1 /* 2 * DaVinci DA850 AHCI SATA platform driver 3 * 4 * This program is free software; you can redistribute it and/or modify 5 * it under the terms of the GNU General Public License as published by 6 * the Free Software Foundation; either version 2, or (at your option) 7 * any later version. 8 */ 9 10 #include <linux/kernel.h> 11 #include <linux/module.h> 12 #include <linux/pm.h> 13 #include <linux/device.h> 14 #include <linux/platform_device.h> 15 #include <linux/libata.h> 16 #include <linux/ahci_platform.h> 17 #include "ahci.h" 18 19 #define DRV_NAME "ahci_da850" 20 #define HARDRESET_RETRIES 5 21 22 /* SATA PHY Control Register offset from AHCI base */ 23 #define SATA_P0PHYCR_REG 0x178 24 25 #define SATA_PHY_MPY(x) ((x) << 0) 26 #define SATA_PHY_LOS(x) ((x) << 6) 27 #define SATA_PHY_RXCDR(x) ((x) << 10) 28 #define SATA_PHY_RXEQ(x) ((x) << 13) 29 #define SATA_PHY_TXSWING(x) ((x) << 19) 30 #define SATA_PHY_ENPLL(x) ((x) << 31) 31 32 static void da850_sata_init(struct device *dev, void __iomem *pwrdn_reg, 33 void __iomem *ahci_base, u32 mpy) 34 { 35 unsigned int val; 36 37 /* Enable SATA clock receiver */ 38 val = readl(pwrdn_reg); 39 val &= ~BIT(0); 40 writel(val, pwrdn_reg); 41 42 val = SATA_PHY_MPY(mpy) | SATA_PHY_LOS(1) | SATA_PHY_RXCDR(4) | 43 SATA_PHY_RXEQ(1) | SATA_PHY_TXSWING(3) | SATA_PHY_ENPLL(1); 44 45 writel(val, ahci_base + SATA_P0PHYCR_REG); 46 } 47 48 static u32 ahci_da850_calculate_mpy(unsigned long refclk_rate) 49 { 50 u32 pll_output = 1500000000, needed; 51 52 /* 53 * We need to determine the value of the multiplier (MPY) bits. 54 * In order to include the 12.5 multiplier we need to first divide 55 * the refclk rate by ten. 56 * 57 * __div64_32() turned out to be unreliable, sometimes returning 58 * false results. 59 */ 60 WARN((refclk_rate % 10) != 0, "refclk must be divisible by 10"); 61 needed = pll_output / (refclk_rate / 10); 62 63 /* 64 * What we have now is (multiplier * 10). 65 * 66 * Let's determine the actual register value we need to write. 67 */ 68 69 switch (needed) { 70 case 50: 71 return 0x1; 72 case 60: 73 return 0x2; 74 case 80: 75 return 0x4; 76 case 100: 77 return 0x5; 78 case 120: 79 return 0x6; 80 case 125: 81 return 0x7; 82 case 150: 83 return 0x8; 84 case 200: 85 return 0x9; 86 case 250: 87 return 0xa; 88 default: 89 /* 90 * We should have divided evenly - if not, return an invalid 91 * value. 92 */ 93 return 0; 94 } 95 } 96 97 static int ahci_da850_softreset(struct ata_link *link, 98 unsigned int *class, unsigned long deadline) 99 { 100 int pmp, ret; 101 102 pmp = sata_srst_pmp(link); 103 104 /* 105 * There's an issue with the SATA controller on da850 SoCs: if we 106 * enable Port Multiplier support, but the drive is connected directly 107 * to the board, it can't be detected. As a workaround: if PMP is 108 * enabled, we first call ahci_do_softreset() and pass it the result of 109 * sata_srst_pmp(). If this call fails, we retry with pmp = 0. 110 */ 111 ret = ahci_do_softreset(link, class, pmp, deadline, ahci_check_ready); 112 if (pmp && ret == -EBUSY) 113 return ahci_do_softreset(link, class, 0, 114 deadline, ahci_check_ready); 115 116 return ret; 117 } 118 119 static int ahci_da850_hardreset(struct ata_link *link, 120 unsigned int *class, unsigned long deadline) 121 { 122 int ret, retry = HARDRESET_RETRIES; 123 bool online; 124 125 /* 126 * In order to correctly service the LCD controller of the da850 SoC, 127 * we increased the PLL0 frequency to 456MHz from the default 300MHz. 128 * 129 * This made the SATA controller unstable and the hardreset operation 130 * does not always succeed the first time. Before really giving up to 131 * bring up the link, retry the reset a couple times. 