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From: Florian Fainelli <f.fainelli@gmail.com>
Subject: [PATCH v3 2/9] mtd: rawnand: brcmnand: Allow SoC to provide I/O operations
Date: Fri, 07 Jan 2022 10:46:07 -0800
Content-Type: text/plain; charset="utf-8"
Allow a brcmnand_soc instance to provide a custom set of I/O operations
which we will require when using this driver on a BCMA bus which is not
directly memory mapped I/O. Update the nand_{read,write}_reg accordingly
to use the SoC operations if provided.
To minimize the penalty on other SoCs which do support standard MMIO
accesses, we use a static key which is disabled by default and gets
enabled if a soc implementation does provide I/O operations.
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
---
drivers/mtd/nand/raw/brcmnand/brcmnand.c | 28 +++++++++++++++++++++--
drivers/mtd/nand/raw/brcmnand/brcmnand.h | 29 ++++++++++++++++++++++++
2 files changed, 55 insertions(+), 2 deletions(-)
--- a/drivers/mtd/nand/raw/brcmnand/brcmnand.c
+++ b/drivers/mtd/nand/raw/brcmnand/brcmnand.c
@@ -25,6 +25,7 @@
#include <linux/of.h>
#include <linux/of_platform.h>
#include <linux/slab.h>
+#include <linux/static_key.h>
#include <linux/list.h>
#include <linux/log2.h>
@@ -207,6 +208,8 @@ enum {
struct brcmnand_host;
+static DEFINE_STATIC_KEY_FALSE(brcmnand_soc_has_ops_key);
+
struct brcmnand_controller {
struct device *dev;
struct nand_controller controller;
@@ -592,15 +595,25 @@ enum {
INTFC_CTLR_READY = BIT(31),
};
+static inline bool brcmnand_non_mmio_ops(struct brcmnand_controller *ctrl)
+{
+ return static_branch_unlikely(&brcmnand_soc_has_ops_key);
+}
+
static inline u32 nand_readreg(struct brcmnand_controller *ctrl, u32 offs)
{
+ if (brcmnand_non_mmio_ops(ctrl))
+ return brcmnand_soc_read(ctrl->soc, offs);
return brcmnand_readl(ctrl->nand_base + offs);
}
static inline void nand_writereg(struct brcmnand_controller *ctrl, u32 offs,
u32 val)
{
- brcmnand_writel(val, ctrl->nand_base + offs);
+ if (brcmnand_non_mmio_ops(ctrl))
+ brcmnand_soc_write(ctrl->soc, val, offs);
+ else
+ brcmnand_writel(val, ctrl->nand_base + offs);
}
static int brcmnand_revision_init(struct brcmnand_controller *ctrl)
@@ -766,13 +779,18 @@ static inline void brcmnand_rmw_reg(stru
static inline u32 brcmnand_read_fc(struct brcmnand_controller *ctrl, int word)
{
+ if (brcmnand_non_mmio_ops(ctrl))
+ return brcmnand_soc_read(ctrl->soc, BRCMNAND_NON_MMIO_FC_ADDR);
return __raw_readl(ctrl->nand_fc + word * 4);
}
static inline void brcmnand_write_fc(struct brcmnand_controller *ctrl,
int word, u32 val)
{
- __raw_writel(val, ctrl->nand_fc + word * 4);
+ if (brcmnand_non_mmio_ops(ctrl))
+ brcmnand_soc_write(ctrl->soc, val, BRCMNAND_NON_MMIO_FC_ADDR);
+ else
+ __raw_writel(val, ctrl->nand_fc + word * 4);
}
static inline void edu_writel(struct brcmnand_controller *ctrl,
@@ -3000,6 +3018,12 @@ int brcmnand_probe(struct platform_devic
ctrl->dev = dev;
ctrl->soc = soc;
+ /* Enable the static key if the soc provides I/O operations indicating
+ * that a non-memory mapped IO access path must be used
+ */
+ if (brcmnand_soc_has_ops(ctrl->soc))
+ static_branch_enable(&brcmnand_soc_has_ops_key);
+
init_completion(&ctrl->done);
init_completion(&ctrl->dma_done);
init_completion(&ctrl->edu_done);
--- a/drivers/mtd/nand/raw/brcmnand/brcmnand.h
+++ b/drivers/mtd/nand/raw/brcmnand/brcmnand.h
@@ -11,12 +11,25 @@
struct platform_device;
struct dev_pm_ops;
+struct brcmnand_io_ops;
+
+/* Special register offset constant to intercept a non-MMIO access
+ * to the flash cache register space. This is intentionally large
+ * not to overlap with an existing offset.
+ */
+#define BRCMNAND_NON_MMIO_FC_ADDR 0xffffffff
struct brcmnand_soc {
bool (*ctlrdy_ack)(struct brcmnand_soc *soc);
void (*ctlrdy_set_enabled)(struct brcmnand_soc *soc, bool en);
void (*prepare_data_bus)(struct brcmnand_soc *soc, bool prepare,
bool is_param);
+ const struct brcmnand_io_ops *ops;
+};
+
+struct brcmnand_io_ops {
+ u32 (*read_reg)(struct brcmnand_soc *soc, u32 offset);
+ void (*write_reg)(struct brcmnand_soc *soc, u32 val, u32 offset);
};
static inline void brcmnand_soc_data_bus_prepare(struct brcmnand_soc *soc,
@@ -58,6 +71,22 @@ static inline void brcmnand_writel(u32 v
writel_relaxed(val, addr);
}
+static inline bool brcmnand_soc_has_ops(struct brcmnand_soc *soc)
+{
+ return soc && soc->ops && soc->ops->read_reg && soc->ops->write_reg;
+}
+
+static inline u32 brcmnand_soc_read(struct brcmnand_soc *soc, u32 offset)
+{
+ return soc->ops->read_reg(soc, offset);
+}
+
+static inline void brcmnand_soc_write(struct brcmnand_soc *soc, u32 val,
+ u32 offset)
+{
+ soc->ops->write_reg(soc, val, offset);
+}
+
int brcmnand_probe(struct platform_device *pdev, struct brcmnand_soc *soc);
int brcmnand_remove(struct platform_device *pdev);
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