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Tom Rini83d290c2018-05-06 17:58:06 -04001// SPDX-License-Identifier: GPL-2.0+
Stefan Roese3fda4ef2016-05-19 15:56:44 +02002/*
3 * Copyright (C) 2015 Marvell International Ltd.
4 *
5 * Copyright (C) 2016 Stefan Roese <sr@denx.de>
Stefan Roese3fda4ef2016-05-19 15:56:44 +02006 */
7
8#include <common.h>
9#include <dm.h>
10#include <malloc.h>
11#include <spi.h>
Marek Behúndbbd5bd2018-04-24 17:21:26 +020012#include <clk.h>
Stefan Roese3fda4ef2016-05-19 15:56:44 +020013#include <wait_bit.h>
14#include <asm/io.h>
15
16DECLARE_GLOBAL_DATA_PTR;
17
18#define MVEBU_SPI_A3700_XFER_RDY BIT(1)
19#define MVEBU_SPI_A3700_FIFO_FLUSH BIT(9)
20#define MVEBU_SPI_A3700_BYTE_LEN BIT(5)
21#define MVEBU_SPI_A3700_CLK_PHA BIT(6)
22#define MVEBU_SPI_A3700_CLK_POL BIT(7)
23#define MVEBU_SPI_A3700_FIFO_EN BIT(17)
24#define MVEBU_SPI_A3700_SPI_EN_0 BIT(16)
Marek Behúndbbd5bd2018-04-24 17:21:26 +020025#define MVEBU_SPI_A3700_CLK_PRESCALE_MASK 0x1f
26
Stefan Roese3fda4ef2016-05-19 15:56:44 +020027
28/* SPI registers */
29struct spi_reg {
30 u32 ctrl; /* 0x10600 */
31 u32 cfg; /* 0x10604 */
32 u32 dout; /* 0x10608 */
33 u32 din; /* 0x1060c */
34};
35
36struct mvebu_spi_platdata {
37 struct spi_reg *spireg;
Marek Behúndbbd5bd2018-04-24 17:21:26 +020038 struct clk clk;
Stefan Roese3fda4ef2016-05-19 15:56:44 +020039};
40
41static void spi_cs_activate(struct spi_reg *reg, int cs)
42{
43 setbits_le32(&reg->ctrl, MVEBU_SPI_A3700_SPI_EN_0 << cs);
44}
45
46static void spi_cs_deactivate(struct spi_reg *reg, int cs)
47{
48 clrbits_le32(&reg->ctrl, MVEBU_SPI_A3700_SPI_EN_0 << cs);
49}
50
51/**
52 * spi_legacy_shift_byte() - triggers the real SPI transfer
53 * @bytelen: Indicate how many bytes to transfer.
54 * @dout: Buffer address of what to send.
55 * @din: Buffer address of where to receive.
56 *
57 * This function triggers the real SPI transfer in legacy mode. It
58 * will shift out char buffer from @dout, and shift in char buffer to
59 * @din, if necessary.
60 *
61 * This function assumes that only one byte is shifted at one time.
62 * However, it is not its responisbility to set the transfer type to
63 * one-byte. Also, it does not guarantee that it will work if transfer
64 * type becomes two-byte. See spi_set_legacy() for details.
65 *
66 * In legacy mode, simply write to the SPI_DOUT register will trigger
67 * the transfer.
68 *
69 * If @dout == NULL, which means no actual data needs to be sent out,
70 * then the function will shift out 0x00 in order to shift in data.
71 * The XFER_RDY flag is checked every time before accessing SPI_DOUT
72 * and SPI_DIN register.
73 *
74 * The number of transfers to be triggerred is decided by @bytelen.
