1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Cavium ThunderX SPI driver.
4  *
5  * Copyright (C) 2016 Cavium Inc.
6  * Authors: Jan Glauber <jglauber@cavium.com>
7  */
8 
9 #include <linux/module.h>
10 #include <linux/pci.h>
11 #include <linux/spi/spi.h>
12 
13 #include "spi-cavium.h"
14 
15 #define DRV_NAME "spi-thunderx"
16 
17 #define SYS_FREQ_DEFAULT 700000000 /* 700 Mhz */
18 
thunderx_spi_probe(struct pci_dev * pdev,const struct pci_device_id * ent)19 static int thunderx_spi_probe(struct pci_dev *pdev,
20 			      const struct pci_device_id *ent)
21 {
22 	struct device *dev = &pdev->dev;
23 	struct spi_master *master;
24 	struct octeon_spi *p;
25 	int ret;
26 
27 	master = spi_alloc_master(dev, sizeof(struct octeon_spi));
28 	if (!master)
29 		return -ENOMEM;
30 
31 	p = spi_master_get_devdata(master);
32 
33 	ret = pcim_enable_device(pdev);
34 	if (ret)
35 		goto error;
36 
37 	ret = pci_request_regions(pdev, DRV_NAME);
38 	if (ret)
39 		goto error;
40 
41 	p->register_base = pcim_iomap(pdev, 0, pci_resource_len(pdev, 0));
42 	if (!p->register_base) {
43 		ret = -EINVAL;
44 		goto error;
45 	}
46 
47 	p->regs.config = 0x1000;
48 	p->regs.status = 0x1008;
49 	p->regs.tx = 0x1010;
50 	p->regs.data = 0x1080;
51 
52 	p->clk = devm_clk_get(dev, NULL);
53 	if (IS_ERR(p->clk)) {
54 		ret = PTR_ERR(p->clk);
55 		goto error;
56 	}
57 
58 	ret = clk_prepare_enable(p->clk);
59 	if (ret)
60 		goto error;
61 
62 	p->sys_freq = clk_get_rate(p->clk);
63 	if (!p->sys_freq)
64 		p->sys_freq = SYS_FREQ_DEFAULT;
65 	dev_info(dev, "Set system clock to %u\n", p->sys_freq);
66 
67 	master->flags = SPI_MASTER_HALF_DUPLEX;
68 	master->num_chipselect = 4;
69 	master->mode_bits = SPI_CPHA | SPI_CPOL | SPI_CS_HIGH |
70 			    SPI_LSB_FIRST | SPI_3WIRE;
71 	master->transfer_one_message = octeon_spi_transfer_one_message;
72 	master->bits_per_word_mask = SPI_BPW_MASK(8);
73 	master->max_speed_hz = OCTEON_SPI_MAX_CLOCK_HZ;
74 	master->dev.of_node = pdev->dev.of_node;
75 
76 	pci_set_drvdata(pdev, master);
77 
78 	ret = devm_spi_register_master(dev, master);
79 	if (ret)
80 		goto error;
81 
82 	return 0;
83 
84 error:
85 	clk_disable_unprepare(p->clk);
86 	pci_release_regions(pdev);
87 	spi_master_put(master);
88 	return ret;
89 }
90 
thunderx_spi_remove(struct pci_dev * pdev)91 static void thunderx_spi_remove(struct pci_dev *pdev)
92 {
93 	struct spi_master *master = pci_get_drvdata(pdev);
94 	struct octeon_spi *p;
95 
96 	p = spi_master_get_devdata(master);
97 	if (!p)
98 		return;
99 
100 	clk_disable_unprepare(p->clk);
101 	pci_release_regions(pdev);
102 	/* Put everything in a known state. */
103 	writeq(0, p->register_base + OCTEON_SPI_CFG(p));
104 }
105 
106 static const struct pci_device_id thunderx_spi_pci_id_table[] = {
107 	{ PCI_DEVICE(PCI_VENDOR_ID_CAVIUM, 0xa00b) },
108 	{ 0, }
109 };
110 
111 MODULE_DEVICE_TABLE(pci, thunderx_spi_pci_id_table);
112 
113 static struct pci_driver thunderx_spi_driver = {
114 	.name		= DRV_NAME,
115 	.id_table	= thunderx_spi_pci_id_table,
116 	.probe		= thunderx_spi_probe,
117 	.remove		= thunderx_spi_remove,
118 };
119 
120 module_pci_driver(thunderx_spi_driver);
121 
122 MODULE_DESCRIPTION("Cavium, Inc. ThunderX SPI bus driver");
123 MODULE_AUTHOR("Jan Glauber");
124 MODULE_LICENSE("GPL");
125