2 * Broadcom BCM63xx SPI controller support
4 * Copyright (C) 2009 Florian Fainelli <florian@openwrt.org>
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version 2
9 * of the License, or (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the
18 * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
21 #include <linux/kernel.h>
22 #include <linux/init.h>
23 #include <linux/clk.h>
24 #include <linux/module.h>
25 #include <linux/platform_device.h>
26 #include <linux/delay.h>
27 #include <linux/interrupt.h>
28 #include <linux/spi/spi.h>
29 #include <linux/spi/spi_bitbang.h>
30 #include <linux/gpio.h>
31 #include <linux/completion.h>
32 #include <linux/err.h>
34 #include <bcm63xx_io.h>
35 #include <bcm63xx_regs.h>
36 #include <bcm63xx_dev_spi.h>
38 #define PFX KBUILD_MODNAME
39 #define DRV_VER "0.1.1"
42 /* bitbang has to be first */
43 struct spi_bitbang bitbang;
44 struct completion done;
51 unsigned msg_fifo_size;
52 unsigned rx_fifo_size;
55 const unsigned char *tx_ptr;
56 unsigned char *rx_ptr;
60 struct resource *ioarea;
61 struct platform_device *pdev;
64 static void bcm63xx_spi_chipselect(struct spi_device *spi, int is_on)
68 val = bcm_spi_readw(SPI_CMD);
69 if (is_on == BITBANG_CS_INACTIVE)
71 else if (is_on == BITBANG_CS_ACTIVE)
72 val |= (1 << spi->chip_select << SPI_CMD_DEVICE_ID_SHIFT);
73 bcm_spi_writew(val, SPI_CMD);
76 static int bcm63xx_spi_setup_transfer(struct spi_device *spi,
77 struct spi_transfer *t)
84 struct bcm63xx_spi *bs = spi_master_get_devdata(spi->master);
86 bits_per_word = (t) ? t->bits_per_word : spi->bits_per_word;
87 hz = (t) ? t->speed_hz : spi->max_speed_hz;
88 if (bits_per_word != 8) {
89 dev_err(&spi->dev, "%s, unsupported bits_per_word=%d\n",
90 __func__, bits_per_word);
94 if (spi->chip_select > spi->master->num_chipselect) {
95 dev_err(&spi->dev, "%s, unsupported slave %d\n",
96 __func__, spi->chip_select);
100 /* Check clock setting */
101 div = (bs->speed_hz / hz);
104 clk_cfg = SPI_CLK_25MHZ;
107 clk_cfg = SPI_CLK_12_50MHZ;
110 clk_cfg = SPI_CLK_6_250MHZ;
113 clk_cfg = SPI_CLK_3_125MHZ;
116 clk_cfg = SPI_CLK_1_563MHZ;
119 clk_cfg = SPI_CLK_0_781MHZ;
123 /* Set to slowest mode for compatibility */
124 clk_cfg = SPI_CLK_0_781MHZ;
128 bcm_spi_writeb(clk_cfg, SPI_CLK_CFG);
129 dev_dbg(&spi->dev, "Setting clock register to %d (hz %d, cmd %02x)\n",
135 /* the spi->mode bits understood by this driver: */
136 #define MODEBITS (SPI_CPOL | SPI_CPHA)
138 static int bcm63xx_spi_setup(struct spi_device *spi)
140 struct spi_bitbang *bitbang;
141 struct bcm63xx_spi *bs;
144 bs = spi_master_get_devdata(spi->master);
145 bitbang = &bs->bitbang;
147 if (!spi->bits_per_word)
148 spi->bits_per_word = 8;
150 if (spi->mode & ~MODEBITS) {
151 dev_err(&spi->dev, "%s, unsupported mode bits %x\n",
152 __func__, spi->mode & ~MODEBITS);
156 retval = bcm63xx_spi_setup_transfer(spi, NULL);
158 dev_err(&spi->dev, "setup: unsupported mode bits %x\n",
159 spi->mode & ~MODEBITS);
