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Diffstat (limited to 'src/pru/pru0.c')
| -rw-r--r-- | src/pru/pru0.c | 229 |
1 files changed, 229 insertions, 0 deletions
diff --git a/src/pru/pru0.c b/src/pru/pru0.c new file mode 100644 index 00000000..e4bd1c46 --- /dev/null +++ b/src/pru/pru0.c @@ -0,0 +1,229 @@ +// Code to handle IO on PRU0 and pass the messages to PRU1 +// +// Copyright (C) 2017 Kevin O'Connor <kevin@koconnor.net> +// +// This file may be distributed under the terms of the GNU GPLv3 license. + +#include <stdint.h> // uint32_t +#include <string.h> // memset +#include <pru/io.h> // write_r31 +#include <pru_cfg.h> // CT_CFG +#include <pru_intc.h> // CT_INTC +#include <pru_rpmsg.h> // pru_rpmsg_send +#include <pru_virtio_ids.h> // VIRTIO_ID_RPMSG +#include <rsc_types.h> // resource_table +#include "board/io.h" // readl +#include "compiler.h" // __section +#include "internal.h" // SHARED_MEM + + +/**************************************************************** + * IO + ****************************************************************/ + +#define CHAN_NAME "rpmsg-pru" +#define CHAN_DESC "Channel 30" +#define CHAN_PORT 30 + +static uint16_t transport_dst; + +static void +check_can_send(struct pru_rpmsg_transport *transport) +{ + for (;;) { + uint32_t send_pop_pos = SHARED_MEM->send_pop_pos; + uint32_t count = readl(&SHARED_MEM->send_data[send_pop_pos].count); + if (!count) + // Queue empty + break; + pru_rpmsg_send( + transport, CHAN_PORT, transport_dst + , &SHARED_MEM->send_data[send_pop_pos].data, count); + barrier(); + writel(&SHARED_MEM->send_data[send_pop_pos].count, 0); + SHARED_MEM->send_pop_pos = ( + (send_pop_pos + 1) % ARRAY_SIZE(SHARED_MEM->send_data)); + } +} + +static void +check_can_read(struct pru_rpmsg_transport *transport) +{ + if (readl(&SHARED_MEM->read_count)) + // main processing pru is busy + return; + uint16_t dst, len; + int16_t ret = pru_rpmsg_receive( + transport, &transport_dst, &dst, SHARED_MEM->read_data, &len); + if (ret || !len) + return; + SHARED_MEM->read_pos = 0; + barrier(); + writel(&SHARED_MEM->read_count, len); + write_r31(R31_WRITE_IRQ_SELECT | (KICK_PRU1_EVENT - R31_WRITE_IRQ_OFFSET)); +} + +static void +process_io(struct pru_rpmsg_transport *transport) +{ + for (;;) { + if (!(read_r31() & (1 << (WAKE_PRU0_IRQ + R31_IRQ_OFFSET)))) + continue; + CT_INTC.SECR0 = (1 << KICK_PRU0_FROM_ARM_EVENT) | (1 << KICK_PRU0_EVENT); + check_can_send(transport); + check_can_read(transport); + } +} + + +/**************************************************************** + * Resource table + ****************************************************************/ + +/* + * Sizes of the virtqueues (expressed in number of buffers supported, + * and must be power of 2) + */ +#define PRU_RPMSG_VQ0_SIZE 16 +#define PRU_RPMSG_VQ1_SIZE 16 + +/* + * The feature bitmap for virtio rpmsg + */ +#define VIRTIO_RPMSG_F_NS 0 //name service notifications + +/* This firmware supports name service notifications as one of its features */ +#define RPMSG_PRU_C0_FEATURES (1 << VIRTIO_RPMSG_F_NS) + +/* Definition for unused interrupts */ +#define HOST_UNUSED 255 + +/* Mapping sysevts to a channel. Each pair contains a sysevt, channel. */ +static struct ch_map pru_intc_map[] = { + {IEP_EVENT, WAKE_PRU1_IRQ}, + {KICK_ARM_EVENT, WAKE_ARM_IRQ}, + {KICK_PRU0_FROM_ARM_EVENT, WAKE_PRU0_IRQ}, + {KICK_PRU0_EVENT, WAKE_PRU0_IRQ}, + {KICK_PRU1_EVENT, WAKE_PRU1_IRQ}, +}; + +struct