]>
Commit | Line | Data |
---|---|---|
ec33de3d MV |
1 | /* |
2 | * Freescale i.MX28 SPI driver | |
3 | * | |
4 | * Copyright (C) 2011 Marek Vasut <marek.vasut@gmail.com> | |
5 | * on behalf of DENX Software Engineering GmbH | |
6 | * | |
7 | * This program is free software; you can redistribute it and/or | |
8 | * modify it under the terms of the GNU General Public License as | |
9 | * published by the Free Software Foundation; either version 2 of | |
10 | * the License, or (at your option) any later version. | |
11 | * | |
12 | * This program is distributed in the hope that it will be useful, | |
13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
15 | * GNU General Public License for more details. | |
16 | * | |
17 | * You should have received a copy of the GNU General Public License | |
18 | * along with this program; if not, write to the Free Software | |
19 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, | |
20 | * MA 02111-1307 USA | |
21 | * | |
22 | * NOTE: This driver only supports the SPI-controller chipselects, | |
23 | * GPIO driven chipselects are not supported. | |
24 | */ | |
25 | ||
26 | #include <common.h> | |
27 | #include <malloc.h> | |
28 | #include <spi.h> | |
29 | #include <asm/errno.h> | |
30 | #include <asm/io.h> | |
31 | #include <asm/arch/clock.h> | |
32 | #include <asm/arch/imx-regs.h> | |
33 | #include <asm/arch/sys_proto.h> | |
7c5e6f7a | 34 | #include <asm/arch/dma.h> |
ec33de3d MV |
35 | |
36 | #define MXS_SPI_MAX_TIMEOUT 1000000 | |
37 | #define MXS_SPI_PORT_OFFSET 0x2000 | |
148ca64f FE |
38 | #define MXS_SSP_CHIPSELECT_MASK 0x00300000 |
39 | #define MXS_SSP_CHIPSELECT_SHIFT 20 | |
ec33de3d | 40 | |
7c5e6f7a MV |
41 | #define MXSSSP_SMALL_TRANSFER 512 |
42 | ||
43 | /* | |
44 | * CONFIG_MXS_SPI_DMA_ENABLE: Experimental mixed PIO/DMA support for MXS SPI | |
45 | * host. Use with utmost caution! | |
46 | * | |
47 | * Enabling this is not yet recommended since this | |
48 | * still doesn't support transfers to/from unaligned | |
49 | * addresses. Therefore this driver will not work | |
50 | * for example with saving environment. This is | |
51 | * caused by DMA alignment constraints on MXS. | |
52 | */ | |
53 | ||
ec33de3d MV |
54 | struct mxs_spi_slave { |
55 | struct spi_slave slave; | |
56 | uint32_t max_khz; | |
57 | uint32_t mode; | |
9c471142 | 58 | struct mxs_ssp_regs *regs; |
7c5e6f7a | 59 | struct mxs_dma_desc *desc; |
ec33de3d MV |
60 | }; |
61 | ||
62 | static inline struct mxs_spi_slave *to_mxs_slave(struct spi_slave *slave) | |
63 | { | |
64 | return container_of(slave, struct mxs_spi_slave, slave); | |
65 | } | |
66 | ||
67 | void spi_init(void) | |
68 | { | |
69 | } | |
70 | ||
79cb14ab FE |
71 | int spi_cs_is_valid(unsigned int bus, unsigned int cs) |
72 | { | |
73 | /* MXS SPI: 4 ports and 3 chip selects maximum */ | |
74 | if (bus > 3 || cs > 2) | |
75 | return 0; | |
76 | else | |
77 | return 1; | |
78 | } | |
79 | ||
ec33de3d MV |
80 | struct spi_slave *spi_setup_slave(unsigned int bus, unsigned int cs, |
81 | unsigned int max_hz, unsigned int mode) | |
82 | { | |
