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spi: dw-mid: clear ongoing DMA transfers on timeout
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7063c0d9 1/*
ca632f55 2 * Special handling for DW core on Intel MID platform
7063c0d9 3 *
197e96b4 4 * Copyright (c) 2009, 2014 Intel Corporation.
7063c0d9
FT
5 *
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms and conditions of the GNU General Public License,
8 * version 2, as published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
13 * more details.
7063c0d9
FT
14 */
15
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>
258aea76 21#include <linux/types.h>
568a60ed 22
ca632f55 23#include "spi-dw.h"
7063c0d9
FT
24
25#ifdef CONFIG_SPI_DW_MID_DMA
26#include <linux/intel_mid_dma.h>
27#include <linux/pci.h>
28
30c8eb52
AS
29#define RX_BUSY 0
30#define TX_BUSY 1
31
7063c0d9
FT
32struct mid_dma {
33 struct intel_mid_dma_slave dmas_tx;
34 struct intel_mid_dma_slave dmas_rx;
35};
36
37static bool mid_spi_dma_chan_filter(struct dma_chan *chan, void *param)
38{
39 struct dw_spi *dws = param;
40
b89e9c87 41 return dws->dma_dev == chan->device->dev;
7063c0d9
FT
42}
43
44static int mid_spi_dma_init(struct dw_spi *dws)
45{
46 struct mid_dma *dw_dma = dws->dma_priv;
b89e9c87 47 struct pci_dev *dma_dev;
7063c0d9
FT
48 struct intel_mid_dma_slave *rxs, *txs;
49 dma_cap_mask_t mask;
50
51 /*
52 * Get pci device for DMA controller, currently it could only
ea092455 53 * be the DMA controller of Medfield
7063c0d9 54 */
b89e9c87
AS
55 dma_dev = pci_get_device(PCI_VENDOR_ID_INTEL, 0x0827, NULL);
56 if (!dma_dev)
57 return -ENODEV;
58
59 dws->dma_dev = &dma_dev->dev;
7063c0d9
FT
60
61 dma_cap_zero(mask);
62 dma_cap_set(DMA_SLAVE, mask);
63
64 /* 1. Init rx channel */
65 dws->rxchan = dma_request_channel(mask, mid_spi_dma_chan_filter, dws);
66 if (!dws->rxchan)
67 goto err_exit;
68 rxs = &dw_dma->dmas_rx;
69 rxs->hs_mode = LNW_DMA_HW_HS;
70 rxs->cfg_mode = LNW_DMA_PER_TO_MEM;
71 dws->rxchan->private = rxs;
72
73 /* 2. Init tx channel */
74 dws->txchan = dma_request_channel(mask, mid_spi_dma_chan_filter, dws);
75 if (!dws->txchan)
76 goto free_rxchan;
77 txs = &dw_dma->dmas_tx;
78 txs->hs_mode = LNW_DMA_HW_HS;
79 txs->cfg_mode = LNW_DMA_MEM_TO_PER;
80 dws->txchan->private = txs;
81
82 dws->dma_inited = 1;
83 return 0;
84
85free_rxchan:
86 dma_release_channel(dws->rxchan);
87err_exit:
b89e9c87 88 return -EBUSY;
7063c0d9
FT
89}
90
91static void mid_spi_dma_exit(struct dw_spi *dws)
92{
fb57862e
AS
93 if (!dws->dma_inited)
94 return;
8e45ef68
AS
95
96 dmaengine_terminate_all(dws->txchan);
7063c0d9 97 dma_release_channel(dws->txchan);
8e45ef68
AS
98
99 dmaengine_terminate_all(dws->rxchan);
7063c0d9
FT
100 dma_release_channel(dws->rxchan);
101}
102
f051fc8f
AS
103static irqreturn_t dma_transfer(struct dw_spi *dws)
104{
105 u16 irq_status = dw_readw(dws, DW_SPI_ISR);
106
107 if (!irq_status)
108 return IRQ_NONE;
109
110 dw_readw(dws, DW_SPI_ICR);
111 spi_reset_chip(dws);
112
113 dev_err(&dws->master->dev, "%s: FIFO overrun/underrun\n", __func__);
114 dws->master->cur_msg->status = -EIO;
115 spi_finalize_current_transfer(dws->master);
116 return IRQ_HANDLED;
117}
118
e31abce7
AS
119static enum dma_slave_buswidth convert_dma_width(u32 dma_width) {
120 if (dma_width == 1)
121 return DMA_SLAVE_BUSWIDTH_1_BYTE;
122 else if (dma_width == 2)
123 return DMA_SLAVE_BUSWIDTH_2_BYTES;
124
125 return DMA_SLAVE_BUSWIDTH_UNDEFINED;
126}
127
7063c0d9 128/*
30c8eb52
AS
129 * dws->dma_chan_busy is set before the dma transfer starts, callback for tx
130 * channel will clear a corresponding bit.
