1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* Copyright (C) 2022 Hewlett-Packard Development Company, L.P. */
3
4 #include <linux/iopoll.h>
5 #include <linux/of.h>
6 #include <linux/of_device.h>
7 #include <linux/platform_device.h>
8 #include <linux/spi/spi.h>
9 #include <linux/spi/spi-mem.h>
10
11 #define GXP_SPI0_MAX_CHIPSELECT 2
12 #define GXP_SPI_SLEEP_TIME 1
13 #define GXP_SPI_TIMEOUT (130 * 1000000 / GXP_SPI_SLEEP_TIME)
14
15 #define MANUAL_MODE 0
16 #define DIRECT_MODE 1
17 #define SPILDAT_LEN 256
18
19 #define OFFSET_SPIMCFG 0x0
20 #define OFFSET_SPIMCTRL 0x4
21 #define OFFSET_SPICMD 0x5
22 #define OFFSET_SPIDCNT 0x6
23 #define OFFSET_SPIADDR 0x8
24 #define OFFSET_SPIINTSTS 0xc
25
26 #define SPIMCTRL_START 0x01
27 #define SPIMCTRL_BUSY 0x02
28 #define SPIMCTRL_DIR 0x08
29
30 struct gxp_spi;
31
32 struct gxp_spi_chip {
33 struct gxp_spi *spifi;
34 u32 cs;
35 };
36
37 struct gxp_spi_data {
38 u32 max_cs;
39 u32 mode_bits;
40 };
41
42 struct gxp_spi {
43 const struct gxp_spi_data *data;
44 void __iomem *reg_base;
45 void __iomem *dat_base;
46 void __iomem *dir_base;
47 struct device *dev;
48 struct gxp_spi_chip chips[GXP_SPI0_MAX_CHIPSELECT];
49 };
50
gxp_spi_set_mode(struct gxp_spi * spifi,int mode)51 static void gxp_spi_set_mode(struct gxp_spi *spifi, int mode)
52 {
53 u8 value;
54 void __iomem *reg_base = spifi->reg_base;
55
56 value = readb(reg_base + OFFSET_SPIMCTRL);
57
58 if (mode == MANUAL_MODE) {
59 writeb(0x55, reg_base + OFFSET_SPICMD);
60 writeb(0xaa, reg_base + OFFSET_SPICMD);
61 value &= ~0x30;
62 } else {
63 value |= 0x30;
64 }
65 writeb(value, reg_base + OFFSET_SPIMCTRL);
66 }
67
gxp_spi_read_reg(struct gxp_spi_chip * chip,const struct spi_mem_op * op)68 static int gxp_spi_read_reg(struct gxp_spi_chip *chip, const struct spi_mem_op *op)
69 {
70 int ret;
71 struct gxp_spi *spifi = chip->spifi;
72 void __iomem *reg_base = spifi->reg_base;
73 u32 value;
74
75 value = readl(reg_base + OFFSET_SPIMCFG);
76 value &= ~(1 << 24);
77 value |= (chip->cs << 24);
78 value &= ~(0x07 << 16);
79 value &= ~(0x1f << 19);
80 writel(value, reg_base + OFFSET_SPIMCFG);
81
82 writel(0, reg_base + OFFSET_SPIADDR);
83
84 writeb(op->cmd.opcode, reg_base + OFFSET_SPICMD);
85
86 writew(op->data.nbytes, reg_base + OFFSET_SPIDCNT);
87
88 value = readb(reg_base + OFFSET_SPIMCTRL);
89 value &= ~SPIMCTRL_DIR;
90 value |= SPIMCTRL_START;
91
92 writeb(value, reg_base + OFFSET_SPIMCTRL);
93
94 ret = readb_poll_timeout(reg_base + OFFSET_SPIMCTRL, value,
95 !(value & SPIMCTRL_BUSY),
96 GXP_SPI_SLEEP_TIME, GXP_SPI_TIMEOUT);
97 if (ret) {
98 dev_warn(spifi->dev, "read reg busy time out\n");
99 return ret;
100 }
101
102 memcpy_fromio(op->data.buf.in, spifi->dat_base, op->data.nbytes);
103 return ret;
104 }
105
gxp_spi_write_reg(struct gxp_spi_chip * chip,const struct spi_mem_op * op)106 static int gxp_spi_write_reg(struct gxp_spi_chip *chip, const struct spi_mem_op *op)
107 {
108 int ret;
109 struct gxp_spi *spifi = chip->spifi;
110 void __iomem *reg_base = spifi->reg_base;
