From: "Antoine Ténart" <antoine.tenart@free-electrons.com> To: Rob Herring <robherring2@gmail.com> Cc: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com>, Tejun Heo <tj@kernel.org>, zmxu@marvell.com, Jisheng Zhang <jszhang@marvell.com>, "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>, linux-ide@vger.kernel.org, Alexandre Belloni <alexandre.belloni@free-electrons.com>, "linux-arm-kernel@lists.infradead.org" <linux-arm-kernel@lists.infradead.org> Subject: Re: [PATCH 1/6] ata: ahci: add AHCI support for Berlin SoCs Date: Wed, 23 Apr 2014 10:33:26 +0200 [thread overview] Message-ID: <20140423083326.GD24355@kwain> (raw) In-Reply-To: <CAL_JsqKE_Z3kBhS1VaQADV5ob8x6AKHhbHaQEGoVSwkwdd50zA@mail.gmail.com> Rob, On Tue, Apr 22, 2014 at 01:47:43PM -0500, Rob Herring wrote: > On Tue, Apr 22, 2014 at 10:38 AM, Antoine Ténart > <antoine.tenart@free-electrons.com> wrote: […] > > +static inline void ahci_berlin_reg_clear_set(void __iomem *reg, u32 clear_val, > > + u32 set_val) > > +{ > > + u32 regval; > > + > > + regval = readl(reg); > > + regval &= ~(clear_val); > > + regval |= set_val; > > + writel(regval, reg); > > +} > > + > > +static void ahci_berlin_init(void __iomem *mmio) > > I don't really see the point of a function to do 2 register writes of > magic values especially when the function name doesn't provide any > indication of what you are doing really. > > > +{ > > + /* interface select */ > > + ahci_berlin_reg_set(mmio + HOST_VSA_ADDR, BIT(2)); > > + ahci_berlin_reg_set(mmio + HOST_VSA_ADDR, > > 2 writes to the same reg? Is this supposed to be the VSA_DATA register? You're right it's VSA_DATA. > > > + BIT(21) | BIT(18) | BIT(5) | BIT(4) | BIT(2)); > > Use of BIT is only helpful to people that don't understand hex. Can > you define what these bits are. Otherwise, just use 0x00240034 and > note that it is magic value which you have no idea what the bits are. This is magic. I'll update and add a comment. > > +static void ahci_berlin_port_init(void __iomem *mmio, unsigned int ports) > > +{ > > + int p; > > + > > + /* power down pll */ > > + ahci_berlin_reg_set(mmio + HOST_VSA_ADDR, 0x0); > > + ahci_berlin_reg_setbits(mmio + HOST_VSA_DATA, BIT(6)); > > + > > + for (p = 0; p < ports; p++) { > > + /* port control register */ > > + void __iomem *ctrl_reg = mmio + 0x100 + (p * 0x80); > > + > > + /* set PHY mode to SATA, ref freq to 25 MHz */ > > + ahci_berlin_reg_set(ctrl_reg + PORT_VSR_ADDR, 0x201); > > + ahci_berlin_reg_clear_set(ctrl_reg + PORT_VSR_DATA, > > + 0xff, BIT(0)); > > So you have registers hidden behind an address and data register. > Perhaps a read and write function to provide that access rather than > all these set/clear bit functions. I'd like to do so if I could name 0x201, 0x225 ... I can also merge the two functions if you think it's better for readability. Thanks! Antoine -- Antoine Ténart, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com
WARNING: multiple messages have this Message-ID (diff)
From: antoine.tenart@free-electrons.com (Antoine Ténart) To: linux-arm-kernel@lists.infradead.org Subject: [PATCH 1/6] ata: ahci: add AHCI support for Berlin SoCs Date: Wed, 23 Apr 2014 10:33:26 +0200 [thread overview] Message-ID: <20140423083326.GD24355@kwain> (raw) In-Reply-To: <CAL_JsqKE_Z3kBhS1VaQADV5ob8x6AKHhbHaQEGoVSwkwdd50zA@mail.gmail.com> Rob, On Tue, Apr 22, 2014 at 01:47:43PM -0500, Rob Herring wrote: > On Tue, Apr 22, 2014 at 10:38 AM, Antoine T?nart > <antoine.tenart@free-electrons.com> wrote: [?] > > +static inline void ahci_berlin_reg_clear_set(void __iomem *reg, u32 clear_val, > > + u32 set_val) > > +{ > > + u32 regval; > > + > > + regval = readl(reg); > > + regval &= ~(clear_val); > > + regval |= set_val; > > + writel(regval, reg); > > +} > > + > > +static void ahci_berlin_init(void __iomem *mmio) > > I don't really see the point of a function to do 2 register writes of > magic values especially when the function name doesn't provide any > indication of what you are doing really. > > > +{ > > + /* interface select */ > > + ahci_berlin_reg_set(mmio + HOST_VSA_ADDR, BIT(2)); > > + ahci_berlin_reg_set(mmio + HOST_VSA_ADDR, > > 2 writes to the same reg? Is this supposed to be the VSA_DATA register? You're right it's VSA_DATA. > > > + BIT(21) | BIT(18) | BIT(5) | BIT(4) | BIT(2)); > > Use