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author | Tom Rini <trini@konsulko.com> | 2016-11-07 21:34:54 -0500 |
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committer | Tom Rini <trini@konsulko.com> | 2016-11-21 14:07:29 -0500 |
commit | 983e37007da506e8145f9b3a9e1dce5c11116fb0 (patch) | |
tree | c1d5449e1c56e17f22bb4f75b6f11336abca41a4 /arch/arm/mach-omap2/am33xx/clk_synthesizer.c | |
parent | 272686eb7576c02df4616bcf893fde993e7ba57e (diff) | |
download | u-boot-983e37007da506e8145f9b3a9e1dce5c11116fb0.zip u-boot-983e37007da506e8145f9b3a9e1dce5c11116fb0.tar.gz u-boot-983e37007da506e8145f9b3a9e1dce5c11116fb0.tar.bz2 |
arm: Introduce arch/arm/mach-omap2 for OMAP2 derivative platforms
This moves what was in arch/arm/cpu/armv7/omap-common in to
arch/arm/mach-omap2 and moves
arch/arm/cpu/armv7/{am33xx,omap3,omap4,omap5} in to arch/arm/mach-omap2
as subdirectories. All refernces to the former locations are updated to
the current locations. For the logic to decide what our outputs are,
consolidate the tests into a single config.mk rather than including 4.
Signed-off-by: Tom Rini <trini@konsulko.com>
Diffstat (limited to 'arch/arm/mach-omap2/am33xx/clk_synthesizer.c')
-rw-r--r-- | arch/arm/mach-omap2/am33xx/clk_synthesizer.c | 104 |
1 files changed, 104 insertions, 0 deletions
diff --git a/arch/arm/mach-omap2/am33xx/clk_synthesizer.c b/arch/arm/mach-omap2/am33xx/clk_synthesizer.c new file mode 100644 index 0000000..316e677 --- /dev/null +++ b/arch/arm/mach-omap2/am33xx/clk_synthesizer.c @@ -0,0 +1,104 @@ +/* + * clk-synthesizer.c + * + * Clock synthesizer apis + * + * Copyright (C) 2016, Texas Instruments, Incorporated - http://www.ti.com/ + * + * SPDX-License-Identifier: GPL-2.0+ + */ + + +#include <common.h> +#include <asm/arch/clk_synthesizer.h> +#include <i2c.h> + +/** + * clk_synthesizer_reg_read - Read register from synthesizer. + * @addr: addr within the i2c device + * buf: Buffer to which value is to be read. + * + * For reading the register from this clock synthesizer, a command needs to + * be send along with enabling byte read more, and then read can happen. + * Returns 0 on success + */ +static int clk_synthesizer_reg_read(int addr, uint8_t *buf) +{ + int rc; + + /* Enable Bye read */ + addr = addr | CLK_SYNTHESIZER_BYTE_MODE; + + /* Send the command byte */ + rc = i2c_write(CLK_SYNTHESIZER_I2C_ADDR, addr, 1, buf, 1); + if (rc) + printf("Failed to send command to clock synthesizer\n"); + + /* Read the Data */ + return i2c_read(CLK_SYNTHESIZER_I2C_ADDR, addr, 1, buf, 1); +} + +/** + * clk_synthesizer_reg_write - Write a value to register in synthesizer. + * @addr: addr within the i2c device + * val: Value to be written in the addr. + * + * Enable the byte read mode in the address and start the i2c transfer. + * Returns 0 on success + */ +static int clk_synthesizer_reg_write(int addr, uint8_t val) +{ + uint8_t cmd[2]; + int rc = 0; + + /* Enable byte write */ + cmd[0] = addr | CLK_SYNTHESIZER_BYTE_MODE; + cmd[1] = val; + + rc = i2c_write(CLK_SYNTHESIZER_I2C_ADDR, addr, 1, cmd, 2); + if (rc) + printf("Clock synthesizer reg write failed at addr = 0x%x\n", + addr); + return rc; +} + +/** + * setup_clock_syntherizer - Program the clock synthesizer to get the desired + * frequency. + * @data: Data containing the desired output + * + * This is a PLL-based high performance synthesizer which gives 3 outputs + * as per the PLL_DIV and load capacitor programmed. + */ +int setup_clock_synthesizer(struct clk_synth *data) +{ + int rc; + uint8_t val; + + rc = i2c_probe(CLK_SYNTHESIZER_I2C_ADDR); + if (rc) { + printf("i2c probe failed at address 0x%x\n", + CLK_SYNTHESIZER_I2C_ADDR); + return rc; + } + + rc = clk_synthesizer_reg_read(CLK_SYNTHESIZER_ID_REG, &val); + if (val != data->id) + return rc; + + /* Crystal Load capacitor selection */ + rc = clk_synthesizer_reg_write(CLK_SYNTHESIZER_XCSEL, data->capacitor); + if (rc) + return rc; + rc = clk_synthesizer_reg_write(CLK_SYNTHESIZER_MUX_REG, data->mux); + if (rc) + return rc; + rc = clk_synthesizer_reg_write(CLK_SYNTHESIZER_PDIV2_REG, data->pdiv2); + if (rc) + return rc; + rc = clk_synthesizer_reg_write(CLK_SYNTHESIZER_PDIV3_REG, data->pdiv3); + if (rc) + return rc; + + return 0; +} |