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Mika Westerberg59288082013-01-22 12:26:29 +02001/*
2 * PXA2xx SPI DMA engine support.
3 *
4 * Copyright (C) 2013, Intel Corporation
5 * Author: Mika Westerberg <mika.westerberg@linux.intel.com>
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License version 2 as
9 * published by the Free Software Foundation.
10 */
11
Mika Westerberg59288082013-01-22 12:26:29 +020012#include <linux/device.h>
13#include <linux/dma-mapping.h>
14#include <linux/dmaengine.h>
15#include <linux/pxa2xx_ssp.h>
16#include <linux/scatterlist.h>
17#include <linux/sizes.h>
18#include <linux/spi/spi.h>
19#include <linux/spi/pxa2xx_spi.h>
20
21#include "spi-pxa2xx.h"
22
Mika Westerberg59288082013-01-22 12:26:29 +020023static void pxa2xx_spi_dma_transfer_complete(struct driver_data *drv_data,
24 bool error)
25{
26 struct spi_message *msg = drv_data->cur_msg;
27
28 /*
29 * It is possible that one CPU is handling ROR interrupt and other
30 * just gets DMA completion. Calling pump_transfers() twice for the
31 * same transfer leads to problems thus we prevent concurrent calls
32 * by using ->dma_running.
33 */
34 if (atomic_dec_and_test(&drv_data->dma_running)) {
Mika Westerberg59288082013-01-22 12:26:29 +020035 /*
36 * If the other CPU is still handling the ROR interrupt we
37 * might not know about the error yet. So we re-check the
38 * ROR bit here before we clear the status register.
39 */
40 if (!error) {
Jarkko Nikulac039dd22014-12-18 15:04:23 +020041 u32 status = pxa2xx_spi_read(drv_data, SSSR)
42 & drv_data->mask_sr;
Mika Westerberg59288082013-01-22 12:26:29 +020043 error = status & SSSR_ROR;
44 }
45
46 /* Clear status & disable interrupts */
Jarkko Nikulac039dd22014-12-18 15:04:23 +020047 pxa2xx_spi_write(drv_data, SSCR1,
48 pxa2xx_spi_read(drv_data, SSCR1)
49 & ~drv_data->dma_cr1);
Mika Westerberg59288082013-01-22 12:26:29 +020050 write_SSSR_CS(drv_data, drv_data->clear_sr);
51 if (!pxa25x_ssp_comp(drv_data))
Jarkko Nikulac039dd22014-12-18 15:04:23 +020052 pxa2xx_spi_write(drv_data, SSTO, 0);
Mika Westerberg59288082013-01-22 12:26:29 +020053
54 if (!error) {
Mika Westerberg59288082013-01-22 12:26:29 +020055 msg->actual_length += drv_data->len;
56 msg->state = pxa2xx_spi_next_transfer(drv_data);
57 } else {
58 /* In case we got an error we disable the SSP now */
Jarkko Nikulac039dd22014-12-18 15:04:23 +020059 pxa2xx_spi_write(drv_data, SSCR0,
60 pxa2xx_spi_read(drv_data, SSCR0)
61 & ~SSCR0_SSE);
Mika Westerberg59288082013-01-22 12:26:29 +020062
63 msg->state = ERROR_STATE;
64 }
65
66 tasklet_schedule(&drv_data->pump_transfers);
67 }
68}
69
70static void pxa2xx_spi_dma_callback(void *data)
71{
72 pxa2xx_spi_dma_transfer_complete(data, false);
73}
74
75static struct dma_async_tx_descriptor *
76pxa2xx_spi_dma_prepare_one(struct driver_data *drv_data,
77 enum dma_transfer_direction dir)
78{
Mika Westerberg59288082013-01-22 12:26:29 +020079 struct chip_data *chip = drv_data->cur_chip;
Jarkko Nikulab6ced292016-06-21 13:21:34 +030080 struct spi_transfer *xfer = drv_data->cur_transfer;
Mika Westerberg59288082013-01-22 12:26:29 +020081 enum dma_slave_buswidth width;
82 struct dma_slave_config cfg;
83 struct dma_chan *chan;
84 struct sg_table *sgt;
