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1/*
2 * Altera SPI driver
3 *
4 * Copyright (C) 2008 Thomas Chou <thomas@wytron.com.tw>
5 *
6 * Based on spi_s3c24xx.c, which is:
7 * Copyright (c) 2006 Ben Dooks
8 * Copyright (c) 2006 Simtec Electronics
9 * Ben Dooks <ben@simtec.co.uk>
10 *
11 * This program is free software; you can redistribute it and/or modify
12 * it under the terms of the GNU General Public License version 2 as
13 * published by the Free Software Foundation.
14 */
15
16#include <linux/interrupt.h>
17#include <linux/errno.h>
18#include <linux/module.h>
19#include <linux/platform_device.h>
20#include <linux/spi/spi.h>
21#include <linux/io.h>
22#include <linux/of.h>
23
24#define DRV_NAME "spi_altera"
25
26#define ALTERA_SPI_RXDATA 0
27#define ALTERA_SPI_TXDATA 4
28#define ALTERA_SPI_STATUS 8
29#define ALTERA_SPI_CONTROL 12
30#define ALTERA_SPI_SLAVE_SEL 20
31
32#define ALTERA_SPI_STATUS_ROE_MSK 0x8
33#define ALTERA_SPI_STATUS_TOE_MSK 0x10
34#define ALTERA_SPI_STATUS_TMT_MSK 0x20
35#define ALTERA_SPI_STATUS_TRDY_MSK 0x40
36#define ALTERA_SPI_STATUS_RRDY_MSK 0x80
37#define ALTERA_SPI_STATUS_E_MSK 0x100
38
39#define ALTERA_SPI_CONTROL_IROE_MSK 0x8
40#define ALTERA_SPI_CONTROL_ITOE_MSK 0x10
41#define ALTERA_SPI_CONTROL_ITRDY_MSK 0x40
42#define ALTERA_SPI_CONTROL_IRRDY_MSK 0x80
43#define ALTERA_SPI_CONTROL_IE_MSK 0x100
44#define ALTERA_SPI_CONTROL_SSO_MSK 0x400
45
46struct altera_spi {
47 void __iomem *base;
48 int irq;
49 int len;
50 int count;
51 int bytes_per_word;
52 unsigned long imr;
53
54 /* data buffers */
55 const unsigned char *tx;
56 unsigned char *rx;
57};
58
59static inline struct altera_spi *altera_spi_to_hw(struct spi_device *sdev)
60{
61 return spi_master_get_devdata(sdev->master);
62}
63
64static void altera_spi_set_cs(struct spi_device *spi, bool is_high)
65{
66 struct altera_spi *hw = altera_spi_to_hw(spi);
67
68 if (is_high) {
69 hw->imr &= ~ALTERA_SPI_CONTROL_SSO_MSK;
70 writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);
71 writel(0, hw->base + ALTERA_SPI_SLAVE_SEL);
72 } else {
73 writel(BIT(spi->chip_select), hw->base + ALTERA_SPI_SLAVE_SEL);
74 hw->imr |= ALTERA_SPI_CONTROL_SSO_MSK;
75 writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);
76 }
77}
78
79static void altera_spi_tx_word(struct altera_spi *hw)
80{
81 unsigned int txd = 0;
82
83 if (hw->tx) {
84 switch (hw->bytes_per_word) {
85 case 1:
86 txd = hw->tx[hw->count];
87 break;
88 case 2:
89 txd = (hw->tx[hw->count * 2]
90 | (hw->tx[hw->count * 2 + 1] << 8));
91 break;
92 }
93 }
94
95 writel(txd, hw->base + ALTERA_SPI_TXDATA);
96}
97
98static void altera_spi_rx_word(struct altera_spi *hw)
99{
100 unsigned int rxd;
101
102 rxd = readl(hw->base + ALTERA_SPI_RXDATA);
103 if (hw->rx) {
104 switch (hw->bytes_per_word) {
105 case 1:
106 hw->rx[hw->count] = rxd;
107 break;
108 case 2:
109 hw->rx[hw->count * 2] = rxd;
110 hw->rx[hw->count * 2 + 1] = rxd >> 8;
111 break;
112 }
113 }
114
115 hw->count++;
116}
117
118static int altera_spi_txrx(struct spi_master *master,
119 struct spi_device *spi, struct spi_transfer *t)
120{
121 struct altera_spi *hw = spi_master_get_devdata(master);
122
123 hw->tx = t->tx_buf;
124 hw->rx = t->rx_buf;
125 hw->count = 0;
126 hw->bytes_per_word = DIV_ROUND_UP(t->bits_per_word, 8);
