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git.ipfire.org Git - thirdparty/u-boot.git/blob - drivers/i2c/rcar_iic.c
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
);
64 for (i
= 0; i
< IRQ_WAIT
; i
++) {
65 icsr
= readb(priv
->base
+ RCAR_IIC_ICSR
);
66 if (RCAR_IC_DTE
& icsr
)
68 if (RCAR_IC_TACK
& icsr
)
75 static void sh_irq_busy(struct udevice
*dev
)
77 struct rcar_iic_priv
*priv
= dev_get_priv(dev
);
80 for (i
= 0; i
< IRQ_WAIT
; i
++) {
81 if (!(RCAR_IC_BUSY
& readb(priv
->base
+ RCAR_IIC_ICSR
)))
87 static int rcar_iic_set_addr(struct udevice
*dev
, u8 chip
, u8 read
)
89 struct rcar_iic_priv
*priv
= dev_get_priv(dev
);
91 clrbits_8(priv
->base
+ RCAR_IIC_ICCR
, RCAR_IIC_ICCR_ICE
);
92 setbits_8(priv
->base
+ RCAR_IIC_ICCR
, RCAR_IIC_ICCR_ICE
);
94 writeb(priv
->iccl
, priv
->base
+ RCAR_IIC_ICCL
);
95 writeb(priv
->icch
, priv
->base
+ RCAR_IIC_ICCH
);
96 writeb(RCAR_IC_TACK
, priv
->base
+ RCAR_IIC_ICIC
);
98 writeb(RCAR_IIC_ICCR_ICE
| RCAR_IIC_ICCR_RTS
| RCAR_IIC_ICCR_BUSY
,
99 priv
->base
+ RCAR_IIC_ICCR
);
102 clrbits_8(priv
->base
+ RCAR_IIC_ICSR
, RCAR_IC_TACK
);
103 writeb(chip
<< 1 | read
, priv
->base
+ RCAR_IIC_ICDR
);
104 return sh_irq_dte_with_tack(dev
);
107 static void rcar_iic_finish(struct udevice
*dev
)
109 struct rcar_iic_priv
*priv
= dev_get_priv(dev
);
111 writeb(0, priv
->base
+ RCAR_IIC_ICSR
);
112 clrbits_8(priv
->base
+ RCAR_IIC_ICCR
, RCAR_IIC_ICCR_ICE
);
115 static int rcar_iic_read_common(struct udevice
*dev
, struct i2c_msg
*msg
)
117 struct rcar_iic_priv
*priv
= dev_get_priv(dev
);
118 int i
, ret
= -EREMOTEIO
;
120 if (rcar_iic_set_addr(dev
, msg
->addr
, 1) != 0)
125 writeb(RCAR_IIC_ICCR_ICE
| RCAR_IIC_ICCR_SCP
,
126 priv
->base
+ RCAR_IIC_ICCR
);
128 for (i
= 0; i
< msg
->len
; i
++) {
129 if (sh_irq_dte_with_tack(dev
) != 0)
132 msg
->buf
[i
] = readb(priv
->base
+ RCAR_IIC_ICDR
) & 0xff;
134 if (msg
->len
- 1 == i
) {
135 writeb(RCAR_IIC_ICCR_ICE
| RCAR_IIC_ICCR_RACK
,
136 priv
->base
+ RCAR_IIC_ICCR
);
144 rcar_iic_finish(dev
);
148 static int rcar_iic_write_common(struct udevice
*dev
, struct i2c_msg
*msg
)
150 struct rcar_iic_priv
*priv
= dev_get_priv(dev
);
151 int i
, ret
= -EREMOTEIO
;
153 if (rcar_iic_set_addr(dev
, msg
->addr
, 0) != 0)
158 for (i
= 0; i
< msg
->len
; i
++) {
159 writeb(msg
->buf
[i
], priv
->base
+ RCAR_IIC_ICDR
);
160 if (sh_irq_dte_with_tack(dev
) != 0)
164 if (msg
->flags
& I2C_M_STOP
) {
165 writeb(RCAR_IIC_ICCR_ICE
| RCAR_IIC_ICCR_RTS
,
166 priv
->base
+ RCAR_IIC_ICCR
);
167 if (sh_irq_dte_with_tack(dev
) != 0)
175 rcar_iic_finish(dev
);
179 static int rcar_iic_xfer(struct udevice
*dev
, struct i2c_msg
*msg
, int nmsgs
)
183 for (; nmsgs
> 0; nmsgs
--, msg
++) {
184 if (msg
->flags
& I2C_M_RD
)
185 ret
= rcar_iic_read_common(dev
, msg
);
187 ret
= rcar_iic_write_common(dev
, msg
);
196 static int rcar_iic_set_speed(struct udevice
*dev
, uint speed
)
198 struct rcar_iic_priv
*priv
= dev_get_priv(dev
);
199 const unsigned int ratio_high
= 4;
200 const unsigned int ratio_low
= 5;
203 clkrate
= clk_get_rate(&priv
->clk
);
208 * Calculate the value for ICCL and ICCH. From the data sheet:
209 * iccl = (p-clock / transfer-rate) * (L / (L + H))
210 * icch = (p clock / transfer rate) * (H / (L + H))
211 * where L and H are the SCL low and high ratio.
213 denom
= speed
* (ratio_high
+ ratio_low
);
214 priv
->iccl
= DIV_ROUND_CLOSEST(clkrate
* ratio_low
, denom
);
215 priv
->icch
= DIV_ROUND_CLOSEST(clkrate
* ratio_high
, denom
);
220 static int rcar_iic_probe_chip(struct udevice
*dev
, uint addr
, uint flags
)
222 struct rcar_iic_priv
*priv
= dev_get_priv(dev
);
225 rcar_iic_set_addr(dev
, addr
, 1);
226 writeb(RCAR_IIC_ICCR_ICE
| RCAR_IIC_ICCR_SCP
,
227 priv
->base
+ RCAR_IIC_ICCR
);
228 ret
= sh_irq_dte_with_tack(dev
);
229 rcar_iic_finish(dev
);
234 static int rcar_iic_probe(struct udevice
*dev
)
236 struct rcar_iic_priv
*priv
= dev_get_priv(dev
);
239 priv
->base
= dev_read_addr_ptr(dev
);
241 ret
= clk_get_by_index(dev
, 0, &priv
->clk
);
245 ret
= clk_enable(&priv
->clk
);
249 rcar_iic_finish(dev
);
251 return rcar_iic_set_speed(dev
, 100000);
254 static const struct dm_i2c_ops rcar_iic_ops
= {
255 .xfer
= rcar_iic_xfer
,
256 .probe_chip
= rcar_iic_probe_chip
,
257 .set_bus_speed
= rcar_iic_set_speed
,
260 static const struct udevice_id rcar_iic_ids
[] = {
261 { .compatible
= "renesas,rmobile-iic" },
265 U_BOOT_DRIVER(iic_rcar
) = {
268 .of_match
= rcar_iic_ids
,
269 .probe
= rcar_iic_probe
,
270 .priv_auto_alloc_size
= sizeof(struct rcar_iic_priv
),
271 .ops
= &rcar_iic_ops
,