2 * (C) Copyright 2016 Stephen Warren <swarren@wwwdotorg.org>
4 * Derived from pl01x code:
7 * Rob Taylor, Flying Pig Systems. robt@flyingpig.com.
11 * Philippe Robin, <philippe.robin@arm.com>
13 * SPDX-License-Identifier: GPL-2.0+
16 /* Simple U-Boot driver for the BCM283x mini UART */
24 #include <dm/platform_data/serial_bcm283x_mu.h>
25 #include <linux/compiler.h>
28 DECLARE_GLOBAL_DATA_PTR
;
30 struct bcm283x_mu_regs
{
44 #define BCM283X_MU_LCR_DATA_SIZE_8 3
46 #define BCM283X_MU_LSR_TX_IDLE BIT(6)
47 /* This actually means not full, but is named not empty in the docs */
48 #define BCM283X_MU_LSR_TX_EMPTY BIT(5)
49 #define BCM283X_MU_LSR_RX_READY BIT(0)
51 struct bcm283x_mu_priv
{
52 struct bcm283x_mu_regs
*regs
;
55 static int bcm283x_mu_serial_setbrg(struct udevice
*dev
, int baudrate
)
57 struct bcm283x_mu_serial_platdata
*plat
= dev_get_platdata(dev
);
58 struct bcm283x_mu_priv
*priv
= dev_get_priv(dev
);
59 struct bcm283x_mu_regs
*regs
= priv
->regs
;
62 if (plat
->disabled
|| plat
->skip_init
)
65 divider
= plat
->clock
/ (baudrate
* 8);
67 writel(BCM283X_MU_LCR_DATA_SIZE_8
, ®s
->lcr
);
68 writel(divider
- 1, ®s
->baud
);
73 static int bcm283x_mu_serial_probe(struct udevice
*dev
)
75 struct bcm283x_mu_serial_platdata
*plat
= dev_get_platdata(dev
);
76 struct bcm283x_mu_priv
*priv
= dev_get_priv(dev
);
81 priv
->regs
= (struct bcm283x_mu_regs
*)plat
->base
;
86 static int bcm283x_mu_serial_getc(struct udevice
*dev
)
88 struct bcm283x_mu_serial_platdata
*plat
= dev_get_platdata(dev
);
89 struct bcm283x_mu_priv
*priv
= dev_get_priv(dev
);
90 struct bcm283x_mu_regs
*regs
= priv
->regs
;
96 /* Wait until there is data in the FIFO */
97 if (!(readl(®s
->lsr
) & BCM283X_MU_LSR_RX_READY
))
100 data
= readl(®s
->io
);
105 static int bcm283x_mu_serial_putc(struct udevice
*dev
, const char data
)
107 struct bcm283x_mu_serial_platdata
*plat
= dev_get_platdata(dev
);
108 struct bcm283x_mu_priv
*priv
= dev_get_priv(dev
);
109 struct bcm283x_mu_regs
*regs
= priv
->regs
;
114 /* Wait until there is space in the FIFO */
115 if (!(readl(®s
->lsr
) & BCM283X_MU_LSR_TX_EMPTY
))
118 /* Send the character */
119 writel(data
, ®s
->io
);
124 static int bcm283x_mu_serial_pending(struct udevice
*dev
, bool input
)
126 struct bcm283x_mu_serial_platdata
*plat
= dev_get_platdata(dev
);
127 struct bcm283x_mu_priv
*priv
= dev_get_priv(dev
);
128 struct bcm283x_mu_regs
*regs
= priv
->regs
;
134 lsr
= readl(®s
->lsr
);
138 return (lsr
& BCM283X_MU_LSR_RX_READY
) ? 1 : 0;
140 return (lsr
& BCM283X_MU_LSR_TX_IDLE
) ? 0 : 1;
144 static const struct dm_serial_ops bcm283x_mu_serial_ops
= {
145 .putc
= bcm283x_mu_serial_putc
,
146 .pending
= bcm283x_mu_serial_pending
,
147 .getc
= bcm283x_mu_serial_getc
,
148 .setbrg
= bcm283x_mu_serial_setbrg
,
151 #if CONFIG_IS_ENABLED(OF_CONTROL)
152 static const struct udevice_id bcm283x_mu_serial_id
[] = {
153 {.compatible
= "brcm,bcm2835-aux-uart"},
157 static int bcm283x_mu_serial_ofdata_to_platdata(struct udevice
*dev
)
159 struct bcm283x_mu_serial_platdata
*plat
= dev_get_platdata(dev
);
162 addr
= devfdt_get_addr(dev
);
163 if (addr
== FDT_ADDR_T_NONE
)
167 plat
->clock
= fdtdec_get_int(gd
->fdt_blob
, dev_of_offset(dev
), "clock",
169 plat
->skip_init
= fdtdec_get_bool(gd
->fdt_blob
, dev_of_offset(dev
),
171 plat
->disabled
= false;
176 U_BOOT_DRIVER(serial_bcm283x_mu
) = {
177 .name
= "serial_bcm283x_mu",
179 .of_match
= of_match_ptr(bcm283x_mu_serial_id
),
180 .ofdata_to_platdata
= of_match_ptr(bcm283x_mu_serial_ofdata_to_platdata
),
181 .platdata_auto_alloc_size
= sizeof(struct bcm283x_mu_serial_platdata
),
182 .probe
= bcm283x_mu_serial_probe
,
183 .ops
= &bcm283x_mu_serial_ops
,
184 .flags
= DM_FLAG_PRE_RELOC
,
185 .priv_auto_alloc_size
= sizeof(struct bcm283x_mu_priv
),