xref: /openbmc/linux/drivers/spi/spi-ppc4xx.c (revision 34d6f206a88c2651d216bd3487ac956a40b2ba8e)
1d2912cb1SThomas Gleixner // SPDX-License-Identifier: GPL-2.0-only
2ca632f55SGrant Likely /*
3ca632f55SGrant Likely  * SPI_PPC4XX SPI controller driver.
4ca632f55SGrant Likely  *
5ca632f55SGrant Likely  * Copyright (C) 2007 Gary Jennejohn <garyj@denx.de>
6ca632f55SGrant Likely  * Copyright 2008 Stefan Roese <sr@denx.de>, DENX Software Engineering
7ca632f55SGrant Likely  * Copyright 2009 Harris Corporation, Steven A. Falco <sfalco@harris.com>
8ca632f55SGrant Likely  *
9ca632f55SGrant Likely  * Based in part on drivers/spi/spi_s3c24xx.c
10ca632f55SGrant Likely  *
11ca632f55SGrant Likely  * Copyright (c) 2006 Ben Dooks
12ca632f55SGrant Likely  * Copyright (c) 2006 Simtec Electronics
13ca632f55SGrant Likely  *	Ben Dooks <ben@simtec.co.uk>
14ca632f55SGrant Likely  */
15ca632f55SGrant Likely 
16ca632f55SGrant Likely /*
17ca632f55SGrant Likely  * The PPC4xx SPI controller has no FIFO so each sent/received byte will
18ca632f55SGrant Likely  * generate an interrupt to the CPU. This can cause high CPU utilization.
19ca632f55SGrant Likely  * This driver allows platforms to reduce the interrupt load on the CPU
20ca632f55SGrant Likely  * during SPI transfers by setting max_speed_hz via the device tree.
21ca632f55SGrant Likely  */
22ca632f55SGrant Likely 
23ca632f55SGrant Likely #include <linux/module.h>
24ca632f55SGrant Likely #include <linux/sched.h>
25ca632f55SGrant Likely #include <linux/slab.h>
26ca632f55SGrant Likely #include <linux/errno.h>
27ca632f55SGrant Likely #include <linux/wait.h>
28c11eede6SRob Herring #include <linux/of_address.h>
29ca632f55SGrant Likely #include <linux/of_platform.h>
30ca632f55SGrant Likely #include <linux/interrupt.h>
31ca632f55SGrant Likely #include <linux/delay.h>
32ca632f55SGrant Likely 
33ca632f55SGrant Likely #include <linux/spi/spi.h>
34ca632f55SGrant Likely #include <linux/spi/spi_bitbang.h>
35ca632f55SGrant Likely 
3666fe7403SJay Fang #include <linux/io.h>
37ca632f55SGrant Likely #include <asm/dcr.h>
38ca632f55SGrant Likely #include <asm/dcr-regs.h>
39ca632f55SGrant Likely 
40ca632f55SGrant Likely /* bits in mode register - bit 0 is MSb */
41ca632f55SGrant Likely 
42ca632f55SGrant Likely /*
43ca632f55SGrant Likely  * SPI_PPC4XX_MODE_SCP = 0 means "data latched on trailing edge of clock"
44ca632f55SGrant Likely  * SPI_PPC4XX_MODE_SCP = 1 means "data latched on leading edge of clock"
45ca632f55SGrant Likely  * Note: This is the inverse of CPHA.
46ca632f55SGrant Likely  */
47ca632f55SGrant Likely #define SPI_PPC4XX_MODE_SCP	(0x80 >> 3)
48ca632f55SGrant Likely 
49ca632f55SGrant Likely /* SPI_PPC4XX_MODE_SPE = 1 means "port enabled" */
50ca632f55SGrant Likely #define SPI_PPC4XX_MODE_SPE	(0x80 >> 4)
51ca632f55SGrant Likely 
52ca632f55SGrant Likely /*
53ca632f55SGrant Likely  * SPI_PPC4XX_MODE_RD = 0 means "MSB first" - this is the normal mode
54ca632f55SGrant Likely  * SPI_PPC4XX_MODE_RD = 1 means "LSB first" - this is bit-reversed mode
55ca632f55SGrant Likely  * Note: This is identical to SPI_LSB_FIRST.
