xref: /openbmc/linux/drivers/spi/spi-fsl-lib.c (revision 293d5b43)
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/dma-mapping.h>
20 #include <linux/fsl_devices.h>
21 #include <linux/interrupt.h>
22 #include <linux/kernel.h>
23 #include <linux/mm.h>
24 #include <linux/module.h>
25 #include <linux/of_platform.h>
26 #include <linux/spi/spi.h>
27 #ifdef CONFIG_FSL_SOC
28 #include <sysdev/fsl_soc.h>
29 #endif
30 
31 #include "spi-fsl-lib.h"
32 
33 #define MPC8XXX_SPI_RX_BUF(type) 					  \
34 void mpc8xxx_spi_rx_buf_##type(u32 data, struct mpc8xxx_spi *mpc8xxx_spi) \
35 {									  \
36 	type *rx = mpc8xxx_spi->rx;					  \
37 	*rx++ = (type)(data >> mpc8xxx_spi->rx_shift);			  \
38 	mpc8xxx_spi->rx = rx;						  \
39 }									  \
40 EXPORT_SYMBOL_GPL(mpc8xxx_spi_rx_buf_##type);
41 
42 #define MPC8XXX_SPI_TX_BUF(type)				\
43 u32 mpc8xxx_spi_tx_buf_##type(struct mpc8xxx_spi *mpc8xxx_spi)	\
44 {								\
45 	u32 data;						\
46 	const type *tx = mpc8xxx_spi->tx;			\
47 	if (!tx)						\
48 		return 0;					\
49 	data = *tx++ << mpc8xxx_spi->tx_shift;			\
50 	mpc8xxx_spi->tx = tx;					\
51 	return data;						\
52 }								\
53 EXPORT_SYMBOL_GPL(mpc8xxx_spi_tx_buf_##type);
54 
55 MPC8XXX_SPI_RX_BUF(u8)
56 MPC8XXX_SPI_RX_BUF(u16)
57 MPC8XXX_SPI_RX_BUF(u32)
58 MPC8XXX_SPI_TX_BUF(u8)
59 MPC8XXX_SPI_TX_BUF(u16)
60 MPC8XXX_SPI_TX_BUF(u32)
61 
62 struct mpc8xxx_spi_probe_info *to_of_pinfo(struct fsl_spi_platform_data *pdata)
63 {
64 	return container_of(pdata, struct mpc8xxx_spi_probe_info, pdata);
65 }
66 EXPORT_SYMBOL_GPL(to_of_pinfo);
67 
68 const char *mpc8xxx_spi_strmode(unsigned int flags)
69 {
70 	if (flags & SPI_QE_CPU_MODE) {
71 		return "QE CPU";
72 	} else if (flags & SPI_CPM_MODE) {
73 		if (flags & SPI_QE)
74 			return "QE";
75 		else if (flags & SPI_CPM2)
76 			return "CPM2";
77 		else
78 			return "CPM1";
79 	}
80 	return "CPU";
81 }
82 EXPORT_SYMBOL_GPL(mpc8xxx_spi_strmode);
83 
84 void mpc8xxx_spi_probe(struct device *dev, struct resource *mem,
85 			unsigned int irq)
86 {
87 	struct fsl_spi_platform_data *pdata = dev_get_platdata(dev);
88 	struct spi_master *master;
89 	struct mpc8xxx_spi *mpc8xxx_spi;
90 
91 	master = dev_get_drvdata(dev);
92 
93 	/* the spi->mode bits understood by this driver: */
94 	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH
95 			| SPI_LSB_FIRST | SPI_LOOP;
96 
97 	master->dev.of_node = dev->of_node;
98 
99 	mpc8xxx_spi = spi_master_get_devdata(master);
100 	mpc8xxx_spi->dev = dev;
101 	mpc8xxx_spi->get_rx = mpc8xxx_spi_rx_buf_u8;
102 	mpc8xxx_spi->get_tx = mpc8xxx_spi_tx_buf_u8;
103 	mpc8xxx_spi->flags = pdata->flags;
104 	mpc8xxx_spi->spibrg = pdata->sysclk;
105 	mpc8xxx_spi->irq = irq;
106 
107 	mpc8xxx_spi->rx_shift = 0;
108 	mpc8xxx_spi->tx_shift = 0;
109 
110 	master->bus_num = pdata->bus_num;
111 	master->num_chipselect = pdata->max_chipselect;
112 
113 	init_completion(&mpc8xxx_spi->done);
114 }
115 EXPORT_SYMBOL_GPL(mpc8xxx_spi_probe);
116 
117 int of_mpc8xxx_spi_probe(struct platform_device *ofdev)
118 {
119 	struct device *dev = &ofdev->dev;
120 	struct device_node *np = ofdev->dev.of_node;
121 	struct mpc8xxx_spi_probe_info *pinfo;
122 	struct fsl_spi_platform_data *pdata;
123 	const void *prop;
124 	int ret = -ENOMEM;
125 
126 	pinfo = devm_kzalloc(&ofdev->dev, sizeof(*pinfo), GFP_KERNEL);
127 	if (!pinfo)
128 		return ret;
129 
130 	pdata = &pinfo->pdata;
131 	dev->platform_data = pdata;
132 
133 	/* Allocate bus num dynamically. */
134 	pdata->bus_num = -1;
135 
136 #ifdef CONFIG_FSL_SOC
137 	/* SPI controller is either clocked from QE or SoC clock. */
138 	pdata->sysclk = get_brgfreq();
139 	if (pdata->sysclk == -1) {
140 		pdata->sysclk = fsl_get_sys_freq();
141 		if (pdata->sysclk == -1)
142 			return -ENODEV;
143 	}
144 #else
145 	ret = of_property_read_u32(np, "clock-frequency", &pdata->sysclk);
146 	if (ret)
147 		return ret;
148 #endif
149 
150 	prop = of_get_property(np, "mode", NULL);
151 	if (prop && !strcmp(prop, "cpu-qe"))
152 		pdata->flags = SPI_QE_CPU_MODE;
153 	else if (prop && !strcmp(prop, "qe"))
154 		pdata->flags = SPI_CPM_MODE | SPI_QE;
155 	else if (of_device_is_compatible(np, "fsl,cpm2-spi"))
156 		pdata->flags = SPI_CPM_MODE | SPI_CPM2;
157 	else if (of_device_is_compatible(np, "fsl,cpm1-spi"))
158 		pdata->flags = SPI_CPM_MODE | SPI_CPM1;
159 
160 	return 0;
161 }
162 EXPORT_SYMBOL_GPL(of_mpc8xxx_spi_probe);
163 
164 MODULE_LICENSE("GPL");
165