--- /dev/null
+/*
+ * drivers/i2c/rcar_i2c.c
+ *
+ * Copyright (C) 2013 Renesas Electronics Corporation
+ * Copyright (C) 2013 Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com>
+ *
+ * SPDX-License-Identifier: GPL-2.0
+ */
+
+#include <common.h>
+#include <i2c.h>
+#include <asm/io.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+struct rcar_i2c {
+ u32 icscr;
+ u32 icmcr;
+ u32 icssr;
+ u32 icmsr;
+ u32 icsier;
+ u32 icmier;
+ u32 icccr;
+ u32 icsar;
+ u32 icmar;
+ u32 icrxdtxd;
+ u32 icccr2;
+ u32 icmpr;
+ u32 ichpr;
+ u32 iclpr;
+};
+
+#define MCR_MDBS 0x80 /* non-fifo mode switch */
+#define MCR_FSCL 0x40 /* override SCL pin */
+#define MCR_FSDA 0x20 /* override SDA pin */
+#define MCR_OBPC 0x10 /* override pins */
+#define MCR_MIE 0x08 /* master if enable */
+#define MCR_TSBE 0x04
+#define MCR_FSB 0x02 /* force stop bit */
+#define MCR_ESG 0x01 /* en startbit gen. */
+
+#define MSR_MASK 0x7f
+#define MSR_MNR 0x40 /* nack received */
+#define MSR_MAL 0x20 /* arbitration lost */
+#define MSR_MST 0x10 /* sent a stop */
+#define MSR_MDE 0x08
+#define MSR_MDT 0x04
+#define MSR_MDR 0x02
+#define MSR_MAT 0x01 /* slave addr xfer done */
+
+static const struct rcar_i2c *i2c_dev[CONFIF_SYS_RCAR_I2C_NUM_CONTROLLERS] = {
+ (struct rcar_i2c *)CONFIG_SYS_RCAR_I2C0_BASE,
+ (struct rcar_i2c *)CONFIG_SYS_RCAR_I2C1_BASE,
+ (struct rcar_i2c *)CONFIG_SYS_RCAR_I2C2_BASE,
+ (struct rcar_i2c *)CONFIG_SYS_RCAR_I2C3_BASE,
+};
+
+static void rcar_i2c_raw_rw_common(struct rcar_i2c *dev, u8 chip, uint addr)
+{
+ /* set slave address */
+ writel(chip << 1, &dev->icmar);
+ /* set register address */
+ writel(addr, &dev->icrxdtxd);
+ /* clear status */
+ writel(0, &dev->icmsr);
+ /* start master send */
+ writel(MCR_MDBS | MCR_MIE | MCR_ESG, &dev->icmcr);
+
+ while ((readl(&dev->icmsr) & (MSR_MAT | MSR_MDE))
+ != (MSR_MAT | MSR_MDE))
+ udelay(10);
+
+ /* clear ESG */
+ writel(MCR_MDBS | MCR_MIE, &dev->icmcr);
+ /* start SCLclk */
+ writel(~(MSR_MAT | MSR_MDE), &dev->icmsr);
+
+ while (!(readl(&dev->icmsr) & MSR_MDE))
+ udelay(10);
+}
+
+static void rcar_i2c_raw_rw_finish(struct rcar_i2c *dev)
+{
+ while (!(readl(&dev->icmsr) & MSR_MST))
+ udelay(10);
+
+ writel(0, &dev->icmcr);
+}
+
+static int
+rcar_i2c_raw_write(struct rcar_i2c *dev, u8 chip, uint addr, u8 *val, int size)
+{
+ rcar_i2c_raw_rw_common(dev, chip, addr);
+
+ /* set send date */
+ writel(*val, &dev->icrxdtxd);
+ /* start SCLclk */
+ writel(~MSR_MDE, &dev->icmsr);
+
+ while (!(readl(&dev->icmsr) & MSR_MDE))
+ udelay(10);
+
+ /* set stop condition */
+ writel(MCR_MDBS | MCR_MIE | MCR_FSB, &dev->icmcr);
+ /* start SCLclk */
+ writel(~MSR_MDE, &dev->icmsr);
+
+ rcar_i2c_raw_rw_finish(dev);
+
+ return 0;
+}
+
+static u8
+rcar_i2c_raw_read(struct rcar_i2c *dev, u8 chip, uint addr)
+{
+ u8 ret;
+
+ rcar_i2c_raw_rw_common(dev, chip, addr);
+
+ /* set slave address, receive */
+ writel((chip << 1) | 1, &dev->icmar);
+ /* start master receive */
+ writel(MCR_MDBS | MCR_MIE | MCR_ESG, &dev->icmcr);
+
+ while ((readl(&dev->icmsr) & (MSR_MAT | MSR_MDE))
+ != (MSR_MAT | MSR_MDE))
+ udelay(10);
+
+ /* clear ESG */
+ writel(MCR_MDBS | MCR_MIE, &dev->icmcr);
+ /* prepare stop condition */
+ writel(MCR_MDBS | MCR_MIE | MCR_FSB, &dev->icmcr);
+ /* start SCLclk */
+ writel(~(MSR_MAT | MSR_MDR), &dev->icmsr);
+
+ while (!(readl(&dev->icmsr) & MSR_MDR))
+ udelay(10);
+
+ /* get receive data */
+ ret = (u8)readl(&dev->icrxdtxd);
+ /* start SCLclk */
+ writel(~MSR_MDR, &dev->icmsr);
+
+ rcar_i2c_raw_rw_finish(dev);
+
+ return ret;
+}
+
+/*
+ * SCL = iicck / (20 + SCGD * 8 + F[(ticf + tr + intd) * iicck])
