1 // SPDX-License-Identifier: GPL-2.0+
3 * Renesas RCar IIC driver
5 * Copyright (C) 2017 Marek Vasut <marek.vasut@gmail.com>
8 * Copyright (C) 2011, 2013 Renesas Solutions Corp.
9 * Copyright (C) 2011, 2013 Nobuhiro Iwamatsu <nobuhiro.iwamatsu.yj@renesas.com>
18 struct rcar_iic_priv {
25 #define RCAR_IIC_ICDR 0x00
26 #define RCAR_IIC_ICCR 0x04
27 #define RCAR_IIC_ICSR 0x08
28 #define RCAR_IIC_ICIC 0x0c
29 #define RCAR_IIC_ICCL 0x10
30 #define RCAR_IIC_ICCH 0x14
33 #define RCAR_IIC_ICCR_ICE BIT(7)
34 #define RCAR_IIC_ICCR_RACK BIT(6)
35 #define RCAR_IIC_ICCR_RTS BIT(4)
36 #define RCAR_IIC_ICCR_BUSY BIT(2)
37 #define RCAR_IIC_ICCR_SCP BIT(0)
40 #define RCAR_IC_BUSY BIT(4)
41 #define RCAR_IC_TACK BIT(2)
42 #define RCAR_IC_DTE BIT(0)
46 static void sh_irq_dte(struct udevice *dev)
48 struct rcar_iic_priv *priv = dev_get_priv(dev);
51 for (i = 0; i < IRQ_WAIT; i++) {
52 if (RCAR_IC_DTE & readb(priv->base + RCAR_IIC_ICSR))
58 static int sh_irq_dte_with_tack(struct udevice *dev)
60 struct rcar_iic_priv *priv = dev_get_priv(dev);
63 for (i = 0; i < IRQ_WAIT; i++) {
64 if (RCAR_IC_DTE & readb(priv->base + RCAR_IIC_ICSR))
66 if (RCAR_IC_TACK & readb(priv->base + RCAR_IIC_ICSR))
73 static void sh_irq_busy(struct udevice *dev)
75 struct rcar_iic_priv *priv = dev_get_priv(dev);
78 for (i = 0; i < IRQ_WAIT; i++) {
79 if (!(RCAR_IC_BUSY & readb(priv->base + RCAR_IIC_ICSR)))
85 static int rcar_iic_set_addr(struct udevice *dev, u8 chip, u8 read)
87 struct rcar_iic_priv *priv = dev_get_priv(dev);
89 clrbits_8(priv->base + RCAR_IIC_ICCR, RCAR_IIC_ICCR_ICE);
90 setbits_8(priv->base + RCAR_IIC_ICCR, RCAR_IIC_ICCR_ICE);
92 writeb(priv->iccl, priv->base + RCAR_IIC_ICCL);
93 writeb(priv->icch, priv->base + RCAR_IIC_ICCH);
94 writeb(RCAR_IC_TACK, priv->base + RCAR_IIC_ICIC);
96 writeb(RCAR_IIC_ICCR_ICE | RCAR_IIC_ICCR_RTS | RCAR_IIC_ICCR_BUSY,
97 priv->base + RCAR_IIC_ICCR);
100 clrbits_8(priv->base + RCAR_IIC_ICSR, RCAR_IC_TACK);
101 writeb(chip << 1 | read, priv->base + RCAR_IIC_ICDR);
102 return sh_irq_dte_with_tack(dev);
105 static void rcar_iic_finish(struct udevice *dev)
107 struct rcar_iic_priv *priv = dev_get_priv(dev);
109 writeb(0, priv->base + RCAR_IIC_ICSR);
110 clrbits_8(priv->base + RCAR_IIC_ICCR, RCAR_IIC_ICCR_ICE);
113 static int rcar_iic_read_common(struct udevice *dev, struct i2c_msg *msg)
115 struct rcar_iic_priv *priv = dev_get_priv(dev);
116 int i, ret = -EREMOTEIO;
118 if (rcar_iic_set_addr(dev, msg->addr, 1) != 0)
123 writeb(RCAR_IIC_ICCR_ICE | RCAR_IIC_ICCR_SCP,
124 priv->base + RCAR_IIC_ICCR);
126 for (i = 0; i < msg->len; i++) {
127 if (sh_irq_dte_with_tack(dev) != 0)