56ca632f55SGrant Likely  */
57ca632f55SGrant Likely #define SPI_PPC4XX_MODE_RD	(0x80 >> 5)
58ca632f55SGrant Likely 
59ca632f55SGrant Likely /*
60ca632f55SGrant Likely  * SPI_PPC4XX_MODE_CI = 0 means "clock idles low"
61ca632f55SGrant Likely  * SPI_PPC4XX_MODE_CI = 1 means "clock idles high"
62ca632f55SGrant Likely  * Note: This is identical to CPOL.
63ca632f55SGrant Likely  */
64ca632f55SGrant Likely #define SPI_PPC4XX_MODE_CI	(0x80 >> 6)
65ca632f55SGrant Likely 
66ca632f55SGrant Likely /*
67ca632f55SGrant Likely  * SPI_PPC4XX_MODE_IL = 0 means "loopback disable"
68ca632f55SGrant Likely  * SPI_PPC4XX_MODE_IL = 1 means "loopback enable"
69ca632f55SGrant Likely  */
70ca632f55SGrant Likely #define SPI_PPC4XX_MODE_IL	(0x80 >> 7)
71ca632f55SGrant Likely 
72ca632f55SGrant Likely /* bits in control register */
73ca632f55SGrant Likely /* starts a transfer when set */
74ca632f55SGrant Likely #define SPI_PPC4XX_CR_STR	(0x80 >> 7)
75ca632f55SGrant Likely 
76ca632f55SGrant Likely /* bits in status register */
77ca632f55SGrant Likely /* port is busy with a transfer */
78ca632f55SGrant Likely #define SPI_PPC4XX_SR_BSY	(0x80 >> 6)
79ca632f55SGrant Likely /* RxD ready */
80ca632f55SGrant Likely #define SPI_PPC4XX_SR_RBR	(0x80 >> 7)
81ca632f55SGrant Likely 
82ca632f55SGrant Likely /* clock settings (SCP and CI) for various SPI modes */
83ca632f55SGrant Likely #define SPI_CLK_MODE0	(SPI_PPC4XX_MODE_SCP | 0)
84ca632f55SGrant Likely #define SPI_CLK_MODE1	(0 | 0)
85ca632f55SGrant Likely #define SPI_CLK_MODE2	(SPI_PPC4XX_MODE_SCP | SPI_PPC4XX_MODE_CI)
86ca632f55SGrant Likely #define SPI_CLK_MODE3	(0 | SPI_PPC4XX_MODE_CI)
87ca632f55SGrant Likely 
88ca632f55SGrant Likely #define DRIVER_NAME	"spi_ppc4xx_of"
89ca632f55SGrant Likely 
90ca632f55SGrant Likely struct spi_ppc4xx_regs {
91ca632f55SGrant Likely 	u8 mode;
92ca632f55SGrant Likely 	u8 rxd;
93ca632f55SGrant Likely 	u8 txd;
94ca632f55SGrant Likely 	u8 cr;
95ca632f55SGrant Likely 	u8 sr;
96ca632f55SGrant Likely 	u8 dummy;
97ca632f55SGrant Likely 	/*
98ca632f55SGrant Likely 	 * Clock divisor modulus register
99886db6acSMasanari Iida 	 * This uses the following formula:
100ca632f55SGrant Likely 	 *    SCPClkOut = OPBCLK/(4(CDM + 1))
101ca632f55SGrant Likely 	 * or
102ca632f55SGrant Likely 	 *    CDM = (OPBCLK/4*SCPClkOut) - 1
103ca632f55SGrant Likely 	 * bit 0 is the MSb!
