]>
git.ipfire.org Git - people/ms/u-boot.git/blob - drivers/i2c/rcar_iic.c
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
,