0 = 46,
+    SIFIVE_U_DEV_PWM1_1 = 47,
+    SIFIVE_U_DEV_PWM1_2 = 48,
+    SIFIVE_U_DEV_PWM1_3 = 49,
     SIFIVE_U_QSPI0_IRQ = 51,
     SIFIVE_U_GEM_IRQ = 53
 };
diff --git a/hw/riscv/sifive_u.c b/hw/riscv/sifive_u.c
index 7b59942369..ba36a91ef8 100644
--- a/hw/riscv/sifive_u.c
+++ b/hw/riscv/sifive_u.c
@@ -74,6 +74,8 @@ static const MemMapEntry sifive_u_memmap[] = {
     [SIFIVE_U_DEV_PRCI] =     { 0x10000000,     0x1000 },
     [SIFIVE_U_DEV_UART0] =    { 0x10010000,     0x1000 },
     [SIFIVE_U_DEV_UART1] =    { 0x10011000,     0x1000 },
+    [SIFIVE_U_DEV_PWM0] =     { 0x10020000,     0x1000 },
+    [SIFIVE_U_DEV_PWM1] =     { 0x10021000,     0x1000 },
     [SIFIVE_U_DEV_QSPI0] =    { 0x10040000,     0x1000 },
     [SIFIVE_U_DEV_QSPI2] =    { 0x10050000,     0x1000 },
     [SIFIVE_U_DEV_GPIO] =     { 0x10060000,     0x1000 },
@@ -757,6 +759,8 @@ static void sifive_u_soc_instance_init(Object *obj)
     object_initialize_child(obj, "pdma", &s->dma, TYPE_SIFIVE_PDMA);
     object_initialize_child(obj, "spi0", &s->spi0, TYPE_SIFIVE_SPI);
     object_initialize_child(obj, "spi2", &s->spi2, TYPE_SIFIVE_SPI);
+    object_initialize_child(obj, "pwm0", &s->pwm[0], TYPE_SIFIVE_U_PWM);
+    object_initialize_child(obj, "pwm1", &s->pwm[1], TYPE_SIFIVE_U_PWM);
 }
 
 static void sifive_u_soc_realize(DeviceState *dev, Error **errp)
@@ -769,7 +773,7 @@ static void sifive_u_soc_realize(DeviceState *dev, Error **errp)
     MemoryRegion *l2lim_mem = g_new(MemoryRegion, 1);
     char *plic_hart_config;
     size_t plic_hart_config_len;
-    int i;
+    int i, j;
     NICInfo *nd = &nd_table[0];
 
     qdev_prop_set_uint32(DEVICE(&s->u_cpus), "num-harts", ms->smp.cpus - 1);
@@ -896,6 +900,23 @@ static void sifive_u_soc_realize(DeviceState *dev, Error **errp)
     sysbus_connect_irq(SYS_BUS_DEVICE(&s->gem), 0,
                        qdev_get_gpio_in(DEVICE(s->plic), SIFIVE_U_GEM_IRQ));
 
+    /* PWM */
+    for (i = 0; i < 2; i++) {
+        if (!sysbus_realize(SYS_BUS_DEVICE(&s->pwm[i]), errp)) {
+            return;
+        }
+        sysbus_mmio_map(SYS_BUS_DEVICE(&s->pwm[i]), 0,
+                                memmap[SIFIVE_U_DEV_PWM0].base + (0x1000 * i));
+
+        /* Connect PWM interrupts to the PLIC */
+        for (j = 0; j < SIFIVE_U_PWM_IRQS; j++) {
+            sysbus_connect_irq(SYS_BUS_DEVICE(&s->pwm[i]), j,
+                               qdev_get_gpio_in(DEVICE(s->plic),
+                                            SIFIVE_U_DEV_PWM0_0 +
+                                                (i * SIFIVE_PDMA_IRQS) + j));
+        }
+    }
+
     create_unimplemented_device("riscv.sifive.u.gem-mgmt",
         memmap[SIFIVE_U_DEV_GEM_MGMT].base, memmap[SIFIVE_U_DEV_GEM_MGMT].size);
 
-- 
2.31.0

Re: [PATCH v1 2/2] sifive_u: Connect the SiFive PWM device

[Bin Meng]

