Hi Sascha: Thanks for your comments. Best Regards Richard Zhu ________________________________________ From: Sascha Hauer [s.hauer@xxxxxxxxxxxxxx] Sent: Friday, July 05, 2013 11:59 PM To: Richard Zhu Cc: shawn.guo@xxxxxxxxxx; linux-arm-kernel@xxxxxxxxxxxxxxxxxxx; jgarzik@xxxxxxxxx; avorontsov@xxxxxxxxxxxxx; rob.herring@xxxxxxxxxxx; linux-ide@xxxxxxxxxxxxxxx; Zhu Richard-R65037 Subject: Re: [v3 3/3] sata: imx: add ahci sata support on imx platforms On Fri, Jul 05, 2013 at 05:52:22PM +0800, Richard Zhu wrote: > From: Richard Zhu <r65037@xxxxxxxxxxxxx> > > imx6q contains one Synopsys AHCI SATA controller, > But it can't shares ahci_platform driver with other > controllers. > Because there are some misalignments of the bits > definitions of the HBA registers and the Vendor > Specific registers > - CAP_SSS(bit20) of the HOST_CAP is writable, default > value is '0', should be configured to be '1' > - bit0 (only one AHCI SATA port on imx6q) of the > HOST_PORTS_IMPL should be set to be '1'.(default 0) > - One Vendor Specific register HOST_TIMER1MS(offset:0xe0) > should be configured regarding to the frequency of AHB > bus clock. > - Configurations of the AHCI PHY clock, and the signal > parameters of the GPR13 > > Setup its own ahci sata driver, enable the imx6q ahci > sata support. > > Signed-off-by: Richard Zhu <r65037@xxxxxxxxxxxxx> > --- > drivers/ata/Kconfig | 9 ++ > drivers/ata/Makefile | 1 + > drivers/ata/sata_imx.c | 230 ++++++++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 240 insertions(+), 0 deletions(-) > create mode 100644 drivers/ata/sata_imx.c > > diff --git a/drivers/ata/Kconfig b/drivers/ata/Kconfig > index a5a3ebc..45ed2f0 100644 > --- a/drivers/ata/Kconfig > +++ b/drivers/ata/Kconfig > @@ -97,6 +97,15 @@ config SATA_AHCI_PLATFORM > > If unsure, say N. > > +config SATA_IMX > + tristate "Freescale iMX AHCI SATA support" It's rather untypical to write iMX. Please write i.MX. [Richard] Accepted. > + depends on SATA_AHCI_PLATFORM > + help > + This option enables support for the Freescale iMX SoC's > + onboard AHCI SATA. > + > + If unsure, say N. > + > config SATA_FSL > tristate "Freescale 3.0Gbps SATA support" > depends on FSL_SOC > diff --git a/drivers/ata/Makefile b/drivers/ata/Makefile > index c04d0fd..04b1c6c 100644 > --- a/drivers/ata/Makefile > +++ b/drivers/ata/Makefile > @@ -10,6 +10,7 @@ obj-$(CONFIG_SATA_INIC162X) += sata_inic162x.o > obj-$(CONFIG_SATA_SIL24) += sata_sil24.o > obj-$(CONFIG_SATA_DWC) += sata_dwc_460ex.o > obj-$(CONFIG_SATA_HIGHBANK) += sata_highbank.o libahci.o > +obj-$(CONFIG_SATA_IMX) += sata_imx.o > > # SFF w/ custom DMA > obj-$(CONFIG_PDC_ADMA) += pdc_adma.o > diff --git a/drivers/ata/sata_imx.c b/drivers/ata/sata_imx.c > new file mode 100644 > index 0000000..a129efb > --- /dev/null > +++ b/drivers/ata/sata_imx.c > @@ -0,0 +1,230 @@ > +/* > + * Freescale IMX AHCI SATA platform driver > + * Copyright 2013 Freescale Semiconductor, Inc. > + * > + * based on the AHCI SATA platform driver by Jeff Garzik and Anton Vorontsov > + * > + * This program is free software; you can redistribute it and/or modify it > + * under the terms and conditions of the GNU General Public License, > + * version 2, as published by the Free Software Foundation. > + * > + * This program is distributed in the hope it will be useful, but WITHOUT > + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or > + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for > + * more details. > + * > + * You