104ca632f55SGrant Likely 	 */
105ca632f55SGrant Likely 	u8 cdm;
106ca632f55SGrant Likely };
107ca632f55SGrant Likely 
108ca632f55SGrant Likely /* SPI Controller driver's private data. */
109ca632f55SGrant Likely struct ppc4xx_spi {
110ca632f55SGrant Likely 	/* bitbang has to be first */
111ca632f55SGrant Likely 	struct spi_bitbang bitbang;
112ca632f55SGrant Likely 	struct completion done;
113ca632f55SGrant Likely 
114ca632f55SGrant Likely 	u64 mapbase;
115ca632f55SGrant Likely 	u64 mapsize;
116ca632f55SGrant Likely 	int irqnum;
117ca632f55SGrant Likely 	/* need this to set the SPI clock */
118ca632f55SGrant Likely 	unsigned int opb_freq;
119ca632f55SGrant Likely 
120ca632f55SGrant Likely 	/* for transfers */
121ca632f55SGrant Likely 	int len;
122ca632f55SGrant Likely 	int count;
123ca632f55SGrant Likely 	/* data buffers */
124ca632f55SGrant Likely 	const unsigned char *tx;
125ca632f55SGrant Likely 	unsigned char *rx;
126ca632f55SGrant Likely 
127ca632f55SGrant Likely 	struct spi_ppc4xx_regs __iomem *regs; /* pointer to the registers */
12871345830SYang Yingliang 	struct spi_controller *host;
129ca632f55SGrant Likely 	struct device *dev;
130ca632f55SGrant Likely };
131ca632f55SGrant Likely 
132ca632f55SGrant Likely /* need this so we can set the clock in the chipselect routine */
133ca632f55SGrant Likely struct spi_ppc4xx_cs {
134ca632f55SGrant Likely 	u8 mode;
135ca632f55SGrant Likely };
136ca632f55SGrant Likely 
spi_ppc4xx_txrx(struct spi_device * spi,struct spi_transfer * t)137ca632f55SGrant Likely static int spi_ppc4xx_txrx(struct spi_device *spi, struct spi_transfer *t)
138ca632f55SGrant Likely {
139ca632f55SGrant Likely 	struct ppc4xx_spi *hw;
140ca632f55SGrant Likely 	u8 data;
141ca632f55SGrant Likely 
142ca632f55SGrant Likely 	dev_dbg(&spi->dev, "txrx: tx %p, rx %p, len %d\n",
143ca632f55SGrant Likely 		t->tx_buf, t->rx_buf, t->len);
144ca632f55SGrant Likely 
14571345830SYang Yingliang 	hw = spi_controller_get_devdata(spi->controller);
146ca632f55SGrant Likely 
147ca632f55SGrant Likely 	hw->tx = t->tx_buf;
148ca632f55SGrant Likely 	hw->rx = t->rx_buf;
149ca632f55SGrant Likely 	hw->len = t->len;
150ca632f55SGrant Likely 	hw->count = 0;
151ca632f55SGrant Likely 
152ca632f55SGrant Likely 	/* send the first byte */
153ca632f55SGrant Likely 	data = hw->tx ? hw->tx[0] : 0;
154ca632f55SGrant Likely 	out_8(&hw->regs->txd, data);
155ca632f55SGrant Likely 	out_8(&hw->regs->cr, SPI_PPC4XX_CR_STR);
156ca632f55SGrant Likely 	wait_for_completion(&hw->done);
157ca632f55SGrant Likely 
158ca632f55SGrant Likely 	return hw->count;
159ca632f55SGrant Likely }
160ca632f55SGrant Likely 
spi_ppc4xx_setupxfer(struct spi_device * spi,struct spi_transfer * t)161ca632f55SGrant Likely static int spi_ppc4xx_setupxfer(struct spi_device *spi, struct spi_transfer *t)
162ca632f55SGrant Likely {
16371345830SYang Yingliang 	struct ppc4xx_spi *hw = spi_controller_get_devdata(spi->controller);
164ca632f55SGrant Likely 	struct spi_ppc4xx_cs *cs = spi->controller_state;
165ca632f55SGrant Likely 	int scr;
166ca632f55SGrant Likely 	u8 cdm = 0;
167ca632f55SGrant Likely 	u32 speed;
168ca632f55SGrant Likely 
169ca632f55SGrant Likely 	/* Start with the generic configuration for this device. */
170ca632f55SGrant Likely 	speed = spi->max_speed_hz;
171ca632f55SGrant Likely 
172ca632f55SGrant Likely 	/*
173ca632f55SGrant Likely 	 * Modify the configuration if the transfer overrides it.  Do not allow
174ca632f55SGrant Likely 	 * the transfer to overwrite the generic configuration with zeros.
