mmc:host:sdhci-pci:Addition of Arasan PCI Controller with integrated phy.

The Arasan Controller is based on a FPGA platform and has integrated phy
with specific registers used during initialization and
management of different modes. The phy and the controller are integrated
and registers are very specific to Arasan.

Arasan being an IP provider, licenses these IPs to various companies for
integration of IP in custom SOCs. The custom SOCs define own register
map depending on how bits are tied inside the SOC for phy registers,
depending on SOC memory plan and hence will require own platform drivers.

If more details on phy registers are required, an interface document is
hosted at https://arasan.com/NF/eMMC5.1 PHY Programming in Linux.pdf.

Signed-off-by: Atul Garg <agarg@arasan.com>
Acked-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

1 files changed, 331 insertions, 0 deletions

diff --git a/drivers/mmc/host/sdhci-pci-arasan.c b/drivers/mmc/host/sdhci-pci-arasan.c
new file mode 100644
index 000000000000..499f3205ec5c
--- /dev/null
+++ b/drivers/mmc/host/sdhci-pci-arasan.c
@@ -0,0 +1,331 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * sdhci-pci-arasan.c - Driver for Arasan PCI Controller with
+ * integrated phy.
+ *
+ * Copyright (C) 2017 Arasan Chip Systems Inc.
+ *
+ * Author: Atul Garg <agarg@arasan.com>
+ */
+
+#include <linux/pci.h>
+#include <linux/delay.h>
+
+#include "sdhci.h"
+#include "sdhci-pci.h"
+
+/* Extra registers for Arasan SD/SDIO/MMC Host Controller with PHY */
+#define PHY_ADDR_REG	0x300
+#define PHY_DAT_REG	0x304
+
+#define PHY_WRITE	BIT(8)
+#define PHY_BUSY	BIT(9)
+#define DATA_MASK	0xFF
+
+/* PHY Specific Registers */
+#define DLL_STATUS	0x00
+#define IPAD_CTRL1	0x01
+#define IPAD_CTRL2	0x02
+#define IPAD_STS	0x03
+#define IOREN_CTRL1	0x06
+#define IOREN_CTRL2	0x07
+#define IOPU_CTRL1	0x08
+#define IOPU_CTRL2	0x09
+#define ITAP_DELAY	0x0C
+#define OTAP_DELAY	0x0D
+#define STRB_SEL	0x0E
+#define CLKBUF_SEL	0x0F
+#define MODE_CTRL	0x11
+#define DLL_TRIM	0x12
+#define CMD_CTRL	0x20
+#define DATA_CTRL	0x21
+#define STRB_CTRL	0x22
+#define CLK_CTRL	0x23
+#define PHY_CTRL	0x24
+
+#define DLL_ENBL	BIT(3)
+#define RTRIM_EN	BIT(1)
+#define PDB_ENBL	BIT(1)
+#define RETB_ENBL	BIT(6)
+#define ODEN_CMD	BIT(1)
+#define ODEN_DAT	0xFF
+#define REN_STRB	BIT(0)
+#define REN_CMND	BIT(1)
+#define REN_DATA	0xFF
+#define PU_CMD		BIT(1)
+#define PU_DAT		0xFF
+#define ITAPDLY_EN	BIT(0)
+#define OTAPDLY_EN	BIT(0)
+#define OD_REL_CMD	BIT(1)
+#define OD_REL_DAT	0xFF
+#define DLLTRM_ICP	0x8
+#define PDB_CMND	BIT(0)
+#define PDB_DATA	0xFF
+#define PDB_STRB	BIT(0)
+#define PDB_CLOCK	BIT(0)
+#define CALDONE_MASK	0x10
+#define DLL_RDY_MASK	0x10
+#define MAX_CLK_BUF	0x7
+
+/* Mode Controls */
+#define ENHSTRB_MODE	BIT(0)
+#define HS400_MODE	BIT(1)
+#define LEGACY_MODE	BIT(2)
+#define DDR50_MODE	BIT(3)
+
+/*
+ * Controller has no specific bits for HS200/HS.
+ * Used BIT(4), BIT(5) for software programming.
+ */
+#define HS200_MODE	BIT(4)
+#define HISPD_MODE	BIT(5)
+
+#define OTAPDLY(x)	(((x) << 1) | OTAPDLY_EN)
+#define ITAPDLY(x)	(((x) << 1) | ITAPDLY_EN)
+#define FREQSEL(x)	(((x) << 5) | DLL_ENBL)
+#define IOPAD(x, y)	((x) | ((y) << 2))
+
+/* Arasan private data */
+struct arasan_host {
+	u32 chg_clk;
+};
+
+static int arasan_phy_addr_poll(struct sdhci_host *host, u32 offset, u32 mask)