Jarkko Nikulab6ced292016-06-21 13:21:34 +030085 int ret;
Mika Westerberg59288082013-01-22 12:26:29 +020086
87 switch (drv_data->n_bytes) {
88 case 1:
89 width = DMA_SLAVE_BUSWIDTH_1_BYTE;
90 break;
91 case 2:
92 width = DMA_SLAVE_BUSWIDTH_2_BYTES;
93 break;
94 default:
95 width = DMA_SLAVE_BUSWIDTH_4_BYTES;
96 break;
97 }
98
99 memset(&cfg, 0, sizeof(cfg));
100 cfg.direction = dir;
101
102 if (dir == DMA_MEM_TO_DEV) {
103 cfg.dst_addr = drv_data->ssdr_physical;
104 cfg.dst_addr_width = width;
105 cfg.dst_maxburst = chip->dma_burst_size;
Mika Westerberg59288082013-01-22 12:26:29 +0200106
Jarkko Nikulab6ced292016-06-21 13:21:34 +0300107 sgt = &xfer->tx_sg;
108 chan = drv_data->master->dma_tx;
Mika Westerberg59288082013-01-22 12:26:29 +0200109 } else {
110 cfg.src_addr = drv_data->ssdr_physical;
111 cfg.src_addr_width = width;
112 cfg.src_maxburst = chip->dma_burst_size;
Mika Westerberg59288082013-01-22 12:26:29 +0200113
Jarkko Nikulab6ced292016-06-21 13:21:34 +0300114 sgt = &xfer->rx_sg;
115 chan = drv_data->master->dma_rx;
Mika Westerberg59288082013-01-22 12:26:29 +0200116 }
117
118 ret = dmaengine_slave_config(chan, &cfg);
119 if (ret) {
120 dev_warn(&drv_data->pdev->dev, "DMA slave config failed\n");
121 return NULL;
122 }
123
Jarkko Nikulab6ced292016-06-21 13:21:34 +0300124 return dmaengine_prep_slave_sg(chan, sgt->sgl, sgt->nents, dir,
Mika Westerberg59288082013-01-22 12:26:29 +0200125 DMA_PREP_INTERRUPT | DMA_CTRL_ACK);
126}
127
Mika Westerberg59288082013-01-22 12:26:29 +0200128irqreturn_t pxa2xx_spi_dma_transfer(struct driver_data *drv_data)
129{
130 u32 status;
131
Jarkko Nikulac039dd22014-12-18 15:04:23 +0200132 status = pxa2xx_spi_read(drv_data, SSSR) & drv_data->mask_sr;
Mika Westerberg59288082013-01-22 12:26:29 +0200133 if (status & SSSR_ROR) {
134 dev_err(&drv_data->pdev->dev, "FIFO overrun\n");
135
Jarkko Nikulab6ced292016-06-21 13:21:34 +0300136 dmaengine_terminate_async(drv_data->master->dma_rx);
137 dmaengine_terminate_async(drv_data->master->dma_tx);
Mika Westerberg59288082013-01-22 12:26:29 +0200138
139 pxa2xx_spi_dma_transfer_complete(drv_data, true);
140 return IRQ_HANDLED;
141 }
142
143 return IRQ_NONE;
144}
145
146int pxa2xx_spi_dma_prepare(struct driver_data *drv_data, u32 dma_burst)
147{
148 struct dma_async_tx_descriptor *tx_desc, *rx_desc;
Andy Shevchenko7d1f1bf2016-03-24 15:35:42 +0200149 int err = 0;
Mika Westerberg59288082013-01-22 12:26:29 +0200150
151 tx_desc = pxa2xx_spi_dma_prepare_one(drv_data, DMA_MEM_TO_DEV);
152 if (!tx_desc) {
153 dev_err(&drv_data->pdev->dev,
154 "failed to get DMA TX descriptor\n");
Andy Shevchenko7d1f1bf2016-03-24 15:35:42 +0200155 err = -EBUSY;
156 goto err_tx;
Mika Westerberg59288082013-01-22 12:26:29 +0200157 }
158
159 rx_desc = pxa2xx_spi_dma_prepare_one(drv_data, DMA_DEV_TO_MEM);
160 if (!rx_desc) {
161 dev_err(&drv_data->pdev->dev,
162 "failed to get DMA RX descriptor\n");
Andy Shevchenko7d1f1bf2016-03-24 15:35:42 +0200163 err = -EBUSY;
164 goto err_rx;
Mika Westerberg59288082013-01-22 12:26:29 +0200165 }
166
167 /* We are ready when RX completes */
168 rx_desc->callback = pxa2xx_spi_dma_callback;
169 rx_desc->callback_param = drv_data;
170
171 dmaengine_submit(rx_desc);
172 dmaengine_submit(tx_desc);
