xref: /openbmc/linux/drivers/spi/spi-rpc-if.c (revision 2fa5ebe3)
1 // SPDX-License-Identifier: GPL-2.0
2 //
3 // RPC-IF SPI/QSPI/Octa driver
4 //
5 // Copyright (C) 2018 ~ 2019 Renesas Solutions Corp.
6 // Copyright (C) 2019 Macronix International Co., Ltd.
7 // Copyright (C) 2019 - 2020 Cogent Embedded, Inc.
8 //
9 
10 #include <linux/module.h>
11 #include <linux/platform_device.h>
12 #include <linux/spi/spi.h>
13 #include <linux/spi/spi-mem.h>
14 
15 #include <memory/renesas-rpc-if.h>
16 
17 #include <asm/unaligned.h>
18 
19 static void rpcif_spi_mem_prepare(struct spi_device *spi_dev,
20 				  const struct spi_mem_op *spi_op,
21 				  u64 *offs, size_t *len)
22 {
23 	struct rpcif *rpc = spi_controller_get_devdata(spi_dev->controller);
24 	struct rpcif_op rpc_op = { };
25 
26 	rpc_op.cmd.opcode = spi_op->cmd.opcode;
27 	rpc_op.cmd.buswidth = spi_op->cmd.buswidth;
28 
29 	if (spi_op->addr.nbytes) {
30 		rpc_op.addr.buswidth = spi_op->addr.buswidth;
31 		rpc_op.addr.nbytes = spi_op->addr.nbytes;
32 		rpc_op.addr.val = spi_op->addr.val;
33 	}
34 
35 	if (spi_op->dummy.nbytes) {
36 		rpc_op.dummy.buswidth = spi_op->dummy.buswidth;
37 		rpc_op.dummy.ncycles  = spi_op->dummy.nbytes * 8 /
38 					spi_op->dummy.buswidth;
39 	}
40 
41 	if (spi_op->data.nbytes || (offs && len)) {
42 		rpc_op.data.buswidth = spi_op->data.buswidth;
43 		rpc_op.data.nbytes = spi_op->data.nbytes;
44 		switch (spi_op->data.dir) {
45 		case SPI_MEM_DATA_IN:
46 			rpc_op.data.dir = RPCIF_DATA_IN;
47 			rpc_op.data.buf.in = spi_op->data.buf.in;
48 			break;
49 		case SPI_MEM_DATA_OUT:
50 			rpc_op.data.dir = RPCIF_DATA_OUT;
51 			rpc_op.data.buf.out = spi_op->data.buf.out;
52 			break;
53 		case SPI_MEM_NO_DATA:
54 			rpc_op.data.dir = RPCIF_NO_DATA;
55 			break;
56 		}
57 	} else	{
58 		rpc_op.data.dir = RPCIF_NO_DATA;
59 	}
60 
61 	rpcif_prepare(rpc->dev, &rpc_op, offs, len);
62 }
63 
64 static bool rpcif_spi_mem_supports_op(struct spi_mem *mem,
65 				      const struct spi_mem_op *op)
66 {
67 	if (!spi_mem_default_supports_op(mem, op))
68 		return false;
69 
70 	if (op->data.buswidth > 4 || op->addr.buswidth > 4 ||
71 	    op->dummy.buswidth > 4 || op->cmd.buswidth > 4 ||
72 	    op->addr.nbytes > 4)
73 		return false;
74 
75 	return true;
76 }
77 
78 static ssize_t rpcif_spi_mem_dirmap_read(struct spi_mem_dirmap_desc *desc,
79 					 u64 offs, size_t len, void *buf)
80 {
81 	struct rpcif *rpc =
82 		spi_controller_get_devdata(desc->mem->spi->controller);
83 
84 	if (offs + desc->info.offset + len > U32_MAX)
85 		return -EINVAL;
86 
87 	rpcif_spi_mem_prepare(desc->mem->spi, &desc->info.op_tmpl, &offs, &len);
88 
89 	return rpcif_dirmap_read(rpc->dev, offs, len, buf);
90 }
91 
92 static int rpcif_spi_mem_dirmap_create(struct spi_mem_dirmap_desc *desc)
93 {
94 	struct rpcif *rpc =
95 		spi_controller_get_devdata(desc->mem->spi->controller);
96 
97 	if (desc->info.offset + desc->info.length > U32_MAX)
98 		return -ENOTSUPP;
99 
100 	if (!rpcif_spi_mem_supports_op(desc->mem, &desc->info.op_tmpl))
101 		return -ENOTSUPP;
102 
