Message ID | 20220324001628.13028-7-Sergey.Semin@baikalelectronics.ru |
---|---|
State | New |
Headers | show |
Series | ata: ahci: Add DWC/Baikal-T1 AHCI SATA support | expand |
On Thu, Mar 24, 2022 at 10:36:04AM +0900, Damien Le Moal wrote: > On 3/24/22 09:16, Serge Semin wrote: > > Since all the clocks are retrieved by the method > > ahci_platform_get_resources() there is no need for the glue-drivers to be > > looking for some particular of them in the kernel clocks table again. > > Instead we suggest to add a simple method returning a device-specific > > clock with passed connection ID if it is managed to be found. Otherwise > > the function will return NULL. Thus the glue-drivers won't need to either > > "glue-drivers" is really unclear. What do you mean ? "Glue drivers" is a common name to address the drivers which are used to pre-initialize the platform-specifics, then normally create a core driver descriptor/data and finally call some core method (like ahci_platform_init_host()) to really bind the device in the particular bus. You can find them in almost all the kernel subsystems. For instance in case of this patchset the glue-driver is drivers/ata/ahci_dwc.c, while the main/core part of the driver is implemented in drivers/ata/achi.c, drivers/ata/libahci.c, drivers/ata/libahci_platform.c, etc. It's not like I've come up with the term by myself. I've seen it used in a plenty of the kernel patches and subsystems and will unlikely stop using it since it determines the particular type of the kernel drivers in a short and direct manner. > > > manually touching the hpriv->clks array or calling clk_get()-friends. The > > AHCI platform drivers will be able to use the new function right after the > > ahci_platform_get_resources() method invocation and up to the device > > removal. > > > > Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru> > > --- > > drivers/ata/libahci_platform.c | 27 +++++++++++++++++++++++++++ > > include/linux/ahci_platform.h | 3 +++ > > 2 files changed, 30 insertions(+) > > > > diff --git a/drivers/ata/libahci_platform.c b/drivers/ata/libahci_platform.c > > index d805ddc3a024..4fb9629c03ab 100644 > > --- a/drivers/ata/libahci_platform.c > > +++ b/drivers/ata/libahci_platform.c > > @@ -94,6 +94,33 @@ void ahci_platform_disable_phys(struct ahci_host_priv *hpriv) > > } > > EXPORT_SYMBOL_GPL(ahci_platform_disable_phys); > > > > +/** > > + * ahci_platform_find_clk - Find platform clock > > + * @hpriv: host private area to store config values > > + * @con_id: clock connection ID > > + * > > + * This function returns point to the clock descriptor of the clock with > > + * passed ID. > > + * > > + * RETURNS: > > + * Pointer to the clock descriptor on success otherwise NULL > > + */ > > +struct clk *ahci_platform_find_clk(struct ahci_host_priv *hpriv, const char *con_id) > > +{ > > + struct clk *clk = NULL; > > + int i; > > + > > + for (i = 0; i < hpriv->n_clks; i++) { > > + if (!strcmp(hpriv->clks[i].id, con_id)) { > > + clk = hpriv->clks[i].clk; > > + break; > > + } > > + } > > + > > + return clk; > > +} > > +EXPORT_SYMBOL_GPL(ahci_platform_find_clk); > > + > > /** > > * ahci_platform_enable_clks - Enable platform clocks > > * @hpriv: host private area to store config values > > diff --git a/include/linux/ahci_platform.h b/include/linux/ahci_platform.h > > index 49e5383d4222..fd964e6a68d6 100644 > > --- a/include/linux/ahci_platform.h > > +++ b/include/linux/ahci_platform.h > > @@ -13,6 +13,7 @@ > > > > #include <linux/compiler.h> > > > > +struct clk; > > struct device; > > struct