blob: 489178243d88d6427c688a1611c11cca604f82df [file] [log] [blame]
Feng Tang7063c0d2010-12-24 13:59:11 +08001/*
2 * dw_spi_mid.c - special handling for DW core on Intel MID platform
3 *
4 * Copyright (c) 2009, Intel Corporation.
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.
14 *
15 * You should have received a copy of the GNU General Public License along
16 * with this program; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
18 */
19
20#include <linux/dma-mapping.h>
21#include <linux/dmaengine.h>
22#include <linux/interrupt.h>
23#include <linux/slab.h>
24#include <linux/spi/spi.h>
Grant Likely568a60e2011-02-28 12:47:12 -070025
26#include "dw_spi.h"
Feng Tang7063c0d2010-12-24 13:59:11 +080027
28#ifdef CONFIG_SPI_DW_MID_DMA
29#include <linux/intel_mid_dma.h>
30#include <linux/pci.h>
31
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
41 return dws->dmac && (&dws->dmac->dev == chan->device->dev);
42}
43
44static int mid_spi_dma_init(struct dw_spi *dws)
45{
46 struct mid_dma *dw_dma = dws->dma_priv;
47 struct intel_mid_dma_slave *rxs, *txs;
48 dma_cap_mask_t mask;
49
50 /*
51 * Get pci device for DMA controller, currently it could only
52 * be the DMA controller of either Moorestown or Medfield
53 */
54 dws->dmac = pci_get_device(PCI_VENDOR_ID_INTEL, 0x0813, NULL);
55 if (!dws->dmac)
56 dws->dmac = pci_get_device(PCI_VENDOR_ID_INTEL, 0x0827, NULL);
57
58 dma_cap_zero(mask);
59 dma_cap_set(DMA_SLAVE, mask);
60
61 /* 1. Init rx channel */
62 dws->rxchan = dma_request_channel(mask, mid_spi_dma_chan_filter, dws);
63 if (!dws->rxchan)
64 goto err_exit;
65 rxs = &dw_dma->dmas_rx;
66 rxs->hs_mode = LNW_DMA_HW_HS;
67 rxs->cfg_mode = LNW_DMA_PER_TO_MEM;
68 dws->rxchan->private = rxs;
69
70 /* 2. Init tx channel */
71 dws->txchan = dma_request_channel(mask, mid_spi_dma_chan_filter, dws);
72 if (!dws->txchan)
73 goto free_rxchan;
74 txs = &dw_dma->dmas_tx;
75 txs->hs_mode = LNW_DMA_HW_HS;
76 txs->cfg_mode = LNW_DMA_MEM_TO_PER;
77 dws->txchan->private = txs;
78
79 dws->dma_inited = 1;
80 return 0;
81
82free_rxchan:
83 dma_release_channel(dws->rxchan);
84err_exit:
85 return -1;
86
87}
88
89static void mid_spi_dma_exit(struct dw_spi *dws)
90{
91 dma_release_channel(dws->txchan);
92 dma_release_channel(dws->rxchan);
93}
94
95/*
96 * dws->dma_chan_done is cleared before the dma transfer starts,
97 * callback for rx/tx channel will each increment it by 1.
98 * Reaching 2 means the whole spi transaction is done.