111 u32 value;
112
113 value = readl(reg_base + OFFSET_SPIMCFG);
114 value &= ~(1 << 24);
115 value |= (chip->cs << 24);
116 value &= ~(0x07 << 16);
117 value &= ~(0x1f << 19);
118 writel(value, reg_base + OFFSET_SPIMCFG);
119
120 writel(0, reg_base + OFFSET_SPIADDR);
121
122 writeb(op->cmd.opcode, reg_base + OFFSET_SPICMD);
123
124 memcpy_toio(spifi->dat_base, op->data.buf.in, op->data.nbytes);
125
126 writew(op->data.nbytes, reg_base + OFFSET_SPIDCNT);
127
128 value = readb(reg_base + OFFSET_SPIMCTRL);
129 value |= SPIMCTRL_DIR;
130 value |= SPIMCTRL_START;
131
132 writeb(value, reg_base + OFFSET_SPIMCTRL);
133
134 ret = readb_poll_timeout(reg_base + OFFSET_SPIMCTRL, value,
135 !(value & SPIMCTRL_BUSY),
136 GXP_SPI_SLEEP_TIME, GXP_SPI_TIMEOUT);
137 if (ret)
138 dev_warn(spifi->dev, "write reg busy time out\n");
139
140 return ret;
141 }
142
gxp_spi_read(struct gxp_spi_chip * chip,const struct spi_mem_op * op)143 static ssize_t gxp_spi_read(struct gxp_spi_chip *chip, const struct spi_mem_op *op)
144 {
145 struct gxp_spi *spifi = chip->spifi;
146 u32 offset = op->addr.val;
147
148 if (chip->cs == 0)
149 offset += 0x4000000;
150
151 memcpy_fromio(op->data.buf.in, spifi->dir_base + offset, op->data.nbytes);
152
153 return 0;
154 }
155
gxp_spi_write(struct gxp_spi_chip * chip,const struct spi_mem_op * op)156 static ssize_t gxp_spi_write(struct gxp_spi_chip *chip, const struct spi_mem_op *op)
157 {
158 struct gxp_spi *spifi = chip->spifi;
159 void __iomem *reg_base = spifi->reg_base;
160 u32 write_len;
161 u32 value;
162 int ret;
163
164 write_len = op->data.nbytes;
165 if (write_len > SPILDAT_LEN)
166 write_len = SPILDAT_LEN;
167
168 value = readl(reg_base + OFFSET_SPIMCFG);
169 value &= ~(1 << 24);
170 value |= (chip->cs << 24);
171 value &= ~(0x07 << 16);
172 value |= (op->addr.nbytes << 16);
173 value &= ~(0x1f << 19);
174 writel(value, reg_base + OFFSET_SPIMCFG);
175
176 writel(op->addr.val, reg_base + OFFSET_SPIADDR);
177
178 writeb(op->cmd.opcode, reg_base + OFFSET_SPICMD);
179
180 writew(write_len, reg_base + OFFSET_SPIDCNT);
181
182 memcpy_toio(spifi->dat_base, op->data.buf.in, write_len);
183
184 value = readb(reg_base + OFFSET_SPIMCTRL);
185 value |= SPIMCTRL_DIR;
186 value |= SPIMCTRL_START;
187
188 writeb(value, reg_base + OFFSET_SPIMCTRL);
189
190 ret = readb_poll_timeout(reg_base + OFFSET_SPIMCTRL, value,
191 !(value & SPIMCTRL_BUSY),
192 GXP_SPI_SLEEP_TIME, GXP_SPI_TIMEOUT);
193 if (ret) {
194 dev_warn(spifi->dev, "write busy time out\n");
195 return ret;
196 }
197
198 return 0;
199 }
200
do_gxp_exec_mem_op(struct spi_mem * mem,const struct spi_mem_op * op)201 static int do_gxp_exec_mem_op(struct spi_mem *mem, const struct spi_mem_op *op)
202 {
203 struct gxp_spi *spifi = spi_controller_get_devdata(mem->spi->master);
204 struct gxp_spi_chip *chip = &spifi->chips[mem->spi->chip_select];
205 int ret;
206
207 if (op->data.dir == SPI_MEM_DATA_IN) {
208 if (!op->addr.nbytes)
209 ret = gxp_spi_read_reg(chip, op);
210 else
211 ret = gxp_spi_read(chip, op);