175ca632f55SGrant Likely 	 */
176ca632f55SGrant Likely 	if (t) {
177ca632f55SGrant Likely 		if (t->speed_hz)
178ca632f55SGrant Likely 			speed = min(t->speed_hz, spi->max_speed_hz);
179ca632f55SGrant Likely 	}
180ca632f55SGrant Likely 
181ca632f55SGrant Likely 	if (!speed || (speed > spi->max_speed_hz)) {
182ca632f55SGrant Likely 		dev_err(&spi->dev, "invalid speed_hz (%d)\n", speed);
183ca632f55SGrant Likely 		return -EINVAL;
184ca632f55SGrant Likely 	}
185ca632f55SGrant Likely 
186886db6acSMasanari Iida 	/* Write new configuration */
187ca632f55SGrant Likely 	out_8(&hw->regs->mode, cs->mode);
188ca632f55SGrant Likely 
189ca632f55SGrant Likely 	/* Set the clock */
190ca632f55SGrant Likely 	/* opb_freq was already divided by 4 */
191ca632f55SGrant Likely 	scr = (hw->opb_freq / speed) - 1;
192ca632f55SGrant Likely 	if (scr > 0)
193ca632f55SGrant Likely 		cdm = min(scr, 0xff);
194ca632f55SGrant Likely 
195ca632f55SGrant Likely 	dev_dbg(&spi->dev, "setting pre-scaler to %d (hz %d)\n", cdm, speed);
196ca632f55SGrant Likely 
197ca632f55SGrant Likely 	if (in_8(&hw->regs->cdm) != cdm)
198ca632f55SGrant Likely 		out_8(&hw->regs->cdm, cdm);
199ca632f55SGrant Likely 
200c15f6ed3SNicolas Boichat 	mutex_lock(&hw->bitbang.lock);
201ca632f55SGrant Likely 	if (!hw->bitbang.busy) {
202ca632f55SGrant Likely 		hw->bitbang.chipselect(spi, BITBANG_CS_INACTIVE);
203ca632f55SGrant Likely 		/* Need to ndelay here? */
204ca632f55SGrant Likely 	}
205c15f6ed3SNicolas Boichat 	mutex_unlock(&hw->bitbang.lock);
206ca632f55SGrant Likely 
207ca632f55SGrant Likely 	return 0;
208ca632f55SGrant Likely }
209ca632f55SGrant Likely 
spi_ppc4xx_setup(struct spi_device * spi)210ca632f55SGrant Likely static int spi_ppc4xx_setup(struct spi_device *spi)
211ca632f55SGrant Likely {
212ca632f55SGrant Likely 	struct spi_ppc4xx_cs *cs = spi->controller_state;
213ca632f55SGrant Likely 
214ca632f55SGrant Likely 	if (!spi->max_speed_hz) {
215ca632f55SGrant Likely 		dev_err(&spi->dev, "invalid max_speed_hz (must be non-zero)\n");
216ca632f55SGrant Likely 		return -EINVAL;
217ca632f55SGrant Likely 	}
218ca632f55SGrant Likely 
219ca632f55SGrant Likely 	if (cs == NULL) {
22007c74f84SZhiqi Song 		cs = kzalloc(sizeof(*cs), GFP_KERNEL);
221ca632f55SGrant Likely 		if (!cs)
222ca632f55SGrant Likely 			return -ENOMEM;
223ca632f55SGrant Likely 		spi->controller_state = cs;
224ca632f55SGrant Likely 	}
225ca632f55SGrant Likely 
226ca632f55SGrant Likely 	/*
227ca632f55SGrant Likely 	 * We set all bits of the SPI0_MODE register, so,
228ca632f55SGrant Likely 	 * no need to read-modify-write
229ca632f55SGrant Likely 	 */
230ca632f55SGrant Likely 	cs->mode = SPI_PPC4XX_MODE_SPE;
231ca632f55SGrant Likely 
2324ccf0557SAndy Shevchenko 	switch (spi->mode & SPI_MODE_X_MASK) {
233ca632f55SGrant Likely 	case SPI_MODE_0:
234ca632f55SGrant Likely 		cs->mode |= SPI_CLK_MODE0;
235ca632f55SGrant Likely 		break;
236ca632f55SGrant Likely 	case SPI_MODE_1:
237ca632f55SGrant Likely 		cs->mode |= SPI_CLK_MODE1;
238ca632f55SGrant Likely 		break;
239ca632f55SGrant Likely 	case SPI_MODE_2:
240ca632f55SGrant Likely 		cs->mode |= SPI_CLK_MODE2;
241ca632f55SGrant Likely 		break;
242ca632f55SGrant Likely 	case SPI_MODE_3:
243ca632f55SGrant Likely 		cs->mode |= SPI_CLK_MODE3;
244ca632f55SGrant Likely 		break;
245ca632f55SGrant Likely 	}
246ca632f55SGrant Likely 
247ca632f55SGrant Likely 	if (spi->mode & SPI_LSB_FIRST)
248ca632f55SGrant Likely 		cs->mode |= SPI_PPC4XX_MODE_RD;
249ca632f55SGrant Likely 
250ca632f55SGrant Likely 	return 0;
251ca632f55SGrant Likely }
