linux/drivers/spi/spi-rpc-if.c
Sergei Shtylyov eb8d6d464a
spi: add Renesas RPC-IF driver
Add the SPI driver for the Renesas RPC-IF.  It's the "front end" driver
using the "back end" APIs in the main driver to talk to the real hardware.
We only implement the 'spi-mem' interface -- there's no need to implement
the usual SPI driver methods...

Based on the original patch by Mason Yang <masonccyang@mxic.com.tw>.

Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Link: https://lore.kernel.org/r/1ece0e6c-71af-f0f1-709e-571f4b0b4853@cogentembedded.com
Signed-off-by: Mark Brown <broonie@kernel.org>
2020-06-16 00:38:38 +01:00

217 lines
5.1 KiB
C

// SPDX-License-Identifier: GPL-2.0
//
// RPC-IF SPI/QSPI/Octa driver
//
// Copyright (C) 2018 ~ 2019 Renesas Solutions Corp.
// Copyright (C) 2019 Macronix International Co., Ltd.
// Copyright (C) 2019 - 2020 Cogent Embedded, Inc.
//
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/spi/spi.h>
#include <linux/spi/spi-mem.h>
#include <memory/renesas-rpc-if.h>
#include <asm/unaligned.h>
static void rpcif_spi_mem_prepare(struct spi_device *spi_dev,
const struct spi_mem_op *spi_op,
u64 *offs, size_t *len)
{
struct rpcif *rpc = spi_controller_get_devdata(spi_dev->controller);
struct rpcif_op rpc_op = { };
rpc_op.cmd.opcode = spi_op->cmd.opcode;
rpc_op.cmd.buswidth = spi_op->cmd.buswidth;
if (spi_op->addr.nbytes) {
rpc_op.addr.buswidth = spi_op->addr.buswidth;
rpc_op.addr.nbytes = spi_op->addr.nbytes;
rpc_op.addr.val = spi_op->addr.val;
}
if (spi_op->dummy.nbytes) {
rpc_op.dummy.buswidth = spi_op->dummy.buswidth;
rpc_op.dummy.ncycles = spi_op->dummy.nbytes * 8 /
spi_op->dummy.buswidth;
}
if (spi_op->data.nbytes || (offs && len)) {
rpc_op.data.buswidth = spi_op->data.buswidth;
rpc_op.data.nbytes = spi_op->data.nbytes;
switch (spi_op->data.dir) {
case SPI_MEM_DATA_IN:
rpc_op.data.dir = RPCIF_DATA_IN;
rpc_op.data.buf.in = spi_op->data.buf.in;
break;
case SPI_MEM_DATA_OUT:
rpc_op.data.dir = RPCIF_DATA_OUT;
rpc_op.data.buf.out = spi_op->data.buf.out;
break;
case SPI_MEM_NO_DATA:
rpc_op.data.dir = RPCIF_NO_DATA;
break;
}
} else {
rpc_op.data.dir = RPCIF_NO_DATA;
}
rpcif_prepare(rpc, &rpc_op, offs, len);
}
static bool rpcif_spi_mem_supports_op(struct spi_mem *mem,
const struct spi_mem_op *op)
{
if (!spi_mem_default_supports_op(mem, op))
return false;
if (op->data.buswidth > 4 || op->addr.buswidth > 4 ||
op->dummy.buswidth > 4 || op->cmd.buswidth > 4 ||
op->addr.nbytes > 4)
return false;
return true;
}
static ssize_t rpcif_spi_mem_dirmap_read(struct spi_mem_dirmap_desc *desc,
u64 offs, size_t len, void *buf)
{
struct rpcif *rpc =
spi_controller_get_devdata(desc->mem->spi->controller);
if (offs + desc->info.offset + len > U32_MAX)
return -EINVAL;
rpcif_spi_mem_prepare(desc->mem->spi, &desc->info.op_tmpl, &offs, &len);
