/* * DaVinci DA850 AHCI SATA platform driver * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation; either version 2, or (at your option) * any later version. */ #include <linux/kernel.h> #include <linux/module.h> #include <linux/pm.h> #include <linux/device.h> #include <linux/platform_device.h> #include <linux/libata.h> #include <linux/ahci_platform.h> #include "ahci.h" #define DRV_NAME "ahci_da850" #define HARDRESET_RETRIES 5 /* SATA PHY Control Register offset from AHCI base */ #define SATA_P0PHYCR_REG 0x178 #define SATA_PHY_MPY(x) ((x) << 0) #define SATA_PHY_LOS(x) ((x) << 6) #define SATA_PHY_RXCDR(x) ((x) << 10) #define SATA_PHY_RXEQ(x) ((x) << 13) #define SATA_PHY_TXSWING(x) ((x) << 19) #define SATA_PHY_ENPLL(x) ((x) << 31) static void da850_sata_init(struct device *dev, void __iomem *pwrdn_reg, void __iomem *ahci_base, u32 mpy) { unsigned int val; /* Enable SATA clock receiver */ val = readl(pwrdn_reg); val &= ~BIT(0); writel(val, pwrdn_reg); val = SATA_PHY_MPY(mpy) | SATA_PHY_LOS(1) | SATA_PHY_RXCDR(4) | SATA_PHY_RXEQ(1) | SATA_PHY_TXSWING(3) | SATA_PHY_ENPLL(1); writel(val, ahci_base + SATA_P0PHYCR_REG); } static u32 ahci_da850_calculate_mpy(unsigned long refclk_rate) { u32 pll_output = 1500000000, needed; /* * We need to determine the value of the multiplier (MPY) bits. * In order to include the 12.5 multiplier we need to first divide * the refclk rate by ten. * * __div64_32() turned out to be unreliable, sometimes returning * false results. */ WARN((refclk_rate % 10) != 0, "refclk must be divisible by 10"); needed = pll_output / (refclk_rate / 10); /* * What we have now is (multiplier * 10). * * Let's determine the actual register value we need to write. */ switch (needed) { case 50: return 0x1; case 60: return 0x2; case 80: return 0x4; case 100: return 0x5; case 120: return 0x6; case 125: return 0x7; case 150: return 0x8; case 200: return 0x9; case 250: return 0xa; default: /* * We should have divided evenly - if not, return an invalid * value. */ return 0; } } static int ahci_da850_softreset(struct ata_link *link, unsigned int *class, unsigned long deadline) { int pmp, ret; pmp = sata_srst_pmp(link); /* * There's an issue with the SATA controller on da850 SoCs: if we * enable Port Multiplier support, but the drive is connected directly * to the board, it can't be detected. As a workaround: if PMP is * enabled, we first call ahci_do_softreset() and pass it the result of * sata_srst_pmp(). If this call fails, we retry with pmp = 0. */ ret = ahci_do_softreset(link, class, pmp, deadline, ahci_check_ready); if (pmp && ret == -EBUSY) return ahci_do_softreset(link, class, 0, deadline, ahci_check_ready); return ret; } static int ahci_da850_hardreset(struct ata_link *link, unsigned int *class, unsigned long deadline) { int ret, retry = HARDRESET_RETRIES; bool online; /* * In order to correctly service the LCD controller of the da850 SoC, * we increased the PLL0 frequency to 456MHz from the default 300MHz. * * This made the SATA controller unstable and the hardreset operation * does not always succeed the first time. Before really giving up to * bring up the link, retry the reset a couple times. */ do { ret = ahci_do_hardreset(link, class, deadline, &online); if (online) return ret; } while (retry--); return ret; } static struct ata_port_operations ahci_da850_port_ops = { .inherits = &ahci_platform_ops, .softreset = ahci_da850_softreset, /* * No need to override .pmp_softreset - it's only used for actual * PMP-enabled ports. */ .hardreset = ahci_da850_hardreset, .pmp_hardreset = ahci_da850_hardreset, }; static const struct ata_port_info ahci_da850_port_info = { .flags = AHCI_FLAG_COMMON, .pio_mask = ATA_PIO4, .udma_mask = ATA_UDMA6, .port_ops = &ahci_da850_port_ops, }; static struct scsi_host_template ahci_platform_sht = { AHCI_SHT(DRV_NAME), }; static int ahci_da850_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; struct ahci_host_priv *hpriv; void __iomem *pwrdn_reg; struct resource *res; struct clk *clk; u32 mpy; int rc; hpriv = ahci_platform_get_resources(pdev); if (IS_ERR(hpriv)) return PTR_ERR(hpriv); /* * Internally ahci_platform_get_resources() calls clk_get(dev, NULL) * when trying to obtain the functional clock. This SATA controller * uses two clocks for which we specify two connection ids. If we don't * have the functional clock at this point - call clk_get() again with * con_id = "fck". */ if (!hpriv->clks[0]) { clk = clk_get(dev, "fck"); if (IS_ERR(clk)) return PTR_ERR(clk); hpriv->clks[0] = clk; } /* * The second clock used by ahci-da850 is the external REFCLK. If we * didn't get it from ahci_platform_get_resources(), let's try to * specify the con_id in clk_get(). */ if (!hpriv->clks[1]) { clk = clk_get(dev, "refclk"); if (IS_ERR(clk)) { dev_err(dev, "unable to obtain the reference clock"); return -ENODEV; } hpriv->clks[1] = clk; } mpy = ahci_da850_calculate_mpy(clk_get_rate(hpriv->clks[1])); if (mpy == 0) { dev_err(dev, "invalid REFCLK multiplier value: 0x%x", mpy); return -EINVAL; } rc = ahci_platform_enable_resources(hpriv); if (rc) return rc; res = platform_get_resource(pdev, IORESOURCE_MEM, 1); if (!res) { rc = -ENODEV; goto disable_resources; } pwrdn_reg = devm_ioremap(dev, res->start, resource_size(res)); if (!pwrdn_reg) { rc = -ENOMEM; goto disable_resources; } da850_sata_init(dev, pwrdn_reg, hpriv->mmio, mpy); rc = ahci_platform_init_host(pdev, hpriv, &ahci_da850_port_info, &ahci_platform_sht); if (rc) goto disable_resources; return 0; disable_resources: ahci_platform_disable_resources(hpriv); return rc; } static SIMPLE_DEV_PM_OPS(ahci_da850_pm_ops, ahci_platform_suspend, ahci_platform_resume); static const struct of_device_id ahci_da850_of_match[] = { { .compatible = "ti,da850-ahci", }, { }, }; MODULE_DEVICE_TABLE(of, ahci_da850_of_match); static struct platform_driver ahci_da850_driver = { .probe = ahci_da850_probe, .remove = ata_platform_remove_one, .driver = { .name = DRV_NAME, .of_match_table = ahci_da850_of_match, .pm = &ahci_da850_pm_ops, }, }; module_platform_driver(ahci_da850_driver); MODULE_DESCRIPTION("DaVinci DA850 AHCI SATA platform driver"); MODULE_AUTHOR("Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>"); MODULE_LICENSE("GPL");