should have received a copy of the GNU General Public License along with > + * this program. If not, see <http://www.gnu.org/licenses/>. > + */ > + > +#include <linux/clk.h> > +#include <linux/kernel.h> > +#include <linux/gfp.h> > +#include <linux/regmap.h> > +#include <linux/slab.h> > +#include <linux/module.h> > +#include <linux/init.h> > +#include <linux/interrupt.h> > +#include <linux/device.h> > +#include <linux/platform_device.h> > +#include <linux/libata.h> > +#include <linux/ahci_platform.h> > +#include <linux/of_device.h> > +#include <linux/mfd/syscon.h> > +#include <linux/mfd/syscon/imx6q-iomuxc-gpr.h> > +#include "ahci.h" > +#include <linux/clk-private.h> Do you need anything from clk-private.h? You shouldn't. [Richard]it would be removed. > + > +enum { > + HOST_TIMER1MS = 0xe0, /* Timer 1-ms */ > +}; > + > +/* imx6q ahci module initialization. */ > +static int imx6q_sata_phy_clk(struct device *dev, int enable) > +{ > + int ret = 0; > + struct clk *sata_ref_clk; > + > + sata_ref_clk = devm_clk_get(dev, "sata_ref_100m"); > + if (IS_ERR(sata_ref_clk)) { > + dev_err(dev, "can't get sata_ref clock.\n"); > + return PTR_ERR(sata_ref_clk); > + } clk_get must be balanced with clk_put. You need to have some private data and keep a pointer to the clock. [Richard] Ok, I can create the private data, and keep a pointer to this clock. > + if (enable) { > + /* Enable PHY clock */ > + ret = clk_prepare_enable(sata_ref_clk); > + if (ret < 0) > + dev_err(dev, "can't prepare-enable sata_ref clock\n"); When printing error messages it's always helpful to print the error code aswell. [Richard] Ok, the return-err code would be added. > + } else { > + /* Disable PHY clock */ This comment (also the one above enable) doesn't contain any useful information. [Richard] ok, they would be removed. > + clk_disable_unprepare(sata_ref_clk); > + } > + > + return ret; > +} > + > +static int imx6q_sata_init(struct device *dev, void __iomem *mmio) > +{ > + int ret = 0; > + struct regmap *gpr; > + struct clk *ahb_clk; > + > + ret = imx6q_sata_phy_clk(dev, true); > + if (ret < 0) > + return ret; > + > + gpr = syscon_regmap_lookup_by_compatible("fsl,imx6q-iomuxc-gpr"); > + if (IS_ERR(gpr)) { > + dev_err(dev, "failed to find fsl,imx6q-iomux-gpr regmap\n"); > + return PTR_ERR(gpr); > + } > + > + /* > + * set PHY Paremeters, two steps to configure the GPR13, > + * one write for rest of parameters, mask of first write > + * is 0x07fffffd, and the other one write for setting > + * the mpll_clk_en. > + */ > + regmap_update_bits(gpr, 0x34, IMX6Q_GPR13_SATA_RX_EQ_VAL_MASK > + | IMX6Q_GPR13_SATA_RX_LOS_LVL_MASK > + | IMX6Q_GPR13_SATA_RX_DPLL_MODE_MASK > + | IMX6Q_GPR13_SATA_SPD_MODE_MASK > + | IMX6Q_GPR13_SATA_MPLL_SS_EN > + | IMX6Q_GPR13_SATA_TX_ATTEN_MASK > + | IMX6Q_GPR13_SATA_TX_BOOST_MASK > + | IMX6Q_GPR13_SATA_TX_LVL_MASK > + | IMX6Q_GPR13_SATA_TX_EDGE_RATE > + , IMX6Q_GPR13_SATA_RX_EQ_VAL_3_0_DB > + | IMX6Q_GPR13_SATA_RX_LOS_LVL_SATA2M > + | IMX6Q_GPR13_SATA_RX_DPLL_MODE_2P_4F > + | IMX6Q_GPR13_SATA_SPD_MODE_3P0G > + | IMX6Q_GPR13_SATA_MPLL_SS_EN > + | IMX6Q_GPR13_SATA_TX_ATTEN_9_16 > + | IMX6Q_GPR13_SATA_TX_BOOST_3_33_DB > + | IMX6Q_GPR13_SATA_TX_LVL_1_025_V); > + regmap_update_bits(gpr, 0x34, IMX6Q_GPR13_SATA_MPLL_CLK_EN, > + IMX6Q_GPR13_SATA_MPLL_CLK_EN); > + usleep_range(100, 200); > + > + /* > + * Configure the HWINIT bits of the HOST_CAP and HOST_PORTS_IMPL, > + * and IP vendor specific register HOST_TIMER1MS. > + * > + * Configure CAP_SSS (support stagered spin up). > + * Implement the port0. > + * Get the ahb clock rate, and configure the TIMER1MS register. > + */ > + ret = readl(mmio + HOST_CAP); You should use a u32 type for storing readl results. [Richard] Accepted. > + if (!