xref: /openbmc/linux/drivers/spi/spi-fsl-lib.c (revision 95e9fd10)
1 /*
2  * Freescale SPI/eSPI controller driver library.
3  *
4  * Maintainer: Kumar Gala
5  *
6  * Copyright (C) 2006 Polycom, Inc.
7  *
8  * CPM SPI and QE buffer descriptors mode support:
9  * Copyright (c) 2009  MontaVista Software, Inc.
10  * Author: Anton Vorontsov <avorontsov@ru.mvista.com>
11  *
12  * Copyright 2010 Freescale Semiconductor, Inc.
13  *
14  * This program is free software; you can redistribute  it and/or modify it
15  * under  the terms of  the GNU General  Public License as published by the
16  * Free Software Foundation;  either version 2 of the  License, or (at your
17  * option) any later version.
18  */
19 #include <linux/kernel.h>
20 #include <linux/interrupt.h>
21 #include <linux/fsl_devices.h>
22 #include <linux/dma-mapping.h>
23 #include <linux/mm.h>
24 #include <linux/of_platform.h>
25 #include <linux/spi/spi.h>
26 #include <sysdev/fsl_soc.h>
27 
28 #include "spi-fsl-lib.h"
29 
30 #define MPC8XXX_SPI_RX_BUF(type) 					  \
31 void mpc8xxx_spi_rx_buf_##type(u32 data, struct mpc8xxx_spi *mpc8xxx_spi) \
32 {									  \
33 	type *rx = mpc8xxx_spi->rx;					  \
34 	*rx++ = (type)(data >> mpc8xxx_spi->rx_shift);			  \
35 	mpc8xxx_spi->rx = rx;						  \
36 }
37 
38 #define MPC8XXX_SPI_TX_BUF(type)				\
39 u32 mpc8xxx_spi_tx_buf_##type(struct mpc8xxx_spi *mpc8xxx_spi)	\
40 {								\
41 	u32 data;						\
42 	const type *tx = mpc8xxx_spi->tx;			\
43 	if (!tx)						\
44 		return 0;					\
45 	data = *tx++ << mpc8xxx_spi->tx_shift;			\
46 	mpc8xxx_spi->tx = tx;					\
47 	return data;						\
48 }
49 
50 MPC8XXX_SPI_RX_BUF(u8)
51 MPC8XXX_SPI_RX_BUF(u16)
52 MPC8XXX_SPI_RX_BUF(u32)
53 MPC8XXX_SPI_TX_BUF(u8)
54 MPC8XXX_SPI_TX_BUF(u16)
55 MPC8XXX_SPI_TX_BUF(u32)
56 
57 struct mpc8xxx_spi_probe_info *to_of_pinfo(struct fsl_spi_platform_data *pdata)
58 {
59 	return container_of(pdata, struct mpc8xxx_spi_probe_info, pdata);
60 }
61 
62 void mpc8xxx_spi_work(struct work_struct *work)
63 {
64 	struct mpc8xxx_spi *mpc8xxx_spi = container_of(work, struct mpc8xxx_spi,
65 						       work);
66 
67 	spin_lock_irq(&mpc8xxx_spi->lock);
68 	while (!list_empty(&mpc8xxx_spi->queue)) {
69 		struct spi_message *m = container_of(mpc8xxx_spi->queue.next,
70 						   struct spi_message, queue);
71 
72 		list_del_init(&m->queue);
73 		spin_unlock_irq(&mpc8xxx_spi->lock);
74 
75 		if (mpc8xxx_spi->spi_do_one_msg)
76 			mpc8xxx_spi->spi_do_one_msg(m);
77 
78 		spin_lock_irq(&mpc8xxx_spi->lock);
79 	}
80 	spin_unlock_irq(&mpc8xxx_spi->lock);
81 }
82 
83 int mpc8xxx_spi_transfer(struct spi_device *spi,
84 				struct spi_message *m)
85 {
86 	struct mpc8xxx_spi *mpc8xxx_spi = spi_master_get_devdata(spi->master);
87 	unsigned long flags;
88 
89 	m->actual_length = 0;
90 	m->status = -EINPROGRESS;
91 
92 	spin_lock_irqsave(&mpc8xxx_spi->lock, flags);
93 	list_add_tail(&m->queue, &mpc8xxx_spi->queue);
94 	queue_work(mpc8xxx_spi->workqueue, &mpc8xxx_spi->work);
95 	spin_unlock_irqrestore(&mpc8xxx_spi->lock, flags);
96 
97 	return 0;
98 }
99 
100 void mpc8xxx_spi_cleanup(struct spi_device *spi)
101 {
102 	kfree(spi->controller_state);
103 }
104 
105 const char *mpc8xxx_spi_strmode(unsigned int flags)
106 {
107 	if (flags & SPI_QE_CPU_MODE) {
108 		return "QE CPU";
109 	} else if (flags & SPI_CPM_MODE) {
110 		if (flags & SPI_QE)
111 			return "QE";
112 		else if (flags & SPI_CPM2)
113 			return "CPM2";
114 		else