163 dev_dbg(&spi->dev, "%s, mode %d, %u bits/w, %u nsec/bit\n",
164 __func__, spi->mode & MODEBITS, spi->bits_per_word, 0);
169 /* Fill the TX FIFO with as many bytes as possible */
170 static void bcm63xx_spi_fill_tx_fifo(struct bcm63xx_spi *bs)
174 /* Fill the Tx FIFO with as many bytes as possible */
175 tail = bcm_spi_readb(SPI_MSG_TAIL);
176 while ((tail < bs->msg_fifo_size) && (bs->remaining_bytes > 0)) {
178 bcm_spi_writeb(*bs->tx_ptr++, SPI_MSG_DATA);
180 bcm_spi_writeb(0, SPI_MSG_DATA);
181 bs->remaining_bytes--;
182 tail = bcm_spi_readb(SPI_MSG_TAIL);
186 static int bcm63xx_txrx_bufs(struct spi_device *spi, struct spi_transfer *t)
188 struct bcm63xx_spi *bs = spi_master_get_devdata(spi->master);
192 dev_dbg(&spi->dev, "txrx: tx %p, rx %p, len %d\n",
193 t->tx_buf, t->rx_buf, t->len);
195 /* Transmitter is inhibited */
196 bs->tx_ptr = t->tx_buf;
197 bs->rx_ptr = t->rx_buf;
198 bs->remaining_bytes = t->len;
199 init_completion(&bs->done);
201 bcm63xx_spi_fill_tx_fifo(bs);
203 /* Enable the command done interrupt which
204 * we use to determine completion of a command */
205 bcm_writeb(SPI_INTR_CMD_DONE, SPI_INT_MASK);
207 /* Fill in the Message control register */
208 msg_ctl = bcm_spi_readb(SPI_MSG_CTL);
209 msg_ctl |= (t->len << SPI_BYTE_CNT_SHIFT);
210 msg_ctl |= (SPI_FD_RW << SPI_MSG_TYPE_SHIFT);
211 bcm_spi_writeb(msg_ctl, SPI_MSG_CTL);
213 /* Issue the transfer */
214 cmd = bcm_spi_readb(SPI_CMD);
215 cmd |= SPI_CMD_START_IMMEDIATE;
216 cmd |= (0 << SPI_CMD_PREPEND_BYTE_CNT_SHIFT);
217 bcm_spi_writeb(cmd, SPI_CMD);
219 wait_for_completion(&bs->done);
221 /* Disable the CMD_DONE interrupt */
222 bcm_spi_writeb(~(SPI_INTR_CMD_DONE), SPI_INT_MASK);
224 return t->len - bs->remaining_bytes;
227 /* This driver supports single master mode only. Hence
228 * CMD_DONE is the only interrupt we care about
230 static irqreturn_t bcm63xx_spi_interrupt(int irq, void *dev_id)
232 struct spi_master *master = (struct spi_master *)dev_id;
233 struct bcm63xx_spi *bs = spi_master_get_devdata(master);
237 /* Read interupts and clear them immediately */
238 intr = bcm_spi_readb(SPI_INT_STATUS);
239 bcm_writeb(SPI_INTR_CLEAR_ALL, SPI_INT_STATUS);
241 /* A tansfer completed */
242 if (intr & SPI_INTR_CMD_DONE) {
245 rx_empty = bcm_spi_readb(SPI_ST);
246 /* Read out all the data */
247 while ((rx_empty & SPI_RX_EMPTY) == 0) {
250 data = bcm_spi_readb(SPI_RX_DATA);
252 *bs->rx_ptr++ = data;
254 rx_empty = bcm_spi_readb(SPI_RX_EMPTY);
257 /* See if there is more data to send */
258 if (bs->remaining_bytes > 0) {
259 bcm63xx_spi_fill_tx_fifo(bs);
261 /* Start the transfer */
262 cmd = bcm_spi_readb(SPI_CMD);
263 cmd |= SPI_CMD_START_IMMEDIATE;
264 cmd |= (0 << SPI_CMD_PREPEND_BYTE_CNT_SHIFT);
265 bcm_spi_writeb(cmd, SPI_CMD);
274 static int __init bcm63xx_spi_probe(struct platform_device *pdev)
277 struct bcm63xx_spi_pdata *pdata = pdev->dev.platform_data;
279 struct spi_master *master;
281 struct bcm63xx_spi *bs;
284 r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
