2 * Renesas RCar IIC driver
4 * Copyright (C) 2017 Marek Vasut <marek.vasut@gmail.com>
7 * Copyright (C) 2011, 2013 Renesas Solutions Corp.
8 * Copyright (C) 2011, 2013 Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com>
10 * SPDX-License-Identifier: GPL-2.0+
19 struct rcar_iic_priv {
26 #define RCAR_IIC_ICDR 0x00
27 #define RCAR_IIC_ICCR 0x04
28 #define RCAR_IIC_ICSR 0x08
29 #define RCAR_IIC_ICIC 0x0c
30 #define RCAR_IIC_ICCL 0x10
31 #define RCAR_IIC_ICCH 0x14
34 #define RCAR_IIC_ICCR_ICE BIT(7)
35 #define RCAR_IIC_ICCR_RACK BIT(6)
36 #define RCAR_IIC_ICCR_RTS BIT(4)
37 #define RCAR_IIC_ICCR_BUSY BIT(2)
38 #define RCAR_IIC_ICCR_SCP BIT(0)
41 #define RCAR_IC_BUSY BIT(4)
42 #define RCAR_IC_TACK BIT(2)
43 #define RCAR_IC_DTE BIT(0)
47 static void sh_irq_dte(struct udevice *dev)
49 struct rcar_iic_priv *priv = dev_get_priv(dev);
52 for (i = 0; i < IRQ_WAIT; i++) {
53 if (RCAR_IC_DTE & readb(priv->base + RCAR_IIC_ICSR))
59 static int sh_irq_dte_with_tack(struct udevice *dev)
61 struct rcar_iic_priv *priv = dev_get_priv(dev);
64 for (i = 0; i < IRQ_WAIT; i++) {
65 if (RCAR_IC_DTE & readb(priv->base + RCAR_IIC_ICSR))
67 if (RCAR_IC_TACK & readb(priv->base + RCAR_IIC_ICSR))
74 static void sh_irq_busy(struct udevice *dev)
76 struct rcar_iic_priv *priv = dev_get_priv(dev);
79 for (i = 0; i < IRQ_WAIT; i++) {
80 if (!(RCAR_IC_BUSY & readb(priv->base + RCAR_IIC_ICSR)))
86 static int rcar_iic_set_addr(struct udevice *dev, u8 chip, u8 read)
88 struct rcar_iic_priv *priv = dev_get_priv(dev);
90 clrbits_8(priv->base + RCAR_IIC_ICCR, RCAR_IIC_ICCR_ICE);
91 setbits_8(priv->base + RCAR_IIC_ICCR, RCAR_IIC_ICCR_ICE);
93 writeb(priv->iccl, priv->base + RCAR_IIC_ICCL);
94 writeb(priv->icch, priv->base + RCAR_IIC_ICCH);
95 writeb(RCAR_IC_TACK, priv->base + RCAR_IIC_ICIC);
97 writeb(RCAR_IIC_ICCR_ICE | RCAR_IIC_ICCR_RTS | RCAR_IIC_ICCR_BUSY,
98 priv->base + RCAR_IIC_ICCR);
101 clrbits_8(priv->base + RCAR_IIC_ICSR, RCAR_IC_TACK);
102 writeb(chip << 1 | read, priv->base + RCAR_IIC_ICDR);
103 return sh_irq_dte_with_tack(dev);
106 static void rcar_iic_finish(struct udevice *dev)
108 struct rcar_iic_priv *priv = dev_get_priv(dev);
110 writeb(0, priv->base + RCAR_IIC_ICSR);
111 clrbits_8(priv->base + RCAR_IIC_ICCR, RCAR_IIC_ICCR_ICE);
114 static int rcar_iic_read_common(struct udevice *dev, struct i2c_msg *msg)
116 struct rcar_iic_priv *priv = dev_get_priv(dev);
117 int i, ret = -EREMOTEIO;
119 if (rcar_iic_set_addr(dev, msg->addr, 1) != 0)
124 writeb(RCAR_IIC_ICCR_ICE | RCAR_IIC_ICCR_SCP,
125 priv->base + RCAR_IIC_ICCR);
127 for (i = 0; i < msg->len; i++) {
128 if (sh_irq_dte_with_tack(dev) != 0)