75 *
76 * Return: 0 - cool
77 * -ETIMEDOUT - XFER_RDY flag timeout
78 */
79static int spi_legacy_shift_byte(struct spi_reg *reg, unsigned int bytelen,
80 const void *dout, void *din)
81{
82 const u8 *dout_8;
83 u8 *din_8;
84 int ret;
85
86 /* Use 0x00 as dummy dout */
87 const u8 dummy_dout = 0x0;
88 u32 pending_dout = 0x0;
89
90 /* dout_8: pointer of current dout */
91 dout_8 = dout;
92 /* din_8: pointer of current din */
93 din_8 = din;
94
95 while (bytelen) {
Álvaro Fernández Rojas48263502018-01-23 17:14:55 +010096 ret = wait_for_bit_le32(&reg->ctrl,
97 MVEBU_SPI_A3700_XFER_RDY,
98 true,100, false);
Stefan Roese3fda4ef2016-05-19 15:56:44 +020099 if (ret)
100 return ret;
101
102 if (dout)
103 pending_dout = (u32)*dout_8;
104 else
105 pending_dout = (u32)dummy_dout;
106
107 /* Trigger the xfer */
108 writel(pending_dout, &reg->dout);
109
110 if (din) {
Álvaro Fernández Rojas48263502018-01-23 17:14:55 +0100111 ret = wait_for_bit_le32(&reg->ctrl,
112 MVEBU_SPI_A3700_XFER_RDY,
113 true, 100, false);
Stefan Roese3fda4ef2016-05-19 15:56:44 +0200114 if (ret)
115 return ret;
116
117 /* Read what is transferred in */
118 *din_8 = (u8)readl(&reg->din);
119 }
120
121 /* Don't increment the current pointer if NULL */
122 if (dout)
123 dout_8++;
124 if (din)
125 din_8++;
126
127 bytelen--;
128 }
129
130 return 0;
131}
132
133static int mvebu_spi_xfer(struct udevice *dev, unsigned int bitlen,
134 const void *dout, void *din, unsigned long flags)
135{
136 struct udevice *bus = dev->parent;
137 struct mvebu_spi_platdata *plat = dev_get_platdata(bus);
138 struct spi_reg *reg = plat->spireg;
139 unsigned int bytelen;
140 int ret;
141
142 bytelen = bitlen / 8;
143
144 if (dout && din)
145 debug("This is a duplex transfer.\n");
146
147 /* Activate CS */
148 if (flags & SPI_XFER_BEGIN) {
149 debug("SPI: activate cs.\n");
150 spi_cs_activate(reg, spi_chip_select(dev));
151 }
152
153 /* Send and/or receive */
154 if (dout || din) {
155 ret = spi_legacy_shift_byte(reg, bytelen, dout, din);
156 if (ret)
157 return ret;
158 }
159
160 /* Deactivate CS */
161 if (flags & SPI_XFER_END) {
Álvaro Fernández Rojas48263502018-01-23 17:14:55 +0100162 ret = wait_for_bit_le32(&reg->ctrl,
163 MVEBU_SPI_A3700_XFER_RDY,
164 true, 100, false);
Stefan Roese3fda4ef2016-05-19 15:56:44 +0200165 if (ret)
166 return ret;
167
168 debug("SPI: deactivate cs.\n");
169 spi_cs_deactivate(reg, spi_chip_select(dev));
170 }
171
172 return 0;
173}
174
175static int mvebu_spi_set_speed(struct udevice *bus, uint hz)
176{
177 struct mvebu_spi_platdata *plat = dev_get_platdata(bus);
178 struct spi_reg *reg = plat->spireg;
Marek Behúndbbd5bd2018-04-24 17:21:26 +0200179 u32 data, prescale;
Stefan Roese3fda4ef2016-05-19 15:56:44 +0200180
181 data = readl(&reg->cfg);
182
Marek Behúndbbd5bd2018-04-24 17:21:26 +0200183 prescale = DIV_ROUND_UP(clk_get_rate(&plat->clk), hz);
184 if (prescale > 0x1f)
185 prescale = 0x1f;
186 else if (prescale > 0xf)
187 prescale = 0x10 + (prescale + 1) / 2;
Stefan Roese3fda4ef2016-05-19 15:56:44 +0200188
Marek Behúndbbd5bd2018-04-24 17:21:26 +0200189 data &= ~MVEBU_SPI_A3700_CLK_PRESCALE_MASK;
190 data |= prescale & MVEBU_SPI_A3700_CLK_PRESCALE_MASK;
Stefan Roese3fda4ef2016-05-19 15:56:44 +0200191
192 writel(data, &reg->cfg);
193
194 return 0;
195}
196
197static int mvebu_spi_set_mode(struct udevice *bus, uint mode)
198{
199 struct mvebu_spi_platdata *plat = dev_get_platdata(bus);
200 struct spi_reg *reg = plat->spireg;
201
202 /*
203 * Set SPI polarity
204 * 0: Serial interface clock is low when inactive
205 * 1: Serial interface clock is high when inactive
206 */
207 if (mode & SPI_CPOL)
208 setbits_le32(&reg->cfg, MVEBU_SPI_A3700_CLK_POL);
209 else
210 clrbits_le32(&reg->cfg, MVEBU_SPI_A3700_CLK_POL);
211 if (mode & SPI_CPHA)
212 setbits_le32(&reg->cfg, MVEBU_SPI_A3700_CLK_PHA);
213 else
214 clrbits_le32(&reg->cfg, MVEBU_SPI_A3700_CLK_PHA);
215
216 return 0;
217}
218
219static int mvebu_spi_probe(struct udevice *bus)
220{
221 struct mvebu_spi_platdata *plat = dev_get_platdata(bus);
222 struct spi_reg *reg = plat->spireg;
223 u32 data;
224 int ret;
225
226 /*
227 * Settings SPI controller to be working in legacy mode, which
228 * means use only DO pin (I/O 1) for Data Out, and DI pin (I/O 0)
229 * for Data In.