290 irq = platform_get_irq(pdev, 0);
296 clk = clk_get(&pdev->dev, "spi");
298 dev_err(&pdev->dev, "No clock for device\n");
303 master = spi_alloc_master(&pdev->dev, sizeof(struct bcm63xx_spi));
309 bs = spi_master_get_devdata(master);
310 bs->bitbang.master = spi_master_get(master);
311 bs->bitbang.chipselect = bcm63xx_spi_chipselect;
312 bs->bitbang.setup_transfer = bcm63xx_spi_setup_transfer;
313 bs->bitbang.txrx_bufs = bcm63xx_txrx_bufs;
314 bs->bitbang.master->setup = bcm63xx_spi_setup;
315 init_completion(&bs->done);
317 platform_set_drvdata(pdev, master);
320 bs->regs = ioremap_nocache(r->start, r->end - r->start);
322 printk(KERN_ERR PFX " unable to ioremap regs\n");
328 bs->msg_fifo_size = pdata->msg_fifo_size;
329 bs->rx_fifo_size = pdata->rx_fifo_size;
331 ret = request_irq(irq, bcm63xx_spi_interrupt, 0,
332 pdev->dev.bus_id, master);
334 printk(KERN_ERR PFX " unable to request irq\n");
338 master->bus_num = pdata->bus_num;
339 master->num_chipselect = pdata->num_chipselect;
340 bs->speed_hz = pdata->speed_hz;
342 /* Initialize hardware */
344 bcm_spi_writew(SPI_CMD_HARD_RESET, SPI_CMD);
345 bcm_spi_writeb(SPI_INTR_CLEAR_ALL, SPI_INT_MASK);
347 dev_info(&pdev->dev, PFX " at 0x%08x (irq %d) %s\n",
348 r->start, irq, DRV_VER);
350 ret = spi_bitbang_start(&bs->bitbang);
352 dev_err(&pdev->dev, "spi_bitbang_start FAILED\n");
360 free_irq(irq, master);
365 spi_master_put(master);
370 static int __exit bcm63xx_spi_remove(struct platform_device *pdev)
372 struct spi_master *master = platform_get_drvdata(pdev);
373 struct bcm63xx_spi *bs = spi_master_get_devdata(master);
375 spi_bitbang_stop(&bs->bitbang);
376 clk_disable(bs->clk);
378 free_irq(bs->irq, master);
380 platform_set_drvdata(pdev, 0);
381 spi_master_put(bs->bitbang.master);
387 static int bcm63xx_spi_suspend(struct platform_device *pdev, pm_message_t mesg)
389 struct spi_master *master = platform_get_drvdata(pdev);
390 struct bcm63xx_spi *bs = spi_master_get_devdata(master);
392 clk_disable(bs->clk);
397 static int bcm63xx_spi_resume(struct platform_device *pdev)
399 struct bcm63xx_spi *bs = spi_master_get_devdata(master);
400 struct bcm63xx_spi *bs = spi_master_get_devdata(master);
407 #define bcm63xx_spi_suspend NULL
408 #define bcm63xx_spi_resume NULL
411 static struct platform_driver bcm63xx_spi_driver = {
413 .name = "bcm63xx-spi",
414 .owner = THIS_MODULE,
416 .probe = bcm63xx_spi_probe,
417 .remove = bcm63xx_spi_remove,
418 .suspend = bcm63xx_spi_suspend,
419 .resume = bcm63xx_spi_resume,
423 static int __init bcm63xx_spi_init(void)
425 return platform_driver_register(&bcm63xx_spi_driver);
428 static void __exit bcm63xx_spi_exit(void)
430 platform_driver_unregister(&bcm63xx_spi_driver);
433 module_init(bcm63xx_spi_init);
434 module_exit(bcm63xx_spi_exit);
436 MODULE_ALIAS("platform:bcm63xx_spi");
437 MODULE_AUTHOR("Florian Fainelli <florian@openwrt.org>");
438 MODULE_DESCRIPTION("Broadcom BCM63xx SPI Controller driver");
439 MODULE_LICENSE("GPL");