of BIT is only helpful to people that don't understand hex. Can > you define what these bits are. Otherwise, just use 0x00240034 and > note that it is magic value which you have no idea what the bits are. This is magic. I'll update and add a comment. > > +static void ahci_berlin_port_init(void __iomem *mmio, unsigned int ports) > > +{ > > + int p; > > + > > + /* power down pll */ > > + ahci_berlin_reg_set(mmio + HOST_VSA_ADDR, 0x0); > > + ahci_berlin_reg_setbits(mmio + HOST_VSA_DATA, BIT(6)); > > + > > + for (p = 0; p < ports; p++) { > > + /* port control register */ > > + void __iomem *ctrl_reg = mmio + 0x100 + (p * 0x80); > > + > > + /* set PHY mode to SATA, ref freq to 25 MHz */ > > + ahci_berlin_reg_set(ctrl_reg + PORT_VSR_ADDR, 0x201); > > + ahci_berlin_reg_clear_set(ctrl_reg + PORT_VSR_DATA, > > + 0xff, BIT(0)); > > So you have registers hidden behind an address and data register. > Perhaps a read and write function to provide that access rather than > all these set/clear bit functions. I'd like to do so if I could name 0x201, 0x225 ... I can also merge the two functions if you think it's better for readability. Thanks! Antoine -- Antoine T?nart, Free Electrons Embedded Linux, Kernel and Android engineering http://free-electrons.com
next prev parent reply other threads:[~2014-04-23 8:33 UTC|newest] Thread overview: 68+ messages / expand[flat|nested] mbox.gz Atom feed top 2014-04-22 15:38 [PATCH 0/6] ARM: berlin: add AHCI support Antoine Ténart 2014-04-22 15:38 ` Antoine Ténart 2014-04-22 15:38 ` Antoine Ténart 2014-04-22 15:38 ` [PATCH 1/6] ata: ahci: add AHCI support for Berlin SoCs Antoine Ténart 2014-04-22 15:38 ` Antoine Ténart 2014-04-22 16:54 ` Bartlomiej Zolnierkiewicz 2014-04-22 16:54 ` Bartlomiej Zolnierkiewicz 2014-04-23 8:13 ` Antoine Ténart 2014-04-23 8:13 ` Antoine Ténart 2014-04-22 17:20 ` Sebastian Hesselbarth 2014-04-22 17:20 ` Sebastian Hesselbarth 2014-04-22 17:20 ` Sebastian Hesselbarth 2014-04-23 8:21 ` Antoine Ténart 2014-04-23 8:21 ` Antoine Ténart 2014-04-22 18:47 ` Rob Herring 2014-04-22 18:47 ` Rob Herring 2014-04-22 18:47 ` Rob Herring 2014-04-22 18:54 ` Rob Herring 2014-04-22 18:54 ` Rob Herring 2014-04-22 18:54 ` Rob Herring 2014-04-23 8:24 ` Antoine Ténart 2014-04-23 8:24 ` Antoine Ténart 2014-04-23 8:24 ` Antoine Ténart 2014-04-23 8:33 ` Antoine Ténart [this message] 2014-04-23 8:33 ` Antoine Ténart 2014-04-23 8:33 ` Antoine Ténart 2014-04-22 20:56 ` Andrew Lunn 2014-04-22 20:56 ` Andrew Lunn 2014-04-24 9:50 ` Jisheng Zhang 2014-04-24 9:50 ` Jisheng Zhang 2014-04-24 9:50 ` Jisheng Zhang 2014-04-24 10:26 ` Antoine Ténart 2014-04-24 10:26 ` Antoine Ténart 2014-04-24 10:26 ` Antoine Ténart 2014-04-22 15:38 ` [PATCH 2/6] Documentation: bindings: add the berlin-achi compatible to the ahci platform Antoine Ténart 2014-04-22 15:38 ` Antoine Ténart 2014-04-22 16:27 ` Thomas Petazzoni 2014-04-22 16:27 ` Thomas Petazzoni 2014-04-22 17:21 ` Sebastian Hesselbarth 2014-04-22 17:21 ` Sebastian Hesselbarth 2014-04-22 17:21 ` Sebastian Hesselbarth 2014-04-22 15:38 ` [PATCH 3/6] ARM: berlin: add the AHCI node for the BG2Q Antoine Ténart 2014-04-22 15:38 ` Antoine Ténart 2014-04-22 15:38 ` Antoine Ténart 2014-04-22 16:28 ` Thomas Petazzoni 2014-04-22 16:28 ` Thomas Petazzoni 2014-04-22 17:22 ` Sebastian Hesselbarth 2014-04-22 17:22 ` Sebastian Hesselbarth 2014-04-22 17:22 ` Sebastian Hesselbarth 2014-04-22 16:28 ` Thomas Petazzoni 2014-04-22 16:28 ` Thomas Petazzoni 2014-04-22 15:38 ` [PATCH 4/6] ARM: berlin: enable the eSATA interface on the BG2Q DMP Antoine Ténart 2014-04-22 15:38 ` Antoine Ténart 2014-04-22 15:38 ` Antoine Ténart 2014-04-22 15:38 ` [PATCH 5/6] ARM: berlin: add the AHCI node for the BG2 Antoine Ténart 2014-04-22 15:38 ` Antoine Ténart 2014-04-23 2:45 ` Jisheng Zhang 2014-04-23 2:45 ` Jisheng Zhang 2014-04-23 2:45 ` Jisheng Zhang 2014-04-23 8:58 ` Antoine Ténart 2014-04-23 8:58 ` Antoine Ténart 2014-04-23 8:58 ` Antoine Ténart 2014-04-22 15:38 ` [PATCH 6/6] ARM: berlin: add the AHCI node for the BG2CD Antoine Ténart 2014-04-22 15:38 ` Antoine Ténart 2014-04-22 15:38 ` Antoine Ténart 2014-04-23 2:43 ` Jisheng Zhang 2014-04-23 2:43 ` Jisheng Zhang 2014-04-23 2:43 ` Jisheng Zhang
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