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16#include <linux/dma-mapping.h>
17#include <linux/dmaengine.h>
18#include <linux/interrupt.h>
19#include <linux/slab.h>
20#include <linux/spi/spi.h>
21#include <linux/types.h>
22
23#include "spi-dw.h"
24
25#ifdef CONFIG_SPI_DW_MID_DMA
26#include <linux/pci.h>
27#include <linux/platform_data/dma-dw.h>
28
29#define RX_BUSY 0
30#define TX_BUSY 1
31
32static struct dw_dma_slave mid_dma_tx = { .dst_id = 1 };
33static struct dw_dma_slave mid_dma_rx = { .src_id = 0 };
34
35static bool mid_spi_dma_chan_filter(struct dma_chan *chan, void *param)
36{
37 struct dw_dma_slave *s = param;
38
39 if (s->dma_dev != chan->device->dev)
40 return false;
41
42 chan->private = s;
43 return true;
44}
45
46static int mid_spi_dma_init(struct dw_spi *dws)
47{
48 struct pci_dev *dma_dev;
49 struct dw_dma_slave *tx = dws->dma_tx;
50 struct dw_dma_slave *rx = dws->dma_rx;
51 dma_cap_mask_t mask;
52
53
54
55
56
57 dma_dev = pci_get_device(PCI_VENDOR_ID_INTEL, 0x0827, NULL);
58 if (!dma_dev)
59 return -ENODEV;
60
61 dma_cap_zero(mask);
62 dma_cap_set(DMA_SLAVE, mask);
63
64
65 rx->dma_dev = &dma_dev->dev;
66 dws->rxchan = dma_request_channel(mask, mid_spi_dma_chan_filter, rx);
67 if (!dws->rxchan)
68 goto err_exit;
69 dws->master->dma_rx = dws->rxchan;
70
71
72 tx->dma_dev = &dma_dev->dev;
73 dws->txchan = dma_request_channel(mask, mid_spi_dma_chan_filter, tx);
74 if (!dws->txchan)
75 goto free_rxchan;
76 dws->master->dma_tx = dws->txchan;
77
78 dws->dma_inited = 1;
79 return 0;
80
81free_rxchan:
82 dma_release_channel(dws->rxchan);
83err_exit:
84 return -EBUSY;
85}
86
87static void mid_spi_dma_exit(struct dw_spi *dws)
88{
89 if (!dws->dma_inited)
90 return;
91
92 dmaengine_terminate_sync(dws->txchan);
93 dma_release_channel(dws->txchan);
94
95 dmaengine_terminate_sync(dws->rxchan);
96 dma_release_channel(dws->rxchan);
97}
98
99static irqreturn_t dma_transfer(struct dw_spi *dws)
100{
101 u16 irq_status = dw_readl(dws, DW_SPI_ISR);
102
103 if (!irq_status)
104 return IRQ_NONE;
105
106 dw_readl(dws, DW_SPI_ICR);
107 spi_reset_chip(dws);
108
109 dev_err(&dws->master->dev, "%s: FIFO overrun/underrun\n", __func__);
110 dws->master->cur_msg->status = -EIO;
111 spi_finalize_current_transfer(dws->master);
112 return IRQ_HANDLED;
113}
114
115static bool mid_spi_can_dma(struct spi_master *master, struct spi_device *spi,
116 struct spi_transfer *xfer)
117{
118 struct dw_spi *dws = spi_master_get_devdata(master);
119
120 if (!dws->dma_inited)
121 return false;
122
123 return xfer->len > dws->fifo_len;
124}
125
126static enum dma_slave_buswidth convert_dma_width(u32 dma_width) {
127 if (dma_width == 1)
128 return DMA_SLAVE_BUSWIDTH_1_BYTE;
129 else if (dma_width == 2)
130 return DMA_SLAVE_BUSWIDTH_2_BYTES;
131
132 return DMA_SLAVE_BUSWIDTH_UNDEFINED;
133}
134
135
136
137
138
139static void dw_spi_dma_tx_done(void *arg)
140{
141 struct dw_spi *dws = arg;
142
143 clear_bit(TX_BUSY, &dws->dma_chan_busy);
144 if (test_bit(RX_BUSY, &dws->dma_chan_busy))
145 return;
146 spi_finalize_current_transfer(dws->master);
147}
148
149static struct dma_async_tx_descriptor *dw_spi_dma_prepare_tx(struct dw_spi *dws,
150 struct spi_transfer *xfer)
151{
152 struct dma_slave_config txconf;
153 struct dma_async_tx_descriptor *txdesc;
154
155 if (!xfer->tx_buf)
156 return NULL;
157
158 txconf.direction = DMA_MEM_TO_DEV;
159 txconf.dst_addr = dws->dma_addr;
160 txconf.dst_maxburst = 16;
161 txconf.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
162 txconf.dst_addr_width = convert_dma_width(dws->dma_width);
163 txconf.device_fc = false;
164
165 dmaengine_slave_config(dws->txchan, &txconf);
166
167 txdesc = dmaengine_prep_slave_sg(dws->txchan,
168 xfer->tx_sg.sgl,
169 xfer->tx_sg.nents,
170 DMA_MEM_TO_DEV,
171 DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
172 if (!txdesc)
