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