From bac70b54ecb53b3d5af862dd4fcbaaad8f34ed23 Mon Sep 17 00:00:00 2001 From: Lars Povlsen Date: Mon, 24 Aug 2020 22:30:05 +0200 Subject: [PATCH 1/3] spi: dw: Add support for RX sample delay register This add support for the RX_SAMPLE_DLY register. If enabled in the Designware IP, it allows tuning of the rx data signal by means of an internal rx sample fifo. The register is controlled by the rx-sample-delay-ns DT property, which is defined per SPI slave as well on controller level. The controller level rx-sample-delay-ns will apply to all slaves without the property explicitly defined. The register is located at offset 0xf0, and if the option is not enabled in the IP, changing the register will have no effect. The register will only be written if any slave defines a nonzero value (after scaling by the clock period). Signed-off-by: Lars Povlsen Link: https://lore.kernel.org/r/20200824203010.2033-2-lars.povlsen@microchip.com Signed-off-by: Mark Brown --- drivers/spi/spi-dw-core.c | 26 ++++++++++++++++++++++++++ drivers/spi/spi-dw.h | 3 +++ 2 files changed, 29 insertions(+) diff --git a/drivers/spi/spi-dw-core.c b/drivers/spi/spi-dw-core.c index 323c66c5db50..55afdcee7d2b 100644 --- a/drivers/spi/spi-dw-core.c +++ b/drivers/spi/spi-dw-core.c @@ -12,6 +12,7 @@ #include #include #include +#include #include "spi-dw.h" @@ -26,6 +27,8 @@ struct chip_data { u16 clk_div; /* baud rate divider */ u32 speed_hz; /* baud rate */ + + u32 rx_sample_dly; /* RX sample delay */ }; #ifdef CONFIG_DEBUG_FS @@ -52,6 +55,7 @@ static const struct debugfs_reg32 dw_spi_dbgfs_regs[] = { DW_SPI_DBGFS_REG("DMACR", DW_SPI_DMACR), DW_SPI_DBGFS_REG("DMATDLR", DW_SPI_DMATDLR), DW_SPI_DBGFS_REG("DMARDLR", DW_SPI_DMARDLR), + DW_SPI_DBGFS_REG("RX_SAMPLE_DLY", DW_SPI_RX_SAMPLE_DLY), }; static int dw_spi_debugfs_init(struct dw_spi *dws) @@ -328,6 +332,12 @@ static int dw_spi_transfer_one(struct spi_controller *master, if (master->can_dma && master->can_dma(master, spi, transfer)) dws->dma_mapped = master->cur_msg_mapped; + /* Update RX sample delay if required */ + if (dws->cur_rx_sample_dly != chip->rx_sample_dly) { + dw_writel(dws, DW_SPI_RX_SAMPLE_DLY, chip->rx_sample_dly); + dws->cur_rx_sample_dly = chip->rx_sample_dly; + } + /* For poll mode just disable all interrupts */ spi_mask_intr(dws, 0xff); @@ -380,10 +390,22 @@ static int dw_spi_setup(struct spi_device *spi) /* Only alloc on first setup */ chip = spi_get_ctldata(spi); if (!chip) { + struct dw_spi *dws = spi_controller_get_devdata(spi->controller); + u32 rx_sample_dly_ns; + chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL); if (!chip) return -ENOMEM; spi_set_ctldata(spi, chip); + /* Get specific / default rx-sample-delay */ + if (device_property_read_u32(&spi->dev, + "rx-sample-delay-ns", + &rx_sample_dly_ns) != 0) + /* Use default controller value */ + rx_sample_dly_ns = dws->def_rx_sample_dly_ns; + chip->rx_sample_dly = DIV_ROUND_CLOSEST(rx_sample_dly_ns, + NSEC_PER_SEC / + dws->max_freq); } chip->tmode = SPI_TMOD_TR; @@ -472,6 +494,10 @@ int dw_spi_add_host(struct device *dev, struct dw_spi *dws) if (dws->set_cs) master->set_cs = dws->set_cs; + /* Get default rx sample delay */ + device_property_read_u32(dev, "rx-sample-delay-ns", + &dws->def_rx_sample_dly_ns); + /* Basic HW init */ spi_hw_init(dev, dws); diff --git a/drivers/spi/spi-dw.h b/drivers/spi/spi-dw.h index 151ba316619e..90dfd21622d6 100644 --- a/drivers/spi/spi-dw.h +++ b/drivers/spi/spi-dw.h @@ -34,6 +34,7 @@ #define DW_SPI_IDR 0x58 #define DW_SPI_VERSION 0x5c #define DW_SPI_DR 0x60 +#define DW_SPI_RX_SAMPLE_DLY 0xf0 #define DW_SPI_CS_OVERRIDE 0xf4 /* Bit fields in CTRLR0 */ @@ -140,6 +141,8 @@ struct dw_spi { u8 n_bytes; /* current is a 1/2 bytes op */ irqreturn_t (*transfer_handler)(struct dw_spi *dws); u32 current_freq; /* frequency in hz */ + u32 cur_rx_sample_dly; + u32 def_rx_sample_dly_ns; /* DMA info */ struct dma_chan *txchan; From 53a09635ce56e3041fb3cbc7ceef8f5de28259a5 Mon Sep 17 00:00:00 2001 From: Lars Povlsen Date: Mon, 24 Aug 2020 22:30:06 +0200 Subject: [PATCH 2/3] spi: dw: Add Microchip Sparx5 support This adds SPI support for the Sparx5 SoC, which is using the MMIO Designware SPI controller. The Sparx5 differs from the Ocelot version in these areas: * The CS override is controlled by a new set of registers for this purpose. * The Sparx5 SPI controller has the RX sample delay register, and it must be configured for the (SPI NAND) device on SPI2. * The Sparx5 SPI controller has 2 different SPI bus interfaces on the same controller (don't ask...). The "spi-mux" driver should be used in conjunction with the SPI driver to select the appropriate bus. Signed-off-by: Lars Povlsen Link: https://lore.kernel.org/r/20200824203010.2033-3-lars.povlsen@microchip.com Signed-off-by: Mark Brown --- drivers/spi/spi-dw-mmio.c | 70 ++++++++++++++++++++++++++++++++++++++- 1 file changed, 69 insertions(+), 1 deletion(-) diff --git a/drivers/spi/spi-dw-mmio.c b/drivers/spi/spi-dw-mmio.c index 403403deae66..18772c0c9220 100644 --- a/drivers/spi/spi-dw-mmio.c +++ b/drivers/spi/spi-dw-mmio.c @@ -45,6 +45,9 @@ struct dw_spi_mmio { #define MSCC_SPI_MST_SW_MODE_SW_PIN_CTRL_MODE BIT(13) #define MSCC_SPI_MST_SW_MODE_SW_SPI_CS(x) (x << 5) +#define SPARX5_FORCE_ENA 0xa4 +#define SPARX5_FORCE_VAL 0xa8 + /* * For Keem Bay, CTRLR0[31] is used to select controller mode. * 0: SSI is slave @@ -54,7 +57,7 @@ struct dw_spi_mmio { struct dw_spi_mscc { struct regmap *syscon; - void __iomem *spi_mst; + void __iomem *spi_mst; /* Not sparx5 */ }; /* @@ -134,6 +137,70 @@ static int dw_spi_mscc_jaguar2_init(struct platform_device *pdev, JAGUAR2_IF_SI_OWNER_OFFSET); } +/* + * The Designware SPI controller (referred to as master in the + * documentation) automatically deasserts chip select when the tx fifo + * is empty. The chip selects then needs to be driven by a CS override + * register. enable is an active low signal. + */ +static void dw_spi_sparx5_set_cs(struct spi_device *spi, bool enable) +{ + struct dw_spi *dws = spi_master_get_devdata(spi->master); + struct dw_spi_mmio *dwsmmio = container_of(dws, struct dw_spi_mmio, dws); + struct dw_spi_mscc *dwsmscc = dwsmmio->priv; + u8 cs = spi->chip_select; + + if (!enable) { + /* CS override drive enable */ + regmap_write(dwsmscc->syscon, SPARX5_FORCE_ENA, 1); + /* Now set CSx enabled */ + regmap_write(dwsmscc->syscon, SPARX5_FORCE_VAL, ~BIT(cs)); + /* Allow settle */ + usleep_range(1, 5); + } else { + /* CS value */ + regmap_write(dwsmscc->syscon, SPARX5_FORCE_VAL, ~0); + /* Allow settle */ + usleep_range(1, 5); + /* CS override drive disable */ + regmap_write(dwsmscc->syscon, SPARX5_FORCE_ENA, 0); + } + + dw_spi_set_cs(spi, enable); +} + +static int dw_spi_mscc_sparx5_init(struct platform_device *pdev, + struct dw_spi_mmio *dwsmmio) +{ + const char *syscon_name = "microchip,sparx5-cpu-syscon"; + struct