On Fri, Apr 2, 2021 at 8:45 PM Alistair Francis
<alistair.francis@wdc.com> wrote:
>
> Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
> ---
>  include/hw/riscv/sifive_u.h | 14 +++++++++++++-
>  hw/riscv/sifive_u.c         | 23 ++++++++++++++++++++++-
>  2 files changed, 35 insertions(+), 2 deletions(-)
>
> diff --git a/include/hw/riscv/sifive_u.h b/include/hw/riscv/sifive_u.h
> index 2656b39808..6e0779562d 100644
> --- a/include/hw/riscv/sifive_u.h
> +++ b/include/hw/riscv/sifive_u.h
> @@ -27,6 +27,7 @@
>  #include "hw/misc/sifive_u_otp.h"
>  #include "hw/misc/sifive_u_prci.h"
>  #include "hw/ssi/sifive_spi.h"
> +#include "hw/timer/sifive_u_pwm.h"
>
>  #define TYPE_RISCV_U_SOC "riscv.sifive.u.soc"
>  #define RISCV_U_SOC(obj) \
> @@ -49,6 +50,7 @@ typedef struct SiFiveUSoCState {
>      SiFiveSPIState spi0;
>      SiFiveSPIState spi2;
>      CadenceGEMState gem;
> +    SiFiveUPwmState pwm[2];
>
>      uint32_t serial;
>      char *cpu_type;
> @@ -92,7 +94,9 @@ enum {
>      SIFIVE_U_DEV_FLASH0,
>      SIFIVE_U_DEV_DRAM,
>      SIFIVE_U_DEV_GEM,
> -    SIFIVE_U_DEV_GEM_MGMT
> +    SIFIVE_U_DEV_GEM_MGMT,
> +    SIFIVE_U_DEV_PWM0,
> +    SIFIVE_U_DEV_PWM1
>  };
>
>  enum {
> @@ -126,6 +130,14 @@ enum {
>      SIFIVE_U_PDMA_IRQ5 = 28,
>      SIFIVE_U_PDMA_IRQ6 = 29,
>      SIFIVE_U_PDMA_IRQ7 = 30,
> +    SIFIVE_U_DEV_PWM0_0 = 42,

These should be named as SIFIVE_U_PWM0_IRQ0, etc.

> +    SIFIVE_U_DEV_PWM0_1 = 43,
> +    SIFIVE_U_DEV_PWM0_2 = 44,
> +    SIFIVE_U_DEV_PWM0_3 = 45,
> +    SIFIVE_U_DEV_PWM1_0 = 46,
> +    SIFIVE_U_DEV_PWM1_1 = 47,
> +    SIFIVE_U_DEV_PWM1_2 = 48,
> +    SIFIVE_U_DEV_PWM1_3 = 49,
>      SIFIVE_U_QSPI0_IRQ = 51,
>      SIFIVE_U_GEM_IRQ = 53
>  };
> diff --git a/hw/riscv/sifive_u.c b/hw/riscv/sifive_u.c
> index 7b59942369..ba36a91ef8 100644

Missing update on supported device lists at the beginning of this file

> --- a/hw/riscv/sifive_u.c
> +++ b/hw/riscv/sifive_u.c
> @@ -74,6 +74,8 @@ static const MemMapEntry sifive_u_memmap[] = {
>      [SIFIVE_U_DEV_PRCI] =     { 0x10000000,     0x1000 },
>      [SIFIVE_U_DEV_UART0] =    { 0x10010000,     0x1000 },
>      [SIFIVE_U_DEV_UART1] =    { 0x10011000,     0x1000 },
> +    [SIFIVE_U_DEV_PWM0] =     { 0x10020000,     0x1000 },
> +    [SIFIVE_U_DEV_PWM1] =     { 0x10021000,     0x1000 },
>      [SIFIVE_U_DEV_QSPI0] =    { 0x10040000,     0x1000 },
>      [SIFIVE_U_DEV_QSPI2] =    { 0x10050000,     0x1000 },
>      [SIFIVE_U_DEV_GPIO] =     { 0x10060000,     0x1000 },
> @@ -757,6 +759,8 @@ static void sifive_u_soc_instance_init(Object *obj)
>      object_initialize_child(obj, "pdma", &s->dma, TYPE_SIFIVE_PDMA);
>      object_initialize_child(obj, "spi0", &s->spi0, TYPE_SIFIVE_SPI);
>      object_initialize_child(obj, "spi2", &s->spi2, TYPE_SIFIVE_SPI);
> +    object_initialize_child(obj, "pwm0", &s->pwm[0], TYPE_SIFIVE_U_PWM);
> +    object_initialize_child(obj, "pwm1", &s->pwm[1], TYPE_SIFIVE_U_PWM);
>  }
>
>  static void sifive_u_soc_realize(DeviceState *dev, Error **errp)
> @@ -769,7 +773,7 @@ static void sifive_u_soc_realize(DeviceState *dev, Error **errp)
>      MemoryRegion *l2lim_mem = g_new(MemoryRegion, 1);
>      char *plic_hart_config;
>      size_t plic_hart_config_len;
> -    int i;
> +    int i, j;
>      NICInfo *nd = &nd_table[0];
>
>      qdev_prop_set_uint32(DEVICE(&s->u_cpus), "num-harts", ms->smp.cpus - 1);
> @@ -896,6 +900,23 @@ static void sifive_u_soc_realize(DeviceState *dev, Error **errp)
>      sysbus_connect_irq(SYS_BUS_DEVICE(&s->gem), 0,
>                         qdev_get_gpio_in(DEVICE(s->plic), SIFIVE_U_GEM_IRQ));
>
> +    /* PWM */
> +    for (i = 0; i < 2; i++) {
> +        if (!sysbus_realize(SYS_BUS_DEVICE(&s->pwm[i]), errp)) {
> +            return;
> +        }
> +        sysbus_mmio_map(SYS_BUS_DEVICE(&s->pwm[i]), 0,
> +                                memmap[SIFIVE_U_DEV_PWM0].base + (0x1000 * i));
> +
> +        /* Connect PWM interrupts to the PLIC */
> +        for (j = 0; j < SIFIVE_U_PWM_IRQS; j++) {
> +            sysbus_connect_irq(SYS_BUS_DEVICE(&s->pwm[i]), j,
> +                               qdev_get_gpio_in(DEVICE(s->plic),
> +                                            SIFIVE_U_DEV_PWM0_0 +
> +                                                (i * SIFIVE_PDMA_IRQS) + j));
> +        }
> +    }
> +
>      create_unimplemented_device("riscv.sifive.u.gem-mgmt",
>          memmap[SIFIVE_U_DEV_GEM_MGMT].base, memmap[SIFIVE_U_DEV_GEM_MGMT].size);
>