131 msg->buf[i] = readb(priv->base + RCAR_IIC_ICDR) & 0xff;
133 if (msg->len - 1 == i) {
134 writeb(RCAR_IIC_ICCR_ICE | RCAR_IIC_ICCR_RACK,
135 priv->base + RCAR_IIC_ICCR);
143 rcar_iic_finish(dev);
147 static int rcar_iic_write_common(struct udevice *dev, struct i2c_msg *msg)
149 struct rcar_iic_priv *priv = dev_get_priv(dev);
150 int i, ret = -EREMOTEIO;
152 if (rcar_iic_set_addr(dev, msg->addr, 0) != 0)
157 for (i = 0; i < msg->len; i++) {
158 writeb(msg->buf[i], priv->base + RCAR_IIC_ICDR);
159 if (sh_irq_dte_with_tack(dev) != 0)
163 if (msg->flags & I2C_M_STOP) {
164 writeb(RCAR_IIC_ICCR_ICE | RCAR_IIC_ICCR_RTS,
165 priv->base + RCAR_IIC_ICCR);
166 if (sh_irq_dte_with_tack(dev) != 0)
174 rcar_iic_finish(dev);
178 static int rcar_iic_xfer(struct udevice *dev, struct i2c_msg *msg, int nmsgs)
182 for (; nmsgs > 0; nmsgs--, msg++) {
183 if (msg->flags & I2C_M_RD)
184 ret = rcar_iic_read_common(dev, msg);
186 ret = rcar_iic_write_common(dev, msg);
195 static int rcar_iic_set_speed(struct udevice *dev, uint speed)
197 struct rcar_iic_priv *priv = dev_get_priv(dev);
198 const unsigned int ratio_high = 4;
199 const unsigned int ratio_low = 5;
202 clkrate = clk_get_rate(&priv->clk);
207 * Calculate the value for ICCL and ICCH. From the data sheet:
208 * iccl = (p-clock / transfer-rate) * (L / (L + H))
209 * icch = (p clock / transfer rate) * (H / (L + H))
210 * where L and H are the SCL low and high ratio.
212 denom = speed * (ratio_high + ratio_low);
213 priv->iccl = DIV_ROUND_CLOSEST(clkrate * ratio_low, denom);
214 priv->icch = DIV_ROUND_CLOSEST(clkrate * ratio_high, denom);
219 static int rcar_iic_probe_chip(struct udevice *dev, uint addr, uint flags)
221 struct rcar_iic_priv *priv = dev_get_priv(dev);
224 rcar_iic_set_addr(dev, addr, 1);
225 writeb(RCAR_IIC_ICCR_ICE | RCAR_IIC_ICCR_SCP,
226 priv->base + RCAR_IIC_ICCR);
227 ret = sh_irq_dte_with_tack(dev);
228 rcar_iic_finish(dev);
233 static int rcar_iic_probe(struct udevice *dev)
235 struct rcar_iic_priv *priv = dev_get_priv(dev);
238 priv->base = dev_read_addr_ptr(dev);
240 ret = clk_get_by_index(dev, 0, &priv->clk);
244 ret = clk_enable(&priv->clk);
248 rcar_iic_finish(dev);
250 return rcar_iic_set_speed(dev, 100000);
253 static const struct dm_i2c_ops rcar_iic_ops = {
254 .xfer = rcar_iic_xfer,
255 .probe_chip = rcar_iic_probe_chip,
256 .set_bus_speed = rcar_iic_set_speed,
259 static const struct udevice_id rcar_iic_ids[] = {
260 { .compatible = "renesas,rmobile-iic" },
264 U_BOOT_DRIVER(iic_rcar) = {
267 .of_match = rcar_iic_ids,
268 .probe = rcar_iic_probe,
269 .priv_auto_alloc_size = sizeof(struct rcar_iic_priv),
270 .ops = &rcar_iic_ops,