[PATCH v2 3/5] tegra: add driver for the clock and reset module

Antony Pavlov antonynpavlov at gmail.com
Sun Mar 10 03:41:44 EDT 2013


On 7 March 2013 14:33, Lucas Stach <dev at lynxeye.de> wrote:
> Only a basic set of clocks is supported as of now.
>
> Signed-off-by: Lucas Stach <dev at lynxeye.de>
> ---
>  arch/arm/Kconfig                          |   2 +
>  arch/arm/mach-tegra/Makefile              |   2 +
>  arch/arm/mach-tegra/include/mach/clkdev.h |   7 ++
>  arch/arm/mach-tegra/tegra20-car.c         | 121 ++++++++++++++++++++++++++++++
>  arch/arm/mach-tegra/tegra20.c             |  30 ++++++++
>  5 files changed, 162 insertions(+)
>  create mode 100644 arch/arm/mach-tegra/include/mach/clkdev.h
>  create mode 100644 arch/arm/mach-tegra/tegra20-car.c
>  create mode 100644 arch/arm/mach-tegra/tegra20.c
>
> diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
> index 5dbf74d..9724494 100644
> --- a/arch/arm/Kconfig
> +++ b/arch/arm/Kconfig
> @@ -127,6 +127,8 @@ config ARCH_TEGRA
>         bool "Nvidia Tegra-based boards"
>         select CPU_V7
>         select HAS_DEBUG_LL
> +       select COMMON_CLK
> +       select CLKDEV_LOOKUP
>
>  endchoice
>
> diff --git a/arch/arm/mach-tegra/Makefile b/arch/arm/mach-tegra/Makefile
> index 11915e5..3391528 100644
> --- a/arch/arm/mach-tegra/Makefile
> +++ b/arch/arm/mach-tegra/Makefile
> @@ -1,2 +1,4 @@
>  obj-y += clock.o
>  obj-y += reset.o
> +obj-y += tegra20.o
> +obj-y += tegra20-car.o
> diff --git a/arch/arm/mach-tegra/include/mach/clkdev.h b/arch/arm/mach-tegra/include/mach/clkdev.h
> new file mode 100644
> index 0000000..04b37a8
> --- /dev/null
> +++ b/arch/arm/mach-tegra/include/mach/clkdev.h
> @@ -0,0 +1,7 @@
> +#ifndef __ASM_MACH_CLKDEV_H
> +#define __ASM_MACH_CLKDEV_H
> +
> +#define __clk_get(clk) ({ 1; })
> +#define __clk_put(clk) do { } while (0)
> +
> +#endif
> diff --git a/arch/arm/mach-tegra/tegra20-car.c b/arch/arm/mach-tegra/tegra20-car.c
> new file mode 100644
> index 0000000..eec3cc3
> --- /dev/null
> +++ b/arch/arm/mach-tegra/tegra20-car.c
> @@ -0,0 +1,121 @@
> +/*
> + * Copyright (C) 2013 Lucas Stach <l.stach at pengutronix.de>
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms and conditions of the GNU General Public License,
> + * version 2, as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope it will be useful, but WITHOUT
> + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
> + * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
> + * more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program.  If not, see <http://www.gnu.org/licenses/>.
> + */
> +
> +/**
> + * @file
> + * @brief Device driver for the Tegra 20 clock and reset (CAR) controller
> + */
> +
> +#include <common.h>
> +#include <init.h>
> +#include <io.h>
> +#include <linux/clk.h>
> +#include <linux/err.h>
> +#include <mach/iomap.h>
> +
> +/* Register definitions */
> +#define OSC_CTRL 0x50
> +#define OSC_CTRL_OSC_FREQ_SHIFT                30
> +#define OSC_CTRL_OSC_FREQ_MASK         (3 << OSC_CTRL_OSC_FREQ_SHIFT)
> +#define OSC_CTRL_PLL_REF_DIV_SHIFT     28
> +#define OSC_CTRL_PLL_REF_DIV_MASK      (3 << OSC_CTRL_PLL_REF_DIV_SHIFT)
> +
> +static void __iomem *car_base;
> +
> +enum tegra20_clks {
> +       cpu, ac97 = 3, rtc, timer, uarta, gpio = 8, sdmmc2, i2s1 = 11, i2c1,
> +       ndflash, sdmmc1, sdmmc4, twc, pwm, i2s2, epp, gr2d = 21, usbd, isp,
> +       gr3d, ide, disp2, disp1, host1x, vcp, cache2 = 31, mem, ahbdma, apbdma,
> +       kbc = 36, stat_mon, pmc, fuse, kfuse, sbc1, nor, spi, sbc2, xio, sbc3,
> +       dvc, dsi, mipi = 50, hdmi, csi, tvdac, i2c2, uartc, emc = 57, usb2,
> +       usb3, mpe, vde, bsea, bsev, speedo, uartd, uarte, i2c3, sbc4, sdmmc3,
> +       pex, owr, afi, csite, pcie_xclk, avpucq = 75, la, irama = 84, iramb,
> +       iramc, iramd, cram2, audio_2x, clk_d, csus = 92, cdev1, cdev2,
> +       uartb = 96, vfir, spdif_in, spdif_out, vi, vi_sensor, tvo, cve,
> +       osc, clk_32k, clk_m, sclk, cclk, hclk, pclk, blink, pll_a, pll_a_out0,
> +       pll_c, pll_c_out1, pll_d, pll_d_out0, pll_e, pll_m, pll_m_out1,
> +       pll_p, pll_p_out1, pll_p_out2, pll_p_out3, pll_p_out4, pll_u,
> +       pll_x, audio, pll_ref, twd, clk_max,
> +};
> +
Please remove unused constants or register appropriate clocks.