device *dev = &pdev->dev; + struct dw_spi_mscc *dwsmscc; + + if (!IS_ENABLED(CONFIG_SPI_MUX)) { + dev_err(dev, "This driver needs CONFIG_SPI_MUX\n"); + return -EOPNOTSUPP; + } + + dwsmscc = devm_kzalloc(dev, sizeof(*dwsmscc), GFP_KERNEL); + if (!dwsmscc) + return -ENOMEM; + + dwsmscc->syscon = + syscon_regmap_lookup_by_compatible(syscon_name); + if (IS_ERR(dwsmscc->syscon)) { + dev_err(dev, "No syscon map %s\n", syscon_name); + return PTR_ERR(dwsmscc->syscon); + } + + dwsmmio->dws.set_cs = dw_spi_sparx5_set_cs; + dwsmmio->priv = dwsmscc; + + /* Register hook to configure CTRLR0 */ + dwsmmio->dws.update_cr0 = dw_spi_update_cr0; + + return 0; +} + static int dw_spi_alpine_init(struct platform_device *pdev, struct dw_spi_mmio *dwsmmio) { @@ -297,6 +364,7 @@ static const struct of_device_id dw_spi_mmio_of_match[] = { { .compatible = "renesas,rzn1-spi", .data = dw_spi_dw_apb_init}, { .compatible = "snps,dwc-ssi-1.01a", .data = dw_spi_dwc_ssi_init}, { .compatible = "intel,keembay-ssi", .data = dw_spi_keembay_init}, + { .compatible = "microchip,sparx5-spi", dw_spi_mscc_sparx5_init}, { /* end of table */} }; MODULE_DEVICE_TABLE(of, dw_spi_mmio_of_match); From 5ce78f4456a9b2cb103f5bad9e62636e8d086152 Mon Sep 17 00:00:00 2001 From: Lars Povlsen Date: Mon, 24 Aug 2020 22:30:08 +0200 Subject: [PATCH 3/3] dt-bindings: snps, dw-apb-ssi: Add sparx5 support, plus rx-sample-delay-ns property This has the following changes for the snps,dw-apb-ss DT bindings: - Add "microchip,sparx5-spi" as the compatible for the Sparx5 SoC controller - Add the property "rx-sample-delay-ns" Signed-off-by: Lars Povlsen Reviewed-by: Rob Herring Link: https://lore.kernel.org/r/20200824203010.2033-5-lars.povlsen@microchip.com Signed-off-by: Mark Brown --- .../bindings/spi/snps,dw-apb-ssi.yaml | 21 +++++++++++++++++++ 1 file changed, 21 insertions(+) diff --git a/Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.yaml b/Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.yaml index c62cbe79f00d..c79c8a167c46 100644 --- a/Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.yaml +++ b/Documentation/devicetree/bindings/spi/snps,dw-apb-ssi.yaml @@ -36,6 +36,8 @@ properties: - mscc,ocelot-spi - mscc,jaguar2-spi - const: snps,dw-apb-ssi + - description: Microchip Sparx5 SoC SPI Controller + const: microchip,sparx5-spi - description: Amazon Alpine SPI Controller const: amazon,alpine-dw-apb-ssi - description: Renesas RZ/N1 SPI Controller @@ -93,6 +95,12 @@ properties: - const: tx - const: rx + rx-sample-delay-ns: + default: 0 + description: Default value of the rx-sample-delay-ns property. + This value will be used if the property is not explicitly defined + for a SPI slave device. See below. + patternProperties: "^.*@[0-9a-f]+$": type: object @@ -107,6 +115,13 @@ patternProperties: spi-tx-bus-width: const: 1 + rx-sample-delay-ns: + description: SPI Rx sample delay offset, unit is nanoseconds. + The delay from the default sample time before the actual + sample of the rxd input signal occurs. The "rx_sample_delay" + is an optional feature of the designware controller, and the + upper limit is also subject to controller configuration. + unevaluatedProperties: false required: @@ -129,5 +144,11 @@ examples: num-cs = <2>; cs-gpios = <&gpio0 13 0>, <&gpio0 14 0>; + rx-sample-delay-ns = <3>; + spi-flash@1 { + compatible = "spi-nand"; + reg = <1>; + rx-sample-delay-ns = <7>; + }; }; ...