83 | struct mxs_spi_slave *mxs_slave; | |
84 | uint32_t addr; | |
9c471142 | 85 | struct mxs_ssp_regs *ssp_regs; |
148ca64f | 86 | int reg; |
7c5e6f7a | 87 | struct mxs_dma_desc *desc; |
ec33de3d | 88 | |
79cb14ab FE |
89 | if (!spi_cs_is_valid(bus, cs)) { |
90 | printf("mxs_spi: invalid bus %d / chip select %d\n", bus, cs); | |
ec33de3d MV |
91 | return NULL; |
92 | } | |
93 | ||
94 | mxs_slave = malloc(sizeof(struct mxs_spi_slave)); | |
95 | if (!mxs_slave) | |
96 | return NULL; | |
97 | ||
7c5e6f7a MV |
98 | desc = mxs_dma_desc_alloc(); |
99 | if (!desc) | |
100 | goto err_desc; | |
101 | ||
102 | if (mxs_dma_init_channel(bus)) | |
103 | goto err_init; | |
104 | ||
ec33de3d MV |
105 | addr = MXS_SSP0_BASE + (bus * MXS_SPI_PORT_OFFSET); |
106 | ||
107 | mxs_slave->slave.bus = bus; | |
108 | mxs_slave->slave.cs = cs; | |
109 | mxs_slave->max_khz = max_hz / 1000; | |
110 | mxs_slave->mode = mode; | |
9c471142 | 111 | mxs_slave->regs = (struct mxs_ssp_regs *)addr; |
7c5e6f7a | 112 | mxs_slave->desc = desc; |
148ca64f | 113 | ssp_regs = mxs_slave->regs; |
ec33de3d | 114 | |
148ca64f FE |
115 | reg = readl(&ssp_regs->hw_ssp_ctrl0); |
116 | reg &= ~(MXS_SSP_CHIPSELECT_MASK); | |
117 | reg |= cs << MXS_SSP_CHIPSELECT_SHIFT; | |
118 | ||
119 | writel(reg, &ssp_regs->hw_ssp_ctrl0); | |
ec33de3d | 120 | return &mxs_slave->slave; |
7c5e6f7a MV |
121 | |
122 | err_init: | |
123 | mxs_dma_desc_free(desc); | |
124 | err_desc: | |
125 | free(mxs_slave); | |
126 | return NULL; | |
ec33de3d MV |
127 | } |
128 | ||
129 | void spi_free_slave(struct spi_slave *slave) | |
130 | { | |
131 | struct mxs_spi_slave *mxs_slave = to_mxs_slave(slave); | |
7c5e6f7a | 132 | mxs_dma_desc_free(mxs_slave->desc); |
ec33de3d MV |
133 | free(mxs_slave); |
134 | } | |
135 | ||
136 | int spi_claim_bus(struct spi_slave *slave) | |
137 | { | |
138 | struct mxs_spi_slave *mxs_slave = to_mxs_slave(slave); | |
9c471142 | 139 | struct mxs_ssp_regs *ssp_regs = mxs_slave->regs; |
ec33de3d MV |
140 | uint32_t reg = 0; |
141 | ||
142 | mx28_reset_block(&ssp_regs->hw_ssp_ctrl0_reg); | |
143 | ||
144 | writel(SSP_CTRL0_BUS_WIDTH_ONE_BIT, &ssp_regs->hw_ssp_ctrl0); | |
145 | ||
146 | reg = SSP_CTRL1_SSP_MODE_SPI | SSP_CTRL1_WORD_LENGTH_EIGHT_BITS; | |
147 | reg |= (mxs_slave->mode & SPI_CPOL) ? SSP_CTRL1_POLARITY : 0; | |
148 | reg |= (mxs_slave->mode & SPI_CPHA) ? SSP_CTRL1_PHASE : 0; | |
149 | writel(reg, &ssp_regs->hw_ssp_ctrl1); | |
150 | ||
151 | writel(0, &ssp_regs->hw_ssp_cmd0); | |
152 | ||
153 | mx28_set_ssp_busclock(slave->bus, mxs_slave->max_khz); | |
154 | ||
155 | return 0; | |
156 | } | |
157 | ||
158 | void spi_release_bus(struct spi_slave *slave) | |
159 | { | |
160 | } | |
161 | ||
9c471142 | 162 | static void mxs_spi_start_xfer(struct mxs_ssp_regs *ssp_regs) |
ec33de3d MV |
163 | { |
164 | writel(SSP_CTRL0_LOCK_CS, &ssp_regs->hw_ssp_ctrl0_set); | |
165 | writel(SSP_CTRL0_IGNORE_CRC, &ssp_regs->hw_ssp_ctrl0_clr); | |
166 | } | |
167 | ||
9c471142 | 168 | static void mxs_spi_end_xfer(struct mxs_ssp_regs *ssp_regs) |
ec33de3d MV |
169 | { |