7063c0d9 131 */
30c8eb52 132static void dw_spi_dma_tx_done(void *arg)
7063c0d9
FT
133{
134 struct dw_spi *dws = arg;
135
854d2f24
AS
136 clear_bit(TX_BUSY, &dws->dma_chan_busy);
137 if (test_bit(RX_BUSY, &dws->dma_chan_busy))
7063c0d9 138 return;
c22c62db 139 spi_finalize_current_transfer(dws->master);
7063c0d9
FT
140}
141
a5c2db96 142static struct dma_async_tx_descriptor *dw_spi_dma_prepare_tx(struct dw_spi *dws)
7063c0d9 143{
a5c2db96
AS
144 struct dma_slave_config txconf;
145 struct dma_async_tx_descriptor *txdesc;
7063c0d9 146
30c8eb52
AS
147 if (!dws->tx_dma)
148 return NULL;
149
a485df4b 150 txconf.direction = DMA_MEM_TO_DEV;
7063c0d9
FT
151 txconf.dst_addr = dws->dma_addr;
152 txconf.dst_maxburst = LNW_DMA_MSIZE_16;
153 txconf.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
e31abce7 154 txconf.dst_addr_width = convert_dma_width(dws->dma_width);
258aea76 155 txconf.device_fc = false;
7063c0d9 156
2a285299 157 dmaengine_slave_config(dws->txchan, &txconf);
7063c0d9
FT
158
159 memset(&dws->tx_sgl, 0, sizeof(dws->tx_sgl));
160 dws->tx_sgl.dma_address = dws->tx_dma;
161 dws->tx_sgl.length = dws->len;
162
2a285299 163 txdesc = dmaengine_prep_slave_sg(dws->txchan,
7063c0d9
FT
164 &dws->tx_sgl,
165 1,
a485df4b 166 DMA_MEM_TO_DEV,
f7477c2b 167 DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
c9dafb27
AS
168 if (!txdesc)
169 return NULL;
170
30c8eb52 171 txdesc->callback = dw_spi_dma_tx_done;
7063c0d9
FT
172 txdesc->callback_param = dws;
173
a5c2db96
AS
174 return txdesc;
175}
176
30c8eb52
AS
177/*
178 * dws->dma_chan_busy is set before the dma transfer starts, callback for rx
179 * channel will clear a corresponding bit.
180 */
181static void dw_spi_dma_rx_done(void *arg)
182{
183 struct dw_spi *dws = arg;
184
854d2f24
AS
185 clear_bit(RX_BUSY, &dws->dma_chan_busy);
186 if (test_bit(TX_BUSY, &dws->dma_chan_busy))
30c8eb52 187 return;
c22c62db 188 spi_finalize_current_transfer(dws->master);
30c8eb52
AS
189}
190
a5c2db96
AS
191static struct dma_async_tx_descriptor *dw_spi_dma_prepare_rx(struct dw_spi *dws)
192{
193 struct dma_slave_config rxconf;
194 struct dma_async_tx_descriptor *rxdesc;
195
30c8eb52
AS
196 if (!dws->rx_dma)
197 return NULL;
198
a485df4b 199 rxconf.direction = DMA_DEV_TO_MEM;
7063c0d9
FT
200 rxconf.src_addr = dws->dma_addr;
201 rxconf.src_maxburst = LNW_DMA_MSIZE_16;
202 rxconf.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
e31abce7 203 rxconf.src_addr_width = convert_dma_width(dws->dma_width);
258aea76 204 rxconf.device_fc = false;
7063c0d9 205
2a285299 206 dmaengine_slave_config(dws->rxchan, &rxconf);
7063c0d9
FT
207
208 memset(&dws->rx_sgl, 0, sizeof(dws->rx_sgl));
209 dws->rx_sgl.dma_address = dws->rx_dma;
210 dws->rx_sgl.length = dws->len;
211
2a285299 212 rxdesc = dmaengine_prep_slave_sg(dws->rxchan,
7063c0d9
FT
213 &dws->rx_sgl,
214 1,
a485df4b 215 DMA_DEV_TO_MEM,
f7477c2b 216 DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
c9dafb27
AS
217 if (!rxdesc)
218 return NULL;
219
30c8eb52 220 rxdesc->callback = dw_spi_dma_rx_done;
7063c0d9
FT
221 rxdesc->callback_param = dws;
222
a5c2db96
AS
223 return rxdesc;
224}
225
9f14538e 226static int mid_spi_dma_setup(struct dw_spi *dws)
