diff options
Diffstat (limited to 'src/pru/console.c')
| -rw-r--r-- | src/pru/console.c | 230 |
1 files changed, 230 insertions, 0 deletions
diff --git a/src/pru/console.c b/src/pru/console.c new file mode 100644 index 00000000..c22e6c82 --- /dev/null +++ b/src/pru/console.c @@ -0,0 +1,230 @@ +// PRU input/output via RPMsg +// +// 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> // memcpy +#include <pru/io.h> // read_r31 +#include <pru_intc.h> // CT_INTC +#include <pru_rpmsg.h> // pru_rpmsg_send +#include <pru_virtio_ids.h> // VIRTIO_ID_RPMSG +#include "board/misc.h" // console_get_input +#include "internal.h" // WAKE_ARM_EVENT +#include "sched.h" // DECL_INIT + +#define CHAN_NAME "rpmsg-pru" +#define CHAN_DESC "Channel 30" +#define CHAN_PORT 30 + + +/**************************************************************** + * Console interface + ****************************************************************/ + +static void +clear_pending(void) +{ + CT_INTC.SECR0 = 1 << GOT_ARM_EVENT; +} + +static struct pru_rpmsg_transport transport; +static uint16_t transport_dst; +static char input_data[64]; + +// XXX +struct pru_rpmsg_hdr { + uint32_t src; + uint32_t dst; + uint32_t reserved; + uint16_t len; + uint16_t flags; + uint8_t data[0]; +}; + +// Return a buffer (and length) containing any incoming messages +char * +console_get_input(uint8_t *plen) +{ + if (!(read_r31() & (1 << (GOT_ARM_IRQ + R31_IRQ_OFFSET)))) + goto nodata; + struct pru_rpmsg_hdr *msg; + uint32_t msg_len; + int16_t head = pru_virtqueue_get_avail_buf( + &transport.virtqueue1, (void**)&msg, &msg_len); + if (head < 0) { + clear_pending(); + goto nodata; + } + transport_dst = msg->src; + int len = msg->len < sizeof(input_data) ? msg->len : sizeof(input_data); + memcpy(input_data, msg->data, len); + pru_virtqueue_add_used_buf(&transport.virtqueue1, head, msg_len); + pru_virtqueue_kick(&transport.virtqueue1); + *plen = len; + return input_data; +nodata: + *plen = 0; + return input_data; +} + +// Remove from the receive buffer the given number of bytes +void +console_pop_input(uint8_t len) +{ +} + +static char output_data[64]; + +// Return an output buffer that the caller may fill with transmit messages +char * +console_get_output(uint8_t len) +{ + if (len > sizeof(output_data)) + return NULL; + return output_data; +} + +// Accept the given number of bytes added to the transmit buffer +void +console_push_output(uint8_t len) +{ + pru_rpmsg_send(&transport, CHAN_PORT, transport_dst, output_data, len); +} + + +/**************************************************************** + * 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, IEP_IRQ}, + {WAKE_ARM_EVENT, WAKE_ARM_IRQ}, + {GOT_ARM_EVENT, GOT_ARM_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 */ + { + IEP_IRQ, GOT_ARM_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, + }, + }, + }, +}; + + +/**************************************************************** + * RPMsg init + ****************************************************************/ + +#define VIRTIO_CONFIG_S_DRIVER_OK 4 + +void +console_init(void) +{ + clear_pending(); + + /* 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 */ + pru_rpmsg_init(&transport, + &resourceTable.rpmsg_vring0, + &resourceTable.rpmsg_vring1, + WAKE_ARM_EVENT, + GOT_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) + ; +} |