xref: /openbmc/linux/drivers/spi/spi-fsl-lib.c (revision e40573a4)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Freescale SPI/eSPI controller driver library.
4  *
5  * Maintainer: Kumar Gala
6  *
7  * Copyright (C) 2006 Polycom, Inc.
8  *
9  * CPM SPI and QE buffer descriptors mode support:
10  * Copyright (c) 2009  MontaVista Software, Inc.
11  * Author: Anton Vorontsov <avorontsov@ru.mvista.com>
12  *
13  * Copyright 2010 Freescale Semiconductor, Inc.
14  */
15 #include <linux/dma-mapping.h>
16 #include <linux/fsl_devices.h>
17 #include <linux/interrupt.h>
18 #include <linux/kernel.h>
19 #include <linux/mm.h>
20 #include <linux/module.h>
21 #include <linux/of_platform.h>
22 #include <linux/spi/spi.h>
23 #ifdef CONFIG_FSL_SOC
24 #include <sysdev/fsl_soc.h>
25 #endif
26 
27 #include "spi-fsl-lib.h"
28 
29 #define MPC8XXX_SPI_RX_BUF(type) 					  \
30 void mpc8xxx_spi_rx_buf_##type(u32 data, struct mpc8xxx_spi *mpc8xxx_spi) \
31 {									  \
32 	type *rx = mpc8xxx_spi->rx;					  \
33 	*rx++ = (type)(data >> mpc8xxx_spi->rx_shift);			  \
34 	mpc8xxx_spi->rx = rx;						  \
35 }									  \
36 EXPORT_SYMBOL_GPL(mpc8xxx_spi_rx_buf_##type);
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 EXPORT_SYMBOL_GPL(mpc8xxx_spi_tx_buf_##type);
50 
51 MPC8XXX_SPI_RX_BUF(u8)
52 MPC8XXX_SPI_RX_BUF(u16)
53 MPC8XXX_SPI_RX_BUF(u32)
54 MPC8XXX_SPI_TX_BUF(u8)
55 MPC8XXX_SPI_TX_BUF(u16)
56 MPC8XXX_SPI_TX_BUF(u32)
57 
58 struct mpc8xxx_spi_probe_info *to_of_pinfo(struct fsl_spi_platform_data *pdata)
59 {
60 	return container_of(pdata, struct mpc8xxx_spi_probe_info, pdata);
61 }
62 EXPORT_SYMBOL_GPL(to_of_pinfo);
63 
64 const char *mpc8xxx_spi_strmode(unsigned int flags)
65 {
66 	if (flags & SPI_QE_CPU_MODE) {
67 		return "QE CPU";
68 	} else if (flags & SPI_CPM_MODE) {
69 		if (flags & SPI_QE)
70 			return "QE";
71 		else if (flags & SPI_CPM2)
72 			return "CPM2";
73 		else
74 			return "CPM1";
75 	}
76 	return "CPU";
77 }
78 EXPORT_SYMBOL_GPL(mpc8xxx_spi_strmode);
79 
80 void mpc8xxx_spi_probe(struct device *dev, struct resource *mem,
81 			unsigned int irq)
82 {
83 	struct fsl_spi_platform_data *pdata = dev_get_platdata(dev);
84 	struct spi_master *master;
85 	struct mpc8xxx_spi *mpc8xxx_spi;
86 
87 	master = dev_get_drvdata(dev);
88 
89 	/* the spi->mode bits understood by this driver: */
90 	master->mode_bits = SPI_CPOL | SPI_CPHA | SPI_CS_HIGH
91 			| SPI_LSB_FIRST | SPI_LOOP;
92 
93 	master->dev.of_node = dev->of_node;
94 
95 	mpc8xxx_spi = spi_master_get_devdata(master);
96 	mpc8xxx_spi->dev = dev;
97 	mpc8xxx_spi->get_rx = mpc8xxx_spi_rx_buf_u8;
98 	mpc8xxx_spi->get_tx = mpc8xxx_spi_tx_buf_u8;
99 	mpc8xxx_spi->flags = pdata->flags;
100 	mpc8xxx_spi->spibrg = pdata->sysclk;
101 	mpc8xxx_spi->irq = irq;
102 
103 	mpc8xxx_spi->rx_shift = 0;
104 	mpc8xxx_spi->tx_shift = 0;
105 
106 	master->bus_num = pdata->bus_num;
107 	master->num_chipselect = pdata->max_chipselect;
108 
109 	init_completion(&mpc8xxx_spi->done);
110 }
111 EXPORT_SYMBOL_GPL(mpc8xxx_spi_probe);
112 
113 int of_mpc8xxx_spi_probe(struct platform_device *ofdev)
114 {
115 	struct device *dev = &ofdev->dev;
116 	struct device_node *np = ofdev->dev.of_node;
117 	struct mpc8xxx_spi_probe_info *pinfo;
118 	struct fsl_spi_platform_data *pdata;
119 	const void *prop;
120 	int ret = -ENOMEM;
121 
122 	pinfo = devm_kzalloc(&ofdev->dev, sizeof(*pinfo), GFP_KERNEL);
123 	if (!pinfo)
124 		return ret;
125 
126 	pdata = &pinfo->pdata;
127 	dev->platform_data = pdata;
128 
129 	/* Allocate bus num dynamically. */
130 	pdata->bus_num = -1;
131 
132 #ifdef CONFIG_FSL_SOC
133 	/* SPI controller is either clocked from QE or SoC clock. */
134 	pdata->sysclk = get_brgfreq();
135 	if (pdata->sysclk == -1) {
136 		pdata->sysclk = fsl_get_sys_freq();
137 		if (pdata->sysclk == -1)
138 			return -ENODEV;
139 	}
140 #else
141 	ret = of_property_read_u32(np, "clock-frequency", &pdata->sysclk);
142 	if (ret)
143 		return ret;
144 #endif
145 
146 	prop = of_get_property(np, "mode", NULL);
147 	if (prop && !strcmp(prop, "cpu-qe"))
148 		pdata->flags = SPI_QE_CPU_MODE;
149 	else if (prop && !strcmp(prop, "qe"))
150 		pdata->flags = SPI_CPM_MODE | SPI_QE;
151 	else if (of_device_is_compatible(np, "fsl,cpm2-spi"))
152 		pdata->flags = SPI_CPM_MODE | SPI_CPM2;
153 	else if (of_device_is_compatible(np, "fsl,cpm1-spi"))
154 		pdata->flags = SPI_CPM_MODE | SPI_CPM1;
155 
156 	return 0;
157 }
158 EXPORT_SYMBOL_GPL(of_mpc8xxx_spi_probe);
159 
160 MODULE_LICENSE("GPL");
161