> +static struct clk *clks[clk_max];
> +
> +static unsigned long get_osc_frequency(void)
> +{
> +       u32 osc_ctrl = readl(car_base + OSC_CTRL);
> +
> +       switch ((osc_ctrl & OSC_CTRL_OSC_FREQ_MASK) >> OSC_CTRL_OSC_FREQ_SHIFT)
> +       {
> +       case 0:
> +               return 13000000;
> +       case 1:
> +               return 19200000;
> +       case 2:
> +               return 12000000;
> +       case 3:
> +               return 26000000;
> +       default:
> +               return 0;
> +       }
> +}
> +
> +static unsigned int get_pll_ref_div(void)
> +{
> +       u32 osc_ctrl = readl(car_base + OSC_CTRL);
> +
> +       return 1U << ((osc_ctrl & OSC_CTRL_PLL_REF_DIV_MASK) >>
> +                     OSC_CTRL_PLL_REF_DIV_SHIFT);
> +}
> +
> +static int tegra20_car_probe(struct device_d *dev)
> +{

Please check car_base befor use, e.g. see your tegra20_timer_probe() function.

> +       car_base = dev_request_mem_region(dev, 0);
> +       if (!car_base)
> +               return -EBUSY;
> +
> +       /* primary clocks */
> +       clks[clk_m] = clk_fixed("clk_m", get_osc_frequency());
> +       clks[clk_32k] = clk_fixed("clk_32k", 32768);
> +
> +       clks[pll_ref] = clk_fixed_factor("pll_ref", "clk_m", 1,
> +                                        get_pll_ref_div());
> +
> +       /* derived clocks */
> +       /* timer is a gate, but as it's enabled by BOOTROM we needn't worry */
> +       clks[timer] = clk_fixed_factor("timer", "clk_m", 1, 1);
> +
> +       return 0;
> +}
> +
> +static __maybe_unused struct of_device_id tegra20_car_dt_ids[] = {
> +       {
> +               .compatible = "nvidia,tegra20-car",
> +       }, {
> +               /* sentinel */
> +       }
> +};
> +
> +static struct driver_d tegra20_car_driver = {
> +       .probe  = tegra20_car_probe,
> +       .name   = "tegra20-car",
> +       .of_compatible = DRV_OF_COMPAT(tegra20_car_dt_ids),
> +};
> +
> +static int tegra20_car_init(void)
> +{
> +       return platform_driver_register(&tegra20_car_driver);
> +}
> +postcore_initcall(tegra20_car_init);
> diff --git a/arch/arm/mach-tegra/tegra20.c b/arch/arm/mach-tegra/tegra20.c
> new file mode 100644
> index 0000000..3831f1b
> --- /dev/null
> +++ b/arch/arm/mach-tegra/tegra20.c
> @@ -0,0 +1,30 @@
> +/*
> + * Copyright (C) 2013 Lucas Stach <l.stach at pengutronix.de>
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms and conditions of the GNU General Public License,
> + * version 2, as published by the Free Software Foundation.
> + *
> + * This program is distributed in the hope it will be useful, but WITHOUT
> + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
> + * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
> + * more details.
> + *
> + * You should have received a copy of the GNU General Public License
> + * along with this program.  If not, see <http://www.gnu.org/licenses/>.
> + */
> +
> +#include <common.h>
> +#include <init.h>
> +#include <mach/iomap.h>
> +
> +static int tegra20_init(void)
> +{
> +       add_generic_device("tegra20-car", DEVICE_ID_SINGLE, NULL,
> +                          TEGRA_CLK_RESET_BASE, TEGRA_CLK_RESET_SIZE,
> +                          IORESOURCE_MEM, NULL);
> +
> +       return 0;
> +}
> +
> +postcore_initcall(tegra20_init);
> --
> 1.8.1.2
>
>
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-- 
Best regards,
  Antony Pavlov



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