return rpcif_dirmap_read(rpc, offs, len, buf);
}
static int rpcif_spi_mem_dirmap_create(struct spi_mem_dirmap_desc *desc)
{
struct rpcif *rpc =
spi_controller_get_devdata(desc->mem->spi->controller);
if (desc->info.offset + desc->info.length > U32_MAX)
return -ENOTSUPP;
if (!rpcif_spi_mem_supports_op(desc->mem, &desc->info.op_tmpl))
return -ENOTSUPP;
if (!rpc->dirmap && desc->info.op_tmpl.data.dir == SPI_MEM_DATA_IN)
return -ENOTSUPP;
if (desc->info.op_tmpl.data.dir == SPI_MEM_DATA_OUT)
return -ENOTSUPP;
return 0;
}
static int rpcif_spi_mem_exec_op(struct spi_mem *mem,
const struct spi_mem_op *op)
{
struct rpcif *rpc =
spi_controller_get_devdata(mem->spi->controller);
rpcif_spi_mem_prepare(mem->spi, op, NULL, NULL);
return rpcif_manual_xfer(rpc);
}
static const struct spi_controller_mem_ops rpcif_spi_mem_ops = {
.supports_op = rpcif_spi_mem_supports_op,
.exec_op = rpcif_spi_mem_exec_op,
.dirmap_create = rpcif_spi_mem_dirmap_create,
.dirmap_read = rpcif_spi_mem_dirmap_read,
};
static int rpcif_spi_probe(struct platform_device *pdev)
{
struct device *parent = pdev->dev.parent;
struct spi_controller *ctlr;
struct rpcif *rpc;
int error;
ctlr = spi_alloc_master(&pdev->dev, sizeof(*rpc));
if (!ctlr)
return -ENOMEM;
rpc = spi_controller_get_devdata(ctlr);
rpcif_sw_init(rpc, parent);
platform_set_drvdata(pdev, ctlr);
ctlr->dev.of_node = parent->of_node;
rpcif_enable_rpm(rpc);
ctlr->num_chipselect = 1;
ctlr->mem_ops = &rpcif_spi_mem_ops;
ctlr->bits_per_word_mask = SPI_BPW_MASK(8);
ctlr->mode_bits = SPI_CPOL | SPI_CPHA | SPI_TX_QUAD | SPI_RX_QUAD;
ctlr->flags = SPI_CONTROLLER_HALF_DUPLEX;
rpcif_hw_init(rpc, false);
error = spi_register_controller(ctlr);
if (error) {
dev_err(&pdev->dev, "spi_register_controller failed\n");
goto err_put_ctlr;
}
return 0;
err_put_ctlr:
rpcif_disable_rpm(rpc);
spi_controller_put(ctlr);
return error;
}
static int rpcif_spi_remove(struct platform_device *pdev)
{
struct spi_controller *ctlr = platform_get_drvdata(pdev);
struct rpcif *rpc = spi_controller_get_devdata(ctlr);
spi_unregister_controller(ctlr);
rpcif_disable_rpm(rpc);
return 0;
}
#ifdef CONFIG_PM_SLEEP
static int rpcif_spi_suspend(struct device *dev)
{
struct spi_controller *ctlr = dev_get_drvdata(dev);
return spi_controller_suspend(ctlr);
}
static int rpcif_spi_resume(struct device *dev)
{
struct spi_controller *ctlr = dev_get_drvdata(dev);
return spi_controller_resume(ctlr);
}
static SIMPLE_DEV_PM_OPS(rpcif_spi_pm_ops, rpcif_spi_suspend, rpcif_spi_resume);
#define DEV_PM_OPS (&rpcif_spi_pm_ops)
#else
#define DEV_PM_OPS NULL
#endif
static struct platform_driver rpcif_spi_driver = {
.probe = rpcif_spi_probe,
.remove = rpcif_spi_remove,
.driver = {
.name = "rpc-if-spi",
.pm = DEV_PM_OPS,
},
};
module_platform_driver(rpcif_spi_driver);
MODULE_DESCRIPTION("Renesas RPC-IF SPI driver");
MODULE_LICENSE("GPL v2");