From: Florian Fainelli 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 --- 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 #include #include +#include #include #include @@ -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, @@ -3035,6 +3053,12 @@ 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);