a5c2db96
AS
227{
228 u16 dma_ctrl = 0;
229
a5c2db96
AS
230 dw_writew(dws, DW_SPI_DMARDLR, 0xf);
231 dw_writew(dws, DW_SPI_DMATDLR, 0x10);
232
233 if (dws->tx_dma)
234 dma_ctrl |= SPI_DMA_TDMAE;
235 if (dws->rx_dma)
236 dma_ctrl |= SPI_DMA_RDMAE;
237 dw_writew(dws, DW_SPI_DMACR, dma_ctrl);
238
f051fc8f
AS
239 /* Set the interrupt mask */
240 spi_umask_intr(dws, SPI_INT_TXOI | SPI_INT_RXUI | SPI_INT_RXOI);
241
242 dws->transfer_handler = dma_transfer;
243
9f14538e 244 return 0;
a5c2db96
AS
245}
246
9f14538e 247static int mid_spi_dma_transfer(struct dw_spi *dws)
a5c2db96
AS
248{
249 struct dma_async_tx_descriptor *txdesc, *rxdesc;
250
9f14538e 251 /* Prepare the TX dma transfer */
a5c2db96
AS
252 txdesc = dw_spi_dma_prepare_tx(dws);
253
9f14538e 254 /* Prepare the RX dma transfer */
a5c2db96
AS
255 rxdesc = dw_spi_dma_prepare_rx(dws);
256
7063c0d9 257 /* rx must be started before tx due to spi instinct */
30c8eb52
AS
258 if (rxdesc) {
259 set_bit(RX_BUSY, &dws->dma_chan_busy);
260 dmaengine_submit(rxdesc);
261 dma_async_issue_pending(dws->rxchan);
262 }
263
264 if (txdesc) {
265 set_bit(TX_BUSY, &dws->dma_chan_busy);
266 dmaengine_submit(txdesc);
267 dma_async_issue_pending(dws->txchan);
268 }
f7477c2b 269
7063c0d9
FT
270 return 0;
271}
272
4d5ac1ed
AS
273static void mid_spi_dma_stop(struct dw_spi *dws)
274{
275 if (test_bit(TX_BUSY, &dws->dma_chan_busy)) {
276 dmaengine_terminate_all(dws->txchan);
277 clear_bit(TX_BUSY, &dws->dma_chan_busy);
278 }
279 if (test_bit(RX_BUSY, &dws->dma_chan_busy)) {
280 dmaengine_terminate_all(dws->rxchan);
281 clear_bit(RX_BUSY, &dws->dma_chan_busy);
282 }
283}
284
7063c0d9
FT
285static struct dw_spi_dma_ops mid_dma_ops = {
286 .dma_init = mid_spi_dma_init,
287 .dma_exit = mid_spi_dma_exit,
9f14538e 288 .dma_setup = mid_spi_dma_setup,
7063c0d9 289 .dma_transfer = mid_spi_dma_transfer,
4d5ac1ed 290 .dma_stop = mid_spi_dma_stop,
7063c0d9
FT
291};
292#endif
293
ea092455 294/* Some specific info for SPI0 controller on Intel MID */
7063c0d9 295
d9c14743 296/* HW info for MRST Clk Control Unit, 32b reg per controller */
7063c0d9 297#define MRST_SPI_CLK_BASE 100000000 /* 100m */
d9c14743 298#define MRST_CLK_SPI_REG 0xff11d86c
7063c0d9
FT
299#define CLK_SPI_BDIV_OFFSET 0
300#define CLK_SPI_BDIV_MASK 0x00000007
301#define CLK_SPI_CDIV_OFFSET 9
302#define CLK_SPI_CDIV_MASK 0x00000e00
303#define CLK_SPI_DISABLE_OFFSET 8
304
305int dw_spi_mid_init(struct dw_spi *dws)
306{
7eb187b3
HS
307 void __iomem *clk_reg;
308 u32 clk_cdiv;
7063c0d9 309
d9c14743 310 clk_reg = ioremap_nocache(MRST_CLK_SPI_REG, 16);
7063c0d9
FT
311 if (!clk_reg)
312 return -ENOMEM;
313
d9c14743
AS
314 /* Get SPI controller operating freq info */
315 clk_cdiv = readl(clk_reg + dws->bus_num * sizeof(u32));
316 clk_cdiv &= CLK_SPI_CDIV_MASK;
317 clk_cdiv >>= CLK_SPI_CDIV_OFFSET;
7063c0d9 318 dws->max_freq = MRST_SPI_CLK_BASE / (clk_cdiv + 1);
d9c14743 319
7063c0d9
FT
320 iounmap(clk_reg);
321
7063c0d9
FT
322#ifdef CONFIG_SPI_DW_MID_DMA
323 dws->dma_priv = kzalloc(sizeof(struct mid_dma), GFP_KERNEL);
324 if (!dws->dma_priv)
325 return -ENOMEM;
326 dws->dma_ops = &mid_dma_ops;
327#endif
328 return 0;
329}