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authorStefano Babic <sbabic@denx.de>2016-11-29 16:28:28 +0100
committerStefano Babic <sbabic@denx.de>2016-11-29 16:28:28 +0100
commit2d221489df021393654805536be7effcb9d39702 (patch)
tree1b636f10b4ccde42624ec665df13288408b59b7f /arch/arm/mach-omap2/am33xx/clk_synthesizer.c
parent45a3ad81fafe3090f7f89b458f6bd9f547a453df (diff)
parente94793c844a40606252f2e3f6428063e057b3fd2 (diff)
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Merge branch 'master' of git://git.denx.de/u-boot
Signed-off-by: Stefano Babic <sbabic@denx.de>
Diffstat (limited to 'arch/arm/mach-omap2/am33xx/clk_synthesizer.c')
-rw-r--r--arch/arm/mach-omap2/am33xx/clk_synthesizer.c104
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
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+++ 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;
+}