Re: [PATCH v3] SATA: OCTEON: support SATA on OCTEON platform

From: Hans de Goede
Date: Fri Mar 06 2015 - 05:12:03 EST


Hi,

On 05-03-15 15:58, Aleksey Makarov wrote:
The OCTEON SATA controller is currently found on cn71XX devices.

Signed-off-by: David Daney <david.daney@xxxxxxxxxx>
Signed-off-by: Vinita Gupta <vgupta@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Aleksey Makarov <aleksey.makarov@xxxxxxxxxx>
---

Version 2:
https://lkml.kernel.org/g/<1422038495-5204-1-git-send-email-aleksey.makarov@xxxxxxxxxx>

Changes in v3:
- Rebased to v4.0-rc2
- Cosmetic changes

Changes in v2:
- The driver was rewritten as a driver for the UCTL SATA controller glue.
It allowed to get rid of the most changes in ahci_platform.c
- Documentation for the device tree bindings was fixed.

.../devicetree/bindings/ata/ahci-platform.txt | 1 +
.../devicetree/bindings/mips/cavium/sata-uctl.txt | 28 ++++
drivers/ata/Kconfig | 9 ++
drivers/ata/Makefile | 1 +
drivers/ata/ahci_platform.c | 1 +
drivers/ata/sata_octeon.c | 157 +++++++++++++++++++++
6 files changed, 197 insertions(+)
create mode 100644 Documentation/devicetree/bindings/mips/cavium/sata-uctl.txt
create mode 100644 drivers/ata/sata_octeon.c

diff --git a/Documentation/devicetree/bindings/ata/ahci-platform.txt b/Documentation/devicetree/bindings/ata/ahci-platform.txt
index c2340ee..3d84dca 100644
--- a/Documentation/devicetree/bindings/ata/ahci-platform.txt
+++ b/Documentation/devicetree/bindings/ata/ahci-platform.txt
@@ -11,6 +11,7 @@ Required properties:
- compatible : compatible string, one of:
- "allwinner,sun4i-a10-ahci"
- "hisilicon,hisi-ahci"
+ - "cavium,octeon-7130-ahci"
- "ibm,476gtr-ahci"
- "marvell,armada-380-ahci"
- "snps,dwc-ahci"
diff --git a/Documentation/devicetree/bindings/mips/cavium/sata-uctl.txt b/Documentation/devicetree/bindings/mips/cavium/sata-uctl.txt
new file mode 100644
index 0000000..59e86a7
--- /dev/null
+++ b/Documentation/devicetree/bindings/mips/cavium/sata-uctl.txt
@@ -0,0 +1,28 @@
+* UCTL SATA controller glue
+
+Properties:
+- compatible: "cavium,octeon-7130-sata-uctl"
+
+ Compatibility with the cn7130 SOC.
+
+- reg: The base address of the UCTL register bank.
+
+- #address-cells, #size-cells, and ranges must be present and hold
+ suitable values to map all child nodes.
+
+Example:
+
+ uctl@118006c000000 {
+ compatible = "cavium,octeon-7130-sata-uctl";
+ reg = <0x11800 0x6c000000 0x0 0x100>;
+ ranges; /* Direct mapping */
+ #address-cells = <2>;
+ #size-cells = <2>;
+
+ sata: sata@16c0000000000 {
+ compatible = "cavium,octeon-7130-ahci";
+ reg = <0x16c00 0x00000000 0x0 0x200>;
+ interrupt-parent = <&cibsata>;
+ interrupts = <2 4>; /* Bit: 2, level */
+ };
+ };

Sorry for jumping into this discussion a bit late, but this nonsense
nesting of what clearly are 2 related but different hw blocks,
both living at completely different register addresses is unacceptable,
this is not a proper operating system dependent hw description as
devicetree is supposed to be. This is an ugly hack to ensure a
certain init ordering, and requiring manual instantiation of
the platform device for the nested dt-node.

NACK.

The proper solution for this would be to have a single sata node,
with 2 register ranges, the first one for the actual ahci block,
and the second range for the uctl glue, and then write your
own ahci_octeon.c platform driver (you can start with a copy of
ahci_platform.c) which can do the uctl poking in its probe function
before calling ahci_platform_get_resources,
ahci_platform_enable_resources and ahci_platform_init_host.

