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path: root/drivers/base/regmap/regmap-mmio.c
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Diffstat (limited to 'drivers/base/regmap/regmap-mmio.c')
-rw-r--r--drivers/base/regmap/regmap-mmio.c379
1 files changed, 379 insertions, 0 deletions
diff --git a/drivers/base/regmap/regmap-mmio.c b/drivers/base/regmap/regmap-mmio.c
new file mode 100644
index 000000000..af967d8f9
--- /dev/null
+++ b/drivers/base/regmap/regmap-mmio.c
@@ -0,0 +1,379 @@
+// SPDX-License-Identifier: GPL-2.0
+//
+// Register map access API - MMIO support
+//
+// Copyright (c) 2012, NVIDIA CORPORATION. All rights reserved.
+
+#include <linux/clk.h>
+#include <linux/err.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/slab.h>
+
+#include "internal.h"
+
+struct regmap_mmio_context {
+ void __iomem *regs;
+ unsigned val_bytes;
+
+ bool attached_clk;
+ struct clk *clk;
+
+ void (*reg_write)(struct regmap_mmio_context *ctx,
+ unsigned int reg, unsigned int val);
+ unsigned int (*reg_read)(struct regmap_mmio_context *ctx,
+ unsigned int reg);
+};
+
+static int regmap_mmio_regbits_check(size_t reg_bits)
+{
+ switch (reg_bits) {
+ case 8:
+ case 16:
+ case 32:
+#ifdef CONFIG_64BIT
+ case 64:
+#endif
+ return 0;
+ default:
+ return -EINVAL;
+ }
+}
+
+static int regmap_mmio_get_min_stride(size_t val_bits)
+{
+ int min_stride;
+
+ switch (val_bits) {
+ case 8:
+ /* The core treats 0 as 1 */
+ min_stride = 0;
+ return 0;
+ case 16:
+ min_stride = 2;
+ break;
+ case 32:
+ min_stride = 4;
+ break;
+#ifdef CONFIG_64BIT
+ case 64:
+ min_stride = 8;
+ break;
+#endif
+ default:
+ return -EINVAL;
+ }
+
+ return min_stride;
+}
+
+static void regmap_mmio_write8(struct regmap_mmio_context *ctx,
+ unsigned int reg,
+ unsigned int val)
+{
+ writeb(val, ctx->regs + reg);
+}
+
+static void regmap_mmio_write16le(struct regmap_mmio_context *ctx,
+ unsigned int reg,
+ unsigned int val)
+{
+ writew(val, ctx->regs + reg);
+}
+
+static void regmap_mmio_write16be(struct regmap_mmio_context *ctx,
+ unsigned int reg,
+ unsigned int val)
+{
+ iowrite16be(val, ctx->regs + reg);
+}
+
+static void regmap_mmio_write32le(struct regmap_mmio_context *ctx,
+ unsigned int reg,
+ unsigned int val)
+{
+ writel(val, ctx->regs + reg);
+}
+
+static void regmap_mmio_write32be(struct regmap_mmio_context *ctx,
+ unsigned int reg,
+ unsigned int val)
+{
+ iowrite32be(val, ctx->regs + reg);
+}
+
+#ifdef CONFIG_64BIT
+static void regmap_mmio_write64le(struct regmap_mmio_context *ctx,
+ unsigned int reg,
+ unsigned int val)
+{
+ writeq(val, ctx->regs + reg);
+}
+#endif
+
+static int regmap_mmio_write(void *context, unsigned int reg, unsigned int val)
+{
+ struct regmap_mmio_context *ctx = context;
+ int ret;
+
+ if (!IS_ERR(ctx->clk)) {
+ ret = clk_enable(ctx->clk);
+ if (ret < 0)