212 } else {
213 if (!op->addr.nbytes)
214 ret = gxp_spi_write_reg(chip, op);
215 else
216 ret = gxp_spi_write(chip, op);
217 }
218
219 return ret;
220 }
221
gxp_exec_mem_op(struct spi_mem * mem,const struct spi_mem_op * op)222 static int gxp_exec_mem_op(struct spi_mem *mem, const struct spi_mem_op *op)
223 {
224 int ret;
225
226 ret = do_gxp_exec_mem_op(mem, op);
227 if (ret)
228 dev_err(&mem->spi->dev, "operation failed: %d", ret);
229
230 return ret;
231 }
232
233 static const struct spi_controller_mem_ops gxp_spi_mem_ops = {
234 .exec_op = gxp_exec_mem_op,
235 };
236
gxp_spi_setup(struct spi_device * spi)237 static int gxp_spi_setup(struct spi_device *spi)
238 {
239 struct gxp_spi *spifi = spi_controller_get_devdata(spi->master);
240 unsigned int cs = spi->chip_select;
241 struct gxp_spi_chip *chip = &spifi->chips[cs];
242
243 chip->spifi = spifi;
244 chip->cs = cs;
245
246 gxp_spi_set_mode(spifi, MANUAL_MODE);
247
248 return 0;
249 }
250
gxp_spifi_probe(struct platform_device * pdev)251 static int gxp_spifi_probe(struct platform_device *pdev)
252 {
253 struct device *dev = &pdev->dev;
254 const struct gxp_spi_data *data;
255 struct spi_controller *ctlr;
256 struct gxp_spi *spifi;
257 int ret;
258
259 data = of_device_get_match_data(&pdev->dev);
260
261 ctlr = devm_spi_alloc_master(dev, sizeof(*spifi));
262 if (!ctlr)
263 return -ENOMEM;
264
265 spifi = spi_controller_get_devdata(ctlr);
266
267 platform_set_drvdata(pdev, spifi);
268 spifi->data = data;
269 spifi->dev = dev;
270
271 spifi->reg_base = devm_platform_ioremap_resource(pdev, 0);
272 if (IS_ERR(spifi->reg_base))
273 return PTR_ERR(spifi->reg_base);
274
275 spifi->dat_base = devm_platform_ioremap_resource(pdev, 1);
276 if (IS_ERR(spifi->dat_base))
277 return PTR_ERR(spifi->dat_base);
278
279 spifi->dir_base = devm_platform_ioremap_resource(pdev, 2);
280 if (IS_ERR(spifi->dir_base))
281 return PTR_ERR(spifi->dir_base);
282
283 ctlr->mode_bits = data->mode_bits;
284 ctlr->bus_num = pdev->id;
285 ctlr->mem_ops = &gxp_spi_mem_ops;
286 ctlr->setup = gxp_spi_setup;
287 ctlr->num_chipselect = data->max_cs;
288 ctlr->dev.of_node = dev->of_node;
289
290 ret = devm_spi_register_controller(dev, ctlr);
291 if (ret) {
292 return dev_err_probe(&pdev->dev, ret,
293 "failed to register spi controller\n");
294 }
295
296 return 0;
297 }
298
299 static const struct gxp_spi_data gxp_spifi_data = {
300 .max_cs = 2,
301 .mode_bits = 0,
302 };
303
304 static const struct of_device_id gxp_spifi_match[] = {
305 {.compatible = "hpe,gxp-spifi", .data = &gxp_spifi_data },
306 { /* null */ }
307 };
308 MODULE_DEVICE_TABLE(of, gxp_spifi_match);
309
310 static struct platform_driver gxp_spifi_driver = {
311 .probe = gxp_spifi_probe,
312 .driver = {
313 .name = "gxp-spifi",
314 .of_match_table = gxp_spifi_match,
315 },
316 };
317 module_platform_driver(gxp_spifi_driver);
318
319 MODULE_DESCRIPTION("HPE GXP SPI Flash Interface driver");
320 MODULE_AUTHOR("Nick Hawkins <nick.hawkins@hpe.com>");
321 MODULE_LICENSE("GPL");
322