my_resource_table { + struct resource_table base; + + uint32_t offset[2]; /* Should match 'num' in actual definition */ + + /* rpmsg vdev entry */ + struct fw_rsc_vdev rpmsg_vdev; + struct fw_rsc_vdev_vring rpmsg_vring0; + struct fw_rsc_vdev_vring rpmsg_vring1; + + /* intc definition */ + struct fw_rsc_custom pru_ints; +} resourceTable __section(".resource_table") = { + { + 1, /* Resource table version: only version 1 is + * supported by the current driver */ + 2, /* number of entries in the table */ + { 0, 0 }, /* reserved, must be zero */ + }, + /* offsets to entries */ + { + offsetof(struct my_resource_table, rpmsg_vdev), + offsetof(struct my_resource_table, pru_ints), + }, + + /* rpmsg vdev entry */ + { + (uint32_t)TYPE_VDEV, //type + (uint32_t)VIRTIO_ID_RPMSG, //id + (uint32_t)0, //notifyid + (uint32_t)RPMSG_PRU_C0_FEATURES, //dfeatures + (uint32_t)0, //gfeatures + (uint32_t)0, //config_len + (uint8_t)0, //status + (uint8_t)2, //num_of_vrings, only two is supported + {(uint8_t)0, (uint8_t)0 }, //reserved + /* no config data */ + }, + /* the two vrings */ + { + 0, //da, will be populated by host, can't pass it in + 16, //align (bytes), + PRU_RPMSG_VQ0_SIZE, //num of descriptors + 0, //notifyid, will be populated, can't pass right now + 0 //reserved + }, + { + 0, //da, will be populated by host, can't pass it in + 16, //align (bytes), + PRU_RPMSG_VQ1_SIZE, //num of descriptors + 0, //notifyid, will be populated, can't pass right now + 0 //reserved + }, + + { + TYPE_CUSTOM, TYPE_PRU_INTS, + sizeof(struct fw_rsc_custom_ints), + { /* PRU_INTS version */ + { + 0x0000, + /* Channel-to-host mapping, 255 for unused */ + { + WAKE_PRU0_IRQ, WAKE_PRU1_IRQ, WAKE_ARM_IRQ, + HOST_UNUSED, HOST_UNUSED, HOST_UNUSED, + HOST_UNUSED, HOST_UNUSED, HOST_UNUSED, HOST_UNUSED + }, + /* Number of evts being mapped to channels */ + (sizeof(pru_intc_map) / sizeof(struct ch_map)), + /* Pointer to the structure containing mapped events */ + pru_intc_map, + }, + }, + }, +}; + + +/**************************************************************** + * Startup + ****************************************************************/ + +#define VIRTIO_CONFIG_S_DRIVER_OK 4 + +int +main(void) +{ + // allow access to external memory + CT_CFG.SYSCFG_bit.STANDBY_INIT = 0; + + // clear all irqs + CT_INTC.SECR0 = 0xffffffff; + CT_INTC.SECR1 = 0xffffffff; + + /* Make sure the Linux drivers are ready for RPMsg communication */ + volatile uint8_t *status = &resourceTable.rpmsg_vdev.status; + while (!(*status & VIRTIO_CONFIG_S_DRIVER_OK)) + ; + + /* Initialize the RPMsg transport structure */ + struct pru_rpmsg_transport transport; + pru_rpmsg_init(&transport, + &resourceTable.rpmsg_vring0, + &resourceTable.rpmsg_vring1, + KICK_ARM_EVENT, + KICK_PRU0_FROM_ARM_EVENT); + + /* Create the RPMsg channel between the PRU and ARM user space + * using the transport structure. */ + while (pru_rpmsg_channel(RPMSG_NS_CREATE, &transport, CHAN_NAME + , CHAN_DESC, CHAN_PORT) != PRU_RPMSG_SUCCESS) + ; + + // Wait for PRU1 to be ready + memset(SHARED_MEM, 0, sizeof(*SHARED_MEM)); + writel(&SHARED_MEM->signal, SIGNAL_PRU0_WAITING); + while (readl(&SHARED_MEM->signal) != SIGNAL_PRU1_READY) + ; + writel(&SHARED_MEM->signal, 0); + + process_io(&transport); +} |