170 | writel(SSP_CTRL0_LOCK_CS, &ssp_regs->hw_ssp_ctrl0_clr); | |
171 | writel(SSP_CTRL0_IGNORE_CRC, &ssp_regs->hw_ssp_ctrl0_set); | |
172 | } | |
173 | ||
ccd4d5a0 MV |
174 | static int mxs_spi_xfer_pio(struct mxs_spi_slave *slave, |
175 | char *data, int length, int write, unsigned long flags) | |
ec33de3d | 176 | { |
9c471142 | 177 | struct mxs_ssp_regs *ssp_regs = slave->regs; |
c7065fa8 | 178 | |
ec33de3d MV |
179 | if (flags & SPI_XFER_BEGIN) |
180 | mxs_spi_start_xfer(ssp_regs); | |
181 | ||
ccd4d5a0 | 182 | while (length--) { |
ec33de3d MV |
183 | /* We transfer 1 byte */ |
184 | writel(1, &ssp_regs->hw_ssp_xfer_size); | |
185 | ||
ccd4d5a0 | 186 | if ((flags & SPI_XFER_END) && !length) |
ec33de3d MV |
187 | mxs_spi_end_xfer(ssp_regs); |
188 | ||
c7065fa8 | 189 | if (write) |
ec33de3d MV |
190 | writel(SSP_CTRL0_READ, &ssp_regs->hw_ssp_ctrl0_clr); |
191 | else | |
192 | writel(SSP_CTRL0_READ, &ssp_regs->hw_ssp_ctrl0_set); | |
193 | ||
194 | writel(SSP_CTRL0_RUN, &ssp_regs->hw_ssp_ctrl0_set); | |
195 | ||
196 | if (mx28_wait_mask_set(&ssp_regs->hw_ssp_ctrl0_reg, | |
197 | SSP_CTRL0_RUN, MXS_SPI_MAX_TIMEOUT)) { | |
198 | printf("MXS SPI: Timeout waiting for start\n"); | |
d9fb6a4c | 199 | return -ETIMEDOUT; |
ec33de3d MV |
200 | } |
201 | ||
c7065fa8 MV |
202 | if (write) |
203 | writel(*data++, &ssp_regs->hw_ssp_data); | |
ec33de3d MV |
204 | |
205 | writel(SSP_CTRL0_DATA_XFER, &ssp_regs->hw_ssp_ctrl0_set); | |
206 | ||
c7065fa8 | 207 | if (!write) { |
ec33de3d MV |
208 | if (mx28_wait_mask_clr(&ssp_regs->hw_ssp_status_reg, |
209 | SSP_STATUS_FIFO_EMPTY, MXS_SPI_MAX_TIMEOUT)) { | |
210 | printf("MXS SPI: Timeout waiting for data\n"); | |
d9fb6a4c | 211 | return -ETIMEDOUT; |
ec33de3d MV |
212 | } |
213 | ||
c7065fa8 MV |
214 | *data = readl(&ssp_regs->hw_ssp_data); |
215 | data++; | |
ec33de3d MV |
216 | } |
217 | ||
218 | if (mx28_wait_mask_clr(&ssp_regs->hw_ssp_ctrl0_reg, | |
219 | SSP_CTRL0_RUN, MXS_SPI_MAX_TIMEOUT)) { | |
220 | printf("MXS SPI: Timeout waiting for finish\n"); | |
d9fb6a4c | 221 | return -ETIMEDOUT; |
ec33de3d MV |
222 | } |
223 | } | |
224 | ||
225 | return 0; | |
ccd4d5a0 MV |
226 | } |
227 | ||
7c5e6f7a MV |
228 | static int mxs_spi_xfer_dma(struct mxs_spi_slave *slave, |
229 | char *data, int length, int write, unsigned long flags) | |
230 | { | |
231 | struct mxs_dma_desc *desc = slave->desc; | |
9c471142 | 232 | struct mxs_ssp_regs *ssp_regs = slave->regs; |
7c5e6f7a MV |
233 | uint32_t ctrl0 = SSP_CTRL0_DATA_XFER; |
234 | uint32_t cache_data_count; | |
235 | int dmach; | |
236 | ||
237 | memset(desc, 0, sizeof(struct mxs_dma_desc)); | |
238 | desc->address = (dma_addr_t)desc; | |
239 | ||
240 | if (flags & SPI_XFER_BEGIN) | |
241 | ctrl0 |= SSP_CTRL0_LOCK_CS; | |
242 | if (flags & SPI_XFER_END) | |
243 | ctrl0 |= SSP_CTRL0_IGNORE_CRC; | |
244 | if (!write) | |
245 | ctrl0 |= SSP_CTRL0_READ; | |
246 | ||
247 | writel(length, &ssp_regs->hw_ssp_xfer_size); | |
248 | ||
249 | if (length % ARCH_DMA_MINALIGN) | |
250 | cache_data_count = roundup(length, ARCH_DMA_MINALIGN); | |
251 | else | |
252 | cache_data_count = length; | |