103 	if (!rpc->dirmap && desc->info.op_tmpl.data.dir == SPI_MEM_DATA_IN)
104 		return -ENOTSUPP;
105 
106 	if (desc->info.op_tmpl.data.dir == SPI_MEM_DATA_OUT)
107 		return -ENOTSUPP;
108 
109 	return 0;
110 }
111 
112 static int rpcif_spi_mem_exec_op(struct spi_mem *mem,
113 				 const struct spi_mem_op *op)
114 {
115 	struct rpcif *rpc =
116 		spi_controller_get_devdata(mem->spi->controller);
117 
118 	rpcif_spi_mem_prepare(mem->spi, op, NULL, NULL);
119 
120 	return rpcif_manual_xfer(rpc->dev);
121 }
122 
123 static const struct spi_controller_mem_ops rpcif_spi_mem_ops = {
124 	.supports_op	= rpcif_spi_mem_supports_op,
125 	.exec_op	= rpcif_spi_mem_exec_op,
126 	.dirmap_create	= rpcif_spi_mem_dirmap_create,
127 	.dirmap_read	= rpcif_spi_mem_dirmap_read,
128 };
129 
130 static int rpcif_spi_probe(struct platform_device *pdev)
131 {
132 	struct device *parent = pdev->dev.parent;
133 	struct spi_controller *ctlr;
134 	struct rpcif *rpc;
135 	int error;
136 
137 	ctlr = devm_spi_alloc_master(&pdev->dev, sizeof(*rpc));
138 	if (!ctlr)
139 		return -ENOMEM;
140 
141 	rpc = spi_controller_get_devdata(ctlr);
142 	error = rpcif_sw_init(rpc, parent);
143 	if (error)
144 		return error;
145 
146 	platform_set_drvdata(pdev, ctlr);
147 
148 	ctlr->dev.of_node = parent->of_node;
149 
150 	pm_runtime_enable(rpc->dev);
151 
152 	ctlr->num_chipselect = 1;
153 	ctlr->mem_ops = &rpcif_spi_mem_ops;
154 
155 	ctlr->bits_per_word_mask = SPI_BPW_MASK(8);
156 	ctlr->mode_bits = SPI_CPOL | SPI_CPHA | SPI_TX_QUAD | SPI_RX_QUAD;
157 	ctlr->flags = SPI_CONTROLLER_HALF_DUPLEX;
158 
159 	error = rpcif_hw_init(rpc->dev, false);
160 	if (error)
161 		goto out_disable_rpm;
162 
163 	error = spi_register_controller(ctlr);
164 	if (error) {
165 		dev_err(&pdev->dev, "spi_register_controller failed\n");
166 		goto out_disable_rpm;
167 	}
168 
169 	return 0;
170 
171 out_disable_rpm:
172 	pm_runtime_disable(rpc->dev);
173 	return error;
174 }
175 
176 static int rpcif_spi_remove(struct platform_device *pdev)
177 {
178 	struct spi_controller *ctlr = platform_get_drvdata(pdev);
179 	struct rpcif *rpc = spi_controller_get_devdata(ctlr);
180 
181 	spi_unregister_controller(ctlr);
182 	pm_runtime_disable(rpc->dev);
183 
184 	return 0;
185 }
186 
187 static int __maybe_unused rpcif_spi_suspend(struct device *dev)
188 {
189 	struct spi_controller *ctlr = dev_get_drvdata(dev);
190 
191 	return spi_controller_suspend(ctlr);
192 }
193 
194 static int __maybe_unused rpcif_spi_resume(struct device *dev)
195 {
196 	struct spi_controller *ctlr = dev_get_drvdata(dev);
197 
198 	return spi_controller_resume(ctlr);
199 }
200 
201 static SIMPLE_DEV_PM_OPS(rpcif_spi_pm_ops, rpcif_spi_suspend, rpcif_spi_resume);
202 
203 static struct platform_driver rpcif_spi_driver = {
204 	.probe	= rpcif_spi_probe,
205 	.remove	= rpcif_spi_remove,
206 	.driver = {
207 		.name	= "rpc-if-spi",
208 #ifdef CONFIG_PM_SLEEP
209 		.pm	= &rpcif_spi_pm_ops,
210 #endif
211 	},
212 };
213 module_platform_driver(rpcif_spi_driver);
214 
215 MODULE_DESCRIPTION("Renesas RPC-IF SPI driver");
216 MODULE_LICENSE("GPL v2");
217