diff options
Diffstat (limited to 'drivers/firmware/arm_scmi/smc.c')
-rw-r--r-- | drivers/firmware/arm_scmi/smc.c | 137 |
1 files changed, 137 insertions, 0 deletions
diff --git a/drivers/firmware/arm_scmi/smc.c b/drivers/firmware/arm_scmi/smc.c new file mode 100644 index 0000000000..67f19a7b43 --- /dev/null +++ b/drivers/firmware/arm_scmi/smc.c @@ -0,0 +1,137 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * System Control and Management Interface (SCMI) Message SMC/HVC + * Transport driver + * + * Copyright 2020 NXP + */ + +#include <common.h> +#include <linux/arm-smccc.h> +#include <driver.h> +#include <linux/err.h> +#include <of.h> +#include <of_address.h> + +#include "common.h" + +/** + * struct scmi_smc - Structure representing a SCMI smc transport + * + * @cinfo: SCMI channel info + * @shmem: Transmit/Receive shared memory area + * @func_id: smc/hvc call function id + */ + +struct scmi_smc { + struct scmi_chan_info *cinfo; + struct scmi_shared_mem __iomem *shmem; + u32 func_id; +}; + +static bool smc_chan_available(struct device_d *dev, int idx) +{ + return of_parse_phandle(dev->device_node, "shmem", 0) != NULL; +} + +static int smc_chan_setup(struct scmi_chan_info *cinfo, struct device_d *dev, + bool tx) +{ + struct device_d *cdev = cinfo->dev; + struct scmi_smc *scmi_info; + resource_size_t size; + struct resource res; + struct device_node *np; + u32 func_id; + int ret; + + if (!tx) + return -ENODEV; + + scmi_info = kzalloc(sizeof(*scmi_info), GFP_KERNEL); + if (!scmi_info) + return -ENOMEM; + + np = of_parse_phandle(cdev->device_node, "shmem", 0); + ret = of_address_to_resource(np, 0, &res); + if (ret) { + dev_err(cdev, "failed to get SCMI Tx shared memory\n"); + return ret; + } + + size = resource_size(&res); + scmi_info->shmem = IOMEM(res.start); + + ret = of_property_read_u32(dev->device_node, "arm,smc-id", &func_id); + if (ret < 0) + return ret; + + scmi_info->func_id = func_id; + scmi_info->cinfo = cinfo; + cinfo->transport_info = scmi_info; + + return 0; +} + +static int smc_chan_free(int id, void *p, void *data) +{ + struct scmi_chan_info *cinfo = p; + struct scmi_smc *scmi_info = cinfo->transport_info; + + cinfo->transport_info = NULL; + scmi_info->cinfo = NULL; + + scmi_free_channel(cinfo, data, id); + + return 0; +} + +static int smc_send_message(struct scmi_chan_info *cinfo, + struct scmi_xfer *xfer) +{ + struct scmi_smc *scmi_info = cinfo->transport_info; + struct arm_smccc_res res; + + shmem_tx_prepare(scmi_info->shmem, xfer); + + arm_smccc_1_1_invoke(scmi_info->func_id, 0, 0, 0, 0, 0, 0, 0, &res); + + scmi_rx_callback(scmi_info->cinfo, shmem_read_header(scmi_info->shmem)); + + /* Only SMCCC_RET_NOT_SUPPORTED is valid error code */ + if (res.a0) + return -EOPNOTSUPP; + return 0; +} + +static void smc_fetch_response(struct scmi_chan_info *cinfo, + struct scmi_xfer *xfer) +{ + struct scmi_smc *scmi_info = cinfo->transport_info; + + shmem_fetch_response(scmi_info->shmem, xfer); +} + +static bool +smc_poll_done(struct scmi_chan_info *cinfo, struct scmi_xfer *xfer) +{ + struct scmi_smc *scmi_info = cinfo->transport_info; + + return shmem_poll_done(scmi_info->shmem, xfer); +} + +static const struct scmi_transport_ops scmi_smc_ops = { + .chan_available = smc_chan_available, + .chan_setup = smc_chan_setup, + .chan_free = smc_chan_free, + .send_message = smc_send_message, + .fetch_response = smc_fetch_response, + .poll_done = smc_poll_done, +}; + +const struct scmi_desc scmi_smc_desc = { + .ops = &scmi_smc_ops, + .max_rx_timeout_ms = 30, + .max_msg = 20, + .max_msg_size = 128, +}; |