1 /*
2  * Freescale i.MX28 Battery measurement init
3  *
4  * Copyright (C) 2011 Marek Vasut <marek.vasut@gmail.com>
5  * on behalf of DENX Software Engineering GmbH
6  *
7  * See file CREDITS for list of people who contributed to this
8  * project.
9  *
10  * This program is free software; you can redistribute it and/or
11  * modify it under the terms of the GNU General Public License as
12  * published by the Free Software Foundation; either version 2 of
13  * the License, or (at your option) any later version.
14  *
15  * This program is distributed in the hope that it will be useful,
16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
18  * GNU General Public License for more details.
19  *
20  * You should have received a copy of the GNU General Public License
21  * along with this program; if not, write to the Free Software
22  * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
23  * MA 02111-1307 USA
24  */
25 
26 #include <common.h>
27 #include <config.h>
28 #include <asm/io.h>
29 #include <asm/arch/imx-regs.h>
30 
31 #include "mx28_init.h"
32 
33 void mx28_lradc_init(void)
34 {
35 	struct mx28_lradc_regs *regs = (struct mx28_lradc_regs *)MXS_LRADC_BASE;
36 
37 	writel(LRADC_CTRL0_SFTRST, &regs->hw_lradc_ctrl0_clr);
38 	writel(LRADC_CTRL0_CLKGATE, &regs->hw_lradc_ctrl0_clr);
39 	writel(LRADC_CTRL0_ONCHIP_GROUNDREF, &regs->hw_lradc_ctrl0_clr);
40 
41 	clrsetbits_le32(&regs->hw_lradc_ctrl3,
42 			LRADC_CTRL3_CYCLE_TIME_MASK,
43 			LRADC_CTRL3_CYCLE_TIME_6MHZ);
44 
45 	clrsetbits_le32(&regs->hw_lradc_ctrl4,
46 			LRADC_CTRL4_LRADC7SELECT_MASK |
47 			LRADC_CTRL4_LRADC6SELECT_MASK,
48 			LRADC_CTRL4_LRADC7SELECT_CHANNEL7 |
49 			LRADC_CTRL4_LRADC6SELECT_CHANNEL10);
50 }
51 
52 void mx28_lradc_enable_batt_measurement(void)
53 {
54 	struct mx28_lradc_regs *regs = (struct mx28_lradc_regs *)MXS_LRADC_BASE;
55 
56 	/* Check if the channel is present at all. */
57 	if (!(readl(&regs->hw_lradc_status) & LRADC_STATUS_CHANNEL7_PRESENT))
58 		return;
59 
60 	writel(LRADC_CTRL1_LRADC7_IRQ_EN, &regs->hw_lradc_ctrl1_clr);
61 	writel(LRADC_CTRL1_LRADC7_IRQ, &regs->hw_lradc_ctrl1_clr);
62 
63 	clrsetbits_le32(&regs->hw_lradc_conversion,
64 			LRADC_CONVERSION_SCALE_FACTOR_MASK,
65 			LRADC_CONVERSION_SCALE_FACTOR_LI_ION);
66 	writel(LRADC_CONVERSION_AUTOMATIC, &regs->hw_lradc_conversion_set);
67 
68 	/* Configure the channel. */
69 	writel((1 << 7) << LRADC_CTRL2_DIVIDE_BY_TWO_OFFSET,
70 		&regs->hw_lradc_ctrl2_clr);
71 	writel(0xffffffff, &regs->hw_lradc_ch7_clr);
72 	clrbits_le32(&regs->hw_lradc_ch7, LRADC_CH_NUM_SAMPLES_MASK);
73 	writel(LRADC_CH_ACCUMULATE, &regs->hw_lradc_ch7_clr);
74 
75 	/* Schedule the channel. */
76 	writel(1 << 7, &regs->hw_lradc_ctrl0_set);
77 
78 	/* Start the channel sampling. */
79 	writel(((1 << 7) << LRADC_DELAY_TRIGGER_LRADCS_OFFSET) |
80 		((1 << 3) << LRADC_DELAY_TRIGGER_DELAYS_OFFSET) |
81 		100, &regs->hw_lradc_delay3);
82 
83 	writel(0xffffffff, &regs->hw_lradc_ch7_clr);
84 
85 	writel(LRADC_DELAY_KICK, &regs->hw_lradc_delay3_set);
86 }
87