1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * Copyright 2009-2010 Pengutronix |
4 | * Uwe Kleine-Koenig <u.kleine-koenig@pengutronix.de> |
5 | * |
6 | * loosely based on an earlier driver that has |
7 | * Copyright 2009 Pengutronix, Sascha Hauer <s.hauer@pengutronix.de> |
8 | */ |
9 | |
10 | #include <linux/slab.h> |
11 | #include <linux/mod_devicetable.h> |
12 | #include <linux/module.h> |
13 | #include <linux/platform_device.h> |
14 | #include <linux/interrupt.h> |
15 | #include <linux/mfd/core.h> |
16 | #include <linux/mfd/mc13xxx.h> |
17 | #include <linux/err.h> |
18 | #include <linux/spi/spi.h> |
19 | |
20 | #include "mc13xxx.h" |
21 | |
22 | static const struct spi_device_id mc13xxx_device_id[] = { |
23 | { |
24 | .name = "mc13783" , |
25 | .driver_data = (kernel_ulong_t)&mc13xxx_variant_mc13783, |
26 | }, { |
27 | .name = "mc13892" , |
28 | .driver_data = (kernel_ulong_t)&mc13xxx_variant_mc13892, |
29 | }, { |
30 | .name = "mc34708" , |
31 | .driver_data = (kernel_ulong_t)&mc13xxx_variant_mc34708, |
32 | }, { |
33 | /* sentinel */ |
34 | } |
35 | }; |
36 | MODULE_DEVICE_TABLE(spi, mc13xxx_device_id); |
37 | |
38 | static const struct of_device_id mc13xxx_dt_ids[] = { |
39 | { .compatible = "fsl,mc13783" , .data = &mc13xxx_variant_mc13783, }, |
40 | { .compatible = "fsl,mc13892" , .data = &mc13xxx_variant_mc13892, }, |
41 | { .compatible = "fsl,mc34708" , .data = &mc13xxx_variant_mc34708, }, |
42 | { /* sentinel */ } |
43 | }; |
44 | MODULE_DEVICE_TABLE(of, mc13xxx_dt_ids); |
45 | |
46 | static const struct regmap_config mc13xxx_regmap_spi_config = { |
47 | .reg_bits = 7, |
48 | .pad_bits = 1, |
49 | .val_bits = 24, |
50 | .write_flag_mask = 0x80, |
51 | |
52 | .max_register = MC13XXX_NUMREGS, |
53 | |
54 | .cache_type = REGCACHE_NONE, |
55 | .use_single_read = true, |
56 | .use_single_write = true, |
57 | }; |
58 | |
59 | static int mc13xxx_spi_read(void *context, const void *reg, size_t reg_size, |
60 | void *val, size_t val_size) |
61 | { |
62 | unsigned char w[4] = { *((unsigned char *) reg), 0, 0, 0}; |
63 | unsigned char r[4]; |
64 | unsigned char *p = val; |
65 | struct device *dev = context; |
66 | struct spi_device *spi = to_spi_device(dev); |
67 | struct spi_transfer t = { |
68 | .tx_buf = w, |
69 | .rx_buf = r, |
70 | .len = 4, |
71 | }; |
72 | |
73 | struct spi_message m; |
74 | int ret; |
75 | |
76 | if (val_size != 3 || reg_size != 1) |
77 | return -ENOTSUPP; |
78 | |
79 | spi_message_init(m: &m); |
80 | spi_message_add_tail(t: &t, m: &m); |
81 | ret = spi_sync(spi, message: &m); |
82 | |
83 | memcpy(p, &r[1], 3); |
84 | |
85 | return ret; |
86 | } |
87 | |
88 | static int mc13xxx_spi_write(void *context, const void *data, size_t count) |
89 | { |
90 | struct device *dev = context; |
91 | struct spi_device *spi = to_spi_device(dev); |
92 | const char *reg = data; |
93 | |
94 | if (count != 4) |
95 | return -ENOTSUPP; |
96 | |
97 | /* include errata fix for spi audio problems */ |
98 | if (*reg == MC13783_AUDIO_CODEC || *reg == MC13783_AUDIO_DAC) |