127 hw->len = t->len / hw->bytes_per_word;
128
129 if (hw->irq >= 0) {
130 /* enable receive interrupt */
131 hw->imr |= ALTERA_SPI_CONTROL_IRRDY_MSK;
132 writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);
133
134 /* send the first byte */
135 altera_spi_tx_word(hw);
136 } else {
137 while (hw->count < hw->len) {
138 altera_spi_tx_word(hw);
139
140 while (!(readl(hw->base + ALTERA_SPI_STATUS) &
141 ALTERA_SPI_STATUS_RRDY_MSK))
142 cpu_relax();
143
144 altera_spi_rx_word(hw);
145 }
146 spi_finalize_current_transfer(master);
147 }
148
149 return t->len;
150}
151
152static irqreturn_t altera_spi_irq(int irq, void *dev)
153{
154 struct spi_master *master = dev;
155 struct altera_spi *hw = spi_master_get_devdata(master);
156
157 altera_spi_rx_word(hw);
158
159 if (hw->count < hw->len) {
160 altera_spi_tx_word(hw);
161 } else {
162 /* disable receive interrupt */
163 hw->imr &= ~ALTERA_SPI_CONTROL_IRRDY_MSK;
164 writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);
165
166 spi_finalize_current_transfer(master);
167 }
168
169 return IRQ_HANDLED;
170}
171
172static int altera_spi_probe(struct platform_device *pdev)
173{
174 struct altera_spi *hw;
175 struct spi_master *master;
176 struct resource *res;
177 int err = -ENODEV;
178
179 master = spi_alloc_master(&pdev->dev, sizeof(struct altera_spi));
180 if (!master)
181 return err;
182
183 /* setup the master state. */
184 master->bus_num = pdev->id;
185 master->num_chipselect = 16;
186 master->mode_bits = SPI_CS_HIGH;
187 master->bits_per_word_mask = SPI_BPW_RANGE_MASK(1, 16);
188 master->dev.of_node = pdev->dev.of_node;
189 master->transfer_one = altera_spi_txrx;
190 master->set_cs = altera_spi_set_cs;
191
192 hw = spi_master_get_devdata(master);
193
194 /* find and map our resources */
195 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
196 hw->base = devm_ioremap_resource(&pdev->dev, res);
197 if (IS_ERR(hw->base)) {
198 err = PTR_ERR(hw->base);
199 goto exit;
200 }
201 /* program defaults into the registers */
202 hw->imr = 0; /* disable spi interrupts */
203 writel(hw->imr, hw->base + ALTERA_SPI_CONTROL);
204 writel(0, hw->base + ALTERA_SPI_STATUS); /* clear status reg */
205 if (readl(hw->base + ALTERA_SPI_STATUS) & ALTERA_SPI_STATUS_RRDY_MSK)
206 readl(hw->base + ALTERA_SPI_RXDATA); /* flush rxdata */
207 /* irq is optional */
208 hw->irq = platform_get_irq(pdev, 0);
209 if (hw->irq >= 0) {
210 err = devm_request_irq(&pdev->dev, hw->irq, altera_spi_irq, 0,
211 pdev->name, master);
212 if (err)
213 goto exit;
214 }
215
216 err = devm_spi_register_master(&pdev->dev, master);
217 if (err)
218 goto exit;
219 dev_info(&pdev->dev, "base %p, irq %d\n", hw->base, hw->irq);
220
221 return 0;
222exit:
223 spi_master_put(master);
224 return err;
225}
226
227#ifdef CONFIG_OF
228static const struct of_device_id altera_spi_match[] = {
229 { .compatible = "ALTR,spi-1.0", },
230 { .compatible = "altr,spi-1.0", },
231 {},
232};
233MODULE_DEVICE_TABLE(of, altera_spi_match);
234#endif /* CONFIG_OF */
235
236static struct platform_driver altera_spi_driver = {
237 .probe = altera_spi_probe,
238 .driver = {
239 .name = DRV_NAME,
240 .pm = NULL,
241 .of_match_table = of_match_ptr(altera_spi_match),
242 },
243};
