1 // SPDX-License-Identifier: GPL-2.0-or-later 2 /* 3 * DaVinci DA850 AHCI SATA platform driver 4 */ 5 6 #include <linux/kernel.h> 7 #include <linux/module.h> 8 #include <linux/pm.h> 9 #include <linux/device.h> 10 #include <linux/platform_device.h> 11 #include <linux/libata.h> 12 #include <linux/ahci_platform.h> 13 #include "ahci.h" 14 15 #define DRV_NAME "ahci_da850" 16 #define HARDRESET_RETRIES 5 17 18 /* SATA PHY Control Register offset from AHCI base */ 19 #define SATA_P0PHYCR_REG 0x178 20 21 #define SATA_PHY_MPY(x) ((x) << 0) 22 #define SATA_PHY_LOS(x) ((x) << 6) 23 #define SATA_PHY_RXCDR(x) ((x) << 10) 24 #define SATA_PHY_RXEQ(x) ((x) << 13) 25 #define SATA_PHY_TXSWING(x) ((x) << 19) 26 #define SATA_PHY_ENPLL(x) ((x) << 31) 27 28 static void da850_sata_init(struct device *dev, void __iomem *pwrdn_reg, 29 void __iomem *ahci_base, u32 mpy) 30 { 31 unsigned int val; 32 33 /* Enable SATA clock receiver */ 34 val = readl(pwrdn_reg); 35 val &= ~BIT(0); 36 writel(val, pwrdn_reg); 37 38 val = SATA_PHY_MPY(mpy) | SATA_PHY_LOS(1) | SATA_PHY_RXCDR(4) | 39 SATA_PHY_RXEQ(1) | SATA_PHY_TXSWING(3) | SATA_PHY_ENPLL(1); 40 41 writel(val, ahci_base + SATA_P0PHYCR_REG); 42 } 43 44 static u32 ahci_da850_calculate_mpy(unsigned long refclk_rate) 45 { 46 u32 pll_output = 1500000000, needed; 47 48 /* 49 * We need to determine the value of the multiplier (MPY) bits. 50 * In order to include the 12.5 multiplier we need to first divide 51 * the refclk rate by ten. 52 * 53 * __div64_32() turned out to be unreliable, sometimes returning 54 * false results. 55 */ 56 WARN((refclk_rate % 10) != 0, "refclk must be divisible by 10"); 57 needed = pll_output / (refclk_rate / 10); 58 59 /* 60 * What we have now is (multiplier * 10). 61 * 62 * Let's determine the actual register value we need to write. 63 */ 64 65 switch (needed) { 66 case 50: 67 return 0x1; 68 case 60: 69 return 0x2; 70 case 80: 71 return 0x4; 72 case 100: 73 return 0x5; 74 case 120: 75 return 0x6; 76 case 125: 77 return 0x7; 78 case 150: 79 return 0x8; 80 case 200: 81 return 0x9; 82 case 250: 83 return 0xa; 84 default: 85 /* 86 * We should have divided evenly - if not, return an invalid 87 * value. 88 */ 89 return 0; 90 } 91 } 92 93 static int ahci_da850_softreset(struct ata_link *link, 94 unsigned int *class, unsigned long deadline) 95 { 96 int pmp, ret; 97 98 pmp = sata_srst_pmp(link); 99 100 /* 101 * There's an issue with the SATA controller on da850 SoCs: if we 102 * enable Port Multiplier support, but the drive is connected directly 103 * to the board, it can't be detected. As a workaround: if PMP is 104 * enabled, we first call ahci_do_softreset() and pass it the result of 105 * sata_srst_pmp(). If this call fails, we retry with pmp = 0. 106 */ 107 ret = ahci_do_softreset(link, class, pmp, deadline, ahci_check_ready); 108 if (pmp && ret == -EBUSY) 109 return ahci_do_softreset(link, class, 0, 110 deadline, ahci_check_ready); 111 112 return ret; 113 } 114 115 static int ahci_da850_hardreset(struct ata_link *link, 116 unsigned int *class, unsigned long deadline) 117 { 118 int ret, retry = HARDRESET_RETRIES; 119 bool online; 120 121 /* 122 * In order to correctly service the LCD controller of the da850 SoC, 123 * we increased the PLL0 frequency to 456MHz from the default 300MHz. 124 * 125 * This made the SATA controller unstable and the hardreset operation 126 * does not always succeed the first time. Before really giving up to 127 * bring up the link, retry the reset a couple times. 