[PATCH, RFC] mfd: add clock API support to asic3 using clocklib
From: Philipp Zabel
Date: Thu Jun 26 2008 - 10:51:18 EST
This patch adds basic clock API support for ASIC3 clocks using Dmitry
Baryshkov's clocklib (http://lkml.org/lkml/2008/6/26/278).
The CDEX clocks can be enabled/disabled and the SD host and bus clock
rates can be changed. Also the clock settings comment for SD HCLK and
BCLK in asic3.h is moved to the right place.
I am missing information about the spi, pwm, led, smbus and cx clock's
rates, and I'm not sure if the SOURCE0/1 bits in CLOCK_CDEX should be
handled here somehow. The CLOCK_SEL_CX bit in CLOCK_SEL is only used
internally by the IRQ controller, so I guess not handling that is fine.
Signed-off-by: Philipp Zabel <philipp.zabel@xxxxxxxxx>
---
drivers/mfd/Kconfig | 2 +-
drivers/mfd/asic3.c | 146 ++++++++++++++++++++++++++++++++++++++++++++-
include/linux/mfd/asic3.h | 2 +-
3 files changed, 147 insertions(+), 3 deletions(-)
diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index 5f87a28..a0da724 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -17,7 +17,7 @@ config MFD_SM501
config MFD_ASIC3
bool "Support for Compaq ASIC3"
- depends on GENERIC_HARDIRQS && HAVE_GPIO_LIB && ARM
+ depends on GENERIC_HARDIRQS && HAVE_GPIO_LIB && HAVE_CLOCKLIB && ARM
---help---
This driver supports the ASIC3 multifunction chip found on many
PDAs (mainly iPAQ and HTC based ones)
diff --git a/drivers/mfd/asic3.c b/drivers/mfd/asic3.c
index 50c773c..ced53c8 100644
--- a/drivers/mfd/asic3.c
+++ b/drivers/mfd/asic3.c
@@ -18,11 +18,13 @@
#include <linux/version.h>
#include <linux/kernel.h>
+#include <linux/platform_device.h>
+#include <linux/clk.h>
+#include <linux/clocklib.h>
#include <linux/irq.h>
#include <linux/gpio.h>
#include <linux/io.h>
#include <linux/spinlock.h>
-#include <linux/platform_device.h>
#include <linux/mfd/asic3.h>
@@ -53,6 +55,132 @@ static inline u32 asic3_read_register(struct asic3 *asic,
(reg >> asic->bus_shift));
}
+/* clocks */
+struct clk_cdex {
+ unsigned int cdex;
+ unsigned long rate;
+ struct asic3 *asic;
+ struct clk clk;
+};
+
+static int asic3_clock_cdex_enable(struct clk *clk)
+{
+ struct clk_cdex *cclk = container_of(clk, struct clk_cdex, clk);
+ struct asic3 *asic = cclk->asic;
+ int cdex = cclk->cdex;
+ unsigned long flags, val;
+
+ local_irq_save(flags);
+
+ val = asic3_read_register(asic, ASIC3_OFFSET(CLOCK, CDEX));
+ val |= cdex;
+ asic3_write_register(asic, ASIC3_OFFSET(CLOCK, CDEX), val);
+
+ local_irq_restore(flags);
+
+ return 0;
+}
+
+static void asic3_clock_cdex_disable(struct clk *clk)
+{
+ struct clk_cdex *cclk = container_of(clk, struct clk_cdex, clk);
+ struct asic3 *asic = cclk->asic;
+ int cdex = cclk->cdex;
+ unsigned long flags, val;
+
+ local_irq_save(flags);
+
+ val = asic3_read_register(asic, ASIC3_OFFSET(CLOCK, CDEX));
+ val &= ~cdex;
+ asic3_write_register(asic, ASIC3_OFFSET(CLOCK, CDEX), val);
+
+ local_irq_restore(flags);
+}
+
+static unsigned long asic3_clock_cdex_get_rate(struct clk *clk)
+{
+ struct clk_cdex *cclk = container_of(clk, struct clk_cdex, clk);
+
+ return cclk->rate;
+}
+
+static long asic3_clock_cdex_round_rate(struct clk *clk, unsigned long hz,
+ bool apply)
+{
+ struct clk_cdex *cclk = container_of(clk, struct clk_cdex, clk);
+ unsigned long bit = 0;
+ long rate;
+
+ if (cclk->cdex == CLOCK_CDEX_SD_HOST)
+ bit = CLOCK_SEL_SD_HCLK_SEL;
+ if (cclk->cdex == CLOCK_CDEX_SD_BUS)
+ bit = CLOCK_SEL_SD_BCLK_SEL;
+
+ if (!bit) {
+ rate = cclk->rate;
+
+ if (apply && hz != rate)
+ return -EINVAL;
+
+ return rate;
+ }
+
+ if (hz < 18432000) /* (12.288 MHz + 24.576 MHz)/2 */
+ rate = 12288000;
