2 * Register map access API - MMIO support
4 * Copyright (c) 2012, NVIDIA CORPORATION. All rights reserved.
6 * This program is free software; you can redistribute it and/or modify it
7 * under the terms and conditions of the GNU General Public License,
8 * version 2, as published by the Free Software Foundation.
10 * This program is distributed in the hope it will be useful, but WITHOUT
11 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
12 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
15 * You should have received a copy of the GNU General Public License
16 * along with this program. If not, see <http://www.gnu.org/licenses/>.
19 #include <linux/clk.h>
20 #include <linux/err.h>
22 #include <linux/module.h>
23 #include <linux/regmap.h>
24 #include <linux/slab.h>
28 struct regmap_mmio_context {
35 void (*reg_write)(struct regmap_mmio_context *ctx,
36 unsigned int reg, unsigned int val);
37 unsigned int (*reg_read)(struct regmap_mmio_context *ctx,
41 static int regmap_mmio_regbits_check(size_t reg_bits)
56 static int regmap_mmio_get_min_stride(size_t val_bits)
62 /* The core treats 0 as 1 */
83 static void regmap_mmio_write8(struct regmap_mmio_context *ctx,
87 writeb(val, ctx->regs + reg);
90 static void regmap_mmio_write16le(struct regmap_mmio_context *ctx,
94 writew(val, ctx->regs + reg);
97 static void regmap_mmio_write16be(struct regmap_mmio_context *ctx,
101 iowrite16be(val, ctx->regs + reg);
104 static void regmap_mmio_write32le(struct regmap_mmio_context *ctx,
108 writel(val, ctx->regs + reg);
111 static void regmap_mmio_write32be(struct regmap_mmio_context *ctx,
115 iowrite32be(val, ctx->regs + reg);
119 static void regmap_mmio_write64le(struct regmap_mmio_context *ctx,
123 writeq(val, ctx->regs + reg);
127 static int regmap_mmio_write(void *context, unsigned int reg, unsigned int val)
129 struct regmap_mmio_context *ctx = context;
132 if (!IS_ERR(ctx->clk)) {
133 ret = clk_enable(ctx->clk);
138 ctx->reg_write(ctx, reg, val);
140 if (!IS_ERR(ctx->clk))
141 clk_disable(ctx->clk);
146 static unsigned int regmap_mmio_read8(struct regmap_mmio_context *ctx,
149 return readb(ctx->regs + reg);
152 static unsigned int regmap_mmio_read16le(struct regmap_mmio_context *ctx,
155 return readw(ctx->regs + reg);
158 static unsigned int regmap_mmio_read16be(struct regmap_mmio_context *ctx,
161 return ioread16be(ctx->regs + reg);
164 static unsigned int regmap_mmio_read32le(struct regmap_mmio_context *ctx,
167 return readl(ctx->regs + reg);
170 static unsigned int regmap_mmio_read32be(struct regmap_mmio_context *ctx,
173 return ioread32be(ctx->regs + reg);
177 static unsigned int regmap_mmio_read64le(struct regmap_mmio_context *ctx,
180 return readq(ctx->regs + reg);
184 static int regmap_mmio_read(void *context, unsigned int reg, unsigned int *val)
186 struct regmap_mmio_context *ctx = context;
189 if (!IS_ERR(ctx->clk)) {
190 ret = clk_enable(ctx->clk);
195 *val = ctx->reg_read(ctx, reg);
197 if (!IS_ERR(ctx->clk))
198 clk_disable(ctx->clk);
203 static void regmap_mmio_free_context(void *context)
205 struct regmap_mmio_context *ctx = context;
207 if (!IS_ERR(ctx->clk)) {
208 clk_unprepare(ctx->clk);
209 if (!ctx->attached_clk)