Minus the standard boilerplate ahci_platform.c is only 60 lines,
it is THAT small because we've put all the common ahci-platform
code into libahci_platform.c exactly so that it is trivial to
create new ahci-platform drivers for special cases like this,
so that we do not need to do these kind of ugly hacks.

Actually libahciplatform was specifically written to remove a couple
of very similar hacks with platform device drivers instantiating
more platform devices from the kernel ...

Regards,

Hans






diff --git a/drivers/ata/Kconfig b/drivers/ata/Kconfig
index 5f60155..55ad870 100644
--- a/drivers/ata/Kconfig
+++ b/drivers/ata/Kconfig
@@ -188,6 +188,15 @@ config SATA_SIL24

If unsure, say N.

+config SATA_OCTEON
+ tristate "Cavium Octeon Soc Serial ATA"
+ depends on SATA_AHCI_PLATFORM && CAVIUM_OCTEON_SOC
+ default y
+ help
+ This option enables support for Cavium Octeon SoC Serial ATA.
+
+ If unsure, say N.
+
config ATA_SFF
bool "ATA SFF support (for legacy IDE and PATA)"
default y
diff --git a/drivers/ata/Makefile b/drivers/ata/Makefile
index ae41107..4a0e5e3 100644
--- a/drivers/ata/Makefile
+++ b/drivers/ata/Makefile
@@ -17,6 +17,7 @@ obj-$(CONFIG_AHCI_SUNXI) += ahci_sunxi.o libahci.o libahci_platform.o
obj-$(CONFIG_AHCI_ST) += ahci_st.o libahci.o libahci_platform.o
obj-$(CONFIG_AHCI_TEGRA) += ahci_tegra.o libahci.o libahci_platform.o
obj-$(CONFIG_AHCI_XGENE) += ahci_xgene.o libahci.o libahci_platform.o
+obj-$(CONFIG_SATA_OCTEON) += sata_octeon.o