(ret & HOST_CAP_SSS)) > + writel(ret |= HOST_CAP_SSS, mmio + HOST_CAP); Why do you write this conditionally? Just write it unconditionally. [Richard]Ok, no problem. Would write it uncontitionally. > + ret = readl(mmio + HOST_PORTS_IMPL); > + if (!(ret & 0x1)) > + writel((ret | 0x1), mmio + HOST_PORTS_IMPL); ditto. > + > + ahb_clk = devm_clk_get(dev, "ahb"); > + if (IS_ERR(ahb_clk)) { > + dev_err(dev, "no ahb clock.\n"); > + return PTR_ERR(ahb_clk); > + } This leaves the phy clock enabled in the error case. [Richard] Yes, it is. the phy clock should be disabled. > + ret = clk_get_rate(ahb_clk) / 1000; > + writel(ret, mmio + HOST_TIMER1MS); > + devm_clk_put(dev, ahb_clk); > + > + return 0; > +} > + > +static void imx6q_sata_exit(struct device *dev) > +{ > + struct regmap *gpr; > + > + gpr = syscon_regmap_lookup_by_compatible("fsl,imx6q-iomuxc-gpr"); > + if (IS_ERR(gpr)) > + dev_err(dev, "failed to find fsl,imx6q-iomux-gpr regmap\n"); > + > + regmap_update_bits(gpr, 0x34, IMX6Q_GPR13_SATA_MPLL_CLK_EN, > + !IMX6Q_GPR13_SATA_MPLL_CLK_EN); > + > + imx6q_sata_phy_clk(dev, false); > +} > + > +static struct ahci_platform_data imx6q_sata_pdata = { > + .init = imx6q_sata_init, > + .exit = imx6q_sata_exit, > +}; > +static const struct of_device_id imx_ahci_of_match[] = { > + { .compatible = "fsl,imx6q-ahci", .data = &imx6q_sata_pdata}, > + {}, > +}; > +MODULE_DEVICE_TABLE(of, imx_ahci_of_match); > + > +static void imx_ahci_platform_release(struct device *dev) > +{ > + return; > +} > + > +static struct platform_device ahci_pdev = { > + .name = "ahci", > + .id = -1, > + .dev = { > + .release = imx_ahci_platform_release, > + } > +}; > + > +static int imx_ahci_probe(struct platform_device *pdev) > +{ > + struct device *dev = &pdev->dev; > + struct resource *mem, *irq, **res; > + const struct of_device_id *of_id; > + const struct ahci_platform_data *pdata = NULL; > + int ret; > + > + of_id = of_match_device(imx_ahci_of_match, &pdev->dev); > + if (of_id) > + pdata = of_id->data; > + else > + return -EINVAL; > + > + mem = platform_get_resource(pdev, IORESOURCE_MEM, 0); > + irq = platform_get_resource(pdev, IORESOURCE_IRQ, 0); > + if (!mem || !irq) { > + dev_err(dev, "no mmio/irq resource\n"); > + return -EINVAL; > + } > + > + ahci_pdev.dev.coherent_dma_mask = DMA_BIT_MASK(32); > + ahci_pdev.dev.dma_mask = &ahci_pdev.dev.coherent_dma_mask; > + ahci_pdev.dev.of_node = pdev->dev.of_node; No need to make ahci_pdev global. platform_device_add_data makes a copy anyway and making it global makes this driver broken for multiple instances. [Richard]accepted. > + > + res[0] = mem; > + res[1] = irq; You have an uninitalized pointer to a pointer to struct resource which you treat as an array here. Doesn't the compiler warn you? [Richard]Compiler doesn't report the warning message, anyway, I would fix it later. > + platform_device_add_resources(&ahci_pdev, *res, 2); > + platform_device_add_data(&ahci_pdev, pdata, sizeof(*pdata)); > + > + ret = platform_device_register(&ahci_pdev); > + if (!ret) > + return ret; s/!ret/ret/ [Richard] Would be fixed. Sascha -- Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | -- 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