132 */ 133 do { 134 ret = ahci_do_hardreset(link, class, deadline, &online); 135 if (online) 136 return ret; 137 } while (retry--); 138 139 return ret; 140 } 141 142 static struct ata_port_operations ahci_da850_port_ops = { 143 .inherits = &ahci_platform_ops, 144 .softreset = ahci_da850_softreset, 145 /* 146 * No need to override .pmp_softreset - it's only used for actual 147 * PMP-enabled ports. 148 */ 149 .hardreset = ahci_da850_hardreset, 150 .pmp_hardreset = ahci_da850_hardreset, 151 }; 152 153 static const struct ata_port_info ahci_da850_port_info = { 154 .flags = AHCI_FLAG_COMMON, 155 .pio_mask = ATA_PIO4, 156 .udma_mask = ATA_UDMA6, 157 .port_ops = &ahci_da850_port_ops, 158 }; 159 160 static struct scsi_host_template ahci_platform_sht = { 161 AHCI_SHT(DRV_NAME), 162 }; 163 164 static int ahci_da850_probe(struct platform_device *pdev) 165 { 166 struct device *dev = &pdev->dev; 167 struct ahci_host_priv *hpriv; 168 void __iomem *pwrdn_reg; 169 struct resource *res; 170 struct clk *clk; 171 u32 mpy; 172 int rc; 173 174 hpriv = ahci_platform_get_resources(pdev); 175 if (IS_ERR(hpriv)) 176 return PTR_ERR(hpriv); 177 178 /* 179 * Internally ahci_platform_get_resources() calls clk_get(dev, NULL) 180 * when trying to obtain the functional clock. This SATA controller 181 * uses two clocks for which we specify two connection ids. If we don't 182 * have the functional clock at this point - call clk_get() again with 183 * con_id = "fck". 184 */ 185 if (!hpriv->clks[0]) { 186 clk = clk_get(dev, "fck"); 187 if (IS_ERR(clk)) 188 return PTR_ERR(clk); 189 190 hpriv->clks[0] = clk; 191 } 192 193 /* 194 * The second clock used by ahci-da850 is the external REFCLK. If we 195 * didn't get it from ahci_platform_get_resources(), let's try to 196 * specify the con_id in clk_get(). 197 */ 198 if (!hpriv->clks[1]) { 199 clk = clk_get(dev, "refclk"); 200 if (IS_ERR(clk)) { 201 dev_err(dev, "unable to obtain the reference clock"); 202 return -ENODEV; 203 } 204 205 hpriv->clks[1] = clk; 206 } 207 208 mpy = ahci_da850_calculate_mpy(clk_get_rate(hpriv->clks[1])); 209 if (mpy == 0) { 210 dev_err(dev, "invalid REFCLK multiplier value: 0x%x", mpy); 211 return -EINVAL; 212 } 213 214 rc = ahci_platform_enable_resources(hpriv); 215 if (rc) 216 return rc; 217 218 res = platform_get_resource(pdev, IORESOURCE_MEM, 1); 219 if (!res) { 220 rc = -ENODEV; 221 goto disable_resources; 222 } 223 224 pwrdn_reg = devm_ioremap(dev, res->start, resource_size(res)); 225 if (!pwrdn_reg) { 226 rc = -ENOMEM; 227 goto disable_resources; 228 } 229 230 da850_sata_init(dev, pwrdn_reg, hpriv->mmio, mpy); 231 232 rc = ahci_platform_init_host(pdev, hpriv, &ahci_da850_port_info, 233 &ahci_platform_sht); 234 if (rc) 235 goto disable_resources; 236 237 return 0; 238 disable_resources: 239 ahci_platform_disable_resources(hpriv); 240 return rc; 241 } 242 243 static SIMPLE_DEV_PM_OPS(ahci_da850_pm_ops, ahci_platform_suspend, 244 ahci_platform_resume); 245 246 static const struct of_device_id ahci_da850_of_match[] = { 247 { .compatible = "ti,da850-ahci", }, 248 { }, 249 }; 250 MODULE_DEVICE_TABLE(of, ahci_da850_of_match); 251 252 static struct platform_driver ahci_da850_driver = { 253 .probe = ahci_da850_probe, 254 .remove = ata_platform_remove_one, 255 .driver = { 256 .name = DRV_NAME, 257 .of_match_table = ahci_da850_of_match, 258 .pm = &ahci_da850_pm_ops, 259 }, 260 }; 261 module_platform_driver(ahci_da850_driver); 262 263 MODULE_DESCRIPTION("DaVinci DA850 AHCI SATA platform driver"); 264 MODULE_AUTHOR("Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>"); 265 MODULE_LICENSE("GPL"); 266