115 			return "CPM1";
116 	}
117 	return "CPU";
118 }
119 
120 int mpc8xxx_spi_probe(struct device *dev, struct resource *mem,
121 			unsigned int irq)
122 {
123 	struct fsl_spi_platform_data *pdata = dev->platform_data;
124 	struct spi_master *master;
125 	struct mpc8xxx_spi *mpc8xxx_spi;
126 	int ret = 0;
127 
128 	master = dev_get_drvdata(dev);
129 
130 	/* the spi->mode bits understood by this driver: */
131 	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH
132 			| SPI_LSB_FIRST | SPI_LOOP;
133 
134 	master->transfer = mpc8xxx_spi_transfer;
135 	master->cleanup = mpc8xxx_spi_cleanup;
136 	master->dev.of_node = dev->of_node;
137 
138 	mpc8xxx_spi = spi_master_get_devdata(master);
139 	mpc8xxx_spi->dev = dev;
140 	mpc8xxx_spi->get_rx = mpc8xxx_spi_rx_buf_u8;
141 	mpc8xxx_spi->get_tx = mpc8xxx_spi_tx_buf_u8;
142 	mpc8xxx_spi->flags = pdata->flags;
143 	mpc8xxx_spi->spibrg = pdata->sysclk;
144 	mpc8xxx_spi->irq = irq;
145 
146 	mpc8xxx_spi->rx_shift = 0;
147 	mpc8xxx_spi->tx_shift = 0;
148 
149 	init_completion(&mpc8xxx_spi->done);
150 
151 	master->bus_num = pdata->bus_num;
152 	master->num_chipselect = pdata->max_chipselect;
153 
154 	spin_lock_init(&mpc8xxx_spi->lock);
155 	init_completion(&mpc8xxx_spi->done);
156 	INIT_WORK(&mpc8xxx_spi->work, mpc8xxx_spi_work);
157 	INIT_LIST_HEAD(&mpc8xxx_spi->queue);
158 
159 	mpc8xxx_spi->workqueue = create_singlethread_workqueue(
160 		dev_name(master->dev.parent));
161 	if (mpc8xxx_spi->workqueue == NULL) {
162 		ret = -EBUSY;
163 		goto err;
164 	}
165 
166 	return 0;
167 
168 err:
169 	return ret;
170 }
171 
172 int __devexit mpc8xxx_spi_remove(struct device *dev)
173 {
174 	struct mpc8xxx_spi *mpc8xxx_spi;
175 	struct spi_master *master;
176 
177 	master = dev_get_drvdata(dev);
178 	mpc8xxx_spi = spi_master_get_devdata(master);
179 
180 	flush_workqueue(mpc8xxx_spi->workqueue);
181 	destroy_workqueue(mpc8xxx_spi->workqueue);
182 	spi_unregister_master(master);
183 
184 	free_irq(mpc8xxx_spi->irq, mpc8xxx_spi);
185 
186 	if (mpc8xxx_spi->spi_remove)
187 		mpc8xxx_spi->spi_remove(mpc8xxx_spi);
188 
189 	return 0;
190 }
191 
192 int __devinit of_mpc8xxx_spi_probe(struct platform_device *ofdev)
193 {
194 	struct device *dev = &ofdev->dev;
195 	struct device_node *np = ofdev->dev.of_node;
196 	struct mpc8xxx_spi_probe_info *pinfo;
197 	struct fsl_spi_platform_data *pdata;
198 	const void *prop;
199 	int ret = -ENOMEM;
200 
201 	pinfo = kzalloc(sizeof(*pinfo), GFP_KERNEL);
202 	if (!pinfo)
203 		return -ENOMEM;
204 
205 	pdata = &pinfo->pdata;
206 	dev->platform_data = pdata;
207 
208 	/* Allocate bus num dynamically. */
209 	pdata->bus_num = -1;
210 
211 	/* SPI controller is either clocked from QE or SoC clock. */
212 	pdata->sysclk = get_brgfreq();
213 	if (pdata->sysclk == -1) {
214 		pdata->sysclk = fsl_get_sys_freq();
215 		if (pdata->sysclk == -1) {
216 			ret = -ENODEV;
217 			goto err;
218 		}
219 	}
220 
221 	prop = of_get_property(np, "mode", NULL);
222 	if (prop && !strcmp(prop, "cpu-qe"))
223 		pdata->flags = SPI_QE_CPU_MODE;
224 	else if (prop && !strcmp(prop, "qe"))
225 		pdata->flags = SPI_CPM_MODE | SPI_QE;
226 	else if (of_device_is_compatible(np, "fsl,cpm2-spi"))
227 		pdata->flags = SPI_CPM_MODE | SPI_CPM2;
228 	else if (of_device_is_compatible(np, "fsl,cpm1-spi"))
229 		pdata->flags = SPI_CPM_MODE | SPI_CPM1;
230 
231 	return 0;
232 
233 err:
234 	kfree(pinfo);
235 	return ret;
236 }
237