128 */ 129 do { 130 ret = ahci_do_hardreset(link, class, deadline, &online); 131 if (online) 132 return ret; 133 } while (retry--); 134 135 return ret; 136 } 137 138 static struct ata_port_operations ahci_da850_port_ops = { 139 .inherits = &ahci_platform_ops, 140 .softreset = ahci_da850_softreset, 141 /* 142 * No need to override .pmp_softreset - it's only used for actual 143 * PMP-enabled ports. 144 */ 145 .hardreset = ahci_da850_hardreset, 146 .pmp_hardreset = ahci_da850_hardreset, 147 }; 148 149 static const struct ata_port_info ahci_da850_port_info = { 150 .flags = AHCI_FLAG_COMMON, 151 .pio_mask = ATA_PIO4, 152 .udma_mask = ATA_UDMA6, 153 .port_ops = &ahci_da850_port_ops, 154 }; 155 156 static struct scsi_host_template ahci_platform_sht = { 157 AHCI_SHT(DRV_NAME), 158 }; 159 160 static int ahci_da850_probe(struct platform_device *pdev) 161 { 162 struct device *dev = &pdev->dev; 163 struct ahci_host_priv *hpriv; 164 void __iomem *pwrdn_reg; 165 struct resource *res; 166 struct clk *clk; 167 u32 mpy; 168 int rc; 169 170 hpriv = ahci_platform_get_resources(pdev, 0); 171 if (IS_ERR(hpriv)) 172 return PTR_ERR(hpriv); 173 174 /* 175 * Internally ahci_platform_get_resources() calls clk_get(dev, NULL) 176 * when trying to obtain the functional clock. This SATA controller 177 * uses two clocks for which we specify two connection ids. If we don't 178 * have the functional clock at this point - call clk_get() again with 179 * con_id = "fck". 180 */ 181 if (!hpriv->clks[0]) { 182 clk = clk_get(dev, "fck"); 183 if (IS_ERR(clk)) 184 return PTR_ERR(clk); 185 186 hpriv->clks[0] = clk; 187 } 188 189 /* 190 * The second clock used by ahci-da850 is the external REFCLK. If we 191 * didn't get it from ahci_platform_get_resources(), let's try to 192 * specify the con_id in clk_get(). 193 */ 194 if (!hpriv->clks[1]) { 195 clk = clk_get(dev, "refclk"); 196 if (IS_ERR(clk)) { 197 dev_err(dev, "unable to obtain the reference clock"); 198 return -ENODEV; 199 } 200 201 hpriv->clks[1] = clk; 202 } 203 204 mpy = ahci_da850_calculate_mpy(clk_get_rate(hpriv->clks[1])); 205 if (mpy == 0) { 206 dev_err(dev, "invalid REFCLK multiplier value: 0x%x", mpy); 207 return -EINVAL; 208 } 209 210 rc = ahci_platform_enable_resources(hpriv); 211 if (rc) 212 return rc; 213 214 res = platform_get_resource(pdev, IORESOURCE_MEM, 1); 215 if (!res) { 216 rc = -ENODEV; 217 goto disable_resources; 218 } 219 220 pwrdn_reg = devm_ioremap(dev, res->start, resource_size(res)); 221 if (!pwrdn_reg) { 222 rc = -ENOMEM; 223 goto disable_resources; 224 } 225 226 da850_sata_init(dev, pwrdn_reg, hpriv->mmio, mpy); 227 228 rc = ahci_platform_init_host(pdev, hpriv, &ahci_da850_port_info, 229 &ahci_platform_sht); 230 if (rc) 231 goto disable_resources; 232 233 return 0; 234 disable_resources: 235 ahci_platform_disable_resources(hpriv); 236 return rc; 237 } 238 239 static SIMPLE_DEV_PM_OPS(ahci_da850_pm_ops, ahci_platform_suspend, 240 ahci_platform_resume); 241 242 static const struct of_device_id ahci_da850_of_match[] = { 243 { .compatible = "ti,da850-ahci", }, 244 { }, 245 }; 246 MODULE_DEVICE_TABLE(of, ahci_da850_of_match); 247 248 static struct platform_driver ahci_da850_driver = { 249 .probe = ahci_da850_probe, 250 .remove = ata_platform_remove_one, 251 .driver = { 252 .name = DRV_NAME, 253 .of_match_table = ahci_da850_of_match, 254 .pm = &ahci_da850_pm_ops, 255 }, 256 }; 257 module_platform_driver(ahci_da850_driver); 258 259 MODULE_DESCRIPTION("DaVinci DA850 AHCI SATA platform driver"); 260 MODULE_AUTHOR("Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>"); 261 MODULE_LICENSE("GPL"); 262