230 */
231
232 /* Flush read/write FIFO */
233 data = readl(&reg->cfg);
234 writel(data | MVEBU_SPI_A3700_FIFO_FLUSH, &reg->cfg);
Álvaro Fernández Rojas48263502018-01-23 17:14:55 +0100235 ret = wait_for_bit_le32(&reg->cfg, MVEBU_SPI_A3700_FIFO_FLUSH,
236 false, 1000, false);
Stefan Roese3fda4ef2016-05-19 15:56:44 +0200237 if (ret)
238 return ret;
239
240 /* Disable FIFO mode */
241 data &= ~MVEBU_SPI_A3700_FIFO_EN;
242
243 /* Always shift 1 byte at a time */
244 data &= ~MVEBU_SPI_A3700_BYTE_LEN;
245
246 writel(data, &reg->cfg);
247
248 return 0;
249}
250
251static int mvebu_spi_ofdata_to_platdata(struct udevice *bus)
252{
253 struct mvebu_spi_platdata *plat = dev_get_platdata(bus);
Marek Behúndbbd5bd2018-04-24 17:21:26 +0200254 int ret;
Stefan Roese3fda4ef2016-05-19 15:56:44 +0200255
Simon Glassa821c4a2017-05-17 17:18:05 -0600256 plat->spireg = (struct spi_reg *)devfdt_get_addr(bus);
Stefan Roese3fda4ef2016-05-19 15:56:44 +0200257
Marek Behúndbbd5bd2018-04-24 17:21:26 +0200258 ret = clk_get_by_index(bus, 0, &plat->clk);
259 if (ret) {
260 dev_err(bus, "cannot get clock\n");
261 return ret;
262 }
263
264 return 0;
265}
266
267static int mvebu_spi_remove(struct udevice *bus)
268{
269 struct mvebu_spi_platdata *plat = dev_get_platdata(bus);
270
271 clk_free(&plat->clk);
Stefan Roese3fda4ef2016-05-19 15:56:44 +0200272
273 return 0;
274}
275
276static const struct dm_spi_ops mvebu_spi_ops = {
277 .xfer = mvebu_spi_xfer,
278 .set_speed = mvebu_spi_set_speed,
279 .set_mode = mvebu_spi_set_mode,
280 /*
281 * cs_info is not needed, since we require all chip selects to be
282 * in the device tree explicitly
283 */
284};
285
286static const struct udevice_id mvebu_spi_ids[] = {
287 { .compatible = "marvell,armada-3700-spi" },
288 { }
289};
290
291U_BOOT_DRIVER(mvebu_spi) = {
292 .name = "mvebu_spi",
293 .id = UCLASS_SPI,
294 .of_match = mvebu_spi_ids,
295 .ops = &mvebu_spi_ops,
296 .ofdata_to_platdata = mvebu_spi_ofdata_to_platdata,
297 .platdata_auto_alloc_size = sizeof(struct mvebu_spi_platdata),
298 .probe = mvebu_spi_probe,
Marek Behúndbbd5bd2018-04-24 17:21:26 +0200299 .remove = mvebu_spi_remove,
Stefan Roese3fda4ef2016-05-19 15:56:44 +0200300};