xref: /openbmc/linux/arch/mips/bcm63xx/cs.c (revision f3539c12)
1 /*
2  * This file is subject to the terms and conditions of the GNU General Public
3  * License.  See the file "COPYING" in the main directory of this archive
4  * for more details.
5  *
6  * Copyright (C) 2008 Maxime Bizon <mbizon@freebox.fr>
7  */
8 
9 #include <linux/kernel.h>
10 #include <linux/module.h>
11 #include <linux/spinlock.h>
12 #include <linux/log2.h>
13 #include <bcm63xx_cpu.h>
14 #include <bcm63xx_io.h>
15 #include <bcm63xx_regs.h>
16 #include <bcm63xx_cs.h>
17 
18 static DEFINE_SPINLOCK(bcm63xx_cs_lock);
19 
20 /*
21  * check if given chip select exists
22  */
23 static int is_valid_cs(unsigned int cs)
24 {
25 	if (cs > 6)
26 		return 0;
27 	return 1;
28 }
29 
30 /*
31  * Configure chipselect base address and size (bytes).
32  * Size must be a power of two between 8k and 256M.
33  */
34 int bcm63xx_set_cs_base(unsigned int cs, u32 base, unsigned int size)
35 {
36 	unsigned long flags;
37 	u32 val;
38 
39 	if (!is_valid_cs(cs))
40 		return -EINVAL;
41 
42 	/* sanity check on size */
43 	if (size != roundup_pow_of_two(size))
44 		return -EINVAL;
45 
46 	if (size < 8 * 1024 || size > 256 * 1024 * 1024)
47 		return -EINVAL;
48 
49 	val = (base & MPI_CSBASE_BASE_MASK);
50 	/* 8k => 0 - 256M => 15 */
51 	val |= (ilog2(size) - ilog2(8 * 1024)) << MPI_CSBASE_SIZE_SHIFT;
52 
53 	spin_lock_irqsave(&bcm63xx_cs_lock, flags);
54 	bcm_mpi_writel(val, MPI_CSBASE_REG(cs));
55 	spin_unlock_irqrestore(&bcm63xx_cs_lock, flags);
56 
57 	return 0;
58 }
59 
60 EXPORT_SYMBOL(bcm63xx_set_cs_base);
61 
62 /*
63  * configure chipselect timing (ns)
64  */
65 int bcm63xx_set_cs_timing(unsigned int cs, unsigned int wait,
66 			   unsigned int setup, unsigned int hold)
67 {
68 	unsigned long flags;
69 	u32 val;
70 
71 	if (!is_valid_cs(cs))
72 		return -EINVAL;
73 
74 	spin_lock_irqsave(&bcm63xx_cs_lock, flags);
75 	val = bcm_mpi_readl(MPI_CSCTL_REG(cs));
76 	val &= ~(MPI_CSCTL_WAIT_MASK);
77 	val &= ~(MPI_CSCTL_SETUP_MASK);
78 	val &= ~(MPI_CSCTL_HOLD_MASK);
79 	val |= wait << MPI_CSCTL_WAIT_SHIFT;
80 	val |= setup << MPI_CSCTL_SETUP_SHIFT;
81 	val |= hold << MPI_CSCTL_HOLD_SHIFT;
82 	bcm_mpi_writel(val, MPI_CSCTL_REG(cs));
83 	spin_unlock_irqrestore(&bcm63xx_cs_lock, flags);
84 
85 	return 0;
86 }
87 
88 EXPORT_SYMBOL(bcm63xx_set_cs_timing);
89 
90 /*
91  * configure other chipselect parameter (data bus size, ...)
92  */
93 int bcm63xx_set_cs_param(unsigned int cs, u32 params)
94 {
95 	unsigned long flags;
96 	u32 val;
97 
98 	if (!is_valid_cs(cs))
99 		return -EINVAL;
100 
101 	/* none of this fields apply to pcmcia */
102 	if (cs == MPI_CS_PCMCIA_COMMON ||
103 	    cs == MPI_CS_PCMCIA_ATTR ||
104 	    cs == MPI_CS_PCMCIA_IO)
105 		return -EINVAL;
106 
107 	spin_lock_irqsave(&bcm63xx_cs_lock, flags);
108 	val = bcm_mpi_readl(MPI_CSCTL_REG(cs));
109 	val &= ~(MPI_CSCTL_DATA16_MASK);
110 	val &= ~(MPI_CSCTL_SYNCMODE_MASK);
111 	val &= ~(MPI_CSCTL_TSIZE_MASK);
112 	val &= ~(MPI_CSCTL_ENDIANSWAP_MASK);
113 	val |= params;
114 	bcm_mpi_writel(val, MPI_CSCTL_REG(cs));
115 	spin_unlock_irqrestore(&bcm63xx_cs_lock, flags);
116 
117 	return 0;
118 }
119 
120 EXPORT_SYMBOL(bcm63xx_set_cs_param);
121 
122 /*
123  * set cs status (enable/disable)
124  */
125 int bcm63xx_set_cs_status(unsigned int cs, int enable)
126 {
127 	unsigned long flags;
128 	u32 val;
129 
130 	if (!is_valid_cs(cs))
131 		return -EINVAL;
132 
133 	spin_lock_irqsave(&bcm63xx_cs_lock, flags);
134 	val = bcm_mpi_readl(MPI_CSCTL_REG(cs));
135 	if (enable)
136 		val |= MPI_CSCTL_ENABLE_MASK;
137 	else
138 		val &= ~MPI_CSCTL_ENABLE_MASK;
139 	bcm_mpi_writel(val, MPI_CSCTL_REG(cs));
140 	spin_unlock_irqrestore(&bcm63xx_cs_lock, flags);
141 	return 0;
142 }
143 
144 EXPORT_SYMBOL(bcm63xx_set_cs_status);
145