252ca632f55SGrant Likely 
spi_ppc4xx_int(int irq,void * dev_id)253ca632f55SGrant Likely static irqreturn_t spi_ppc4xx_int(int irq, void *dev_id)
254ca632f55SGrant Likely {
255ca632f55SGrant Likely 	struct ppc4xx_spi *hw;
256ca632f55SGrant Likely 	u8 status;
257ca632f55SGrant Likely 	u8 data;
258ca632f55SGrant Likely 	unsigned int count;
259ca632f55SGrant Likely 
260ca632f55SGrant Likely 	hw = (struct ppc4xx_spi *)dev_id;
261ca632f55SGrant Likely 
262ca632f55SGrant Likely 	status = in_8(&hw->regs->sr);
263ca632f55SGrant Likely 	if (!status)
264ca632f55SGrant Likely 		return IRQ_NONE;
265ca632f55SGrant Likely 
266ca632f55SGrant Likely 	/*
267ca632f55SGrant Likely 	 * BSY de-asserts one cycle after the transfer is complete.  The
268ca632f55SGrant Likely 	 * interrupt is asserted after the transfer is complete.  The exact
269ca632f55SGrant Likely 	 * relationship is not documented, hence this code.
270ca632f55SGrant Likely 	 */
271ca632f55SGrant Likely 
272ca632f55SGrant Likely 	if (unlikely(status & SPI_PPC4XX_SR_BSY)) {
273ca632f55SGrant Likely 		u8 lstatus;
274ca632f55SGrant Likely 		int cnt = 0;
275ca632f55SGrant Likely 
276ca632f55SGrant Likely 		dev_dbg(hw->dev, "got interrupt but spi still busy?\n");
277ca632f55SGrant Likely 		do {
278ca632f55SGrant Likely 			ndelay(10);
279ca632f55SGrant Likely 			lstatus = in_8(&hw->regs->sr);
280ca632f55SGrant Likely 		} while (++cnt < 100 && lstatus & SPI_PPC4XX_SR_BSY);
281ca632f55SGrant Likely 
282ca632f55SGrant Likely 		if (cnt >= 100) {
283ca632f55SGrant Likely 			dev_err(hw->dev, "busywait: too many loops!\n");
284ca632f55SGrant Likely 			complete(&hw->done);
285ca632f55SGrant Likely 			return IRQ_HANDLED;
286ca632f55SGrant Likely 		} else {
287ca632f55SGrant Likely 			/* status is always 1 (RBR) here */
288ca632f55SGrant Likely 			status = in_8(&hw->regs->sr);
289ca632f55SGrant Likely 			dev_dbg(hw->dev, "loops %d status %x\n", cnt, status);
290ca632f55SGrant Likely 		}
291ca632f55SGrant Likely 	}
292ca632f55SGrant Likely 
293ca632f55SGrant Likely 	count = hw->count;
294ca632f55SGrant Likely 	hw->count++;
295ca632f55SGrant Likely 
296ca632f55SGrant Likely 	/* RBR triggered this interrupt.  Therefore, data must be ready. */
297ca632f55SGrant Likely 	data = in_8(&hw->regs->rxd);
298ca632f55SGrant Likely 	if (hw->rx)
299ca632f55SGrant Likely 		hw->rx[count] = data;
300ca632f55SGrant Likely 
301ca632f55SGrant Likely 	count++;
302ca632f55SGrant Likely 
303ca632f55SGrant Likely 	if (count < hw->len) {
304ca632f55SGrant Likely 		data = hw->tx ? hw->tx[count] : 0;
305ca632f55SGrant Likely 		out_8(&hw->regs->txd, data);
306ca632f55SGrant Likely 		out_8(&hw->regs->cr, SPI_PPC4XX_CR_STR);
307ca632f55SGrant Likely 	} else {
308ca632f55SGrant Likely 		complete(&hw->done);
309ca632f55SGrant Likely 	}
310ca632f55SGrant Likely 
311ca632f55SGrant Likely 	return IRQ_HANDLED;
312ca632f55SGrant Likely }
313ca632f55SGrant Likely 
spi_ppc4xx_cleanup(struct spi_device * spi)314ca632f55SGrant Likely static void spi_ppc4xx_cleanup(struct spi_device *spi)
315ca632f55SGrant Likely {
316ca632f55SGrant Likely 	kfree(spi->controller_state);
317ca632f55SGrant Likely }
318ca632f55SGrant Likely 
spi_ppc4xx_enable(struct ppc4xx_spi * hw)319ca632f55SGrant Likely static void spi_ppc4xx_enable(struct ppc4xx_spi *hw)
320ca632f55SGrant Likely {
321ca632f55SGrant Likely 	/*
322ca632f55SGrant Likely 	 * On all 4xx PPC's the SPI bus is shared/multiplexed with
323db56d030SJay Fang 	 * the 2nd I2C bus. We need to enable the SPI bus before
324ca632f55SGrant Likely 	 * using it.
