drivers/spi/spi-dw-mmio.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Memory-mapped interface driver for DW SPI Core
   4  *
   5  * Copyright (c) 2010, Octasic semiconductor.
   6  */
   7
   8 #include <linux/clk.h>
   9 #include <linux/err.h>
  10 #include <linux/interrupt.h>
  11 #include <linux/platform_device.h>
  12 #include <linux/pm_runtime.h>
  13 #include <linux/slab.h>
  14 #include <linux/spi/spi.h>
  15 #include <linux/scatterlist.h>
  16 #include <linux/mfd/syscon.h>
  17 #include <linux/module.h>
  18 #include <linux/of.h>
  19 #include <linux/of_platform.h>
  20 #include <linux/acpi.h>
  21 #include <linux/property.h>
  22 #include <linux/regmap.h>
  23
  24 #include "spi-dw.h"
  25
  26 #define DRIVER_NAME "dw_spi_mmio"
  27
  28 struct dw_spi_mmio {
  29         struct dw_spi  dws;
  30         struct clk     *clk;
  31         struct clk     *pclk;
  32         void           *priv;
  33 };
  34
  35 #define MSCC_CPU_SYSTEM_CTRL_GENERAL_CTRL       0x24
  36 #define OCELOT_IF_SI_OWNER_OFFSET               4
  37 #define JAGUAR2_IF_SI_OWNER_OFFSET              6
  38 #define MSCC_IF_SI_OWNER_MASK                   GENMASK(1, 0)
  39 #define MSCC_IF_SI_OWNER_SISL                   0
  40 #define MSCC_IF_SI_OWNER_SIBM                   1
  41 #define MSCC_IF_SI_OWNER_SIMC                   2
  42
  43 #define MSCC_SPI_MST_SW_MODE                    0x14
  44 #define MSCC_SPI_MST_SW_MODE_SW_PIN_CTRL_MODE   BIT(13)
  45 #define MSCC_SPI_MST_SW_MODE_SW_SPI_CS(x)       (x << 5)
  46
  47 struct dw_spi_mscc {
  48         struct regmap       *syscon;
  49         void __iomem        *spi_mst;
  50 };
  51
  52 /*
  53  * The Designware SPI controller (referred to as master in the documentation)
  54  * automatically deasserts chip select when the tx fifo is empty. The chip
  55  * selects then needs to be either driven as GPIOs or, for the first 4 using the
  56  * the SPI boot controller registers. the final chip select is an OR gate
  57  * between the Designware SPI controller and the SPI boot controller.
  58  */
  59 static void dw_spi_mscc_set_cs(struct spi_device *spi, bool enable)
  60 {
  61         struct dw_spi *dws = spi_master_get_devdata(spi->master);
  62         struct dw_spi_mmio *dwsmmio = container_of(dws, struct dw_spi_mmio, dws);
  63         struct dw_spi_mscc *dwsmscc = dwsmmio->priv;
  64         u32 cs = spi->chip_select;
  65
  66         if (cs < 4) {
  67                 u32 sw_mode = MSCC_SPI_MST_SW_MODE_SW_PIN_CTRL_MODE;
  68
  69                 if (!enable)
  70                         sw_mode |= MSCC_SPI_MST_SW_MODE_SW_SPI_CS(BIT(cs));
  71
  72                 writel(sw_mode, dwsmscc->spi_mst + MSCC_SPI_MST_SW_MODE);
  73         }
  74
  75         dw_spi_set_cs(spi, enable);
  76 }
  77
  78 static int dw_spi_mscc_init(struct platform_device *pdev,
  79                             struct dw_spi_mmio *dwsmmio,
  80                             const char *cpu_syscon, u32 if_si_owner_offset)
  81 {
  82         struct dw_spi_mscc *dwsmscc;
  83
  84         dwsmscc = devm_kzalloc(&pdev->dev, sizeof(*dwsmscc), GFP_KERNEL);
  85         if (!dwsmscc)
  86                 return -ENOMEM;
  87
  88         dwsmscc->spi_mst = devm_platform_ioremap_resource(pdev, 1);
  89         if (IS_ERR(dwsmscc->spi_mst)) {
  90                 dev_err(&pdev->dev, "SPI_MST region map failed\n");
  91                 return PTR_ERR(dwsmscc->spi_mst);
  92         }
  93
  94         dwsmscc->syscon = syscon_regmap_lookup_by_compatible(cpu_syscon);
  95         if (IS_ERR(dwsmscc->syscon))
  96                 return PTR_ERR(dwsmscc->syscon);
  97
  98         /* Deassert all CS */
  99         writel(0, dwsmscc->spi_mst + MSCC_SPI_MST_SW_MODE);
 100
 101         /* Select the owner of the SI interface */
 102         regmap_update_bits(dwsmscc->syscon, MSCC_CPU_SYSTEM_CTRL_GENERAL_CTRL,
 103                            MSCC_IF_SI_OWNER_MASK << if_si_owner_offset,
 104                            MSCC_IF_SI_OWNER_SIMC << if_si_owner_offset);
 105
 106         dwsmmio->dws.set_cs = dw_spi_mscc_set_cs;
 107         dwsmmio->priv = dwsmscc;
 108
 109         return 0;
 110 }
 111
 112 static int dw_spi_mscc_ocelot_init(struct platform_device *pdev,
 113                                    struct dw_spi_mmio *dwsmmio)
 114 {
 115         return dw_spi_mscc_init(pdev, dwsmmio, "mscc,ocelot-cpu-syscon",
 116                                 OCELOT_IF_SI_OWNER_OFFSET);
 117 }
 118
 119 static int dw_spi_mscc_jaguar2_init(struct platform_device *pdev,
 120                                     struct dw_spi_mmio *dwsmmio)
 121 {
 122         return dw_spi_mscc_init(pdev, dwsmmio, "mscc,jaguar2-cpu-syscon",
