From 78ffc4acceff48522b92d8fbf8f4a0ffe78838b2 Mon Sep 17 00:00:00 2001 From: Russell King Date: Tue, 2 Jan 2018 10:58:43 +0000 Subject: [PATCH] net: phy: add paged phy register accessors Add a set of paged phy register accessors which are inherently safe in their design against other accesses interfering with the paged access. Signed-off-by: Russell King Reviewed-by: Andrew Lunn Signed-off-by: David S. Miller --- drivers/net/phy/phy-core.c | 157 +++++++++++++++++++++++++++++++++++++ include/linux/phy.h | 11 +++ 2 files changed, 168 insertions(+) diff --git a/drivers/net/phy/phy-core.c b/drivers/net/phy/phy-core.c index 028c098e9a00..48e762bf6464 100644 --- a/drivers/net/phy/phy-core.c +++ b/drivers/net/phy/phy-core.c @@ -348,3 +348,160 @@ int __phy_modify(struct phy_device *phydev, u32 regnum, u16 mask, u16 set) return ret; } EXPORT_SYMBOL_GPL(__phy_modify); + +static int __phy_read_page(struct phy_device *phydev) +{ + return phydev->drv->read_page(phydev); +} + +static int __phy_write_page(struct phy_device *phydev, int page) +{ + return phydev->drv->write_page(phydev, page); +} + +/** + * phy_save_page() - take the bus lock and save the current page + * @phydev: a pointer to a &struct phy_device + * + * Take the MDIO bus lock, and return the current page number. On error, + * returns a negative errno. phy_restore_page() must always be called + * after this, irrespective of success or failure of this call. + */ +int phy_save_page(struct phy_device *phydev) +{ + mutex_lock(&phydev->mdio.bus->mdio_lock); + return __phy_read_page(phydev); +} +EXPORT_SYMBOL_GPL(phy_save_page); + +/** + * phy_select_page() - take the bus lock, save the current page, and set a page + * @phydev: a pointer to a &struct phy_device + * @page: desired page + * + * Take the MDIO bus lock to protect against concurrent access, save the + * current PHY page, and set the current page. On error, returns a + * negative errno, otherwise returns the previous page number. + * phy_restore_page() must always be called after this, irrespective + * of success or failure of this call. + */ +int phy_select_page(struct phy_device *phydev, int page) +{ + int ret, oldpage; + + oldpage = ret = phy_save_page(phydev); + if (ret < 0) + return ret; + + if (oldpage != page) { + ret = __phy_write_page(phydev, page); + if (ret < 0) + return ret; + } + + return oldpage; +} +EXPORT_SYMBOL_GPL(phy_select_page); + +/** + * phy_restore_page() - restore the page register and release the bus lock + * @phydev: a pointer to a &struct phy_device + * @oldpage: the old page, return value from phy_save_page() or phy_select_page() + * @ret: operation's return code + * + * Release the MDIO bus lock, restoring @oldpage if it is a valid page. + * This function propagates the earliest error code from the group of + * operations. + * + * Returns: + * @oldpage if it was a negative value, otherwise + * @ret if it was a negative errno value, otherwise + * phy_write_page()'s negative value if it were in error, otherwise + * @ret. + */ +int phy_restore_page(struct phy_device *phydev, int oldpage, int ret) +{ + int r; + + if (oldpage >= 0) { + r = __phy_write_page(phydev, oldpage); + + /* Propagate the operation return code if the page write + * was successful. + */ + if (ret >= 0 && r < 0) + ret = r; + } else { + /* Propagate the phy page selection error code */ + ret = oldpage; + } + + mutex_unlock(&phydev->mdio.bus->mdio_lock); + + return ret; +} +EXPORT_SYMBOL_GPL(phy_restore_page); + +/** + * phy_read_paged() - Convenience function for reading a paged register + * @phydev: a pointer to a &struct phy_device + * @page: the page for the phy + * @regnum: register number + * + * Same rules as for phy_read(). + */ +int phy_read_paged(struct phy_device *phydev, int page, u32 regnum) +{ + int ret = 0, oldpage; + + oldpage = phy_select_page(phydev, page); + if (oldpage >= 0) + ret = __phy_read(phydev, regnum); + + return phy_restore_page(phydev, oldpage, ret); +} +EXPORT_SYMBOL(phy_read_paged); + +/** + * phy_write_paged() - Convenience function for writing a paged register + * @phydev: a pointer to a &struct phy_device + * @page: the page for the phy + * @regnum: register number + * @val: value to write + * + * Same rules as for phy_write(). + */ +int phy_write_paged(struct phy_device *phydev, int page, u32 regnum, u16 val) +{ + int ret = 0, oldpage; + + oldpage = phy_select_page(phydev, page); + if (oldpage >= 0) + ret = __phy_write(phydev, regnum, val); + + return phy_restore_page(phydev, oldpage, ret); +} +EXPORT_SYMBOL(phy_write_paged); + +/** + * phy_modify_paged() - Convenience function for modifying a paged register + * @phydev: a pointer to a &struct phy_device + * @page: the page for the phy + * @regnum: register number + * @mask: bit mask of bits to clear + * @set: bit mask of bits to set + * + * Same rules as for phy_read() and phy_write(). + */ +int phy_modify_paged(struct phy_device *phydev, int page, u32 regnum, + u16 mask, u16 set) +{ + int ret = 0, oldpage; + + oldpage = phy_select_page(phydev, page); + if (oldpage >= 0) + ret = __phy_modify(phydev, regnum, mask, set); + + return phy_restore_page(phydev, oldpage, ret); +} +EXPORT_SYMBOL(phy_modify_paged); diff --git a/include/linux/phy.h b/include/linux/phy.h index 0c5a28520c65..af1a740dafd4 100644 --- a/include/linux/phy.h +++ b/include/linux/phy.h @@ -634,6 +634,9 @@ struct phy_driver { int (*write_mmd)(struct phy_device *dev, int devnum, u16 regnum, u16 val); + int (*read_page)(struct phy_device *dev); + int (*write_page)(struct phy_device *dev, int page); + /* Get the size and type of the eeprom contained within a plug-in * module */ int (*module_info)(struct phy_device *dev, @@ -838,6 +841,14 @@ static inline bool phy_is_pseudo_fixed_link(struct phy_device *phydev) */ int phy_write_mmd(struct phy_device *phydev, int devad, u32 regnum, u16 val); +int phy_save_page(struct phy_device *phydev); +int phy_select_page(struct phy_device *phydev, int page); +int phy_restore_page(struct phy_device *phydev, int oldpage, int ret); +int phy_read_paged(struct phy_device *phydev, int page, u32 regnum); +int phy_write_paged(struct phy_device *phydev, int page, u32 regnum, u16 val); +int phy_modify_paged(struct phy_device *phydev, int page, u32 regnum, + u16 mask, u16 set); + struct phy_device *phy_device_create(struct mii_bus *bus, int addr, int phy_id, bool is_c45, struct phy_c45_device_ids *c45_ids); -- 2.30.2