325ca632f55SGrant Likely 	 */
326ca632f55SGrant Likely 
327ca632f55SGrant Likely 	/* need to clear bit 14 to enable SPC */
328ca632f55SGrant Likely 	dcri_clrset(SDR0, SDR0_PFC1, 0x80000000 >> 14, 0);
329ca632f55SGrant Likely }
330ca632f55SGrant Likely 
331ca632f55SGrant Likely /*
332ca632f55SGrant Likely  * platform_device layer stuff...
333ca632f55SGrant Likely  */
spi_ppc4xx_of_probe(struct platform_device * op)3342deff8d6SGrant Likely static int spi_ppc4xx_of_probe(struct platform_device *op)
335ca632f55SGrant Likely {
336ca632f55SGrant Likely 	struct ppc4xx_spi *hw;
33771345830SYang Yingliang 	struct spi_controller *host;
338ca632f55SGrant Likely 	struct spi_bitbang *bbp;
339ca632f55SGrant Likely 	struct resource resource;
340ca632f55SGrant Likely 	struct device_node *np = op->dev.of_node;
341ca632f55SGrant Likely 	struct device *dev = &op->dev;
342ca632f55SGrant Likely 	struct device_node *opbnp;
343ca632f55SGrant Likely 	int ret;
344ca632f55SGrant Likely 	const unsigned int *clk;
345ca632f55SGrant Likely 
34671345830SYang Yingliang 	host = spi_alloc_host(dev, sizeof(*hw));
34771345830SYang Yingliang 	if (host == NULL)
348ca632f55SGrant Likely 		return -ENOMEM;
34971345830SYang Yingliang 	host->dev.of_node = np;
35071345830SYang Yingliang 	platform_set_drvdata(op, host);
35171345830SYang Yingliang 	hw = spi_controller_get_devdata(host);
35271345830SYang Yingliang 	hw->host = host;
353ca632f55SGrant Likely 	hw->dev = dev;
354ca632f55SGrant Likely 
355ca632f55SGrant Likely 	init_completion(&hw->done);
356ca632f55SGrant Likely 
357ca632f55SGrant Likely 	/* Setup the state for the bitbang driver */
358ca632f55SGrant Likely 	bbp = &hw->bitbang;
35971345830SYang Yingliang 	bbp->master = hw->host;
360ca632f55SGrant Likely 	bbp->setup_transfer = spi_ppc4xx_setupxfer;
361ca632f55SGrant Likely 	bbp->txrx_bufs = spi_ppc4xx_txrx;
362ca632f55SGrant Likely 	bbp->use_dma = 0;
363ca632f55SGrant Likely 	bbp->master->setup = spi_ppc4xx_setup;
364ca632f55SGrant Likely 	bbp->master->cleanup = spi_ppc4xx_cleanup;
36524778be2SStephen Warren 	bbp->master->bits_per_word_mask = SPI_BPW_MASK(8);
36647267732SLinus Walleij 	bbp->master->use_gpio_descriptors = true;
36747267732SLinus Walleij 	/*
36847267732SLinus Walleij 	 * The SPI core will count the number of GPIO descriptors to figure
36947267732SLinus Walleij 	 * out the number of chip selects available on the platform.