244module_platform_driver(altera_spi_driver);
245
246MODULE_DESCRIPTION("Altera SPI driver");
247MODULE_AUTHOR("Thomas Chou <thomas@wytron.com.tw>");
248MODULE_LICENSE("GPL");
249MODULE_ALIAS("platform:" DRV_NAME);
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Altera SPI driver
4 *
5 * Copyright (C) 2008 Thomas Chou <thomas@wytron.com.tw>
6 *
7 * Based on spi_s3c24xx.c, which is:
8 * Copyright (c) 2006 Ben Dooks
9 * Copyright (c) 2006 Simtec Electronics
10 * Ben Dooks <ben@simtec.co.uk>
11 */
12
13#include <linux/interrupt.h>
14#include <linux/errno.h>
15#include <linux/module.h>
16#include <linux/platform_device.h>
17#include <linux/spi/altera.h>
18#include <linux/spi/spi.h>
19#include <linux/io.h>
20#include <linux/of.h>
21
22#define DRV_NAME "spi_altera"
23
24#define ALTERA_SPI_RXDATA 0
25#define ALTERA_SPI_TXDATA 4
26#define ALTERA_SPI_STATUS 8
27#define ALTERA_SPI_CONTROL 12
28#define ALTERA_SPI_SLAVE_SEL 20
29
30#define ALTERA_SPI_STATUS_ROE_MSK 0x8
31#define ALTERA_SPI_STATUS_TOE_MSK 0x10
32#define ALTERA_SPI_STATUS_TMT_MSK 0x20
33#define ALTERA_SPI_STATUS_TRDY_MSK 0x40
34#define ALTERA_SPI_STATUS_RRDY_MSK 0x80
35#define ALTERA_SPI_STATUS_E_MSK 0x100
36
37#define ALTERA_SPI_CONTROL_IROE_MSK 0x8
38#define ALTERA_SPI_CONTROL_ITOE_MSK 0x10
39#define ALTERA_SPI_CONTROL_ITRDY_MSK 0x40
40#define ALTERA_SPI_CONTROL_IRRDY_MSK 0x80
41#define ALTERA_SPI_CONTROL_IE_MSK 0x100
42#define ALTERA_SPI_CONTROL_SSO_MSK 0x400
43
44#define ALTERA_SPI_MAX_CS 32
45
46enum altera_spi_type {
47 ALTERA_SPI_TYPE_UNKNOWN,
48 ALTERA_SPI_TYPE_SUBDEV,
49};
50
51struct altera_spi {
52 int irq;
53 int len;
54 int count;
55 int bytes_per_word;
56 u32 imr;
57
58 /* data buffers */
59 const unsigned char *tx;
60 unsigned char *rx;
61
62 struct regmap *regmap;
63 u32 regoff;
64 struct device *dev;
65};
66
67static const struct regmap_config spi_altera_config = {
68 .reg_bits = 32,
69 .reg_stride = 4,
70 .val_bits = 32,
71 .fast_io = true,
72};
73
74static int altr_spi_writel(struct altera_spi *hw, unsigned int reg,
75 unsigned int val)
76{
77 int ret;
78
79 ret = regmap_write(hw->regmap, hw->regoff + reg, val);
80 if (ret)
81 dev_err(hw->dev, "fail to write reg 0x%x val 0x%x: %d\n",
82 reg, val, ret);
83
84 return ret;
85}
86
87static int altr_spi_readl(struct altera_spi *hw, unsigned int reg,
88 unsigned int *val)
89{
90 int ret;
91
92 ret = regmap_read(hw->regmap, hw->regoff + reg, val);
93 if (ret)
94 dev_err(hw->dev, "fail to read reg 0x%x: %d\n", reg, ret);
95
96 return ret;
97}
98
99static inline struct altera_spi *altera_spi_to_hw(struct spi_device *sdev)
100{
101 return spi_master_get_devdata(sdev->master);
102}
103
104static void altera_spi_set_cs(struct spi_device *spi, bool is_high)
105{
106 struct altera_spi *hw = altera_spi_to_hw(spi);
107
108 if (is_high) {
109 hw->imr &= ~ALTERA_SPI_CONTROL_SSO_MSK;
110 altr_spi_writel(hw, ALTERA_SPI_CONTROL, hw->imr);
111 altr_spi_writel(hw, ALTERA_SPI_SLAVE_SEL, 0);
112 } else {
113 altr_spi_writel(hw, ALTERA_SPI_SLAVE_SEL,
114 BIT(spi->chip_select));
115 hw->imr |= ALTERA_SPI_CONTROL_SSO_MSK;
116 altr_spi_writel(hw, ALTERA_SPI_CONTROL, hw->imr);
117 }
118}
119
120static void altera_spi_tx_word(struct altera_spi *hw)
121{
122 unsigned int txd = 0;
123
124 if (hw->tx) {