215 static const struct regmap_bus regmap_mmio = {
217 .reg_write = regmap_mmio_write,
218 .reg_read = regmap_mmio_read,
219 .free_context = regmap_mmio_free_context,
220 .val_format_endian_default = REGMAP_ENDIAN_LITTLE,
223 static struct regmap_mmio_context *regmap_mmio_gen_context(struct device *dev,
226 const struct regmap_config *config)
228 struct regmap_mmio_context *ctx;
232 ret = regmap_mmio_regbits_check(config->reg_bits);
236 if (config->pad_bits)
237 return ERR_PTR(-EINVAL);
239 min_stride = regmap_mmio_get_min_stride(config->val_bits);
241 return ERR_PTR(min_stride);
243 if (config->reg_stride < min_stride)
244 return ERR_PTR(-EINVAL);
246 ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
248 return ERR_PTR(-ENOMEM);
251 ctx->val_bytes = config->val_bits / 8;
252 ctx->clk = ERR_PTR(-ENODEV);
254 switch (regmap_get_val_endian(dev, ®map_mmio, config)) {
255 case REGMAP_ENDIAN_DEFAULT:
256 case REGMAP_ENDIAN_LITTLE:
257 #ifdef __LITTLE_ENDIAN
258 case REGMAP_ENDIAN_NATIVE:
260 switch (config->val_bits) {
262 ctx->reg_read = regmap_mmio_read8;
263 ctx->reg_write = regmap_mmio_write8;
266 ctx->reg_read = regmap_mmio_read16le;
267 ctx->reg_write = regmap_mmio_write16le;
270 ctx->reg_read = regmap_mmio_read32le;
271 ctx->reg_write = regmap_mmio_write32le;
275 ctx->reg_read = regmap_mmio_read64le;
276 ctx->reg_write = regmap_mmio_write64le;
284 case REGMAP_ENDIAN_BIG:
286 case REGMAP_ENDIAN_NATIVE:
288 switch (config->val_bits) {
290 ctx->reg_read = regmap_mmio_read8;
291 ctx->reg_write = regmap_mmio_write8;
294 ctx->reg_read = regmap_mmio_read16be;
295 ctx->reg_write = regmap_mmio_write16be;
298 ctx->reg_read = regmap_mmio_read32be;
299 ctx->reg_write = regmap_mmio_write32be;
314 ctx->clk = clk_get(dev, clk_id);
315 if (IS_ERR(ctx->clk)) {
316 ret = PTR_ERR(ctx->clk);
320 ret = clk_prepare(ctx->clk);
334 struct regmap *__regmap_init_mmio_clk(struct device *dev, const char *clk_id,
336 const struct regmap_config *config,
337 struct lock_class_key *lock_key,
338 const char *lock_name)
340 struct regmap_mmio_context *ctx;
342 ctx = regmap_mmio_gen_context(dev, clk_id, regs, config);
344 return ERR_CAST(ctx);
346 return __regmap_init(dev, ®map_mmio, ctx, config,
347 lock_key, lock_name);
349 EXPORT_SYMBOL_GPL(__regmap_init_mmio_clk);
351 struct regmap *__devm_regmap_init_mmio_clk(struct device *dev,
354 const struct regmap_config *config,
355 struct lock_class_key *lock_key,
356 const char *lock_name)
358 struct regmap_mmio_context *ctx;
360 ctx = regmap_mmio_gen_context(dev, clk_id, regs, config);
362 return ERR_CAST(ctx);
364 return __devm_regmap_init(dev, ®map_mmio, ctx, config,
365 lock_key, lock_name);
367 EXPORT_SYMBOL_GPL(__devm_regmap_init_mmio_clk);
369 int regmap_mmio_attach_clk(struct regmap *map, struct clk *clk)
371 struct regmap_mmio_context *ctx = map->bus_context;
374 ctx->attached_clk = true;
376 return clk_prepare(ctx->clk);
378 EXPORT_SYMBOL_GPL(regmap_mmio_attach_clk);
380 void regmap_mmio_detach_clk(struct regmap *map)
382 struct regmap_mmio_context *ctx = map->bus_context;
384 clk_unprepare(ctx->clk);
386 ctx->attached_clk = false;
389 EXPORT_SYMBOL_GPL(regmap_mmio_detach_clk);
391 MODULE_LICENSE("GPL v2");