1 // SPDX-License-Identifier: GPL-2.0-only 2 // Copyright (C) 2013 Broadcom Corporation 3 4 #include <linux/kernel.h> 5 #include <linux/module.h> 6 #include <linux/delay.h> 7 #include <linux/highmem.h> 8 #include <linux/platform_device.h> 9 #include <linux/mmc/host.h> 10 #include <linux/io.h> 11 #include <linux/clk.h> 12 #include <linux/regulator/consumer.h> 13 #include <linux/of.h> 14 #include <linux/of_device.h> 15 #include <linux/mmc/slot-gpio.h> 16 17 #include "sdhci-pltfm.h" 18 #include "sdhci.h" 19 20 #define SDHCI_SOFT_RESET 0x01000000 21 #define KONA_SDHOST_CORECTRL 0x8000 22 #define KONA_SDHOST_CD_PINCTRL 0x00000008 23 #define KONA_SDHOST_STOP_HCLK 0x00000004 24 #define KONA_SDHOST_RESET 0x00000002 25 #define KONA_SDHOST_EN 0x00000001 26 27 #define KONA_SDHOST_CORESTAT 0x8004 28 #define KONA_SDHOST_WP 0x00000002 29 #define KONA_SDHOST_CD_SW 0x00000001 30 31 #define KONA_SDHOST_COREIMR 0x8008 32 #define KONA_SDHOST_IP 0x00000001 33 34 #define KONA_SDHOST_COREISR 0x800C 35 #define KONA_SDHOST_COREIMSR 0x8010 36 #define KONA_SDHOST_COREDBG1 0x8014 37 #define KONA_SDHOST_COREGPO_MASK 0x8018 38 39 #define SD_DETECT_GPIO_DEBOUNCE_128MS 128 40 41 #define KONA_MMC_AUTOSUSPEND_DELAY (50) 42 43 struct sdhci_bcm_kona_dev { 44 struct mutex write_lock; /* protect back to back writes */ 45 }; 46 47 48 static int sdhci_bcm_kona_sd_reset(struct sdhci_host *host) 49 { 50 unsigned int val; 51 unsigned long timeout; 52 53 /* This timeout should be sufficent for core to reset */ 54 timeout = jiffies + msecs_to_jiffies(100); 55 56 /* reset the host using the top level reset */ 57 val = sdhci_readl(host, KONA_SDHOST_CORECTRL); 58 val |= KONA_SDHOST_RESET; 59 sdhci_writel(host, val, KONA_SDHOST_CORECTRL); 60 61 while (!(sdhci_readl(host, KONA_SDHOST_CORECTRL) & KONA_SDHOST_RESET)) { 62 if (time_is_before_jiffies(timeout)) { 63 pr_err("Error: sd host is stuck in reset!!!\n"); 64 return -EFAULT; 65 } 66 } 67 68 /* bring the host out of reset */ 69 val = sdhci_readl(host, KONA_SDHOST_CORECTRL); 70 val &= ~KONA_SDHOST_RESET; 71 72 /* 73 * Back-to-Back register write needs a delay of 1ms at bootup (min 10uS) 74 * Back-to-Back writes to same register needs delay when SD bus clock 75 * is very low w.r.t AHB clock, mainly during boot-time and during card 76 * insert-removal. 77 */ 78 usleep_range(1000, 5000); 79 sdhci_writel(host, val, KONA_SDHOST_CORECTRL); 80 81 return 0; 82 } 83 84 static void sdhci_bcm_kona_sd_init(struct sdhci_host *host) 85 { 86 unsigned int val; 87 88 /* enable the interrupt from the IP core */ 89 val = sdhci_readl(host, KONA_SDHOST_COREIMR); 90 val |= KONA_SDHOST_IP; 91 sdhci_writel(host, val, KONA_SDHOST_COREIMR); 92 93 /* Enable the AHB clock gating module to the host */ 94 val = sdhci_readl(host, KONA_SDHOST_CORECTRL); 95 val |= KONA_SDHOST_EN; 96 97 /* 98 * Back-to-Back register write needs a delay of 1ms at bootup (min 10uS) 99 * Back-to-Back writes to same register needs delay when SD bus clock 100 * is very low w.r.t AHB clock, mainly during boot-time and during card 101 * insert-removal. 