+ return ret;
+ }
+
+ ctx->reg_write(ctx, reg, val);
+
+ if (!IS_ERR(ctx->clk))
+ clk_disable(ctx->clk);
+
+ return 0;
+}
+
+static unsigned int regmap_mmio_read8(struct regmap_mmio_context *ctx,
+ unsigned int reg)
+{
+ return readb(ctx->regs + reg);
+}
+
+static unsigned int regmap_mmio_read16le(struct regmap_mmio_context *ctx,
+ unsigned int reg)
+{
+ return readw(ctx->regs + reg);
+}
+
+static unsigned int regmap_mmio_read16be(struct regmap_mmio_context *ctx,
+ unsigned int reg)
+{
+ return ioread16be(ctx->regs + reg);
+}
+
+static unsigned int regmap_mmio_read32le(struct regmap_mmio_context *ctx,
+ unsigned int reg)
+{
+ return readl(ctx->regs + reg);
+}
+
+static unsigned int regmap_mmio_read32be(struct regmap_mmio_context *ctx,
+ unsigned int reg)
+{
+ return ioread32be(ctx->regs + reg);
+}
+
+#ifdef CONFIG_64BIT
+static unsigned int regmap_mmio_read64le(struct regmap_mmio_context *ctx,
+ unsigned int reg)
+{
+ return readq(ctx->regs + reg);
+}
+#endif
+
+static int regmap_mmio_read(void *context, unsigned int reg, unsigned int *val)
+{
+ struct regmap_mmio_context *ctx = context;
+ int ret;
+
+ if (!IS_ERR(ctx->clk)) {
+ ret = clk_enable(ctx->clk);
+ if (ret < 0)
+ return ret;
+ }
+
+ *val = ctx->reg_read(ctx, reg);
+
+ if (!IS_ERR(ctx->clk))
+ clk_disable(ctx->clk);
+
+ return 0;
+}
+
+static void regmap_mmio_free_context(void *context)
+{
+ struct regmap_mmio_context *ctx = context;
+
+ if (!IS_ERR(ctx->clk)) {
+ clk_unprepare(ctx->clk);
+ if (!ctx->attached_clk)
+ clk_put(ctx->clk);
+ }
+ kfree(context);
+}
+
+static const struct regmap_bus regmap_mmio = {
+ .fast_io = true,
+ .reg_write = regmap_mmio_write,
+ .reg_read = regmap_mmio_read,
+ .free_context = regmap_mmio_free_context,
+ .val_format_endian_default = REGMAP_ENDIAN_LITTLE,
+};
+
+static struct regmap_mmio_context *regmap_mmio_gen_context(struct device *dev,
+ const char *clk_id,
+ void __iomem *regs,
+ const struct regmap_config *config)
+{
+ struct regmap_mmio_context *ctx;
+ int min_stride;
+ int ret;
+
+ ret = regmap_mmio_regbits_check(config->reg_bits);
+ if (ret)
+ return ERR_PTR(ret);
+
+ if (config->pad_bits)
+ return ERR_PTR(-EINVAL);
+
+ min_stride = regmap_mmio_get_min_stride(config->val_bits);
+ if (min_stride < 0)
+ return ERR_PTR(min_stride);
+
+ if (config->reg_stride < min_stride)
+ return ERR_PTR(-EINVAL);
+
+ ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
+ if (!ctx)
+ return ERR_PTR(-ENOMEM);
+
+ ctx->regs = regs;
+ ctx->val_bytes = config->val_bits / 8;
+ ctx->clk = ERR_PTR(-ENODEV);
+
+ switch (regmap_get_val_endian(dev, &regmap_mmio, config)) {
+ case REGMAP_ENDIAN_DEFAULT:
+ case REGMAP_ENDIAN_LITTLE:
+#ifdef __LITTLE_ENDIAN
+ case REGMAP_ENDIAN_NATIVE:
+#endif
+ switch (config->val_bits) {
+ case 8:
+ ctx->reg_read = regmap_mmio_read8;