+{
+	ktime_t timeout = ktime_add_us(ktime_get(), 100);
+	bool failed;
+	u8 val = 0;
+
+	while (1) {
+		failed = ktime_after(ktime_get(), timeout);
+		val = sdhci_readw(host, PHY_ADDR_REG);
+		if (!(val & mask))
+			return 0;
+		if (failed)
+			return -EBUSY;
+	}
+}
+
+static int arasan_phy_write(struct sdhci_host *host, u8 data, u8 offset)
+{
+	sdhci_writew(host, data, PHY_DAT_REG);
+	sdhci_writew(host, (PHY_WRITE | offset), PHY_ADDR_REG);
+	return arasan_phy_addr_poll(host, PHY_ADDR_REG, PHY_BUSY);
+}
+
+static int arasan_phy_read(struct sdhci_host *host, u8 offset, u8 *data)
+{
+	int ret;
+
+	sdhci_writew(host, 0, PHY_DAT_REG);
+	sdhci_writew(host, offset, PHY_ADDR_REG);
+	ret = arasan_phy_addr_poll(host, PHY_ADDR_REG, PHY_BUSY);
+
+	/* Masking valid data bits */
+	*data = sdhci_readw(host, PHY_DAT_REG) & DATA_MASK;
+	return ret;
+}
+
+static int arasan_phy_sts_poll(struct sdhci_host *host, u32 offset, u32 mask)
+{
+	int ret;
+	ktime_t timeout = ktime_add_us(ktime_get(), 100);
+	bool failed;
+	u8 val = 0;
+
+	while (1) {
+		failed = ktime_after(ktime_get(), timeout);
+		ret = arasan_phy_read(host, offset, &val);
+		if (ret)
+			return -EBUSY;
+		else if (val & mask)
+			return 0;
+		if (failed)
+			return -EBUSY;
+	}
+}
+
+/* Initialize the Arasan PHY */
+static int arasan_phy_init(struct sdhci_host *host)
+{
+	int ret;
+	u8 val;
+
+	/* Program IOPADs and wait for calibration to be done */
+	if (arasan_phy_read(host, IPAD_CTRL1, &val) ||
+	    arasan_phy_write(host, val | RETB_ENBL | PDB_ENBL, IPAD_CTRL1) ||
+	    arasan_phy_read(host, IPAD_CTRL2, &val) ||
+	    arasan_phy_write(host, val | RTRIM_EN, IPAD_CTRL2))
+		return -EBUSY;
+	ret = arasan_phy_sts_poll(host, IPAD_STS, CALDONE_MASK);
+	if (ret)
+		return -EBUSY;
+
+	/* Program CMD/Data lines */
+	if (arasan_phy_read(host, IOREN_CTRL1, &val) ||
+	    arasan_phy_write(host, val | REN_CMND | REN_STRB, IOREN_CTRL1) ||
+	    arasan_phy_read(host, IOPU_CTRL1, &val) ||
+	    arasan_phy_write(host, val | PU_CMD, IOPU_CTRL1) ||
+	    arasan_phy_read(host, CMD_CTRL, &val) ||
+	    arasan_phy_write(host, val | PDB_CMND, CMD_CTRL) ||
+	    arasan_phy_read(host, IOREN_CTRL2, &val) ||
+	    arasan_phy_write(host, val | REN_DATA, IOREN_CTRL2) ||
+	    arasan_phy_read(host, IOPU_CTRL2, &val) ||
+	    arasan_phy_write(host, val | PU_DAT, IOPU_CTRL2) ||
+	    arasan_phy_read(host, DATA_CTRL, &val) ||
+	    arasan_phy_write(host, val | PDB_DATA, DATA_CTRL) ||
+	    arasan_phy_read(host, STRB_CTRL, &val) ||
+	    arasan_phy_write(host, val | PDB_STRB, STRB_CTRL) ||
+	    arasan_phy_read(host, CLK_CTRL, &val) ||
+	    arasan_phy_write(host, val | PDB_CLOCK, CLK_CTRL) ||
+	    arasan_phy_read(host, CLKBUF_SEL, &val) ||
+	    arasan_phy_write(host, val | MAX_CLK_BUF, CLKBUF_SEL) ||
+	    arasan_phy_write(host, LEGACY_MODE, MODE_CTRL))
+		return -EBUSY;
+	return 0;
+}
+
+/* Set Arasan PHY for different modes */
+static int arasan_phy_set(struct sdhci_host *host, u8 mode, u8 otap,
+			  u8 drv_type, u8 itap, u8 trim, u8 clk)
+{
+	u8 val;
+	int ret;
+
+	if (mode == HISPD_MODE || mode == HS200_MODE)
+		ret = arasan_phy_write(host, 0x0, MODE_CTRL);
+	else
+		ret = arasan_phy_write(host, mode, MODE_CTRL);
+	if (ret)
+		return ret;
+	if (mode == HS400_MODE || mode == HS200_MODE) {
+		ret = arasan_phy_read(host, IPAD_CTRL1, &val);
