1 /*
2 * Static Memory Controller for AT32 chips
3 *
4 * Copyright (C) 2006 Atmel Corporation
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 as
8 * published by the Free Software Foundation.
9 */
10 #include <linux/clk.h>
11 #include <linux/err.h>
12 #include <linux/init.h>
13 #include <linux/module.h>
14 #include <linux/platform_device.h>
15 #include <linux/slab.h>
16
17 #include <asm/io.h>
18 #include <mach/smc.h>
19
20 #include "hsmc.h"
21
22 #define NR_CHIP_SELECTS 6
23
24 struct hsmc {
25 void __iomem *regs;
26 struct clk *pclk;
27 struct clk *mck;
28 };
29
30 static struct hsmc *hsmc;
31
smc_set_timing(struct smc_config * config,const struct smc_timing * timing)32 void smc_set_timing(struct smc_config *config,
33 const struct smc_timing *timing)
34 {
35 int recover;
36 int cycle;
37
38 unsigned long mul;
39
40 /* Reset all SMC timings */
41 config->ncs_read_setup = 0;
42 config->nrd_setup = 0;
43 config->ncs_write_setup = 0;
44 config->nwe_setup = 0;
45 config->ncs_read_pulse = 0;
46 config->nrd_pulse = 0;
47 config->ncs_write_pulse = 0;
48 config->nwe_pulse = 0;
49 config->read_cycle = 0;
50 config->write_cycle = 0;
51
52 /*
53 * cycles = x / T = x * f
54 * = ((x * 1000000000) * ((f * 65536) / 1000000000)) / 65536
55 * = ((x * 1000000000) * (((f / 10000) * 65536) / 100000)) / 65536
56 */
57 mul = (clk_get_rate(hsmc->mck) / 10000) << 16;
58 mul /= 100000;
59
60 #define ns2cyc(x) ((((x) * mul) + 65535) >> 16)
61
62 if (timing->ncs_read_setup > 0)
63 config->ncs_read_setup = ns2cyc(timing->ncs_read_setup);
64
65 if (timing->nrd_setup > 0)
66 config->nrd_setup = ns2cyc(timing->nrd_setup);
67
68 if (timing->ncs_write_setup > 0)
69 config->ncs_write_setup = ns2cyc(timing->ncs_write_setup);
70
71 if (timing->nwe_setup > 0)
72 config->nwe_setup = ns2cyc(timing->nwe_setup);
73
74 if (timing->ncs_read_pulse > 0)
75 config->ncs_read_pulse = ns2cyc(timing->ncs_read_pulse);
76
77 if (timing->nrd_pulse > 0)
78 config->nrd_pulse = ns2cyc(timing->nrd_pulse);
79
80 if (timing->ncs_write_pulse > 0)
81 config->ncs_write_pulse = ns2cyc(timing->ncs_write_pulse);
82
83 if (timing->nwe_pulse > 0)
84 config->nwe_pulse = ns2cyc(timing->nwe_pulse);
85
86 if (timing->read_cycle > 0)
87 config->read_cycle = ns2cyc(timing->read_cycle);
88
89 if (timing->write_cycle > 0)
90 config->write_cycle = ns2cyc(timing->write_cycle);
91
92 /* Extend read cycle in needed */
93 if (timing->ncs_read_recover > 0)
94 recover = ns2cyc(timing->ncs_read_recover);
95 else
96 recover = 1;
97
98 cycle = config->ncs_read_setup + config->ncs_read_pulse + recover;
99
100 if (config->read_cycle < cycle)
101 config->read_cycle = cycle;
102
103 /* Extend read cycle in needed */
104 if (timing->nrd_recover > 0)
105 recover = ns2cyc(timing->nrd_recover);
106 else
107 recover = 1;
108
109 cycle = config->nrd_setup + config->nrd_pulse + recover;
110
111 if (config->read_cycle < cycle)
112 config->read_cycle = cycle;
113
114 /* Extend write cycle in needed */
115 if (timing->ncs_write_recover > 0)
116 recover = ns2cyc(timing->ncs_write_recover);
117 else
118 recover = 1;
119
120 cycle = config->ncs_write_setup + config->ncs_write_pulse + recover;
121
122 if (config->write_cycle < cycle)
123 config->write_cycle = cycle;
124
125 /* Extend write cycle in needed */
126 if (timing->nwe_recover > 0)
127 recover = ns2cyc(timing->nwe_recover);
128 else
129 recover = 1;
130
131 cycle = config->nwe_setup + config->nwe_pulse + recover;
132
133 if (config->write_cycle < cycle)
134 config->write_cycle = cycle;
135 }
136 EXPORT_SYMBOL(smc_set_timing);
137
smc_set_configuration(int cs,const struct smc_config * config)138 int smc_set_configuration(int cs, const struct smc_config *config)