102 */ 103 usleep_range(1000, 5000); 104 sdhci_writel(host, val, KONA_SDHOST_CORECTRL); 105 } 106 107 /* 108 * Software emulation of the SD card insertion/removal. Set insert=1 for insert 109 * and insert=0 for removal. The card detection is done by GPIO. For Broadcom 110 * IP to function properly the bit 0 of CORESTAT register needs to be set/reset 111 * to generate the CD IRQ handled in sdhci.c which schedules card_tasklet. 112 */ 113 static int sdhci_bcm_kona_sd_card_emulate(struct sdhci_host *host, int insert) 114 { 115 struct sdhci_pltfm_host *pltfm_priv = sdhci_priv(host); 116 struct sdhci_bcm_kona_dev *kona_dev = sdhci_pltfm_priv(pltfm_priv); 117 u32 val; 118 119 /* 120 * Back-to-Back register write needs a delay of min 10uS. 121 * Back-to-Back writes to same register needs delay when SD bus clock 122 * is very low w.r.t AHB clock, mainly during boot-time and during card 123 * insert-removal. 124 * We keep 20uS 125 */ 126 mutex_lock(&kona_dev->write_lock); 127 udelay(20); 128 val = sdhci_readl(host, KONA_SDHOST_CORESTAT); 129 130 if (insert) { 131 int ret; 132 133 ret = mmc_gpio_get_ro(host->mmc); 134 if (ret >= 0) 135 val = (val & ~KONA_SDHOST_WP) | 136 ((ret) ? KONA_SDHOST_WP : 0); 137 138 val |= KONA_SDHOST_CD_SW; 139 sdhci_writel(host, val, KONA_SDHOST_CORESTAT); 140 } else { 141 val &= ~KONA_SDHOST_CD_SW; 142 sdhci_writel(host, val, KONA_SDHOST_CORESTAT); 143 } 144 mutex_unlock(&kona_dev->write_lock); 145 146 return 0; 147 } 148 149 /* 150 * SD card interrupt event callback 151 */ 152 static void sdhci_bcm_kona_card_event(struct sdhci_host *host) 153 { 154 if (mmc_gpio_get_cd(host->mmc) > 0) { 155 dev_dbg(mmc_dev(host->mmc), 156 "card inserted\n"); 157 sdhci_bcm_kona_sd_card_emulate(host, 1); 158 } else { 159 dev_dbg(mmc_dev(host->mmc), 160 "card removed\n"); 161 sdhci_bcm_kona_sd_card_emulate(host, 0); 162 } 163 } 164 165 static void sdhci_bcm_kona_init_74_clocks(struct sdhci_host *host, 166 u8 power_mode) 167 { 168 /* 169 * JEDEC and SD spec specify supplying 74 continuous clocks to 170 * device after power up. With minimum bus (100KHz) that 171 * that translates to 740us 172 */ 173 if (power_mode != MMC_POWER_OFF) 174 udelay(740); 175 } 176 177 static const struct sdhci_ops sdhci_bcm_kona_ops = { 178 .set_clock = sdhci_set_clock, 179 .get_max_clock = sdhci_pltfm_clk_get_max_clock, 180 .get_timeout_clock = sdhci_pltfm_clk_get_max_clock, 181 .platform_send_init_74_clocks = sdhci_bcm_kona_init_74_clocks, 182 .set_bus_width = sdhci_set_bus_width, 183 .reset = sdhci_reset, 184 .set_uhs_signaling = sdhci_set_uhs_signaling, 185 .card_event = sdhci_bcm_kona_card_event, 186 }; 187 188 static const struct sdhci_pltfm_data sdhci_pltfm_data_kona = { 189 .ops = &sdhci_bcm_kona_ops, 190 .quirks = SDHCI_QUIRK_NO_CARD_NO_RESET | 191 SDHCI_QUIRK_BROKEN_TIMEOUT_VAL | SDHCI_QUIRK_32BIT_DMA_ADDR | 192 SDHCI_QUIRK_32BIT_DMA_SIZE | SDHCI_QUIRK_32BIT_ADMA_SIZE | 193 SDHCI_QUIRK_FORCE_BLK_SZ_2048 | 194 SDHCI_QUIRK_CAP_CLOCK_BASE_BROKEN, 195 }; 196 197 static const struct of_device_id sdhci_bcm_kona_of_match[] = { 198 { .compatible = "brcm,kona-sdhci"}, 199 { .compatible = "bcm,kona-sdhci"}, /* deprecated name */ 200 {} 201 }; 202 MODULE_DEVICE_TABLE(of, sdhci_bcm_kona_of_match); 203 204 static int sdhci_bcm_kona_probe(struct platform_device *pdev) 205 { 206 struct sdhci_bcm_kona_dev *kona_dev = NULL; 207 struct sdhci_pltfm_host *pltfm_priv; 208 struct device *dev = &pdev->dev; 209 struct sdhci_host *host; 210 int ret; 211 212 ret = 0; 213 214 host = sdhci_pltfm_init(pdev, &sdhci_pltfm_data_kona, 215 sizeof(*kona_dev)); 216 if (IS_ERR(host)) 217 return PTR_ERR(host); 218 219 dev_dbg(dev, "%s: inited. IOADDR=%p\n", __func__, host->ioaddr); 220 221 pltfm_priv = sdhci_priv(host); 222 223 kona_dev = sdhci_pltfm_priv(pltfm_priv); 224 mutex_init(&kona_dev->write_lock); 225 226 ret = mmc_of_parse(host->mmc); 227 if (ret) 228 goto err_pltfm_free; 229 230 if (!host->mmc->f_max) { 231 dev_err(&pdev->dev, "Missing max-freq for SDHCI cfg\n"); 232 ret = -ENXIO; 233 goto err_pltfm_free; 234 } 235 236 /* Get and enable the core clock */ 237 pltfm_priv->clk = devm_clk_get(dev, NULL); 238 if (IS_ERR(pltfm_priv->clk)) { 239 dev_err(dev, "Failed to get core clock\n"); 240 ret = PTR_ERR(pltfm_priv->clk); 241 goto err_pltfm_free; 242 } 243 244 ret = clk_set_rate(pltfm_priv->clk, host->mmc->f_max); 245 if (ret) { 246 dev_err(dev, "Failed to set rate core clock\n"); 247 goto err_pltfm_free; 248 } 249 250 ret = clk_prepare_enable(pltfm_priv->clk); 251 if (ret) { 252 dev_err(dev, "Failed to enable core clock\n"); 253 goto err_pltfm_free; 254 } 255 256 dev_dbg(dev, "non-removable=%c\n", 257 mmc_card_is_removable(host->mmc) ? 'N' : 'Y'); 258 dev_dbg(dev, "cd_gpio %c, wp_gpio %c\n", 259 (mmc_gpio_get_cd(host->mmc) != -ENOSYS) ? 'Y' : 'N', 260 (mmc_gpio_get_ro(host->mmc) != -ENOSYS) ? 'Y' : 'N'); 261 262 if (!mmc_card_is_removable(host->mmc)) 263 host->quirks |= SDHCI_QUIRK_BROKEN_CARD_DETECTION; 264 265 dev_dbg(dev, "is_8bit=%c\n", 266 (host->mmc->caps & MMC_CAP_8_BIT_DATA) ? 'Y' : 'N'); 267 268 ret = sdhci_bcm_kona_sd_reset(host); 269 if (ret) 270 goto err_clk_disable; 271 272 sdhci_bcm_kona_sd_init(host); 273 274 ret = sdhci_add_host(host); 275 if (ret) 276 goto err_reset; 277 278 /* if device is eMMC, emulate card insert right here */ 279 if (!mmc_card_is_removable(host->mmc)) { 280 ret = sdhci_bcm_kona_sd_card_emulate(host, 1); 281 if (ret) { 282 dev_err(dev, 283 "unable to emulate card insertion\n"); 284 goto err_remove_host; 285 } 286 } 287 /* 288 * Since the card detection GPIO interrupt is configured to be 289 * edge sensitive, check the initial GPIO value here, emulate 290 * only if the card is present 291 */ 292 if (mmc_gpio_get_cd(host->mmc) > 0) 293 sdhci_bcm_kona_sd_card_emulate(host, 1); 294 295 dev_dbg(dev, "initialized properly\n"); 296 return 0; 297 298 err_remove_host: 299 sdhci_remove_host(host, 0); 300 301 err_reset: 302 sdhci_bcm_kona_sd_reset(host); 303 304 err_clk_disable: 305 clk_disable_unprepare(pltfm_priv->clk); 306 307 err_pltfm_free: 308 sdhci_pltfm_free(pdev); 309 310 dev_err(dev, "Probing of sdhci-pltfm failed: %d\n", ret); 311 return ret; 312 } 313 314 static struct platform_driver sdhci_bcm_kona_driver = { 315 .driver = { 316 .name = "sdhci-kona", 317 .probe_type = PROBE_PREFER_ASYNCHRONOUS, 318 .pm = &sdhci_pltfm_pmops, 319 .of_match_table = sdhci_bcm_kona_of_match, 320 }, 321 .probe = sdhci_bcm_kona_probe, 322 .remove = sdhci_pltfm_unregister, 323 }; 324 module_platform_driver(sdhci_bcm_kona_driver); 325 326 MODULE_DESCRIPTION("SDHCI driver for Broadcom Kona platform"); 327 MODULE_AUTHOR("Broadcom"); 328 MODULE_LICENSE("GPL v2"); 329