99 | spi_write(spi, buf: data, len: count); |
100 | |
101 | return spi_write(spi, buf: data, len: count); |
102 | } |
103 | |
104 | /* |
105 | * We cannot use regmap-spi generic bus implementation here. |
106 | * The MC13783 chip will get corrupted if CS signal is deasserted |
107 | * and on i.Mx31 SoC (the target SoC for MC13783 PMIC) the SPI controller |
108 | * has the following errata (DSPhl22960): |
109 | * "The CSPI negates SS when the FIFO becomes empty with |
110 | * SSCTL= 0. Software cannot guarantee that the FIFO will not |
111 | * drain because of higher priority interrupts and the |
112 | * non-realtime characteristics of the operating system. As a |
113 | * result, the SS will negate before all of the data has been |
114 | * transferred to/from the peripheral." |
115 | * We workaround this by accessing the SPI controller with a |
116 | * single transfer. |
117 | */ |
118 | |
119 | static struct regmap_bus regmap_mc13xxx_bus = { |
120 | .write = mc13xxx_spi_write, |
121 | .read = mc13xxx_spi_read, |
122 | }; |
123 | |
124 | static int mc13xxx_spi_probe(struct spi_device *spi) |
125 | { |
126 | struct mc13xxx *mc13xxx; |
127 | int ret; |
128 | |
129 | mc13xxx = devm_kzalloc(dev: &spi->dev, size: sizeof(*mc13xxx), GFP_KERNEL); |
130 | if (!mc13xxx) |
131 | return -ENOMEM; |
132 | |
133 | dev_set_drvdata(dev: &spi->dev, data: mc13xxx); |
134 | |
135 | spi->mode = SPI_MODE_0 | SPI_CS_HIGH; |
136 | |
137 | mc13xxx->irq = spi->irq; |
138 | |
139 | spi->max_speed_hz = spi->max_speed_hz ? : 26000000; |
140 | ret = spi_setup(spi); |
141 | if (ret) |
142 | return ret; |
143 | |
144 | mc13xxx->regmap = devm_regmap_init(&spi->dev, ®map_mc13xxx_bus, |
145 | &spi->dev, |
146 | &mc13xxx_regmap_spi_config); |
147 | if (IS_ERR(ptr: mc13xxx->regmap)) { |
148 | ret = PTR_ERR(ptr: mc13xxx->regmap); |
149 | dev_err(&spi->dev, "Failed to initialize regmap: %d\n" , ret); |
150 | return ret; |
151 | } |
152 | |
153 | mc13xxx->variant = spi_get_device_match_data(sdev: spi); |
154 | |
155 | return mc13xxx_common_init(dev: &spi->dev); |
156 | } |
157 | |
158 | static void mc13xxx_spi_remove(struct spi_device *spi) |
159 | { |
160 | mc13xxx_common_exit(dev: &spi->dev); |
161 | } |
162 | |
163 | static struct spi_driver mc13xxx_spi_driver = { |
164 | .id_table = mc13xxx_device_id, |
165 | .driver = { |
166 | .name = "mc13xxx" , |
167 | .of_match_table = mc13xxx_dt_ids, |
168 | }, |
169 | .probe = mc13xxx_spi_probe, |
170 | .remove = mc13xxx_spi_remove, |
171 | }; |
172 | |
173 | static int __init mc13xxx_init(void) |
174 | { |
175 | return spi_register_driver(&mc13xxx_spi_driver); |
176 | } |
177 | subsys_initcall(mc13xxx_init); |
178 | |
179 | static void __exit mc13xxx_exit(void) |
180 | { |
181 | spi_unregister_driver(sdrv: &mc13xxx_spi_driver); |
182 | } |
183 | module_exit(mc13xxx_exit); |
184 | |
185 | MODULE_DESCRIPTION("Core driver for Freescale MC13XXX PMIC" ); |
186 | MODULE_AUTHOR("Uwe Kleine-Koenig <u.kleine-koenig@pengutronix.de>" ); |
187 | MODULE_LICENSE("GPL v2" ); |
188 | |