+ ctx->reg_write = regmap_mmio_write8;
+ break;
+ case 16:
+ ctx->reg_read = regmap_mmio_read16le;
+ ctx->reg_write = regmap_mmio_write16le;
+ break;
+ case 32:
+ ctx->reg_read = regmap_mmio_read32le;
+ ctx->reg_write = regmap_mmio_write32le;
+ break;
+#ifdef CONFIG_64BIT
+ case 64:
+ ctx->reg_read = regmap_mmio_read64le;
+ ctx->reg_write = regmap_mmio_write64le;
+ break;
+#endif
+ default:
+ ret = -EINVAL;
+ goto err_free;
+ }
+ break;
+ case REGMAP_ENDIAN_BIG:
+#ifdef __BIG_ENDIAN
+ case REGMAP_ENDIAN_NATIVE:
+#endif
+ switch (config->val_bits) {
+ case 8:
+ ctx->reg_read = regmap_mmio_read8;
+ ctx->reg_write = regmap_mmio_write8;
+ break;
+ case 16:
+ ctx->reg_read = regmap_mmio_read16be;
+ ctx->reg_write = regmap_mmio_write16be;
+ break;
+ case 32:
+ ctx->reg_read = regmap_mmio_read32be;
+ ctx->reg_write = regmap_mmio_write32be;
+ break;
+ default:
+ ret = -EINVAL;
+ goto err_free;
+ }
+ break;
+ default:
+ ret = -EINVAL;
+ goto err_free;
+ }
+
+ if (clk_id == NULL)
+ return ctx;
+
+ ctx->clk = clk_get(dev, clk_id);
+ if (IS_ERR(ctx->clk)) {
+ ret = PTR_ERR(ctx->clk);
+ goto err_free;
+ }
+
+ ret = clk_prepare(ctx->clk);
+ if (ret < 0) {
+ clk_put(ctx->clk);
+ goto err_free;
+ }
+
+ return ctx;
+
+err_free:
+ kfree(ctx);
+
+ return ERR_PTR(ret);
+}
+
+struct regmap *__regmap_init_mmio_clk(struct device *dev, const char *clk_id,
+ void __iomem *regs,
+ const struct regmap_config *config,
+ struct lock_class_key *lock_key,
+ const char *lock_name)
+{
+ struct regmap_mmio_context *ctx;
+
+ ctx = regmap_mmio_gen_context(dev, clk_id, regs, config);
+ if (IS_ERR(ctx))
+ return ERR_CAST(ctx);
+
+ return __regmap_init(dev, &regmap_mmio, ctx, config,
+ lock_key, lock_name);
+}
+EXPORT_SYMBOL_GPL(__regmap_init_mmio_clk);
+
+struct regmap *__devm_regmap_init_mmio_clk(struct device *dev,
+ const char *clk_id,
+ void __iomem *regs,
+ const struct regmap_config *config,
+ struct lock_class_key *lock_key,
+ const char *lock_name)
+{
+ struct regmap_mmio_context *ctx;
+
+ ctx = regmap_mmio_gen_context(dev, clk_id, regs, config);
+ if (IS_ERR(ctx))
+ return ERR_CAST(ctx);
+
+ return __devm_regmap_init(dev, &regmap_mmio, ctx, config,
+ lock_key, lock_name);
+}
+EXPORT_SYMBOL_GPL(__devm_regmap_init_mmio_clk);
+
+int regmap_mmio_attach_clk(struct regmap *map, struct clk *clk)
+{
+ struct regmap_mmio_context *ctx = map->bus_context;
+
+ ctx->clk = clk;
+ ctx->attached_clk = true;
+
+ return clk_prepare(ctx->clk);
+}
+EXPORT_SYMBOL_GPL(regmap_mmio_attach_clk);
+
+void regmap_mmio_detach_clk(struct regmap *map)
+{
+ struct regmap_mmio_context *ctx = map->bus_context;
+
+ clk_unprepare(ctx->clk);
+
+ ctx->attached_clk = false;
+ ctx->clk = NULL;
+}
+EXPORT_SYMBOL_GPL(regmap_mmio_detach_clk);
+
+MODULE_LICENSE("GPL v2");
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