The generation of the PWM device tree fragment part is missing.

Probably we need another patch to update the document on the support
status of PWM devices, and if possible how to test this, e.g.: in
Linux?

Regards,
Bin

Re: [PATCH v1 2/2] sifive_u: Connect the SiFive PWM device

[Bin Meng]

On Fri, Apr 2, 2021 at 8:45 PM Alistair Francis
<alistair.francis@wdc.com> wrote:
>
> Signed-off-by: Alistair Francis <alistair.francis@wdc.com>
> ---
>  include/hw/riscv/sifive_u.h | 14 +++++++++++++-
>  hw/riscv/sifive_u.c         | 23 ++++++++++++++++++++++-
>  2 files changed, 35 insertions(+), 2 deletions(-)
>
> diff --git a/include/hw/riscv/sifive_u.h b/include/hw/riscv/sifive_u.h
> index 2656b39808..6e0779562d 100644
> --- a/include/hw/riscv/sifive_u.h
> +++ b/include/hw/riscv/sifive_u.h
> @@ -27,6 +27,7 @@
>  #include "hw/misc/sifive_u_otp.h"
>  #include "hw/misc/sifive_u_prci.h"
>  #include "hw/ssi/sifive_spi.h"
> +#include "hw/timer/sifive_u_pwm.h"
>
>  #define TYPE_RISCV_U_SOC "riscv.sifive.u.soc"
>  #define RISCV_U_SOC(obj) \
> @@ -49,6 +50,7 @@ typedef struct SiFiveUSoCState {
>      SiFiveSPIState spi0;
>      SiFiveSPIState spi2;
>      CadenceGEMState gem;
> +    SiFiveUPwmState pwm[2];
>
>      uint32_t serial;
>      char *cpu_type;
> @@ -92,7 +94,9 @@ enum {
>      SIFIVE_U_DEV_FLASH0,
>      SIFIVE_U_DEV_DRAM,
>      SIFIVE_U_DEV_GEM,
> -    SIFIVE_U_DEV_GEM_MGMT
> +    SIFIVE_U_DEV_GEM_MGMT,
> +    SIFIVE_U_DEV_PWM0,
> +    SIFIVE_U_DEV_PWM1
>  };
>
>  enum {
> @@ -126,6 +130,14 @@ enum {
>      SIFIVE_U_PDMA_IRQ5 = 28,
>      SIFIVE_U_PDMA_IRQ6 = 29,
>      SIFIVE_U_PDMA_IRQ7 = 30,
> +    SIFIVE_U_DEV_PWM0_0 = 42,

These should be named as SIFIVE_U_PWM0_IRQ0, etc.