139 {
140 unsigned long offset;
141 u32 setup, pulse, cycle, mode;
142
143 if (!hsmc)
144 return -ENODEV;
145 if (cs >= NR_CHIP_SELECTS)
146 return -EINVAL;
147
148 setup = (HSMC_BF(NWE_SETUP, config->nwe_setup)
149 | HSMC_BF(NCS_WR_SETUP, config->ncs_write_setup)
150 | HSMC_BF(NRD_SETUP, config->nrd_setup)
151 | HSMC_BF(NCS_RD_SETUP, config->ncs_read_setup));
152 pulse = (HSMC_BF(NWE_PULSE, config->nwe_pulse)
153 | HSMC_BF(NCS_WR_PULSE, config->ncs_write_pulse)
154 | HSMC_BF(NRD_PULSE, config->nrd_pulse)
155 | HSMC_BF(NCS_RD_PULSE, config->ncs_read_pulse));
156 cycle = (HSMC_BF(NWE_CYCLE, config->write_cycle)
157 | HSMC_BF(NRD_CYCLE, config->read_cycle));
158
159 switch (config->bus_width) {
160 case 1:
161 mode = HSMC_BF(DBW, HSMC_DBW_8_BITS);
162 break;
163 case 2:
164 mode = HSMC_BF(DBW, HSMC_DBW_16_BITS);
165 break;
166 case 4:
167 mode = HSMC_BF(DBW, HSMC_DBW_32_BITS);
168 break;
169 default:
170 return -EINVAL;
171 }
172
173 switch (config->nwait_mode) {
174 case 0:
175 mode |= HSMC_BF(EXNW_MODE, HSMC_EXNW_MODE_DISABLED);
176 break;
177 case 1:
178 mode |= HSMC_BF(EXNW_MODE, HSMC_EXNW_MODE_RESERVED);
179 break;
180 case 2:
181 mode |= HSMC_BF(EXNW_MODE, HSMC_EXNW_MODE_FROZEN);
182 break;
183 case 3:
184 mode |= HSMC_BF(EXNW_MODE, HSMC_EXNW_MODE_READY);
185 break;
186 default:
187 return -EINVAL;
188 }
189
190 if (config->tdf_cycles) {
191 mode |= HSMC_BF(TDF_CYCLES, config->tdf_cycles);
192 }
193
194 if (config->nrd_controlled)
195 mode |= HSMC_BIT(READ_MODE);
196 if (config->nwe_controlled)
197 mode |= HSMC_BIT(WRITE_MODE);
198 if (config->byte_write)
199 mode |= HSMC_BIT(BAT);
200 if (config->tdf_mode)
201 mode |= HSMC_BIT(TDF_MODE);
202
203 pr_debug("smc cs%d: setup/%08x pulse/%08x cycle/%08x mode/%08x\n",
204 cs, setup, pulse, cycle, mode);
205
206 offset = cs * 0x10;
207 hsmc_writel(hsmc, SETUP0 + offset, setup);
208 hsmc_writel(hsmc, PULSE0 + offset, pulse);
209 hsmc_writel(hsmc, CYCLE0 + offset, cycle);
210 hsmc_writel(hsmc, MODE0 + offset, mode);
211 hsmc_readl(hsmc, MODE0); /* I/O barrier */
212
213 return 0;
214 }
215 EXPORT_SYMBOL(smc_set_configuration);
216
hsmc_probe(struct platform_device * pdev)217 static int hsmc_probe(struct platform_device *pdev)
218 {
219 struct resource *regs;
220 struct clk *pclk, *mck;
221 int ret;
222
223 if (hsmc)
224 return -EBUSY;
225
226 regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
227 if (!regs)
228 return -ENXIO;
229 pclk = clk_get(&pdev->dev, "pclk");
230 if (IS_ERR(pclk))
231 return PTR_ERR(pclk);
232 mck = clk_get(&pdev->dev, "mck");
233 if (IS_ERR(mck)) {
234 ret = PTR_ERR(mck);
235 goto out_put_pclk;
236 }
237
238 ret = -ENOMEM;
239 hsmc = kzalloc(sizeof(struct hsmc), GFP_KERNEL);
240 if (!hsmc)
241 goto out_put_clocks;
242
243 clk_enable(pclk);
244 clk_enable(mck);
245
246 hsmc->pclk = pclk;
247 hsmc->mck = mck;
248 hsmc->regs = ioremap(regs->start, resource_size(regs));
249 if (!hsmc->regs)
250 goto out_disable_clocks;
251
252 dev_info(&pdev->dev, "Atmel Static Memory Controller at 0x%08lx\n",
253 (unsigned long)regs->start);
254
255 platform_set_drvdata(pdev, hsmc);
256
257 return 0;
258
259 out_disable_clocks:
260 clk_disable(mck);
261 clk_disable(pclk);
262 kfree(hsmc);
263 out_put_clocks:
264 clk_put(mck);
265 out_put_pclk:
266 clk_put(pclk);
267 hsmc = NULL;
268 return ret;
269 }
270
271 static struct platform_driver hsmc_driver = {
272 .probe = hsmc_probe,
273 .driver = {
274 .name = "smc",
275 },
276 };
277
hsmc_init(void)278 static int __init hsmc_init(void)
279 {
280 return platform_driver_register(&hsmc_driver);
281 }
282 core_initcall(hsmc_init);
283