130 msg->buf[i] = readb(priv->base + RCAR_IIC_ICDR) & 0xff;
132 if (msg->len - 1 == i) {
133 writeb(RCAR_IIC_ICCR_ICE | RCAR_IIC_ICCR_RACK,
134 priv->base + RCAR_IIC_ICCR);
142 rcar_iic_finish(dev);
146 static int rcar_iic_write_common(struct udevice *dev, struct i2c_msg *msg)
148 struct rcar_iic_priv *priv = dev_get_priv(dev);
149 int i, ret = -EREMOTEIO;
151 if (rcar_iic_set_addr(dev, msg->addr, 0) != 0)
156 for (i = 0; i < msg->len; i++) {
157 writeb(msg->buf[i], priv->base + RCAR_IIC_ICDR);
158 if (sh_irq_dte_with_tack(dev) != 0)
162 if (msg->flags & I2C_M_STOP) {
163 writeb(RCAR_IIC_ICCR_ICE | RCAR_IIC_ICCR_RTS,
164 priv->base + RCAR_IIC_ICCR);
165 if (sh_irq_dte_with_tack(dev) != 0)
173 rcar_iic_finish(dev);
177 static int rcar_iic_xfer(struct udevice *dev, struct i2c_msg *msg, int nmsgs)
181 for (; nmsgs > 0; nmsgs--, msg++) {
182 if (msg->flags & I2C_M_RD)
183 ret = rcar_iic_read_common(dev, msg);
185 ret = rcar_iic_write_common(dev, msg);
194 static int rcar_iic_set_speed(struct udevice *dev, uint speed)
196 struct rcar_iic_priv *priv = dev_get_priv(dev);
197 const unsigned int ratio_high = 4;
198 const unsigned int ratio_low = 5;
201 clkrate = clk_get_rate(&priv->clk);
206 * Calculate the value for ICCL and ICCH. From the data sheet:
207 * iccl = (p-clock / transfer-rate) * (L / (L + H))
208 * icch = (p clock / transfer rate) * (H / (L + H))
209 * where L and H are the SCL low and high ratio.
211 denom = speed * (ratio_high + ratio_low);
212 priv->iccl = DIV_ROUND_CLOSEST(clkrate * ratio_low, denom);
213 priv->icch = DIV_ROUND_CLOSEST(clkrate * ratio_high, denom);
218 static int rcar_iic_probe_chip(struct udevice *dev, uint addr, uint flags)
220 struct rcar_iic_priv *priv = dev_get_priv(dev);
223 rcar_iic_set_addr(dev, addr, 1);
224 writeb(RCAR_IIC_ICCR_ICE | RCAR_IIC_ICCR_SCP,
225 priv->base + RCAR_IIC_ICCR);
226 ret = sh_irq_dte_with_tack(dev);
227 rcar_iic_finish(dev);
232 static int rcar_iic_probe(struct udevice *dev)
234 struct rcar_iic_priv *priv = dev_get_priv(dev);
237 priv->base = dev_read_addr_ptr(dev);
239 ret = clk_get_by_index(dev, 0, &priv->clk);
243 ret = clk_enable(&priv->clk);
247 rcar_iic_finish(dev);
249 return rcar_iic_set_speed(dev, 100000);
252 static const struct dm_i2c_ops rcar_iic_ops = {
253 .xfer = rcar_iic_xfer,
254 .probe_chip = rcar_iic_probe_chip,
255 .set_bus_speed = rcar_iic_set_speed,
258 static const struct udevice_id rcar_iic_ids[] = {
259 { .compatible = "renesas,rmobile-iic" },
263 U_BOOT_DRIVER(iic_rcar) = {
266 .of_match = rcar_iic_ids,
267 .probe = rcar_iic_probe,
268 .priv_auto_alloc_size = sizeof(struct rcar_iic_priv),
269 .ops = &rcar_iic_ops,