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