+ * iicck : I2C internal clock < 20 MHz
+ * ticf : I2C SCL falling time: 35 ns
+ * tr : I2C SCL rising time: 200 ns
+ * intd : LSI internal delay: I2C0: 50 ns I2C1-3: 5
+ * F[n] : n rounded up to an integer
+ */
+static u32 rcar_clock_gen(int i2c_no, u32 bus_speed)
+{
+ u32 iicck, f, scl, scgd;
+ u32 intd = 5;
+
+ int bit = 0, cdf_width = 3;
+ for (bit = 0; bit < (1 << cdf_width); bit++) {
+ iicck = CONFIG_HP_CLK_FREQ / (1 + bit);
+ if (iicck < 20000000)
+ break;
+ }
+
+ if (bit > (1 << cdf_width)) {
+ puts("rcar-i2c: Can not get CDF\n");
+ return 0;
+ }
+
+ if (i2c_no == 0)
+ intd = 50;
+
+ f = (35 + 200 + intd) * (iicck / 1000000000);
+
+ for (scgd = 0; scgd < 0x40; scgd++) {
+ scl = iicck / (20 + (scgd * 8) + f);
+ if (scl <= bus_speed)
+ break;
+ }
+
+ if (scgd > 0x40) {
+ puts("rcar-i2c: Can not get SDGB\n");
+ return 0;
+ }
+
+ debug("%s: scl: %d\n", __func__, scl);
+ debug("%s: bit %x\n", __func__, bit);
+ debug("%s: scgd %x\n", __func__, scgd);
+ debug("%s: iccr %x\n", __func__, (scgd << (cdf_width) | bit));
+
+ return scgd << (cdf_width) | bit;
+}
+
+static void
+rcar_i2c_init(struct i2c_adapter *adap, int speed, int slaveadd)
+{
+ struct rcar_i2c *dev = (struct rcar_i2c *)i2c_dev[adap->hwadapnr];
+ u32 icccr = 0;
+
+ /* No i2c support prior to relocation */
+ if (!(gd->flags & GD_FLG_RELOC))
+ return;
+
+ /*
+ * reset slave mode.
+ * slave mode is not used on this driver
+ */
+ writel(0, &dev->icsier);
+ writel(0, &dev->icsar);
+ writel(0, &dev->icscr);
+ writel(0, &dev->icssr);
+
+ /* reset master mode */
+ writel(0, &dev->icmier);
+ writel(0, &dev->icmcr);
+ writel(0, &dev->icmsr);
+ writel(0, &dev->icmar);
+
+ icccr = rcar_clock_gen(adap->hwadapnr, adap->speed);
+ if (icccr == 0)
+ puts("I2C: Init failed\n");
+ else
+ writel(icccr, &dev->icccr);
+}
+
+static int rcar_i2c_read(struct i2c_adapter *adap, uint8_t chip,
+ uint addr, int alen, u8 *data, int len)
+{
+ struct rcar_i2c *dev = (struct rcar_i2c *)i2c_dev[adap->hwadapnr];
+ int i;
+
+ for (i = 0; i < len; i++)
+ data[i] = rcar_i2c_raw_read(dev, chip, addr + i);
+
+ return 0;
+}
+
+static int rcar_i2c_write(struct i2c_adapter *adap, uint8_t chip, uint addr,
+ int alen, u8 *data, int len)
+{
+ struct rcar_i2c *dev = (struct rcar_i2c *)i2c_dev[adap->hwadapnr];
+ return rcar_i2c_raw_write(dev, chip, addr, data, len);
+}
+
+static int
+rcar_i2c_probe(struct i2c_adapter *adap, u8 dev)
+{
+ return rcar_i2c_read(adap, dev, 0, 0, NULL, 0);
+}
+
+static unsigned int rcar_i2c_set_bus_speed(struct i2c_adapter *adap,
+ unsigned int speed)
+{
+ struct rcar_i2c *dev = (struct rcar_i2c *)i2c_dev[adap->hwadapnr];
+ u32 icccr;
+ int ret = 0;
+
+ rcar_i2c_raw_rw_finish(dev);
+
+ icccr = rcar_clock_gen(adap->hwadapnr, speed);
+ if (icccr == 0) {
+ puts("I2C: Init failed\n");
+ ret = -1;
+ } else {
+ writel(icccr, &dev->icccr);
+ }
+ return ret;
+}
+
+/*
+ * Register RCAR i2c adapters
+ */
+U_BOOT_I2C_ADAP_COMPLETE(rcar_0, rcar_i2c_init, rcar_i2c_probe, rcar_i2c_read,
+ rcar_i2c_write, rcar_i2c_set_bus_speed,
+ CONFIG_SYS_RCAR_I2C0_SPEED, 0, 0)
+U_BOOT_I2C_ADAP_COMPLETE(rcar_1, rcar_i2c_init, rcar_i2c_probe, rcar_i2c_read,
+ rcar_i2c_write, rcar_i2c_set_bus_speed,
+ CONFIG_SYS_RCAR_I2C1_SPEED, 0, 1)
+U_BOOT_I2C_ADAP_COMPLETE(rcar_2, rcar_i2c_init, rcar_i2c_probe, rcar_i2c_read,
+ rcar_i2c_write, rcar_i2c_set_bus_speed,
+ CONFIG_SYS_RCAR_I2C2_SPEED, 0, 2)
+U_BOOT_I2C_ADAP_COMPLETE(rcar_3, rcar_i2c_init, rcar_i2c_probe, rcar_i2c_read,
+ rcar_i2c_write, rcar_i2c_set_bus_speed,
+ CONFIG_SYS_RCAR_I2C3_SPEED, 0, 3)
projects / oweals / u-boot.git / commitdiff