37047267732SLinus Walleij 	 */
37147267732SLinus Walleij 	bbp->master->num_chipselect = 0;
372ca632f55SGrant Likely 
373ca632f55SGrant Likely 	/* the spi->mode bits understood by this driver: */
374ca632f55SGrant Likely 	bbp->master->mode_bits =
375ca632f55SGrant Likely 		SPI_CPHA | SPI_CPOL | SPI_CS_HIGH | SPI_LSB_FIRST;
376ca632f55SGrant Likely 
377ca632f55SGrant Likely 	/* Get the clock for the OPB */
378ca632f55SGrant Likely 	opbnp = of_find_compatible_node(NULL, NULL, "ibm,opb");
379ca632f55SGrant Likely 	if (opbnp == NULL) {
380ca632f55SGrant Likely 		dev_err(dev, "OPB: cannot find node\n");
381ca632f55SGrant Likely 		ret = -ENODEV;
38271345830SYang Yingliang 		goto free_host;
383ca632f55SGrant Likely 	}
384ca632f55SGrant Likely 	/* Get the clock (Hz) for the OPB */
385ca632f55SGrant Likely 	clk = of_get_property(opbnp, "clock-frequency", NULL);
386ca632f55SGrant Likely 	if (clk == NULL) {
387ca632f55SGrant Likely 		dev_err(dev, "OPB: no clock-frequency property set\n");
388ca632f55SGrant Likely 		of_node_put(opbnp);
389ca632f55SGrant Likely 		ret = -ENODEV;
39071345830SYang Yingliang 		goto free_host;
391ca632f55SGrant Likely 	}
392ca632f55SGrant Likely 	hw->opb_freq = *clk;
393ca632f55SGrant Likely 	hw->opb_freq >>= 2;
394ca632f55SGrant Likely 	of_node_put(opbnp);
395ca632f55SGrant Likely 
396ca632f55SGrant Likely 	ret = of_address_to_resource(np, 0, &resource);
397ca632f55SGrant Likely 	if (ret) {
398ca632f55SGrant Likely 		dev_err(dev, "error while parsing device node resource\n");
39971345830SYang Yingliang 		goto free_host;
400ca632f55SGrant Likely 	}
401ca632f55SGrant Likely 	hw->mapbase = resource.start;
4028e2943c0SJoe Perches 	hw->mapsize = resource_size(&resource);
403ca632f55SGrant Likely 
404ca632f55SGrant Likely 	/* Sanity check */
405ca632f55SGrant Likely 	if (hw->mapsize < sizeof(struct spi_ppc4xx_regs)) {
406ca632f55SGrant Likely 		dev_err(dev, "too small to map registers\n");
407ca632f55SGrant Likely 		ret = -EINVAL;
40871345830SYang Yingliang 		goto free_host;
409ca632f55SGrant Likely 	}
410ca632f55SGrant Likely 
411ca632f55SGrant Likely 	/* Request IRQ */
412*3bf127bcSAndy Shevchenko 	ret = platform_get_irq(op, 0);
413*3bf127bcSAndy Shevchenko 	if (ret < 0)
4141b08f7b5SMa Ke 		goto free_host;
415*3bf127bcSAndy Shevchenko 	hw->irqnum = ret;
4161b08f7b5SMa Ke 
417ca632f55SGrant Likely 	ret = request_irq(hw->irqnum, spi_ppc4xx_int,
41838ada214SYong Zhang 			  0, "spi_ppc4xx_of", (void *)hw);
419ca632f55SGrant Likely 	if (ret) {
420ca632f55SGrant Likely 		dev_err(dev, "unable to allocate interrupt\n");
42171345830SYang Yingliang 		goto free_host;
422ca632f55SGrant Likely 	}
423ca632f55SGrant Likely 
424ca632f55SGrant Likely 	if (!request_mem_region(hw->mapbase, hw->mapsize, DRIVER_NAME)) {
425ca632f55SGrant Likely 		dev_err(dev, "resource unavailable\n");
426ca632f55SGrant Likely 		ret = -EBUSY;
427ca632f55SGrant Likely 		goto request_mem_error;
428ca632f55SGrant Likely 	}
429ca632f55SGrant Likely 
430ca632f55SGrant Likely 	hw->regs = ioremap(hw->mapbase, sizeof(struct spi_ppc4xx_regs));
431ca632f55SGrant Likely 
432ca632f55SGrant Likely 	if (!hw->regs) {