+		if (ret)
+			return ret;
+		ret = arasan_phy_write(host, IOPAD(val, drv_type), IPAD_CTRL1);
+		if (ret)
+			return ret;
+	}
+	if (mode == LEGACY_MODE) {
+		ret = arasan_phy_write(host, 0x0, OTAP_DELAY);
+		if (ret)
+			return ret;
+		ret = arasan_phy_write(host, 0x0, ITAP_DELAY);
+	} else {
+		ret = arasan_phy_write(host, OTAPDLY(otap), OTAP_DELAY);
+		if (ret)
+			return ret;
+		if (mode != HS200_MODE)
+			ret = arasan_phy_write(host, ITAPDLY(itap), ITAP_DELAY);
+		else
+			ret = arasan_phy_write(host, 0x0, ITAP_DELAY);
+	}
+	if (ret)
+		return ret;
+	if (mode != LEGACY_MODE) {
+		ret = arasan_phy_write(host, trim, DLL_TRIM);
+		if (ret)
+			return ret;
+	}
+	ret = arasan_phy_write(host, 0, DLL_STATUS);
+	if (ret)
+		return ret;
+	if (mode != LEGACY_MODE) {
+		ret = arasan_phy_write(host, FREQSEL(clk), DLL_STATUS);
+		if (ret)
+			return ret;
+		ret = arasan_phy_sts_poll(host, DLL_STATUS, DLL_RDY_MASK);
+		if (ret)
+			return -EBUSY;
+	}
+	return 0;
+}
+
+static int arasan_select_phy_clock(struct sdhci_host *host)
+{
+	struct sdhci_pci_slot *slot = sdhci_priv(host);
+	struct arasan_host *arasan_host = sdhci_pci_priv(slot);
+	u8 clk;
+
+	if (arasan_host->chg_clk == host->mmc->ios.clock)
+		return 0;
+
+	arasan_host->chg_clk = host->mmc->ios.clock;
+	if (host->mmc->ios.clock == 200000000)
+		clk = 0x0;
+	else if (host->mmc->ios.clock == 100000000)
+		clk = 0x2;
+	else if (host->mmc->ios.clock == 50000000)
+		clk = 0x1;
+	else
+		clk = 0x0;
+
+	if (host->mmc_host_ops.hs400_enhanced_strobe) {
+		arasan_phy_set(host, ENHSTRB_MODE, 1, 0x0, 0x0,
+			       DLLTRM_ICP, clk);
+	} else {
+		switch (host->mmc->ios.timing) {
+		case MMC_TIMING_LEGACY:
+			arasan_phy_set(host, LEGACY_MODE, 0x0, 0x0, 0x0,
+				       0x0, 0x0);
+			break;
+		case MMC_TIMING_MMC_HS:
+		case MMC_TIMING_SD_HS:
+			arasan_phy_set(host, HISPD_MODE, 0x3, 0x0, 0x2,
+				       DLLTRM_ICP, clk);
+			break;
+		case MMC_TIMING_MMC_HS200:
+		case MMC_TIMING_UHS_SDR104:
+			arasan_phy_set(host, HS200_MODE, 0x2,
+				       host->mmc->ios.drv_type, 0x0,
+				       DLLTRM_ICP, clk);
+			break;
+		case MMC_TIMING_MMC_DDR52:
+		case MMC_TIMING_UHS_DDR50:
+			arasan_phy_set(host, DDR50_MODE, 0x1, 0x0,
+				       0x0, DLLTRM_ICP, clk);
+			break;
+		case MMC_TIMING_MMC_HS400:
+			arasan_phy_set(host, HS400_MODE, 0x1,
+				       host->mmc->ios.drv_type, 0xa,
+				       DLLTRM_ICP, clk);
+			break;
+		default:
+			break;
+		}
+	}
+	return 0;
+}
+
+static int arasan_pci_probe_slot(struct sdhci_pci_slot *slot)
+{
+	int err;
+
+	slot->host->mmc->caps |= MMC_CAP_NONREMOVABLE | MMC_CAP_8_BIT_DATA;
+	err = arasan_phy_init(slot->host);
+	if (err)
+		return -ENODEV;
+	return 0;
+}
+
+static void arasan_sdhci_set_clock(struct sdhci_host *host, unsigned int clock)
+{
+	sdhci_set_clock(host, clock);
+
+	/* Change phy settings for the new clock */
+	arasan_select_phy_clock(host);
+}
+
+static const struct sdhci_ops arasan_sdhci_pci_ops = {
+	.set_clock	= arasan_sdhci_set_clock,
+	.enable_dma	= sdhci_pci_enable_dma,
+	.set_bus_width	= sdhci_set_bus_width,
+	.reset		= sdhci_reset,
+	.set_uhs_signaling	= sdhci_set_uhs_signaling,
+};
+
+const struct sdhci_pci_fixes sdhci_arasan = {
+	.probe_slot = arasan_pci_probe_slot,
+	.ops        = &arasan_sdhci_pci_ops,
+	.priv_size  = sizeof(struct arasan_host),
+};