Re: [PATCH v2 2/2] phy: add a driver for the Rockchip SoC internal eMMC PHY

Hi,

On Tuesday 05 January 2016 06:38 AM, Shawn Lin wrote:

2016?

+ *
+ * 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 of the License.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ */
+
+#include <linux/delay.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <linux/phy/phy.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+/*
+ * The higher 16-bit of this register is used for write protection
+ * only if BIT(x + 16) set to 1 the BIT(x) can be written.
+ */
+#define HIWORD_UPDATE(val, mask, shift) \
+		((val) << (shift) | (mask) << ((shift) + 16))
+
+/* Register definition */
+#define GRF_EMMCPHY_CON0	0x0
+#define GRF_EMMCPHY_CON1	0x4
+#define GRF_EMMCPHY_CON2	0x8
+#define GRF_EMMCPHY_CON3	0xc
+#define GRF_EMMCPHY_CON4	0x10
+#define GRF_EMMCPHY_CON5	0x14
+#define GRF_EMMCPHY_CON6	0x18
+#define GRF_EMMCPHY_STATUS	0x20
+
+#define PHYCTRL_PDB_MASK	0x1
+#define PHYCTRL_PDB_SHIFT	0x0
+#define PHYCTRL_PDB_PWR_ON	0x1
+#define PHYCTRL_PDB_PWR_OFF	0x0
+#define PHYCTRL_ENDLL_MASK	0x1
+#define PHYCTRL_ENDLL_SHIFT     0x1
+#define PHYCTRL_ENDLL_ENABLE	0x1
+#define PHYCTRL_ENDLL_DISABLE	0x0
+#define PHYCTRL_CALDONE_MASK	0x1
+#define PHYCTRL_CALDONE_SHIFT   0x6
+#define PHYCTRL_CALDONE_DONE	0x1
+#define PHYCTRL_CALDONE_GOING	0x0
+#define PHYCTRL_DLLRDY_MASK	0x1
+#define PHYCTRL_DLLRDY_SHIFT	0x5
+#define PHYCTRL_DLLRDY_DONE	0x1
+#define PHYCTRL_DLLRDY_GOING	0x0
+
+struct rockchip_emmc_phy {
+	unsigned int	reg_offset;
+	struct regmap	*reg_base;
+};
+
+static int rockchip_emmc_phy_power(struct rockchip_emmc_phy *rk_phy,
+				   bool on_off)
+{
+	unsigned int caldone;
+	unsigned int dllrdy;
+
+	/*
+	 * Keep phyctrl_pdb and phyctrl_endll low to allow
+	 * initialization of CALIO state M/C DFFs
+	 */
+	regmap_write(rk_phy->reg_base,
+		     rk_phy->reg_offset + GRF_EMMCPHY_CON6,
+		     HIWORD_UPDATE(PHYCTRL_PDB_PWR_OFF,
+				   PHYCTRL_PDB_MASK,
+				   PHYCTRL_PDB_SHIFT));
+	regmap_write(rk_phy->reg_base,
+		     rk_phy->reg_offset + GRF_EMMCPHY_CON6,
+		     HIWORD_UPDATE(PHYCTRL_ENDLL_DISABLE,
+				   PHYCTRL_ENDLL_MASK,
+				   PHYCTRL_ENDLL_SHIFT));
+
+	/* Already finish power_off above */
+	if (on_off == PHYCTRL_PDB_PWR_OFF)
+		return 0;
+
+	/*
+	 * According to the user manual, calpad calibration
+	 * cycle takes more than 2us without the minimal recommended
+	 * value, so we may need a little margin here
+	 */
+	udelay(3);
+	regmap_write(rk_phy->reg_base,
+		     rk_phy->reg_offset + GRF_EMMCPHY_CON6,
+		     HIWORD_UPDATE(PHYCTRL_PDB_PWR_ON,
+				   PHYCTRL_PDB_MASK,
+				   PHYCTRL_PDB_SHIFT));
+
+	/*
+	 * According to the user manual, it asks driver to
+	 * wait 5us for calpad busy trimming
+	 */
+	udelay(5);
+	regmap_read(rk_phy->reg_base,
+		    rk_phy->reg_offset + GRF_EMMCPHY_STATUS,
+		    &caldone);
+	caldone = (caldone >> PHYCTRL_CALDONE_SHIFT) & PHYCTRL_CALDONE_MASK;
+	if (caldone != PHYCTRL_CALDONE_DONE) {
+		pr_err("rockchip_emmc_phy_power: caldone timeout.\n");
+		return -ETIMEDOUT;
+	}
+
+	/*
+	 * Enable analog DLL circuits, and we need extra 10.2us
+	 * for dll to be ready for work.
+	 */
+	regmap_write(rk_phy->reg_base,
+		     rk_phy->reg_offset + GRF_EMMCPHY_CON6,
+		     HIWORD_UPDATE(PHYCTRL_ENDLL_ENABLE,
+				   PHYCTRL_ENDLL_MASK,
+				   PHYCTRL_ENDLL_SHIFT));
+	udelay(11);

add a comment for this delay too.

+	regmap_read(rk_phy->reg_base,
+		    rk_phy->reg_offset + GRF_EMMCPHY_STATUS,
+		    &dllrdy);
+	dllrdy = (dllrdy >> PHYCTRL_DLLRDY_SHIFT) & PHYCTRL_DLLRDY_MASK;
+	if (dllrdy != PHYCTRL_DLLRDY_DONE) {
+		pr_err("rockchip_emmc_phy_power: dllrdy timeout.\n");
+		return -ETIMEDOUT;
+	}
+
+	return 0;
+}
+
+static int rockchip_emmc_phy_power_off(struct phy *phy)
+{
+	struct rockchip_emmc_phy *rk_phy = phy_get_drvdata(phy);
+	int ret = 0;
+
+	/* Power down emmc phy analog blocks */
+	ret = rockchip_emmc_phy_power(rk_phy, PHYCTRL_PDB_PWR_OFF);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static int rockchip_emmc_phy_power_on(struct phy *phy)
+{
+	struct rockchip_emmc_phy *rk_phy = phy_get_drvdata(phy);
+	int ret = 0;
+
+	/* Power up emmc phy analog blocks */
+	ret = rockchip_emmc_phy_power(rk_phy, PHYCTRL_PDB_PWR_ON);
+	if (ret)
+		return ret;
+
+	return 0;
+}
+
+static int rockchip_emmc_phy_init(struct phy *phy)
+{
+	return 0;
+}
+
+static int rockchip_emmc_phy_exit(struct phy *phy)
+{
+	return 0;
+}

empty init/exit functions are not required.

Thanks
Kishon