diff options
| author | Marek Szyprowski <m.szyprowski@samsung.com> | 2014-05-22 13:21:38 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-05-27 16:19:04 -0700 |
| commit | 657d898a9320a7cdb9b94565d75ecf75c25cbf0a (patch) | |
| tree | 149cd288d68ee037b4376a8c578cbe59c6dc4219 /drivers/usb/misc | |
| parent | 6fecd4f2a58c60028b1a75deefcf111516d3f836 (diff) | |
usb: usb5303: add support for reference clock specified in device tree
USB3503 chip supports 8 values of reference clock. The value is
specified by REF_SEL[1:0] pins and INT_N line. This patch add support
for getting 'refclk' clock, enabling it and setting INT_N line according
to the value of the gathered clock. If no clock has been specified,
driver defaults to the old behaviour (assuming that clock has been
specified by REF_SEL pins from primary reference clock frequencies
table).
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/usb/misc')
| -rw-r--r-- | drivers/usb/misc/usb3503.c | 59 |
1 files changed, 57 insertions, 2 deletions
diff --git a/drivers/usb/misc/usb3503.c b/drivers/usb/misc/usb3503.c index a31641e18d1..f43c61989ce 100644 --- a/drivers/usb/misc/usb3503.c +++ b/drivers/usb/misc/usb3503.c @@ -18,6 +18,7 @@ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */ +#include <linux/clk.h> #include <linux/i2c.h> #include <linux/gpio.h> #include <linux/delay.h> @@ -57,10 +58,12 @@ struct usb3503 { enum usb3503_mode mode; struct regmap *regmap; struct device *dev; + struct clk *clk; u8 port_off_mask; int gpio_intn; int gpio_reset; int gpio_connect; + bool secondary_ref_clk; }; static int usb3503_reset(struct usb3503 *hub, int state) @@ -184,8 +187,58 @@ static int usb3503_probe(struct usb3503 *hub) hub->gpio_reset = pdata->gpio_reset; hub->mode = pdata->initial_mode; } else if (np) { + struct clk *clk; hub->port_off_mask = 0; + clk = devm_clk_get(dev, "refclk"); + if (IS_ERR(clk) && PTR_ERR(clk) != -ENOENT) { + dev_err(dev, "unable to request refclk (%d)\n", err); + return PTR_ERR(clk); + } + + if (!IS_ERR(clk)) { + u32 rate = 0; + hub->clk = clk; + + if (!of_property_read_u32(np, "refclk-frequency", + &rate)) { + + switch (rate) { + case 38400000: + case 26000000: + case 19200000: + case 12000000: + hub->secondary_ref_clk = 0; + break; + case 24000000: + case 27000000: + case 25000000: + case 50000000: + hub->secondary_ref_clk = 1; + break; + default: + dev_err(dev, + "unsupported reference clock rate (%d)\n", + (int) rate); + return -EINVAL; + } + err = clk_set_rate(hub->clk, rate); + if (err) { + dev_err(dev, + "unable to set reference clock rate to %d\n", + (int) rate); + return err; + } + } + + err = clk_prepare_enable(hub->clk); + if (err) { + dev_err(dev, + "unable to enable reference clock\n"); + return err; + } + } + property = of_get_property(np, "disabled-ports", &len); if (property && (len / sizeof(u32)) > 0) { int i; @@ -213,8 +266,10 @@ static int usb3503_probe(struct usb3503 *hub) dev_err(dev, "Ports disabled with no control interface\n"); if (gpio_is_valid(hub->gpio_intn)) { - err = devm_gpio_request_one(dev, hub->gpio_intn, - GPIOF_OUT_INIT_HIGH, "usb3503 intn"); + int val = hub->secondary_ref_clk ? GPIOF_OUT_INIT_LOW : + GPIOF_OUT_INIT_HIGH; + err = devm_gpio_request_one(dev, hub->gpio_intn, val, + "usb3503 intn"); if (err) { dev_err(dev, "unable to request GPIO %d as connect pin (%d)\n", |