99 */
100static void dw_spi_dma_done(void *arg)
101{
102 struct dw_spi *dws = arg;
103
104 if (++dws->dma_chan_done != 2)
105 return;
106 dw_spi_xfer_done(dws);
107}
108
109static int mid_spi_dma_transfer(struct dw_spi *dws, int cs_change)
110{
111 struct dma_async_tx_descriptor *txdesc = NULL, *rxdesc = NULL;
112 struct dma_chan *txchan, *rxchan;
113 struct dma_slave_config txconf, rxconf;
114 u16 dma_ctrl = 0;
115
116 /* 1. setup DMA related registers */
117 if (cs_change) {
118 spi_enable_chip(dws, 0);
119 dw_writew(dws, dmardlr, 0xf);
120 dw_writew(dws, dmatdlr, 0x10);
121 if (dws->tx_dma)
122 dma_ctrl |= 0x2;
123 if (dws->rx_dma)
124 dma_ctrl |= 0x1;
125 dw_writew(dws, dmacr, dma_ctrl);
126 spi_enable_chip(dws, 1);
127 }
128
129 dws->dma_chan_done = 0;
130 txchan = dws->txchan;
131 rxchan = dws->rxchan;
132
133 /* 2. Prepare the TX dma transfer */
134 txconf.direction = DMA_TO_DEVICE;
135 txconf.dst_addr = dws->dma_addr;
136 txconf.dst_maxburst = LNW_DMA_MSIZE_16;
137 txconf.src_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
138 txconf.dst_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
139
140 txchan->device->device_control(txchan, DMA_SLAVE_CONFIG,
141 (unsigned long) &txconf);
142
143 memset(&dws->tx_sgl, 0, sizeof(dws->tx_sgl));
144 dws->tx_sgl.dma_address = dws->tx_dma;
145 dws->tx_sgl.length = dws->len;
146
147 txdesc = txchan->device->device_prep_slave_sg(txchan,
148 &dws->tx_sgl,
149 1,
150 DMA_TO_DEVICE,
151 DMA_PREP_INTERRUPT | DMA_COMPL_SKIP_DEST_UNMAP);
152 txdesc->callback = dw_spi_dma_done;
153 txdesc->callback_param = dws;
154
155 /* 3. Prepare the RX dma transfer */
156 rxconf.direction = DMA_FROM_DEVICE;
157 rxconf.src_addr = dws->dma_addr;
158 rxconf.src_maxburst = LNW_DMA_MSIZE_16;
159 rxconf.dst_addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
160 rxconf.src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
161
162 rxchan->device->device_control(rxchan, DMA_SLAVE_CONFIG,
163 (unsigned long) &rxconf);
164
165 memset(&dws->rx_sgl, 0, sizeof(dws->rx_sgl));
166 dws->rx_sgl.dma_address = dws->rx_dma;
167 dws->rx_sgl.length = dws->len;
168
169 rxdesc = rxchan->device->device_prep_slave_sg(rxchan,
170 &dws->rx_sgl,
171 1,
172 DMA_FROM_DEVICE,
173 DMA_PREP_INTERRUPT | DMA_COMPL_SKIP_DEST_UNMAP);
174 rxdesc->callback = dw_spi_dma_done;
175 rxdesc->callback_param = dws;
176
177 /* rx must be started before tx due to spi instinct */
178 rxdesc->tx_submit(rxdesc);
179 txdesc->tx_submit(txdesc);
180 return 0;
181}
182
183static struct dw_spi_dma_ops mid_dma_ops = {
184 .dma_init = mid_spi_dma_init,
185 .dma_exit = mid_spi_dma_exit,
186 .dma_transfer = mid_spi_dma_transfer,
187};
188#endif
189
190/* Some specific info for SPI0 controller on Moorestown */
191
192/* HW info for MRST CLk Control Unit, one 32b reg */
193#define MRST_SPI_CLK_BASE 100000000 /* 100m */
194#define MRST_CLK_SPI0_REG 0xff11d86c
195#define CLK_SPI_BDIV_OFFSET 0
196#define CLK_SPI_BDIV_MASK 0x00000007
197#define CLK_SPI_CDIV_OFFSET 9
198#define CLK_SPI_CDIV_MASK 0x00000e00
199#define CLK_SPI_DISABLE_OFFSET 8
200
201int dw_spi_mid_init(struct dw_spi *dws)
202{
203 u32 *clk_reg, clk_cdiv;
204
205 clk_reg = ioremap_nocache(MRST_CLK_SPI0_REG, 16);
206 if (!clk_reg)
207 return -ENOMEM;
208
209 /* get SPI controller operating freq info */
210 clk_cdiv = (readl(clk_reg) & CLK_SPI_CDIV_MASK) >> CLK_SPI_CDIV_OFFSET;
211 dws->max_freq = MRST_SPI_CLK_BASE / (clk_cdiv + 1);
212 iounmap(clk_reg);
213
214 dws->num_cs = 16;
215 dws->fifo_len = 40; /* FIFO has 40 words buffer */
216
217#ifdef CONFIG_SPI_DW_MID_DMA
218 dws->dma_priv = kzalloc(sizeof(struct mid_dma), GFP_KERNEL);
219 if (!dws->dma_priv)
220 return -ENOMEM;
221 dws->dma_ops = &mid_dma_ops;
222#endif
223 return 0;
224}