125 switch (hw->bytes_per_word) {
126 case 1:
127 txd = hw->tx[hw->count];
128 break;
129 case 2:
130 txd = (hw->tx[hw->count * 2]
131 | (hw->tx[hw->count * 2 + 1] << 8));
132 break;
133 case 4:
134 txd = (hw->tx[hw->count * 4]
135 | (hw->tx[hw->count * 4 + 1] << 8)
136 | (hw->tx[hw->count * 4 + 2] << 16)
137 | (hw->tx[hw->count * 4 + 3] << 24));
138 break;
139
140 }
141 }
142
143 altr_spi_writel(hw, ALTERA_SPI_TXDATA, txd);
144}
145
146static void altera_spi_rx_word(struct altera_spi *hw)
147{
148 unsigned int rxd;
149
150 altr_spi_readl(hw, ALTERA_SPI_RXDATA, &rxd);
151 if (hw->rx) {
152 switch (hw->bytes_per_word) {
153 case 1:
154 hw->rx[hw->count] = rxd;
155 break;
156 case 2:
157 hw->rx[hw->count * 2] = rxd;
158 hw->rx[hw->count * 2 + 1] = rxd >> 8;
159 break;
160 case 4:
161 hw->rx[hw->count * 4] = rxd;
162 hw->rx[hw->count * 4 + 1] = rxd >> 8;
163 hw->rx[hw->count * 4 + 2] = rxd >> 16;
164 hw->rx[hw->count * 4 + 3] = rxd >> 24;
165 break;
166
167 }
168 }
169
170 hw->count++;
171}
172
173static int altera_spi_txrx(struct spi_master *master,
174 struct spi_device *spi, struct spi_transfer *t)
175{
176 struct altera_spi *hw = spi_master_get_devdata(master);
177 u32 val;
178
179 hw->tx = t->tx_buf;
180 hw->rx = t->rx_buf;
181 hw->count = 0;
182 hw->bytes_per_word = DIV_ROUND_UP(t->bits_per_word, 8);
183 hw->len = t->len / hw->bytes_per_word;
184
185 if (hw->irq >= 0) {
186 /* enable receive interrupt */
187 hw->imr |= ALTERA_SPI_CONTROL_IRRDY_MSK;
188 altr_spi_writel(hw, ALTERA_SPI_CONTROL, hw->imr);
189
190 /* send the first byte */
191 altera_spi_tx_word(hw);
192 } else {
193 while (hw->count < hw->len) {
194 altera_spi_tx_word(hw);
195
196 for (;;) {
197 altr_spi_readl(hw, ALTERA_SPI_STATUS, &val);
198 if (val & ALTERA_SPI_STATUS_RRDY_MSK)
199 break;
200
201 cpu_relax();
202 }
203
204 altera_spi_rx_word(hw);
205 }
206 spi_finalize_current_transfer(master);
207 }
208
209 return t->len;
210}
211
212static irqreturn_t altera_spi_irq(int irq, void *dev)
213{
214 struct spi_master *master = dev;
215 struct altera_spi *hw = spi_master_get_devdata(master);
216
217 altera_spi_rx_word(hw);
218
219 if (hw->count < hw->len) {
220 altera_spi_tx_word(hw);
221 } else {
222 /* disable receive interrupt */
223 hw->imr &= ~ALTERA_SPI_CONTROL_IRRDY_MSK;
224 altr_spi_writel(hw, ALTERA_SPI_CONTROL, hw->imr);
225
226 spi_finalize_current_transfer(master);
227 }
228
229 return IRQ_HANDLED;
230}
231
232static int altera_spi_probe(struct platform_device *pdev)
233{
234 const struct platform_device_id *platid = platform_get_device_id(pdev);
235 struct altera_spi_platform_data *pdata = dev_get_platdata(&pdev->dev);
236 enum altera_spi_type type = ALTERA_SPI_TYPE_UNKNOWN;
237 struct altera_spi *hw;
238 struct spi_master *master;
239 int err = -ENODEV;
240 u32 val;
241 u16 i;
242
243 master = spi_alloc_master(&pdev->dev, sizeof(struct altera_spi));
244 if (!master)
245 return err;
246
247 /* setup the master state. */
248 master->bus_num = pdev->id;
249
250 if (pdata) {
251 if (pdata->num_chipselect > ALTERA_SPI_MAX_CS) {
252 dev_err(&pdev->dev,
253 "Invalid number of chipselect: %hu\n",
254 pdata->num_chipselect);
255 return -EINVAL;
256 }
257
258 master->num_chipselect = pdata->num_chipselect;