# SFF w/ custom DMA
obj-$(CONFIG_PDC_ADMA) += pdc_adma.o
diff --git a/drivers/ata/ahci_platform.c b/drivers/ata/ahci_platform.c
index 78d6ae0..2c26cde 100644
--- a/drivers/ata/ahci_platform.c
+++ b/drivers/ata/ahci_platform.c
@@ -74,6 +74,7 @@ static const struct of_device_id ahci_of_match[] = {
{ .compatible = "ibm,476gtr-ahci", },
{ .compatible = "snps,dwc-ahci", },
{ .compatible = "hisilicon,hisi-ahci", },
+ { .compatible = "cavium,octeon-7130-ahci", },
{},
};
MODULE_DEVICE_TABLE(of, ahci_of_match);
diff --git a/drivers/ata/sata_octeon.c b/drivers/ata/sata_octeon.c
new file mode 100644
index 0000000..338ea86
--- /dev/null
+++ b/drivers/ata/sata_octeon.c
@@ -0,0 +1,157 @@
+/*
+ * SATA glue for Cavium Octeon III SOCs.
+ *
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2010-2015 Cavium Networks
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/dma-mapping.h>
+#include <linux/platform_device.h>
+#include <linux/of_platform.h>
+
+#include <asm/octeon/octeon.h>
+#include <asm/bitfield.h>
+
+/**
+ * cvmx_sata_uctl_shim_cfg
+ * from cvmx-sata-defs.h
+ *
+ * Accessible by: only when A_CLKDIV_EN
+ * Reset by: IOI reset (srst_n) or SATA_UCTL_CTL[SATA_UCTL_RST]
+ * This register allows configuration of various shim (UCTL) features.
+ * Fields XS_NCB_OOB_* are captured when there are no outstanding OOB errors
+ * indicated in INTSTAT and a new OOB error arrives.
+ * Fields XS_BAD_DMA_* are captured when there are no outstanding DMA errors
+ * indicated in INTSTAT and a new DMA error arrives.
+ */
+union cvmx_sata_uctl_shim_cfg {
+ uint64_t u64;
+ struct cvmx_sata_uctl_shim_cfg_s {
+ /*
+ * Read/write error log for out-of-bound UAHC register access.
+ * 0 = read, 1 = write.
+ */
+ __BITFIELD_FIELD(uint64_t xs_ncb_oob_wrn : 1,
+ __BITFIELD_FIELD(uint64_t reserved_57_62 : 6,
+ /*
+ * SRCID error log for out-of-bound UAHC register access.
+ * The IOI outbound SRCID for the OOB error.
+ */
+ __BITFIELD_FIELD(uint64_t xs_ncb_oob_osrc : 9,
+ /*
+ * Read/write error log for bad DMA access from UAHC.
+ * 0 = read error log, 1 = write error log.
+ */
+ __BITFIELD_FIELD(uint64_t xm_bad_dma_wrn : 1,
+ __BITFIELD_FIELD(uint64_t reserved_44_46 : 3,
+ /*
+ * ErrType error log for bad DMA access from UAHC. Encodes the type of
+ * error encountered (error largest encoded value has priority).
+ * See SATA_UCTL_XM_BAD_DMA_TYPE_E.
+ */
+ __BITFIELD_FIELD(uint64_t xm_bad_dma_type : 4,
+ __BITFIELD_FIELD(uint64_t reserved_13_39 : 27,
+ /*
+ * Selects the IOI read command used by DMA accesses.
+ * See SATA_UCTL_DMA_READ_CMD_E.
+ */
+ __BITFIELD_FIELD(uint64_t dma_read_cmd : 1,
+ __BITFIELD_FIELD(uint64_t reserved_10_11 : 2,
+ /*
+ * Selects the endian format for DMA accesses to the L2C.
+ * See SATA_UCTL_ENDIAN_MODE_E.
+ */
+ __BITFIELD_FIELD(uint64_t dma_endian_mode : 2,
+ __BITFIELD_FIELD(uint64_t reserved_2_7 : 6,
+ /*
+ * Selects the endian format for IOI CSR accesses to the UAHC.
+ * Note that when UAHC CSRs are accessed via RSL, they are returned
+ * as big-endian. See SATA_UCTL_ENDIAN_MODE_E.
+ */
+ __BITFIELD_FIELD(uint64_t csr_endian_mode : 2,
+ ;))))))))))))
+ } s;
+};
+
+#define CVMX_SATA_UCTL_SHIM_CFG 0xE8
+
+static int ahci_octeon_probe(struct platform_device *pdev)
+{
+ union cvmx_sata_uctl_shim_cfg shim_cfg;
+ struct device *dev = &pdev->dev;
+ struct device_node *node = dev->of_node;
+ struct resource *res;
+ void __iomem *base;
+ int ret;
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ if (!res) {
+ dev_err(&pdev->dev, "Platform resource[0] is missing\n");
+ return -ENODEV;
+ }
+
+ base = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(base))
+ return PTR_ERR(base);
+
+ /* set-up endian mode */
+ shim_cfg.u64 = cvmx_read_csr((uint64_t)base + CVMX_SATA_UCTL_SHIM_CFG);
+#ifdef __BIG_ENDIAN
+ shim_cfg.s.dma_endian_mode = 1;
+ shim_cfg.s.csr_endian_mode = 1;
+#else
+ shim_cfg.s.dma_endian_mode = 0;
+ shim_cfg.s.csr_endian_mode = 0;
+#endif
+ shim_cfg.s.dma_read_cmd = 1; /* No allocate L2C */
+ cvmx_write_csr((uint64_t)base + CVMX_SATA_UCTL_SHIM_CFG, shim_cfg.u64);
+
+ ret = dma_coerce_mask_and_coherent(dev, DMA_BIT_MASK(64));
+ if (ret)
+ return ret;
+
+ if (!node) {
+ dev_err(dev, "no device node, failed to add octeon sata\n");
+ return -ENODEV;
+ }
+
+ ret = of_platform_populate(node, NULL, NULL, dev);
+ if (ret) {
+ dev_err(dev, "failed to add ahci-platform core\n");
+ return ret;
+ }
+
+ return 0;
+}
+
+static int ahci_octeon_remove(struct platform_device *pdev)
+{
+ return 0;
+}
+
+static const struct of_device_id octeon_ahci_match[] = {
+ { .compatible = "cavium,octeon-7130-sata-uctl", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, octeon_ahci_match);
+
+static struct platform_driver ahci_octeon_driver = {
+ .probe = ahci_octeon_probe,
+ .remove = ahci_octeon_remove,
+ .driver = {
+ .name = "octeon-ahci",
+ .of_match_table = octeon_ahci_match,
+ },
+};
+
+module_platform_driver(ahci_octeon_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Cavium, Inc. <support@xxxxxxxxxx>");
+MODULE_DESCRIPTION("Cavium Inc. sata config.");

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