> +    SIFIVE_U_DEV_PWM0_1 = 43,
> +    SIFIVE_U_DEV_PWM0_2 = 44,
> +    SIFIVE_U_DEV_PWM0_3 = 45,
> +    SIFIVE_U_DEV_PWM1_0 = 46,
> +    SIFIVE_U_DEV_PWM1_1 = 47,
> +    SIFIVE_U_DEV_PWM1_2 = 48,
> +    SIFIVE_U_DEV_PWM1_3 = 49,
>      SIFIVE_U_QSPI0_IRQ = 51,
>      SIFIVE_U_GEM_IRQ = 53
>  };
> diff --git a/hw/riscv/sifive_u.c b/hw/riscv/sifive_u.c
> index 7b59942369..ba36a91ef8 100644

Missing update on supported device lists at the beginning of this file

> --- a/hw/riscv/sifive_u.c
> +++ b/hw/riscv/sifive_u.c
> @@ -74,6 +74,8 @@ static const MemMapEntry sifive_u_memmap[] = {
>      [SIFIVE_U_DEV_PRCI] =     { 0x10000000,     0x1000 },
>      [SIFIVE_U_DEV_UART0] =    { 0x10010000,     0x1000 },
>      [SIFIVE_U_DEV_UART1] =    { 0x10011000,     0x1000 },
> +    [SIFIVE_U_DEV_PWM0] =     { 0x10020000,     0x1000 },
> +    [SIFIVE_U_DEV_PWM1] =     { 0x10021000,     0x1000 },
>      [SIFIVE_U_DEV_QSPI0] =    { 0x10040000,     0x1000 },
>      [SIFIVE_U_DEV_QSPI2] =    { 0x10050000,     0x1000 },
>      [SIFIVE_U_DEV_GPIO] =     { 0x10060000,     0x1000 },
> @@ -757,6 +759,8 @@ static void sifive_u_soc_instance_init(Object *obj)
>      object_initialize_child(obj, "pdma", &s->dma, TYPE_SIFIVE_PDMA);
>      object_initialize_child(obj, "spi0", &s->spi0, TYPE_SIFIVE_SPI);
>      object_initialize_child(obj, "spi2", &s->spi2, TYPE_SIFIVE_SPI);
> +    object_initialize_child(obj, "pwm0", &s->pwm[0], TYPE_SIFIVE_U_PWM);
> +    object_initialize_child(obj, "pwm1", &s->pwm[1], TYPE_SIFIVE_U_PWM);
>  }
>
>  static void sifive_u_soc_realize(DeviceState *dev, Error **errp)
> @@ -769,7 +773,7 @@ static void sifive_u_soc_realize(DeviceState *dev, Error **errp)
>      MemoryRegion *l2lim_mem = g_new(MemoryRegion, 1);
>      char *plic_hart_config;
>      size_t plic_hart_config_len;
> -    int i;
> +    int i, j;
>      NICInfo *nd = &nd_table[0];
>
>      qdev_prop_set_uint32(DEVICE(&s->u_cpus), "num-harts", ms->smp.cpus - 1);
> @@ -896,6 +900,23 @@ static void sifive_u_soc_realize(DeviceState *dev, Error **errp)
>      sysbus_connect_irq(SYS_BUS_DEVICE(&s->gem), 0,
>                         qdev_get_gpio_in(DEVICE(s->plic), SIFIVE_U_GEM_IRQ));
>
> +    /* PWM */
> +    for (i = 0; i < 2; i++) {
> +        if (!sysbus_realize(SYS_BUS_DEVICE(&s->pwm[i]), errp)) {
> +            return;
> +        }
> +        sysbus_mmio_map(SYS_BUS_DEVICE(&s->pwm[i]), 0,
> +                                memmap[SIFIVE_U_DEV_PWM0].base + (0x1000 * i));
> +
> +        /* Connect PWM interrupts to the PLIC */
> +        for (j = 0; j < SIFIVE_U_PWM_IRQS; j++) {
> +            sysbus_connect_irq(SYS_BUS_DEVICE(&s->pwm[i]), j,
> +                               qdev_get_gpio_in(DEVICE(s->plic),
> +                                            SIFIVE_U_DEV_PWM0_0 +
> +                                                (i * SIFIVE_PDMA_IRQS) + j));
> +        }
> +    }
> +
>      create_unimplemented_device("riscv.sifive.u.gem-mgmt",
>          memmap[SIFIVE_U_DEV_GEM_MGMT].base, memmap[SIFIVE_U_DEV_GEM_MGMT].size);
>

The generation of the PWM device tree fragment part is missing.

Probably we need another patch to update the document on the support
status of PWM devices, and if possible how to test this, e.g.: in
Linux?

Regards,
Bin