+ else
+ rate = 24576000;
+
+ if (apply) {
+ struct asic3 *asic = cclk->asic;
+ unsigned long flags, val;
+
+ local_irq_save(flags);
+ val = asic3_read_register(asic, ASIC3_OFFSET(CLOCK, SEL));
+ if (hz < 18432000)
+ val &= ~bit;
+ else
+ val |= bit;
+ asic3_write_register(asic, ASIC3_OFFSET(CLOCK, SEL), val);
+ local_irq_restore(flags);
+ cclk->rate = rate;
+ }
+
+ return rate;
+}
+
+static struct clk_ops clk_cdex_ops = {
+ .enable = asic3_clock_cdex_enable,
+ .disable = asic3_clock_cdex_disable,
+ .get_rate = asic3_clock_cdex_get_rate,
+ .round_rate = asic3_clock_cdex_round_rate,
+};
+
+#define INIT_CLOCK_CDEX(_name, _cdex, _rate) \
+ &(struct clk_cdex) { \
+ .cdex = CLOCK_CDEX_##_cdex, \
+ .rate = _rate, \
+ .clk = { \
+ .name = _name, \
+ .ops = &clk_cdex_ops, \
+ }, \
+ }.clk
+
+static struct clk *asic3_clks[] = {
+ INIT_CLOCK_CDEX("spi", SPI, 0),
+ INIT_CLOCK_CDEX("ds1wm", OWM, 5000000),
+ INIT_CLOCK_CDEX("pwm0", PWM0, 0),
+ INIT_CLOCK_CDEX("pwm1", PWM1, 0),
+ INIT_CLOCK_CDEX("led0", LED0, 0),
+ INIT_CLOCK_CDEX("led1", LED1, 0),
+ INIT_CLOCK_CDEX("led2", LED2, 0),
+ INIT_CLOCK_CDEX("sdhost", SD_HOST, 12288000),
+ INIT_CLOCK_CDEX("sdbus", SD_BUS, 12288000),
+ INIT_CLOCK_CDEX("smbus", SMBUS, 0),
+ INIT_CLOCK_CDEX("cx", CONTROL_CX, 0),
+ INIT_CLOCK_CDEX("ex0", EX0, 32768),
+ INIT_CLOCK_CDEX("ex1", EX1, 24576000),
+};
+
/* IRQs */
#define MAX_ASIC_ISR_LOOPS 20
#define ASIC3_GPIO_BASE_INCR \
@@ -533,6 +661,7 @@ static int __init asic3_probe(struct platform_device *pdev)
struct resource *mem;
unsigned long clksel;
int ret = 0;
+ int i;
asic = kzalloc(sizeof(struct asic3), GFP_KERNEL);
if (asic == NULL) {
@@ -569,6 +698,17 @@ static int __init asic3_probe(struct platform_device *pdev)
clksel = 0;
asic3_write_register(asic, ASIC3_OFFSET(CLOCK, SEL), clksel);
+ /* Register ASIC3's clocks. */
+ for (i = 0; i < ARRAY_SIZE(asic3_clks); i++) {
+ struct clk_cdex *cclk = container_of(asic3_clks[i], struct clk_cdex, clk);
+ cclk->asic = asic;
+ ret = clk_register(asic3_clks[i]);
+ if (ret < 0)
+ dev_err(asic->dev,
+ "failed to register clock %s (%d)\n",
+ asic3_clks[i]->name, ret);
+ }
+
ret = asic3_irq_probe(pdev);
if (ret < 0) {
dev_err(asic->dev, "Couldn't probe IRQs\n");
@@ -608,6 +748,7 @@ static int __init asic3_probe(struct platform_device *pdev)
static int asic3_remove(struct platform_device *pdev)
{
+ int i;
int ret;
struct asic3 *asic = platform_get_drvdata(pdev);
@@ -616,6 +757,9 @@ static int asic3_remove(struct platform_device *pdev)
return ret;
asic3_irq_remove(pdev);
+ for (i = 0; i < ARRAY_SIZE(asic3_clks); i++)
+ clk_unregister(asic3_clks[i]);
+
asic3_write_register(asic, ASIC3_OFFSET(CLOCK, SEL), 0);
iounmap(asic->mapping);
diff --git a/include/linux/mfd/asic3.h b/include/linux/mfd/asic3.h
index 6461a2a..0610449 100644
--- a/include/linux/mfd/asic3.h
+++ b/include/linux/mfd/asic3.h
@@ -152,7 +152,6 @@ struct asic3_platform_data {
#define CLOCK_CDEX_LED1 (1 << 7)
#define CLOCK_CDEX_LED2 (1 << 8)
-/* Clocks settings: 1 for 24.576 MHz, 0 for 12.288Mhz */
#define CLOCK_CDEX_SD_HOST (1 << 9) /* R/W: SD host clock source */
#define CLOCK_CDEX_SD_BUS (1 << 10) /* R/W: SD bus clock source ctrl */
#define CLOCK_CDEX_SMBUS (1 << 11)
@@ -161,6 +160,7 @@ struct asic3_platform_data {
#define CLOCK_CDEX_EX0 (1 << 13) /* R/W: 32.768 kHz crystal */
#define CLOCK_CDEX_EX1 (1 << 14) /* R/W: 24.576 MHz crystal */
+/* Clocks settings: 1 for 24.576 MHz, 0 for 12.288Mhz */
#define CLOCK_SEL_SD_HCLK_SEL (1 << 0) /* R/W: SDIO host clock select */
#define CLOCK_SEL_SD_BCLK_SEL (1 << 1) /* R/W: SDIO bus clock select */
--
1.5.5.4
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