433ca632f55SGrant Likely 		dev_err(dev, "unable to memory map registers\n");
434ca632f55SGrant Likely 		ret = -ENXIO;
435ca632f55SGrant Likely 		goto map_io_error;
436ca632f55SGrant Likely 	}
437ca632f55SGrant Likely 
438ca632f55SGrant Likely 	spi_ppc4xx_enable(hw);
439ca632f55SGrant Likely 
440ca632f55SGrant Likely 	/* Finally register our spi controller */
441ca632f55SGrant Likely 	dev->dma_mask = 0;
442ca632f55SGrant Likely 	ret = spi_bitbang_start(bbp);
443ca632f55SGrant Likely 	if (ret) {
44471345830SYang Yingliang 		dev_err(dev, "failed to register SPI host\n");
445ca632f55SGrant Likely 		goto unmap_regs;
446ca632f55SGrant Likely 	}
447ca632f55SGrant Likely 
448ca632f55SGrant Likely 	dev_info(dev, "driver initialized\n");
449ca632f55SGrant Likely 
450ca632f55SGrant Likely 	return 0;
451ca632f55SGrant Likely 
452ca632f55SGrant Likely unmap_regs:
453ca632f55SGrant Likely 	iounmap(hw->regs);
454ca632f55SGrant Likely map_io_error:
455ca632f55SGrant Likely 	release_mem_region(hw->mapbase, hw->mapsize);
456ca632f55SGrant Likely request_mem_error:
457ca632f55SGrant Likely 	free_irq(hw->irqnum, hw);
45871345830SYang Yingliang free_host:
45971345830SYang Yingliang 	spi_controller_put(host);
460ca632f55SGrant Likely 
461ca632f55SGrant Likely 	dev_err(dev, "initialization failed\n");
462ca632f55SGrant Likely 	return ret;
463ca632f55SGrant Likely }
464ca632f55SGrant Likely 
spi_ppc4xx_of_remove(struct platform_device * op)465224d9437SUwe Kleine-König static void spi_ppc4xx_of_remove(struct platform_device *op)
466ca632f55SGrant Likely {
46771345830SYang Yingliang 	struct spi_controller *host = platform_get_drvdata(op);
46871345830SYang Yingliang 	struct ppc4xx_spi *hw = spi_controller_get_devdata(host);
469ca632f55SGrant Likely 
470ca632f55SGrant Likely 	spi_bitbang_stop(&hw->bitbang);
471ca632f55SGrant Likely 	release_mem_region(hw->mapbase, hw->mapsize);
472ca632f55SGrant Likely 	free_irq(hw->irqnum, hw);
473ca632f55SGrant Likely 	iounmap(hw->regs);
47471345830SYang Yingliang 	spi_controller_put(host);
475ca632f55SGrant Likely }
476ca632f55SGrant Likely 
477ca632f55SGrant Likely static const struct of_device_id spi_ppc4xx_of_match[] = {
478ca632f55SGrant Likely 	{ .compatible = "ibm,ppc4xx-spi", },
479ca632f55SGrant Likely 	{},
480ca632f55SGrant Likely };
481ca632f55SGrant Likely 
482ca632f55SGrant Likely MODULE_DEVICE_TABLE(of, spi_ppc4xx_of_match);
483ca632f55SGrant Likely 
484ca632f55SGrant Likely static struct platform_driver spi_ppc4xx_of_driver = {
485ca632f55SGrant Likely 	.probe = spi_ppc4xx_of_probe,
486224d9437SUwe Kleine-König 	.remove_new = spi_ppc4xx_of_remove,
487ca632f55SGrant Likely 	.driver = {
488ca632f55SGrant Likely 		.name = DRIVER_NAME,
489ca632f55SGrant Likely 		.of_match_table = spi_ppc4xx_of_match,
490ca632f55SGrant Likely 	},
491ca632f55SGrant Likely };
492940ab889SGrant Likely module_platform_driver(spi_ppc4xx_of_driver);
493ca632f55SGrant Likely 
494ca632f55SGrant Likely MODULE_AUTHOR("Gary Jennejohn & Stefan Roese");
495ca632f55SGrant Likely MODULE_DESCRIPTION("Simple PPC4xx SPI Driver");
496ca632f55SGrant Likely MODULE_LICENSE("GPL");
497