173 return 0;
Andy Shevchenko7d1f1bf2016-03-24 15:35:42 +0200174
175err_rx:
Jarkko Nikulab6ced292016-06-21 13:21:34 +0300176 dmaengine_terminate_async(drv_data->master->dma_tx);
Andy Shevchenko7d1f1bf2016-03-24 15:35:42 +0200177err_tx:
Andy Shevchenko7d1f1bf2016-03-24 15:35:42 +0200178 return err;
Mika Westerberg59288082013-01-22 12:26:29 +0200179}
180
181void pxa2xx_spi_dma_start(struct driver_data *drv_data)
182{
Jarkko Nikulab6ced292016-06-21 13:21:34 +0300183 dma_async_issue_pending(drv_data->master->dma_rx);
184 dma_async_issue_pending(drv_data->master->dma_tx);
Mika Westerberg59288082013-01-22 12:26:29 +0200185
186 atomic_set(&drv_data->dma_running, 1);
187}
188
189int pxa2xx_spi_dma_setup(struct driver_data *drv_data)
190{
191 struct pxa2xx_spi_master *pdata = drv_data->master_info;
Mika Westerbergcddb3392013-05-13 13:45:10 +0300192 struct device *dev = &drv_data->pdev->dev;
Jarkko Nikulab6ced292016-06-21 13:21:34 +0300193 struct spi_master *master = drv_data->master;
Mika Westerberg59288082013-01-22 12:26:29 +0200194 dma_cap_mask_t mask;
195
196 dma_cap_zero(mask);
197 dma_cap_set(DMA_SLAVE, mask);
198
Jarkko Nikulab6ced292016-06-21 13:21:34 +0300199 master->dma_tx = dma_request_slave_channel_compat(mask,
Mika Westerbergb729bf32014-08-19 20:29:19 +0300200 pdata->dma_filter, pdata->tx_param, dev, "tx");
Jarkko Nikulab6ced292016-06-21 13:21:34 +0300201 if (!master->dma_tx)
Mika Westerberg59288082013-01-22 12:26:29 +0200202 return -ENODEV;
203
Jarkko Nikulab6ced292016-06-21 13:21:34 +0300204 master->dma_rx = dma_request_slave_channel_compat(mask,
Mika Westerbergb729bf32014-08-19 20:29:19 +0300205 pdata->dma_filter, pdata->rx_param, dev, "rx");
Jarkko Nikulab6ced292016-06-21 13:21:34 +0300206 if (!master->dma_rx) {
207 dma_release_channel(master->dma_tx);
208 master->dma_tx = NULL;
Mika Westerberg59288082013-01-22 12:26:29 +0200209 return -ENODEV;
210 }
211
212 return 0;
213}
214
215void pxa2xx_spi_dma_release(struct driver_data *drv_data)
216{
Jarkko Nikulab6ced292016-06-21 13:21:34 +0300217 struct spi_master *master = drv_data->master;
218
219 if (master->dma_rx) {
220 dmaengine_terminate_sync(master->dma_rx);
221 dma_release_channel(master->dma_rx);
222 master->dma_rx = NULL;
Mika Westerberg59288082013-01-22 12:26:29 +0200223 }
Jarkko Nikulab6ced292016-06-21 13:21:34 +0300224 if (master->dma_tx) {
225 dmaengine_terminate_sync(master->dma_tx);
226 dma_release_channel(master->dma_tx);
227 master->dma_tx = NULL;
Mika Westerberg59288082013-01-22 12:26:29 +0200228 }
229}
230
Mika Westerberg59288082013-01-22 12:26:29 +0200231int pxa2xx_spi_set_dma_burst_and_threshold(struct chip_data *chip,
232 struct spi_device *spi,
233 u8 bits_per_word, u32 *burst_code,
234 u32 *threshold)
235{
236 struct pxa2xx_spi_chip *chip_info = spi->controller_data;
237
238 /*
239 * If the DMA burst size is given in chip_info we use that,
240 * otherwise we use the default. Also we use the default FIFO
241 * thresholds for now.
242 */
Chew, Chiau Ee01d7aaf2014-06-06 01:45:09 +0800243 *burst_code = chip_info ? chip_info->dma_burst_size : 1;
Mika Westerberg59288082013-01-22 12:26:29 +0200244 *threshold = SSCR1_RxTresh(RX_THRESH_DFLT)
245 | SSCR1_TxTresh(TX_THRESH_DFLT);
246
247 return 0;
248}