173 return NULL;
174
175 txdesc->callback = dw_spi_dma_tx_done;
176 txdesc->callback_param = dws;
177
178 return txdesc;
179}
180
181
182
183
184
185static void dw_spi_dma_rx_done(void *arg)
186{
187 struct dw_spi *dws = arg;
188
189 clear_bit(RX_BUSY, &dws->dma_chan_busy);
190 if (test_bit(TX_BUSY, &dws->dma_chan_busy))
191 return;
192 spi_finalize_current_transfer(dws->master);
193}
194
195static struct dma_async_tx_descriptor *dw_spi_dma_prepare_rx(struct dw_spi *dws,
196 struct spi_transfer *xfer)
197{
198 struct dma_slave_config rxconf;
199 struct dma_async_tx_descriptor *rxdesc;
200
201 if (!xfer->rx_buf)
202 return NULL;
203
204 rxconf.direction = DMA_DEV_TO_MEM;
205 rxconf.src_addr = dws->dma_addr;
206 rxconf.src_maxburst = 16;
207 rxconf.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
208 rxconf.src_addr_width = convert_dma_width(dws->dma_width);
209 rxconf.device_fc = false;
210
211 dmaengine_slave_config(dws->rxchan, &rxconf);
212
213 rxdesc = dmaengine_prep_slave_sg(dws->rxchan,
214 xfer->rx_sg.sgl,
215 xfer->rx_sg.nents,
216 DMA_DEV_TO_MEM,
217 DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
218 if (!rxdesc)
219 return NULL;
220
221 rxdesc->callback = dw_spi_dma_rx_done;
222 rxdesc->callback_param = dws;
223
224 return rxdesc;
225}
226
227static int mid_spi_dma_setup(struct dw_spi *dws, struct spi_transfer *xfer)
228{
229 u16 dma_ctrl = 0;
230
231 dw_writel(dws, DW_SPI_DMARDLR, 0xf);
232 dw_writel(dws, DW_SPI_DMATDLR, 0x10);
233
234 if (xfer->tx_buf)
235 dma_ctrl |= SPI_DMA_TDMAE;
236 if (xfer->rx_buf)
237 dma_ctrl |= SPI_DMA_RDMAE;
238 dw_writel(dws, DW_SPI_DMACR, dma_ctrl);
239
240
241 spi_umask_intr(dws, SPI_INT_TXOI | SPI_INT_RXUI | SPI_INT_RXOI);
242
243 dws->transfer_handler = dma_transfer;
244
245 return 0;
246}
247
248static int mid_spi_dma_transfer(struct dw_spi *dws, struct spi_transfer *xfer)
249{
250 struct dma_async_tx_descriptor *txdesc, *rxdesc;
251
252
253 txdesc = dw_spi_dma_prepare_tx(dws, xfer);
254
255
256 rxdesc = dw_spi_dma_prepare_rx(dws, xfer);
257
258
259 if (rxdesc) {
260 set_bit(RX_BUSY, &dws->dma_chan_busy);
261 dmaengine_submit(rxdesc);
262 dma_async_issue_pending(dws->rxchan);
263 }
264
265 if (txdesc) {
266 set_bit(TX_BUSY, &dws->dma_chan_busy);
267 dmaengine_submit(txdesc);
268 dma_async_issue_pending(dws->txchan);
269 }
270
271 return 0;
272}
273
274static void mid_spi_dma_stop(struct dw_spi *dws)
275{
276 if (test_bit(TX_BUSY, &dws->dma_chan_busy)) {
277 dmaengine_terminate_sync(dws->txchan);
278 clear_bit(TX_BUSY, &dws->dma_chan_busy);
279 }
280 if (test_bit(RX_BUSY, &dws->dma_chan_busy)) {
281 dmaengine_terminate_sync(dws->rxchan);
282 clear_bit(RX_BUSY, &dws->dma_chan_busy);
283 }
284}
285
286static const struct dw_spi_dma_ops mid_dma_ops = {
287 .dma_init = mid_spi_dma_init,
288 .dma_exit = mid_spi_dma_exit,
289 .dma_setup = mid_spi_dma_setup,
290 .can_dma = mid_spi_can_dma,
291 .dma_transfer = mid_spi_dma_transfer,
292 .dma_stop = mid_spi_dma_stop,
293};
294#endif
295
296
297
298
299#define MRST_SPI_CLK_BASE 100000000
300#define MRST_CLK_SPI_REG 0xff11d86c
301#define CLK_SPI_BDIV_OFFSET 0
302#define CLK_SPI_BDIV_MASK 0x00000007
303#define CLK_SPI_CDIV_OFFSET 9
304#define CLK_SPI_CDIV_MASK 0x00000e00
305#define CLK_SPI_DISABLE_OFFSET 8
306
307int dw_spi_mid_init(struct dw_spi *dws)
308{
309 void __iomem *clk_reg;
310 u32 clk_cdiv;
311
312 clk_reg = ioremap_nocache(MRST_CLK_SPI_REG, 16);
313 if (!clk_reg)
314 return -ENOMEM;
315
316
317 clk_cdiv = readl(clk_reg + dws->bus_num * sizeof(u32));
318 clk_cdiv &= CLK_SPI_CDIV_MASK;
319 clk_cdiv >>= CLK_SPI_CDIV_OFFSET;
320 dws->max_freq = MRST_SPI_CLK_BASE / (clk_cdiv + 1);
321
322 iounmap(clk_reg);
323
324#ifdef CONFIG_SPI_DW_MID_DMA
325 dws->dma_tx = &mid_dma_tx;
326 dws->dma_rx = &mid_dma_rx;
327 dws->dma_ops = &mid_dma_ops;
328#endif
329 return 0;
330}
331
