1
2
3
4
5
6
7
8
9
10
11
12
13#include <linux/clk.h>
14#include <linux/module.h>
15#include <linux/kernel.h>
16#include <linux/timer.h>
17#include <linux/delay.h>
18#include <linux/list.h>
19#include <linux/interrupt.h>
20#include <linux/platform_device.h>
21#include <linux/pm_runtime.h>
22#include <linux/io.h>
23#include <linux/spi/spi.h>
24#include <linux/spi/sh_hspi.h>
25
26#define SPCR 0x00
27#define SPSR 0x04
28#define SPSCR 0x08
29#define SPTBR 0x0C
30#define SPRBR 0x10
31#define SPCR2 0x14
32
33
34#define RXFL (1 << 2)
35
36struct hspi_priv {
37 void __iomem *addr;
38 struct spi_controller *ctlr;
39 struct device *dev;
40 struct clk *clk;
41};
42
43
44
45
46static void hspi_write(struct hspi_priv *hspi, int reg, u32 val)
47{
48 iowrite32(val, hspi->addr + reg);
49}
50
51static u32 hspi_read(struct hspi_priv *hspi, int reg)
52{
53 return ioread32(hspi->addr + reg);
54}
55
56static void hspi_bit_set(struct hspi_priv *hspi, int reg, u32 mask, u32 set)
57{
58 u32 val = hspi_read(hspi, reg);
59
60 val &= ~mask;
61 val |= set & mask;
62
63 hspi_write(hspi, reg, val);
64}
65
66
67
68
69static int hspi_status_check_timeout(struct hspi_priv *hspi, u32 mask, u32 val)
70{
71 int t = 256;
72
73 while (t--) {
74 if ((mask & hspi_read(hspi, SPSR)) == val)
75 return 0;
76
77 udelay(10);
78 }
79
80 dev_err(hspi->dev, "timeout\n");
81 return -ETIMEDOUT;
82}
83
84
85
86
87
88#define hspi_hw_cs_enable(hspi) hspi_hw_cs_ctrl(hspi, 0)
89#define hspi_hw_cs_disable(hspi) hspi_hw_cs_ctrl(hspi, 1)
90static void hspi_hw_cs_ctrl(struct hspi_priv *hspi, int hi)
91{
92 hspi_bit_set(hspi, SPSCR, (1 << 6), (hi) << 6);
93}
94
95static void hspi_hw_setup(struct hspi_priv *hspi,
96 struct spi_message *msg,
97 struct spi_transfer *t)
98{
99 struct spi_device *spi = msg->spi;
100 struct device *dev = hspi->dev;
101 u32 spcr, idiv_clk;
102 u32 rate, best_rate, min, tmp;
103
104
105
106
107 min = ~0;
108 best_rate = 0;
109 spcr = 0;
110 for (idiv_clk = 0x00; idiv_clk <= 0x3F; idiv_clk++) {
111 rate = clk_get_rate(hspi->clk);
112
113
114 if (idiv_clk & (1 << 5))
115 rate /= 128;
116 else
117 rate /= 16;
118
119
120 rate /= (((idiv_clk & 0x1F) + 1) * 2);
121
122
123 tmp = abs(t->speed_hz - rate);
124 if (tmp < min) {
125 min = tmp;
126 spcr = idiv_clk;
127 best_rate = rate;
128 }
129 }
130
131 if (spi->mode & SPI_CPHA)
132 spcr |= 1 << 7;
133 if (spi->mode & SPI_CPOL)
134 spcr |= 1 << 6;
135
136 dev_dbg(dev, "speed %d/%d\n", t->speed_hz, best_rate);
137
138 hspi_write(hspi, SPCR, spcr);
139 hspi_write(hspi, SPSR, 0x0);
140 hspi_write(hspi, SPSCR, 0x21);
141}
142
143static int hspi_transfer_one_message(struct spi_controller *ctlr,
144 struct spi_message *msg)
145{
146 struct hspi_priv *hspi = spi_controller_get_devdata(ctlr);
147 struct spi_transfer *t;
148 u32 tx;
149 u32 rx;
150 int ret, i;
151 unsigned int cs_change;
152 const int nsecs = 50;
153
154 dev_dbg(hspi->dev, "%s\n", __func__);
155
156 cs_change = 1;
157 ret = 0;
158 list_for_each_entry(t, &msg->transfers, transfer_list) {
159
160 if (cs_change) {
161 hspi_hw_setup(hspi, msg, t);
162 hspi_hw_cs_enable(hspi);
163 ndelay(nsecs);
164 }
165 cs_change = t->cs_change;