 123                                 JAGUAR2_IF_SI_OWNER_OFFSET);
 124 }
 125
 126 static int dw_spi_alpine_init(struct platform_device *pdev,
 127                               struct dw_spi_mmio *dwsmmio)
 128 {
 129         dwsmmio->dws.cs_override = 1;
 130
 131         return 0;
 132 }
 133
 134 static int dw_spi_mmio_probe(struct platform_device *pdev)
 135 {
 136         int (*init_func)(struct platform_device *pdev,
 137                          struct dw_spi_mmio *dwsmmio);
 138         struct dw_spi_mmio *dwsmmio;
 139         struct dw_spi *dws;
 140         int ret;
 141         int num_cs;
 142
 143         dwsmmio = devm_kzalloc(&pdev->dev, sizeof(struct dw_spi_mmio),
 144                         GFP_KERNEL);
 145         if (!dwsmmio)
 146                 return -ENOMEM;
 147
 148         dws = &dwsmmio->dws;
 149
 150         /* Get basic io resource and map it */
 151         dws->regs = devm_platform_ioremap_resource(pdev, 0);
 152         if (IS_ERR(dws->regs)) {
 153                 dev_err(&pdev->dev, "SPI region map failed\n");
 154                 return PTR_ERR(dws->regs);
 155         }
 156
 157         dws->irq = platform_get_irq(pdev, 0);
 158         if (dws->irq < 0)
 159                 return dws->irq; /* -ENXIO */
 160
 161         dwsmmio->clk = devm_clk_get(&pdev->dev, NULL);
 162         if (IS_ERR(dwsmmio->clk))
 163                 return PTR_ERR(dwsmmio->clk);
 164         ret = clk_prepare_enable(dwsmmio->clk);
 165         if (ret)
 166                 return ret;
 167
 168         /* Optional clock needed to access the registers */
 169         dwsmmio->pclk = devm_clk_get_optional(&pdev->dev, "pclk");
 170         if (IS_ERR(dwsmmio->pclk)) {
 171                 ret = PTR_ERR(dwsmmio->pclk);
 172                 goto out_clk;
 173         }
 174         ret = clk_prepare_enable(dwsmmio->pclk);
 175         if (ret)
 176                 goto out_clk;
 177
 178         dws->bus_num = pdev->id;
 179
 180         dws->max_freq = clk_get_rate(dwsmmio->clk);
 181
 182         device_property_read_u32(&pdev->dev, "reg-io-width", &dws->reg_io_width);
 183
 184         num_cs = 4;
 185
 186         device_property_read_u32(&pdev->dev, "num-cs", &num_cs);
 187
 188         dws->num_cs = num_cs;
 189
 190         init_func = device_get_match_data(&pdev->dev);
 191         if (init_func) {
 192                 ret = init_func(pdev, dwsmmio);
 193                 if (ret)
 194                         goto out;
 195         }
 196
 197         pm_runtime_enable(&pdev->dev);
 198
 199         ret = dw_spi_add_host(&pdev->dev, dws);
 200         if (ret)
 201                 goto out;
 202
 203         platform_set_drvdata(pdev, dwsmmio);
 204         return 0;
 205
 206 out:
 207         pm_runtime_disable(&pdev->dev);
 208         clk_disable_unprepare(dwsmmio->pclk);
 209 out_clk:
 210         clk_disable_unprepare(dwsmmio->clk);
 211         return ret;
 212 }
 213
 214 static int dw_spi_mmio_remove(struct platform_device *pdev)
 215 {
 216         struct dw_spi_mmio *dwsmmio = platform_get_drvdata(pdev);
 217
 218         dw_spi_remove_host(&dwsmmio->dws);
 219         pm_runtime_disable(&pdev->dev);
 220         clk_disable_unprepare(dwsmmio->pclk);
 221         clk_disable_unprepare(dwsmmio->clk);
 222
 223         return 0;
 224 }
 225
 226 static const struct of_device_id dw_spi_mmio_of_match[] = {
 227         { .compatible = "snps,dw-apb-ssi", },
 228         { .compatible = "mscc,ocelot-spi", .data = dw_spi_mscc_ocelot_init},
 229         { .compatible = "mscc,jaguar2-spi", .data = dw_spi_mscc_jaguar2_init},
 230         { .compatible = "amazon,alpine-dw-apb-ssi", .data = dw_spi_alpine_init},
 231         { .compatible = "renesas,rzn1-spi", },
 232         { /* end of table */}
 233 };
 234 MODULE_DEVICE_TABLE(of, dw_spi_mmio_of_match);
 235
 236 static const struct acpi_device_id dw_spi_mmio_acpi_match[] = {
 237         {"HISI0173", 0},
 238         {},
 239 };
 240 MODULE_DEVICE_TABLE(acpi, dw_spi_mmio_acpi_match);
 241
 242 static struct platform_driver dw_spi_mmio_driver = {
 243         .probe          = dw_spi_mmio_probe,
 244         .remove         = dw_spi_mmio_remove,
 245         .driver         = {
 246                 .name   = DRIVER_NAME,
 247                 .of_match_table = dw_spi_mmio_of_match,
 248                 .acpi_match_table = ACPI_PTR(dw_spi_mmio_acpi_match),
 249         },
 250 };
 251 module_platform_driver(dw_spi_mmio_driver);
 252
 253 MODULE_AUTHOR("Jean-Hugues Deschenes <jean-hugues.deschenes@octasic.com>");
 254 MODULE_DESCRIPTION("Memory-mapped I/O interface driver for DW SPI Core");
 255 MODULE_LICENSE("GPL v2");