ata_port_info; > > struct ahci_host_priv; > > @@ -21,6 +22,8 @@ struct scsi_host_template; > > > > int ahci_platform_enable_phys(struct ahci_host_priv *hpriv); > > void ahci_platform_disable_phys(struct ahci_host_priv *hpriv); > > +struct clk * > > +ahci_platform_find_clk(struct ahci_host_priv *hpriv, const char *con_id); > > No users for this function ? It will be used in the next two patches: [PATCH 17/21] ata: ahci: Add DWC AHCI SATA controller support [PATCH 20/21] ata: ahci-dwc: Add Baikal-T1 AHCI SATA interface support and most likely in the new AHCI/SATA drivers which need to tune the clocks up in the platform-specific way. -Sergey > > > int ahci_platform_enable_clks(struct ahci_host_priv *hpriv); > > void ahci_platform_disable_clks(struct ahci_host_priv *hpriv); > > int ahci_platform_enable_regulators(struct ahci_host_priv *hpriv); > > > -- > Damien Le Moal > Western Digital Research
diff --git a/drivers/ata/libahci_platform.c b/drivers/ata/libahci_platform.c index d805ddc3a024..4fb9629c03ab 100644 --- a/drivers/ata/libahci_platform.c +++ b/drivers/ata/libahci_platform.c @@ -94,6 +94,33 @@ void ahci_platform_disable_phys(struct ahci_host_priv *hpriv) } EXPORT_SYMBOL_GPL(ahci_platform_disable_phys); +/** + * ahci_platform_find_clk - Find platform clock + * @hpriv: host private area to store config values + * @con_id: clock connection ID + * + * This function returns point to the clock descriptor of the clock with + * passed ID. + * + * RETURNS: + * Pointer to the clock descriptor on success otherwise NULL + */ +struct clk *ahci_platform_find_clk(struct ahci_host_priv *hpriv, const char *con_id) +{ + struct clk *clk = NULL; + int i; + + for (i = 0; i < hpriv->n_clks; i++) { + if (!strcmp(hpriv->clks[i].id, con_id)) { + clk = hpriv->clks[i].clk; + break; + } + } + + return clk; +} +EXPORT_SYMBOL_GPL(ahci_platform_find_clk); + /** * ahci_platform_enable_clks - Enable platform clocks * @hpriv: host private area to store config values diff --git a/include/linux/ahci_platform.h b/include/linux/ahci_platform.h index 49e5383d4222..fd964e6a68d6 100644 --- a/include/linux/ahci_platform.h +++ b/include/linux/ahci_platform.h @@ -13,6 +13,7 @@ #include <linux/compiler.h> +struct clk; struct device; struct ata_port_info; struct ahci_host_priv; @@ -21,6 +22,8 @@ struct scsi_host_template; int ahci_platform_enable_phys(struct ahci_host_priv *hpriv); void ahci_platform_disable_phys(struct ahci_host_priv *hpriv); +struct clk * +ahci_platform_find_clk(struct ahci_host_priv *hpriv, const char *con_id); int ahci_platform_enable_clks(struct ahci_host_priv *hpriv); void ahci_platform_disable_clks(struct ahci_host_priv *hpriv); int ahci_platform_enable_regulators(struct ahci_host_priv *hpriv);
Since all the clocks are retrieved by the method ahci_platform_get_resources() there is no need for the glue-drivers to be looking for some particular of them in the kernel clocks table again. Instead we suggest to add a simple method returning a device-specific clock with passed connection ID if it is managed to be found. Otherwise the function will return NULL. Thus the glue-drivers won't need to either manually touching the hpriv->clks array or calling clk_get()-friends. The AHCI platform drivers will be able to use the new function right after the ahci_platform_get_resources() method invocation and up to the device removal. Signed-off-by: Serge Semin <Sergey.Semin@baikalelectronics.ru> --- drivers/ata/libahci_platform.c | 27 +++++++++++++++++++++++++++ include/linux/ahci_platform.h | 3 +++ 2 files changed, 30 insertions(+)