Hi Rob, Thanks for reviewing the patch > -----Original Message----- > From: Rob Herring [mailto:robh@xxxxxxxxxx] > Sent: Friday, November 13, 2015 8:02 PM > To: Anurag Kumar Vulisha > Cc: pawel.moll@xxxxxxx; mark.rutland@xxxxxxx; > ijc+devicetree@xxxxxxxxxxxxxx; galak@xxxxxxxxxxxxxx; tj@xxxxxxxxxx; > devicetree@xxxxxxxxxxxxxxx; linux-kernel@xxxxxxxxxxxxxxx; linux- > ide@xxxxxxxxxxxxxxx; Michal Simek; Punnaiah Choudary Kalluri; Anirudha > Sarangi; Srikanth Vemula; Anurag Kumar Vulisha > Subject: Re: [PATCH] drivers: ata: Move vendor specific sata port phy oob > settings to device-tree > > On Fri, Nov 13, 2015 at 04:02:23PM +0530, Anurag Kumar Vulisha wrote: > > In SATA, speed negotiation happens with OOB(Out of Band) signals. > > These OOB signal timing values are configured through vendor specific > > registers in the SATA controller. These OOB timings depends on the > > generator and detector clock frequency, which varies from board to > > board (ex: ep108, zcu102 and zc1751 has different clock frequencies). > > Could you calculate the timings based on the frequency instead? > We can calculate the OOB timing settings based on frequency, but it requires complex calculations and floating point operations in the sata driver , which is running in kernel mode. To my knowledge it is not recommended to do floating operations inside kernel mode(Please correct me if I wrong ) . Because of this reason we are reading those values from device tree. > > Since to make ahci_ceva driver generic, it would be better to move > > these settings to the device-tree node and read them from driver. > > > > This patch does the same. > > > > Signed-off-by: Anurag Kumar Vulisha <anuragku@xxxxxxxxxx> > > --- > > .../devicetree/bindings/ata/ahci-ceva.txt | 38 +++++++++ > > drivers/ata/ahci_ceva.c | 84 ++++++++++++++------ > > 2 files changed, 99 insertions(+), 23 deletions(-) > > > > diff --git a/Documentation/devicetree/bindings/ata/ahci-ceva.txt > > b/Documentation/devicetree/bindings/ata/ahci-ceva.txt > > index 7ca8b97..66fcd10 100644 > > --- a/Documentation/devicetree/bindings/ata/ahci-ceva.txt > > +++ b/Documentation/devicetree/bindings/ata/ahci-ceva.txt > > @@ -5,6 +5,36 @@ Required properties: > > - compatible: Compatibility string. Must be 'ceva,ahci-1v84'. > > - clocks: Input clock specifier. Refer to common clock bindings. > > - interrupts: Interrupt specifier. Refer to interrupt binding. > > + - ceva,p0-cominit-params: OOB timing value for COMINIT parameter for > port 0. > > + - ceva,p1-cominit-params: OOB timing value for COMINIT parameter for > port 1. > > This doesn't really scale when you have more than 2 ports. Given that you > know the length for each port, just make it a single property (i.e. > an array of ports). > The ceva sata controller that we are using has support for 2 ports only and each port can Invidually configured to have different timing settings based on frequency. So for ease of use we thought of having separate DT parameters for port 0 and 1 . > > + The fields for the above parameter must be as shown > below: > > + ceva,phy-cominit-params = /bits/ 8 <CIBGMN > CIBGMX CIBGN CINMP>; > > + CINMP : COMINIT Negate Minimum Period. > > + CIBGN : COMINIT Burst Gap Nominal. > > + CIBGMX: COMINIT Burst Gap Maximum. > > + CIBGMN: COMINIT Burst Gap Minimum. > > + - ceva,p0-comwake-params: OOB timing value for COMWAKE > parameter for port 0. > > + - ceva,p1-comwake-params: OOB timing value for COMWAKE > parameter for port 1. > > + The fields for the above parameter must be as shown > below: > > + ceva,phy-comwake-params = /bits/ 8 <CWBGMN > CWBGMX CWBGN CWNMP>; > > + CWBGMN: COMWAKE Burst Gap Minimum. > > + CWBGMX: COMWAKE Burst Gap Maximum. > > + CWBGN: COMWAKE Burst Gap Nominal. > > + CWNMP: COMWAKE Negate Minimum Period. > > + - ceva,p0-burst-params: Burst timing value for COM parameter for port > 0. > > + - ceva,p1-burst-params: Burst timing value for COM parameter for port > 1. > > + The fields for the above parameter must be as shown > below: > > + ceva,phy-burst-params = /bits/ 8 <BMX BNM SFD > PTST>; > > + BMX: COM Burst Maximum. > > + BNM: COM Burst Nominal. > > + SFD: Signal Failure Detection value. > > + PTST: Partial to Slumber timer value. > > + - ceva,p0-retry-params: Retry interval timing value for port 0. > > + - ceva,p1-retry-params: Retry interval timing value for port 1. > > + The fields for the above parameter must be as shown > below: > > + ceva,phy-retry-params = /bits/ 16 <RIT RCT>; > > + RIT: Retry Interval Timer. > > + RCT: Rate Change Timer. > > > > Optional properties: > > - ceva,broken-gen2: limit to gen1 speed instead of gen2. > > @@ -17,4 +47,12 @@ Examples: > > interrupts = <0 133 4>; > > clocks = <&clkc SATA_CLK_ID>; > > ceva,broken-gen2; > > + ceva,p0-cominit-params = /bits/ 8 <0x0F 0x25 0x18 0x29>; > > + ceva,p0-comwake-params = /bits/ 8 <0x04 0x0B 0x08 0x0F>; > > + ceva,p0-burst-params = /bits/ 8 <0x0A 0x08 0x4A 0x06>; > > + ceva,p0-retry-params = /bits/ 16 <0x0216 0x7F06>; > > + ceva,p1-cominit-params = /bits/ 8 <0x0F 0x25 0x18 0x29>; > > + ceva,p1-comwake-params = /bits/ 8 <0x04 0x0B 0x08 0x0F>; > > + ceva,p1-burst-params = /bits/ 8 <0x0A 0x08 0x4A 0x06>; > > + ceva,p1-retry-params = /bits/ 16 <0x0216 0x7F06>; > > }; > > diff --git a/drivers/ata/ahci_ceva.c b/drivers/ata/ahci_ceva.c index > > 207649d..59de2ca 100644 > > --- a/drivers/ata/ahci_ceva.c > > +++ b/drivers/ata/ahci_ceva.c > > @@ -50,21 +50,6 @@ > > #define PPCFG_PSS_EN (1 << 29) > > #define PPCFG_ESDF_EN (1 << 31) > > > > -#define PP2C_CIBGMN 0x0F > > -#define PP2C_CIBGMX (0x25 << 8) > > -#define PP2C_CIBGN (0x18 << 16) > > -#define PP2C_CINMP (0x29 << 24) > > - > > -#define PP3C_CWBGMN 0x04 > > -#define PP3C_CWBGMX (0x0B << 8) > > -#define PP3C_CWBGN (0x08 << 16) > > -#define PP3C_CWNMP (0x0F << 24) > > - > > -#define PP4C_BMX 0x0a > > -#define PP4C_BNM (0x08 << 8) > > -#define PP4C_SFD (0x4a << 16) > > -#define PP4C_PTST (0x06 << 24) > > - > > #define PP5C_RIT 0x60216 > > #define PP5C_RCT (0x7f0 << 20) > > > > @@ -87,6 +72,11 @@ > > > > struct ceva_ahci_priv { > > struct platform_device *ahci_pdev; > > + /* Port Phy2Cfg Register */ > > + u32 pp2c[NR_PORTS]; > > + u32 pp3c[NR_PORTS]; > > + u32 pp4c[NR_PORTS]; > > + u32 pp5c[NR_PORTS]; > > int flags; > > }; > > > > @@ -131,20 +121,16 @@ static void ahci_ceva_setup(struct ahci_host_priv > *hpriv) > > writel(tmp, mmio + AHCI_VEND_PPCFG); > > > > /* Phy Control OOB timing parameters COMINIT */ > > - tmp = PP2C_CIBGMN | PP2C_CIBGMX | PP2C_CIBGN | > PP2C_CINMP; > > - writel(tmp, mmio + AHCI_VEND_PP2C); > > + writel(cevapriv->pp2c[i], mmio + AHCI_VEND_PP2C); > > > > /* Phy Control OOB timing parameters COMWAKE */ > > - tmp = PP3C_CWBGMN | PP3C_CWBGMX | PP3C_CWBGN | > PP3C_CWNMP; > > - writel(tmp, mmio + AHCI_VEND_PP3C); > > + writel(cevapriv->pp3c[i], mmio + AHCI_VEND_PP3C); > > > > /* Phy Control Burst timing setting */ > > - tmp = PP4C_BMX | PP4C_BNM | PP4C_SFD | PP4C_PTST; > > - writel(tmp, mmio + AHCI_VEND_PP4C); > > + writel(cevapriv->pp4c[i], mmio + AHCI_VEND_PP4C); > > > > /* Rate Change Timer and Retry Interval Timer setting */ > > - tmp = PP5C_RIT | PP5C_RCT; > > - writel(tmp, mmio + AHCI_VEND_PP5C); > > + writel(cevapriv->pp5c[i], mmio + AHCI_VEND_PP5C); > > > > /* Rx Watermark setting */ > > tmp = PTC_RX_WM_VAL | PTC_RSVD; > > @@ -187,6 +173,58 @@ static int ceva_ahci_probe(struct platform_device > *pdev) > > if (of_property_read_bool(np, "ceva,broken-gen2")) > > cevapriv->flags = CEVA_FLAG_BROKEN_GEN2; > > > > + /* Read OOB timing value for COMINIT from device-tree */ > > + if (of_property_read_u8_array(np, "ceva,p0-cominit-params", > > + (u8 *)&cevapriv->pp2c[0], 4) < 0) { > > + dev_warn(dev, "ceva,p0-cominit-params property not > defined\n"); > > I'd really like to move all the error prints into the of_property_* functions > instead, but then we'd probably need *_optional variants to avoid spewing > to the console. We will try to implement this later. Thanks, Anurag Kumar V -- To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