253 | ||
254 | if (!write) { | |
255 | slave->desc->cmd.data = MXS_DMA_DESC_COMMAND_DMA_WRITE; | |
256 | slave->desc->cmd.address = (dma_addr_t)data; | |
257 | } else { | |
258 | slave->desc->cmd.data = MXS_DMA_DESC_COMMAND_DMA_READ; | |
259 | slave->desc->cmd.address = (dma_addr_t)data; | |
260 | ||
261 | /* Flush data to DRAM so DMA can pick them up */ | |
262 | flush_dcache_range((uint32_t)data, | |
263 | (uint32_t)(data + cache_data_count)); | |
264 | } | |
265 | ||
266 | slave->desc->cmd.data |= MXS_DMA_DESC_IRQ | MXS_DMA_DESC_DEC_SEM | | |
267 | (length << MXS_DMA_DESC_BYTES_OFFSET) | | |
268 | (1 << MXS_DMA_DESC_PIO_WORDS_OFFSET) | | |
269 | MXS_DMA_DESC_WAIT4END; | |
270 | ||
271 | slave->desc->cmd.pio_words[0] = ctrl0; | |
272 | ||
273 | dmach = MXS_DMA_CHANNEL_AHB_APBH_SSP0 + slave->slave.bus; | |
274 | mxs_dma_desc_append(dmach, slave->desc); | |
275 | if (mxs_dma_go(dmach)) | |
276 | return -EINVAL; | |
277 | ||
278 | /* The data arrived into DRAM, invalidate cache over them */ | |
279 | if (!write) { | |
280 | invalidate_dcache_range((uint32_t)data, | |
281 | (uint32_t)(data + cache_data_count)); | |
282 | } | |
283 | ||
284 | return 0; | |
285 | } | |
286 | ||
ccd4d5a0 MV |
287 | int spi_xfer(struct spi_slave *slave, unsigned int bitlen, |
288 | const void *dout, void *din, unsigned long flags) | |
289 | { | |
290 | struct mxs_spi_slave *mxs_slave = to_mxs_slave(slave); | |
9c471142 | 291 | struct mxs_ssp_regs *ssp_regs = mxs_slave->regs; |
ccd4d5a0 MV |
292 | int len = bitlen / 8; |
293 | char dummy; | |
294 | int write = 0; | |
295 | char *data = NULL; | |
296 | ||
7c5e6f7a MV |
297 | #ifdef CONFIG_MXS_SPI_DMA_ENABLE |
298 | int dma = 1; | |
299 | #else | |
300 | int dma = 0; | |
301 | #endif | |
302 | ||
ccd4d5a0 MV |
303 | if (bitlen == 0) { |
304 | if (flags & SPI_XFER_END) { | |
305 | din = (void *)&dummy; | |
306 | len = 1; | |
307 | } else | |
308 | return 0; | |
309 | } | |
310 | ||
311 | /* Half-duplex only */ | |
312 | if (din && dout) | |
313 | return -EINVAL; | |
314 | /* No data */ | |
315 | if (!din && !dout) | |
316 | return 0; | |
317 | ||
318 | if (dout) { | |
319 | data = (char *)dout; | |
320 | write = 1; | |
321 | } else if (din) { | |
322 | data = (char *)din; | |
323 | write = 0; | |
324 | } | |
325 | ||
7c5e6f7a MV |
326 | /* |
327 | * Check for alignment, if the buffer is aligned, do DMA transfer, | |
328 | * PIO otherwise. This is a temporary workaround until proper bounce | |
329 | * buffer is in place. | |
330 | */ | |
331 | if (dma) { | |
332 | if (((uint32_t)data) & (ARCH_DMA_MINALIGN - 1)) | |
333 | dma = 0; | |
334 | if (((uint32_t)len) & (ARCH_DMA_MINALIGN - 1)) | |
335 | dma = 0; | |
336 | } | |
337 | ||
338 | if (!dma || (len < MXSSSP_SMALL_TRANSFER)) { | |
339 | writel(SSP_CTRL1_DMA_ENABLE, &ssp_regs->hw_ssp_ctrl1_clr); | |
340 | return mxs_spi_xfer_pio(mxs_slave, data, len, write, flags); | |
341 | } else { | |
342 | writel(SSP_CTRL1_DMA_ENABLE, &ssp_regs->hw_ssp_ctrl1_set); | |
343 | return mxs_spi_xfer_dma(mxs_slave, data, len, write, flags); | |
344 | } | |
ec33de3d | 345 | } |