259 master->mode_bits = pdata->mode_bits;
260 master->bits_per_word_mask = pdata->bits_per_word_mask;
261 } else {
262 master->num_chipselect = 16;
263 master->mode_bits = SPI_CS_HIGH;
264 master->bits_per_word_mask = SPI_BPW_RANGE_MASK(1, 16);
265 }
266
267 master->dev.of_node = pdev->dev.of_node;
268 master->transfer_one = altera_spi_txrx;
269 master->set_cs = altera_spi_set_cs;
270
271 hw = spi_master_get_devdata(master);
272 hw->dev = &pdev->dev;
273
274 if (platid)
275 type = platid->driver_data;
276
277 /* find and map our resources */
278 if (type == ALTERA_SPI_TYPE_SUBDEV) {
279 struct resource *regoff;
280
281 hw->regmap = dev_get_regmap(pdev->dev.parent, NULL);
282 if (!hw->regmap) {
283 dev_err(&pdev->dev, "get regmap failed\n");
284 goto exit;
285 }
286
287 regoff = platform_get_resource(pdev, IORESOURCE_REG, 0);
288 if (regoff)
289 hw->regoff = regoff->start;
290 } else {
291 void __iomem *res;
292
293 res = devm_platform_ioremap_resource(pdev, 0);
294 if (IS_ERR(res)) {
295 err = PTR_ERR(res);
296 goto exit;
297 }
298
299 hw->regmap = devm_regmap_init_mmio(&pdev->dev, res,
300 &spi_altera_config);
301 if (IS_ERR(hw->regmap)) {
302 dev_err(&pdev->dev, "regmap mmio init failed\n");
303 err = PTR_ERR(hw->regmap);
304 goto exit;
305 }
306 }
307
308 /* program defaults into the registers */
309 hw->imr = 0; /* disable spi interrupts */
310 altr_spi_writel(hw, ALTERA_SPI_CONTROL, hw->imr);
311 altr_spi_writel(hw, ALTERA_SPI_STATUS, 0); /* clear status reg */
312 altr_spi_readl(hw, ALTERA_SPI_STATUS, &val);
313 if (val & ALTERA_SPI_STATUS_RRDY_MSK)
314 altr_spi_readl(hw, ALTERA_SPI_RXDATA, &val); /* flush rxdata */
315 /* irq is optional */
316 hw->irq = platform_get_irq(pdev, 0);
317 if (hw->irq >= 0) {
318 err = devm_request_irq(&pdev->dev, hw->irq, altera_spi_irq, 0,
319 pdev->name, master);
320 if (err)
321 goto exit;
322 }
323
324 err = devm_spi_register_master(&pdev->dev, master);
325 if (err)
326 goto exit;
327
328 if (pdata) {
329 for (i = 0; i < pdata->num_devices; i++) {
330 if (!spi_new_device(master, pdata->devices + i))
331 dev_warn(&pdev->dev,
332 "unable to create SPI device: %s\n",
333 pdata->devices[i].modalias);
334 }
335 }
336
337 dev_info(&pdev->dev, "regoff %u, irq %d\n", hw->regoff, hw->irq);
338
339 return 0;
340exit:
341 spi_master_put(master);
342 return err;
343}
344
345#ifdef CONFIG_OF
346static const struct of_device_id altera_spi_match[] = {
347 { .compatible = "ALTR,spi-1.0", },
348 { .compatible = "altr,spi-1.0", },
349 {},
350};
351MODULE_DEVICE_TABLE(of, altera_spi_match);
352#endif /* CONFIG_OF */
353
354static const struct platform_device_id altera_spi_ids[] = {
355 { DRV_NAME, ALTERA_SPI_TYPE_UNKNOWN },
356 { "subdev_spi_altera", ALTERA_SPI_TYPE_SUBDEV },
357 { }
358};
359MODULE_DEVICE_TABLE(platform, altera_spi_ids);
360
361static struct platform_driver altera_spi_driver = {
362 .probe = altera_spi_probe,
363 .driver = {
364 .name = DRV_NAME,
365 .pm = NULL,
366 .of_match_table = of_match_ptr(altera_spi_match),
367 },
368 .id_table = altera_spi_ids,
369};
370module_platform_driver(altera_spi_driver);
371
372MODULE_DESCRIPTION("Altera SPI driver");
373MODULE_AUTHOR("Thomas Chou <thomas@wytron.com.tw>");
374MODULE_LICENSE("GPL");
375MODULE_ALIAS("platform:" DRV_NAME);