166
167 for (i = 0; i < t->len; i++) {
168
169
170 ret = hspi_status_check_timeout(hspi, 0x1, 0);
171 if (ret < 0)
172 break;
173
174 tx = 0;
175 if (t->tx_buf)
176 tx = (u32)((u8 *)t->tx_buf)[i];
177
178 hspi_write(hspi, SPTBR, tx);
179
180
181 ret = hspi_status_check_timeout(hspi, 0x4, 0x4);
182 if (ret < 0)
183 break;
184
185 rx = hspi_read(hspi, SPRBR);
186 if (t->rx_buf)
187 ((u8 *)t->rx_buf)[i] = (u8)rx;
188
189 }
190
191 msg->actual_length += t->len;
192
193 if (t->delay_usecs)
194 udelay(t->delay_usecs);
195
196 if (cs_change) {
197 ndelay(nsecs);
198 hspi_hw_cs_disable(hspi);
199 ndelay(nsecs);
200 }
201 }
202
203 msg->status = ret;
204 if (!cs_change) {
205 ndelay(nsecs);
206 hspi_hw_cs_disable(hspi);
207 }
208 spi_finalize_current_message(ctlr);
209
210 return ret;
211}
212
213static int hspi_probe(struct platform_device *pdev)
214{
215 struct resource *res;
216 struct spi_controller *ctlr;
217 struct hspi_priv *hspi;
218 struct clk *clk;
219 int ret;
220
221
222 res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
223 if (!res) {
224 dev_err(&pdev->dev, "invalid resource\n");
225 return -EINVAL;
226 }
227
228 ctlr = spi_alloc_master(&pdev->dev, sizeof(*hspi));
229 if (!ctlr)
230 return -ENOMEM;
231
232 clk = clk_get(&pdev->dev, NULL);
233 if (IS_ERR(clk)) {
234 dev_err(&pdev->dev, "couldn't get clock\n");
235 ret = -EINVAL;
236 goto error0;
237 }
238
239 hspi = spi_controller_get_devdata(ctlr);
240 platform_set_drvdata(pdev, hspi);
241
242
243 hspi->ctlr = ctlr;
244 hspi->dev = &pdev->dev;
245 hspi->clk = clk;
246 hspi->addr = devm_ioremap(hspi->dev,
247 res->start, resource_size(res));
248 if (!hspi->addr) {
249 ret = -ENOMEM;
250 goto error1;
251 }
252
253 pm_runtime_enable(&pdev->dev);
254
255 ctlr->bus_num = pdev->id;
256 ctlr->mode_bits = SPI_CPOL | SPI_CPHA;
257 ctlr->dev.of_node = pdev->dev.of_node;
258 ctlr->auto_runtime_pm = true;
259 ctlr->transfer_one_message = hspi_transfer_one_message;
260 ctlr->bits_per_word_mask = SPI_BPW_MASK(8);
261
262 ret = devm_spi_register_controller(&pdev->dev, ctlr);
263 if (ret < 0) {
264 dev_err(&pdev->dev, "devm_spi_register_controller error.\n");
265 goto error2;
266 }
267
268 return 0;
269
270 error2:
271 pm_runtime_disable(&pdev->dev);
272 error1:
273 clk_put(clk);
274 error0:
275 spi_controller_put(ctlr);
276
277 return ret;
278}
279
280static int hspi_remove(struct platform_device *pdev)
281{
282 struct hspi_priv *hspi = platform_get_drvdata(pdev);
283
284 pm_runtime_disable(&pdev->dev);
285
286 clk_put(hspi->clk);
287
288 return 0;
289}
290
291static const struct of_device_id hspi_of_match[] = {
292 { .compatible = "renesas,hspi", },
293 { }
294};
295MODULE_DEVICE_TABLE(of, hspi_of_match);
296
297static struct platform_driver hspi_driver = {
298 .probe = hspi_probe,
299 .remove = hspi_remove,
300 .driver = {
301 .name = "sh-hspi",
302 .of_match_table = hspi_of_match,
303 },
304};
305module_platform_driver(hspi_driver);
306
307MODULE_DESCRIPTION("SuperH HSPI bus driver");
308MODULE_LICENSE("GPL v2");
309MODULE_AUTHOR("Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>");
310MODULE_ALIAS("platform:sh-hspi");
311
